Patent Publication Number: US-7591050-B2

Title: Footwear lacing system

Description:
This application is a continuation-in-part of U.S. patent application Ser. No. 09/993,296 filed Nov. 14, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09/956,601 filed on Sep. 18, 2001, which is a continuation of U.S. patent application Ser. No. 09/388,756 filed on Sep. 2, 1999, now U.S. Pat. No. 6,289,558 which is a continuation-in-part of U.S. patent application Ser. No. 09/337,763 filed on Jun. 22, 1999, now U.S. Pat. No. 6,202,953 B1 which is a continuation of U.S. patent application Ser. No. 08/917,056 filed Aug. 22, 1997, now U.S. Pat. No. 5,934,599. 
    
    
     The present invention relates to footwear. More particularly, the present invention relates to a low-friction lacing system that provides equilibrated tightening pressure across a wearer&#39;s foot for sports boots and shoes. 
     BACKGROUND OF THE INVENTION 
     There currently exists a number of mechanisms and methods for tightening a shoe or boot around a wearer&#39;s foot. A traditional method comprises threading a lace in a zig-zag pattern through eyelets that run in two parallel rows attached to opposite sides of the shoe. The shoe is tightened by first tensioning opposite ends of the threaded lace to pull the two rows of eyelets towards the midline of the foot and then tying the ends in a knot to maintain the tension. A number of drawbacks are associated with this type of lacing system. First, laces do not adequately distribute the tightening force along the length of the threaded zone, due to friction between the lace and the eyelets, so that portions of the lace are slack and other portions are in tension. Consequently, the higher tensioned portions of the shoe are tighter around certain sections of the foot, particularly the ankle portions which are closer to the ends. This is uncomfortable and can adversely affect performance in some sports. 
     Another drawback associated with conventional laces is that it is often difficult to untighten or redistribute tension on the lace, as the wearer must loosen the lace from each of the many eyelets through which the laces are threaded. The lace is not easily released by simply untightening the knot. The friction between the lace and the eyelets often maintains the toe portions and sometimes much of the foot in tension even when the knot is released. Consequently, the user must often loosen the lace individually from each of the eyelets. This is especially tedious if the number of eyelets is high, such as in ice-skating boots or other specialized high performance footwear. 
     Another tightening mechanism comprises buckles which clamp together to tighten the shoe around the wearer&#39;s foot. Typically, three to four or more buckles are positioned over the upper portion of the shoe. The buckles may be quickly clamped together and drawn apart to tighten and loosen the shoe around the wearer&#39;s foot. Although buckles may be easily and quickly tightened and untightened, they also have certain drawbacks. Specifically, buckles isolate the closure pressure across three or four points along the wearer&#39;s foot corresponding to the locations of the buckles. This is undesirable in many circumstances, such as for the use of sport boots where the wearer desires a force line that is evenly distributed along the length of the foot. Another drawback of buckles is that they are typically only useful for hard plastic or other rigid material boots. Buckles are not as practical for use with softer boots, such as ice skates or snowboard boots. 
     There is therefore a need for a tightening system for footwear that does not suffer from the aforementioned drawbacks. Such a system should automatically distribute lateral tightening forces along the length of the wearer&#39;s ankle and foot. The tightness of the shoe should desirably be easy to loosen and incrementally adjust. The tightening system should close tightly and should not loosen up with continued use. 
     SUMMARY OF THE INVENTION 
     There is provided in accordance with one aspect of the present invention, a footwear lacing system. The system comprises a footwear member including first and second opposing sides configured to fit around a foot. A plurality of lace guide members are positioned on the opposing sides. A lace is guided by the guide members, the lace being rotationally connected to a spool that is rotatable in a winding direction and an unwinding direction. A tightening mechanism is attached to the footwear member, and coupled to the spool, the tightening mechanism including a control for winding the lace around the spool to place tension on the lace thereby pulling the opposing sides towards each other. A safety device is moveable between a secure position in which the spool is unable to rotate in an unwinding direction, and a releasing position in which the spool is free to rotate in an unwinding direction. 
     In one embodiment, the lace is slideably positioned around the guide members to provide a dynamic fit in response to movement of the foot within the footwear. The guide members may have a substantially C-shaped cross section. 
     Additionally, the tightening mechanism is a rotatable reel that is configured to receive the lace. In accordance with one embodiment, a knob rotates the spool and thereby winds the lace about the spool. In some embodiments, rotating the knob in an unwinding direction releases the spool and allows the lace to unwind. A safety device can be attached, such as a lever, that selectively allows the knob to rotate in an unwinding direction to release the spool. Alternatively, the safety device can be a rotatable release that is rotated separately from the knob to release the spool. 
     In certain embodiments, the footwear lacing system is attached to footwear having a first opposing side configured to extend from one side of the shoe, across the upper midline of the shoe, and to the opposing side of the shoe. As such, the reel can be mounted to the first opposing side. 
     In one embodiment, the lace is formed of a polymeric fiber. 
     According to another aspect of the footwear lacing system, a closure system for footwear having an upper with a lateral side and a medial side, the closure system comprising at least a first lace guide attached to the lateral side of the upper, at least a second lace guide attached to the medial side of the upper, and each of the first and second lace guides comprising a lace pathway, a lace slideably extending along the lace pathway of each of the first and second lace guides. Additionally, a tightening reel of the footwear for retracting the lace and thereby advancing the first lace guide towards the second lace guide to tighten the footwear is positioned on the footwear, and a lock is moveable between a coupled position and an uncoupled position wherein the lock allows the reel to be only rotatable in a forward direction when the lock is engaged, and allows the reel to be rotatable in a reverse direction when the lock is disengaged. 
     An embodiment also includes a closed loop lace wherein the lace is permanently mounted in the reel. Accordingly, each of the at least first and second lace guides comprise an open channel to receive the closed loop lace. 
     According to another embodiment of the footwear lacing system, a spool and lace unit is provided for use in conjunction with a footwear lacing system comprises a spool having ratchet teeth disposed on its periphery configured to interact with a pawl for inhibiting relative rotation of the spool in at least one direction, and a lace securely attached to the spool. Optionally, the lace can be formed of a lubricious polymer having a relatively low elasticity and high tensile strength. Alternatively, the lace can be formed of a multi-strand polymeric cable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a sport boot including a lacing system configured in accordance with the present invention; 
         FIG. 2  is a front view of the sport boot of  FIG. 1 ; 
         FIG. 3  is a perspective schematic view of the lacing system of the sport boot of  FIG. 1 ; 
         FIG. 4A  is an exploded perspective view of a multi-piece lace guide member; 
         FIG. 4B  is a perspective view of an assembled multi-piece guide member; 
         FIG. 4C  is a schematic perspective view of an adjustable guide member in accordance with the present invention; 
         FIG. 5  is a cross-sectional view of the multi-piece guide member of  FIG. 4  along line  5 - 5 ; 
         FIG. 6  is a top plan view of the multi-piece guide member; 
         FIG. 7  is a perspective view of an end portion of a lace having a welded tip; 
         FIG. 8  is an exploded perspective view of one embodiment of a tightening mechanism used with the lacing system described herein; 
         FIG. 9  is a cross-sectional side view of the assembled tightening mechanism of  FIG. 8 ; and 
         FIG. 10  is a cross-sectional view of the tightening mechanism of  FIG. 9  taken along the line  10 - 10 ; 
         FIG. 11  is a side view of the sport boot including an ankle support strap; 
         FIG. 12  is a front view of the sport boot including a central lace guide member disposed adjacent the tongue of the boot; 
         FIG. 13  is a perspective view of the central lace guide member; 
         FIG. 14  is a cross-sectional view taken along the line  14 - 14  in  FIG. 13 ; 
         FIG. 15  is a schematic front view of the instep portion of the boot with a plurality of lace locking members disposed along the lace pathway; 
         FIG. 16  is a side view of one embodiment of a lace locking member engaged with the boot lace; 
         FIG. 17  is a side view of one embodiment of a lace locking member non-engages with the boot lace; 
         FIG. 18  is a side view of a second embodiment of the lace locking member; 
         FIG. 19  is a top plan view of a first member portion of the lace locking member of  FIG. 18 ; 
         FIG. 20  is a front view of the instep portion of the boot; 
         FIG. 21  is an enlarged view of the region within line  21  of  FIG. 20 ; 
         FIG. 22  is a top plan view of an alternative embodiment of a lace guide; 
         FIG. 22A  is a perspective view of a guide tube stop in accordance with the present invention; 
         FIG. 23  is a top plan view of an alternative embodiment of a lace guide; 
         FIG. 24  is a side view of the lace guide of  FIG. 23 ; 
         FIG. 25  is a top view of the lace guide of  FIG. 23  mounted in a boot flap; 
         FIG. 26  is a cross-sectional view of the lace guide and boot flap along line  26 - 26  of  FIG. 25 ; 
         FIG. 27  is a side view of a second embodiment of the tightening mechanism; 
         FIG. 27A  is a top plan view of a mounting ring for a releasable bayonet mounting in accordance with one aspect of the present invention. 
         FIG. 28  is a cross-sectional view of the embodiment of  FIG. 27 ; 
         FIG. 29  is a cross-sectional view of an alternate tightening mechanism. 
         FIG. 30  is a split elevational cross section through a tightening mechanism, with the left side in the coupled position and the right side in the uncoupled position; 
         FIG. 31A  is a cross section through a knob showing integrally molded pawls, while  FIG. 31B  is a cross-section taken along lines  31 B of  FIG. 31A   
         FIG. 32  is a cross section through a tightening mechanism case, illustrating ratchet teeth on the case. 
         FIG. 33  is a perspective view of one embodiment of a reel for use with a lacing system in accordance with an alternative embodiment incorporating mounting structure and a safety device to inhibit accidental loosing of the lace. 
         FIG. 34  is a perspective view of another embodiment of the lacing 
         FIG. 35  is an exploded view of the reel of  FIG. 33 . 
         FIG. 36  is a bottom perspective view of a spool with attached lace. 
         FIG. 37   a  is a perspective view of a pawl spring for use with the reel embodiments of  FIGS. 33 and 34 . 
         FIG. 37   b  is a top plan view of the pawl spring of  FIG. 36   a.    
         FIG. 38  is a perspective bottom view of a knob insert of the reel of  FIG. 33 ; 
         FIG. 39  is a perspective bottom view of the knob of the reel of  FIG. 34 . 
         FIG. 40  is a top plan view of the reel of  FIGS. 33 and 34  with the knob removed to display the interior components. 
         FIG. 41  is a perspective bottom view of the reel of  FIG. 34  showing the safety release lever. 
         FIG. 42   a  is a perspective view of a guide member for use in accordance with the footwear lacing system of the present invention. 
         FIG. 42   b  is a cross sectional view of the guide member of  FIG. 41   a  taken along line B-B. 
         FIG. 43  is a top plan view showing one embodiment of the footwear lacing system of the present invention attached to a shoe that is shown in phantom. 
         FIG. 44  is a side elevational view of a shoe having another embodiment of the footwear lacing system of the present invention attached thereto. 
         FIG. 45  is a side elevational view of a shoe having yet another embodiment of the footwear lacing system of the present invention attached thereto. 
         FIG. 46  is a perspective view of an embodiment of a lacing system having a protective element. 
         FIG. 47  is a side elevational view of the lacing system of  FIG. 46  showing the protective element. 
         FIG. 48  illustrates a perspective view of an embodiment of a lacing system having an alternative protective element. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , there is disclosed one embodiment of a sport boot  20  prepared in accordance with the present invention. The sport boot  20  generally comprises an ice skating or other action sport boot which is tightened around a wearer&#39;s foot using a lacing system  22 . The lacing system  22  includes a lace  23  ( FIG. 2 ) that is threaded through the boot  20  and attached at opposite ends to a tightening mechanism  25 , as described in detail below. As used herein, the terms lace and cable have the same meaning unless specified otherwise. The lace  23  is a low friction lace that slides easily through the boot  20  and automatically equilibrates tightening of the boot  20  over the length of the lacing zone, which generally extends along the ankle and foot. Although the present invention will be described with reference to an ice skating boot, it is to be understood that the principles discussed herein are readily applicable to any of a wide variety of footwear, and are particularly applicable to sports shoes or boots suitable for snow boarding, roller skating, skiing and the like. 
     The boot  20  includes an upper  24  comprising a toe portion  26 , a heel portion  28 , and an ankle portion  29  that surrounds the wearer&#39;s ankle. An instep portion  30  of the upper  24  is interposed between the toe portion  26  and the ankle portion  29 . The instep portion  30  is configured to fit around the upper part of the arch of the medial side of the wearer&#39;s foot between the ankle and the toes. A blade  31  (shown in phantom lines) extends downward from the bottom of the boot  20  in an ice-skating embodiment. 
       FIG. 2  is a front elevational view of the boot  20 . As shown, the top of the boot  20  generally comprises two opposed closure edges or flaps  32  and  34  that partially cover a tongue  36 . Generally, the lace  23  may be tensioned to draw the flaps  32  and  34  toward each other and tighten the boot  20  around the foot, as described in detail below. Although the inner edges of the flaps  32  and  34  are shown separated by a distance, it is understood that the flaps  32  and  34  could also be sized to overlap each other when the boot  20  is tightened, such as is known with ski footwear. Thus, references herein to drawing opposing sides of footwear towards each other refers to the portion of the footwear on the sides of the foot. This reference is thus generic to footwear in which opposing edges remain spaced apart even when tight (e.g. tennis shoes) and footwear in which opposing edges may overlap when tight (e.g. certain snow skiing boots). In both, tightening is accomplished by drawing opposing sides of the footwear towards each other. 
     Referring to  FIG. 2 , the tongue  36  extends rearwardly from the toe portion  26  toward the ankle portion  29  of the boot  20 . Preferably, the tongue  36  is provided with a low friction top surface  37  to facilitate sliding of the flaps  32  and  34  and lace  23  over the surface of the tongue  32  when the lace  23  is tightened. The low friction surface  37  may be formed integrally with the tongue  32  or applied thereto such as by adhesives, heat bonding, stitching or the like. In one embodiment, the surface  37  is formed by adhering a flexible layer of nylon or polytetrafluoroethylene to the top surface of the tongue  36 . The tongue  36  is preferably manufactured of a soft material, such as leather. 
     The upper  24  may be manufactured from any from a wide variety of materials known to those skilled in the art. In the case of a snow board boot, the upper  24  is preferably manufactured from a soft leather material that conforms to the shape of the wearer&#39;s foot. For other types of boots or shoes, the upper  24  may be manufactured of a hard or soft plastic. It is also contemplated that the upper  24  could be manufactured from any of a variety of other known materials. 
     As shown in  FIG. 2 , the lace  23  is threaded in a crossing pattern along the midline of the foot between two generally parallel rows of side retaining members  40  located on the flaps  32  and  34 . In the illustrated embodiment, the side retaining members  40  each consist of a strip of material looped around the top and bottom edges of the flaps  32  and  34  so as to define a space in which guides  50  are positioned. The lace  23  slides through the guides  50  during tightening and untightening of the lace  23 , as described more fully below. In the illustrated embodiment, there are three side retaining members  40  on each flap  32 ,  34  although the number of retaining members  40  may vary. In some embodiments, four, five or six or more retaining members  40  may be desirable on each side of the boot. 
     In certain boot designs, it may be possible during the tightening process for an opposing pair of lace guides to “bottom out” and come in contact with each other before that portion of the boot is suitably tightened. Further tightening of the system will not produce further tightening at that point. Rather, other portions of the boot which may already be sized appropriately would continue to tighten. In the embodiment illustrated in  FIG. 2 , the side retaining members  40  each consist of a strip of material looped around the guides  50 . Additional adjustability may be achieved by providing a releasable attachment between the side retaining members  40  and the corresponding flap  32  or  34  of the shoe. In this manner, the side retaining member  40  may be moved laterally away from the midline of the foot to increase the distance between opposing lace guides. 
     One embodiment of the adjustable side retaining member  40  may be readily constructed, that will appear similar to the structure disclosed in  FIG. 2 . In the adjustable embodiment, a first end of the strip of material is attached to the corresponding flap  32  or  34  using conventional means such as rivets, stitching, adhesives, or others known in the art. The strip of material loops around the guide  50 , and is folded back over the outside of the corresponding flap  32  or  34  as illustrated. Rather than stitching the top end of the strip of material to the flap, the corresponding surfaces between the strip of material and the flap may be provided with a releasable engagement structure such as hook and loop structures (e.g., Velcro®), or other releasable engagement locks or clamps which permits lateral-medial adjustability of the position of the guide  50  with respect to the edge of the corresponding flap  32  or  34 . 
     The guides  50  may be attached to the flaps  32  and  34  or to other spaced apart portions of the shoe through any of a variety of manners, as will be appreciated by those of skill in the art in view of the disclosure herein. For example, the retaining members  40  can be deleted and the guide  50  sewn directly onto the surface of the flap  32  or  34  or opposing sides of the upper. Stitching the guide  50  directly to the flap  32  or  34  may advantageously permit optimal control over the force distribution along the length of the guide  50 . For example, when the lace  23  is under relatively high levels of tension, the guide  50  may tend to want to bend and to possibly even kink near the curved transition in between longitudinal portion  51  and transverse portion  53  as will be discussed. Bending of the guide member under tension may increase friction between the guide member and the lace  23 , and, severe bending or kinking of the guide member  50  may undesirably interfere with the intended operation of the lacing system. Thus, the attachment mechanism for attaching the guide member  50  to the shoe preferably provides sufficient support of the guide member to resist bending and/or kinking. Sufficient support is particularly desirable on the inside radius of any curved portions particularly near the ends of the guide member  50 . 
     As shown in  FIGS. 1 and 2 , the lace  23  also extends around the ankle portion  29  through a pair of upper retaining members  44   a  and  44   b  located on the ankle portion  29 . The upper retaining members  44   a  and  44   b  each comprise a strip of material having a partially raised central portion that defines a space between the retaining members  44  and the upper  24 . An upper guide member  52  extends through each of the spaces for guiding the lace  23  around either side of the ankle portion  29  to the tightening mechanism  25 . 
       FIG. 3  is a schematic perspective view of the lacing system  22  of the boot  20 . As shown, each of the side and top guide members  50  and  52 , has a tube-like configuration having a central lumen  54 . Each lumen  54  has an inside diameter that is larger than the outside diameter of the lace  23  to facilitate sliding of the lace  23  through the side and top guide members  50 ,  52  and prevent binding of the lace  23  during tightening and untightening. In one embodiment, the inside diameter of the lumen is approximately 0.040 inches, to cooperate with a lace having an outside diameter of about 0.027″. However, it will be appreciated that the diameter of the lumen  54  can be varied to fit specific desired lace dimensions and other design considerations. The wall thickness and composition of the guides  50 ,  52  may be varied to take into account the physical requirements imposed by particular shoe designs. 
     Thus, although the guides  50  are illustrated as relatively thin walled tubular structures, any of a variety of guide structures may be utilized as will be apparent to those of skill in the art in view of the disclosure herein. For example, either permanent (stitched, glued, etc.) or user removable (Velcro, etc.) flaps  40  may be utilized to hold down any of a variety of guide structures. In one embodiment, the guide  50  is a molded block having a lumen extending therethrough. This may take a form similar to that illustrated in  FIG. 4A ,  4 B or  6 . Modifications of the forgoing may also be accomplished, such as by extending the length of the lace pathway in a structure such as that illustrated in  FIG. 6 , such that the overall part has a shallow “U” shaped configuration which allows it to be conveniently retained by the retention structure  40 . Providing a guide member  50  having increased structural integrity over that which would be achieved by the thin tube illustrated in  FIG. 2  may be advantageous in embodiments of the invention where the opposing guides  50  may be tightened sufficiently to “bottom out” against the opposing corresponding guide, as will be apparent to those of skill in the art in view of the disclosure herein. Solid and relatively harder lace guides as described above may be utilized throughout the boot, but may be particularly useful in the lower (e.g. toe) portion of the boot. 
     In general, each of the guide members  50  and  52  defines a pair of openings  49  that communicate with opposite ends of the lumen  54 . The openings  49  function as inlets/outlets for the lace  23 . The openings desirably are at least as wide as the cross-section of the lumen  54 . 
     As may be best seen in  FIG. 3 , each top guide  52  has an end  55  which is spaced apart from a corresponding side guide  50  on the opposing side of the footwear, with the lace  23  extending therebetween. As the system is tightened, the spacing distance will be reduced. For some products, the wearer may prefer to tighten the toe or foot portion more than the ankle. This can be conveniently accomplished by limiting the ability of the side guide  50  and top guide  52  to move towards each other beyond a preselected minimum distance during the tightening process. For this purpose, a selection of spacers having an assortment of lengths may be provided with each system. The spacers may be snapped over the section of lace  23  between a corresponding end  55  of top guide  52  and side guide  50 . When the ankle portion of the boot is sufficiently tight, yet the wearer would like to additionally tighten the toe or foot portion of the boot, a spacer having the appropriate length may be positioned on the lace  23  in-between the top guide  52  and side guide  50 . Further tightening of the system will thus not be able to draw the top guide  52  and corresponding side guide  50  any closer together. 
     The stop may be constructed in any of a variety of ways, such that it may be removably positioned between the top guide  52  and side guide  50  to limit relative tightening movement. In one embodiment, the stop comprises a tubular sleeve having an axial slot extending through the wall, along the length thereof. The tubular sleeve may be positioned on the boot by advancing the slot over the lace  23 , as will be apparent to those of skill in the art. A selection of lengths may be provided, such as ½ inch, 1 inch, -1½ inch, and every half inch increment, on up to 3 or 4 inches or more, depending upon the position of the reel on the boot and other design features of a particular embodiment of the boot. Increments of ¼ inch may also be utilized, if desired. 
     In  FIG. 3 , the top guide  52  is illustrated for simplicity as unattached to the corresponding side flap  32 . However, in an actual product, the top guide  52  is preferable secured to the side flap  32 . For example, upper retaining member  44   a , discussed above, is illustrated in  FIG. 2 . Alternatively, the top guide  52  may extend within the material of or between the layers of the side flap  32 . As a further alternative, or in addition to the foregoing, the end  55  of top guide  52  may be anchored to the side flap  32  using any of a variety of tie down or clamping structures. One suitable structure is illustrated in  FIG. 22   a , discussed below. The lace  23  may be slideably positioned within a tubular sleeve extending between the reel and the tie down at the end  55  of the sleeve. 
     Any of a variety of flexible tubular sleeves may be utilized, such as a spring coil with or without a polymeric jacket similar to that used currently on bicycle brake and shift cables. The use of a flexible but axially noncompressible sleeve for surrounding the lace  23  between the reel and the tie down at the end  55  isolates the tightening system from movement of portions of the boot, which may include hinges or flexibility points as is understood in the art. The tie down may comprise any of a variety of structures in addition to that illustrated in  FIG. 22A , including grommets, rivets, staples, stitched or adhesively bonded eyelets, as will be apparent to those of skill in the art in view of the disclosure herein. 
     In the illustrated embodiment, the side guide members  50  each have a generally U-shape that opens towards the midline of the shoe. Preferably, each of the side guide members  50  comprise a longitudinal portion  51  and two inclined or transverse portions  53  extending therefrom. The length of the longitudinal portion  51  may be varied to adjust the distribution of the closing pressure that the lace  23  applies to the upper  24  when the lace  23  is under tension. In addition, the length of the longitudinal portion  51  need not be the same for all guide members  50  on a particular shoe. For example, the longitudinal portion  51  may be shortened near the ankle portion  29  to increase the closing pressure that the lace  23  applies to the ankles of the wearer. In general, the length of the longitudinal portion  51  will fall within the range of from about ½″ to about 3″, and, in some embodiments, within the range of from about ¼″ to about 4″. In one snowboard application, the longitudinal portion  51  had a length of about 2″. The length of the transverse portion  53  is generally within the range of from about ⅛″ to about 1″. In one snowboard embodiment, the length of transverse portion  53  was about ½″. Different specific length combinations can be readily optimized for a particular boot design through routine experimentation by one of ordinary skill in the art in view of the disclosure herein. 
     In between the longitudinal portion  51  and transverse portion  53  is a curved transition. Preferably, the transition has a substantially uniform radius throughout, or smooth progressive curve without any abrupt edges or sharp changes in radius. This construction provides a smooth surface over which the lace  23  can slide, as it rounds the corner. The transverse section  53  can in some embodiments be deleted, as long as a rounded cornering surface is provided to facilitate sliding of the lace  23 . In an embodiment which has a transverse section  53  and a radiused transition, with a guide member  50  having an outside diameter of 0.090″ and a lace  23  having an outside diameter of 0.027″, the radius of the transition is preferably greater than about 0.1″, and generally within the range of from about 0.125″ to about 0.4″. 
     Referring to  FIG. 3 , the upper guide members  52  extend substantially around opposite sides of the ankle portion  29 . Each upper guide member  52  has a proximal end  56  and a distal end  55 . The distal ends  55  are positioned near the top of the tongue  36  for receipt of the lace  23  from the uppermost side guide members  50 . The proximal ends  56  are coupled to the tightening mechanism  25 . In the illustrated embodiment, the proximal ends  56  include rectangular coupling mounts  57  that engage with the tightening mechanism  25  for feeding the ends of the lace  23  therein, as described more fully below. The guide members  50  and/or  52  are preferably manufactured of a low friction material, such as a lubricous polymer or metal, that facilitates the slideability of the lace  23  therethrough. Alternatively, the guides  50 ,  52  can be made from any convenient substantially rigid material, and then be provided with a lubricous coating on at least the inside surface of lumen  54  to enhance slideability. The guide members  50  and  52  are preferably substantially rigid to prevent bending and kinking of the guide members  50 ,  52  and/or the lace  23  within any of the guide members  50  and  52  as the lace  23  is tightened. The guide members  50 ,  52  may be manufactured from straight tube of material that is cold bent or heated and bent to a desired shape. 
     Alternatively, the guide members  50 ,  52  may be constructed in a manner that permits bending, retains a low friction surface, yet resist kinking. For example, guide members  50 ,  52  may comprise a spring coil, either with the spring coil exposed or the spring coil provided with a polymeric coating on the inside surface or outside surface or both. The provision of a spring coil guide satisfies the need for lateral flexibility in some embodiments, yet retains a hard interior surface which help to minimize friction between the guide and the lace. 
     As an alternate guide member  50 ,  52  design which increases lateral flexibility yet retains a hard interior lace contacting surface, the guide  50  may comprise a plurality of coaxially-aligned segments of a hard polymeric or metal tube material. Thus, a plurality of tubing segments, each segment having an axial length within the range of from about 0.1″ to about 1.0″, and preferably about 0.25″ or less can be coaxially aligned, either in end-to-end contact or axially spaced apart along the length of the guide  50 ,  52 . Adjacent tubular segments can be maintained in a coaxial relationship such as by the provision of an outer flexible polymeric jacket. The shape of the tubular guide may be retained such as by stitching the guide onto the side of the shoe in the desired orientation, or through other techniques which will be apparent to those of skill in the art in view of the disclosure herein. 
     As an alternative to the previously described tubular guide members, the guide members  50  and/or  52  comprise an open channel having, for example, a semicircular or “U” shaped cross section. The guide channel is preferably mounted on the boot such that the channel opening faces away from the midline of the boot, so that a lace under tension will be retained therein. One or more retention strips, stitches or flaps may be provided for “closing” the open side of the channel, to prevent the lace from escaping when tension on the lace is released. The axial length of the channel can be preformed in a generally U configuration like the illustrated tubular embodiment, and may be continuous or segmented as described in connection with the tubular embodiment. 
     Several guide channels may be molded as a single piece, such as several guide channels molded to a common backing support strip which can be adhered or stitched to the shoe. Thus, a right lace retainer strip and a left lace retainer strip can be secured to opposing portions of the top or sides of the shoe to provide a right set of guide channels and a left set of guide channels. 
     As an alternative to the previously described tubular guide members, the guide members  50  and/or  52  comprise a multi-piece guide member  199  comprised of a first member  200  and a second member  202  that mates thereto, such as shown in  FIGS. 4A and 4B . The first member  200  and the second member  202  each have a thin, flat shape. A cavity or seat  204  ( FIG. 4A ) extends into an upper surface of the first member  200 . The seat  204  is preferably sized to receive the second member  202  snug therein, such as in a press-fit fashion, as best shown in  FIG. 4B . 
     As shown in the cross-sectional view of  FIG. 5 , the second member  202  may be positioned within the seat so that a gap  206  of predetermined shape is defined between the second member  202  and the first member  200 . A pair of apertures  207  ( FIGS. 4A ,  4 B) are located on one of the first or second member  202 ,  204  to serve as entryways into the gap  206 . The apertures  207  preferably are sufficiently large to allow passage of the lace  23  therethrough. In one embodiment, the apertures  207  are within the range of from about 0.030 inches to about 0.060 inches in diameter. 
     With reference to  FIG. 6 , the gap  206  is elongated so that it defines a lace pathway that functions as the lumen  54  for the lace  23 . The lumen  54  preferably includes an elongate region  209  that extends generally lengthwise along the edges of the flaps  32  or  34  when the guide member  199  is mounted on the boot. The elongate region  209  may be straight or may be defined by a smooth curve along the length thereof, such as a continuous portion of a circle or ellipse. As an example, the elongate region  209  may be defined by a portion of an ellipse having a major axis of about 0.5 inches to about 2 inches and a minor axis of about 0.25 inches to about 1.5 inches. In one embodiment, the major axis is approximately 1.4 inches and the minor axis is about 0.5 inches. The lumen  54  further includes a transverse region  210  on opposite ends of the elongate region  209 . The transverse region  210  extends at an incline to the edges of the flaps  32  and  34 . Alternatively, the elongate region  209  and the transverse region  210  may be merged into one region having a continuous circular or elliptical profile to spread load evenly along the length of the lumen  54  and thereby reduce total friction in the system. 
     The first and second members  200 ,  202  of the multi-piece guide member  199  may be manufactured of a low friction material, such as a lubricous polymer or metal, that facilitates the slideability of the lace  23  therethrough. Alternatively, the guide member  199  can be made from any convenient substantially rigid material, and then be provided with a lubricous coating on at least the surface of the inside curve of lumen  54  to enhance slideability. The guide member  199  may be substantially rigid to prevent bending and kinking of the guide member  199  and/or the lace  23  therein as the lace  23  is tightened. The guide member  199  may alternatively be made of a flexible material when used in portions of the shoe that are subject to bending. The guide members  50 ,  52  may be manufactured through known molding processes. 
     Referring to  FIG. 4A , each of the guide members  199  has a predetermined distance between the first opening  207   a  and second opening  207   b  to the lace pathway therein. The effective linear distance between the first and second openings to the lace pathway may affect the fit of the boot. An embodiment in which the distance between the first opening  207   a  and second opening  207   b  is adjustable is illustrated schematically in  FIG. 4C . Any of a wide variety of other implementations may be readily devised, which incorporate the function of the structure schematically illustrated in  FIG. 4C . 
     In general, a first guide element  211  is spaced apart from a second guide element  213 . The first guide element  211  contains a first partial or complete aperture  207   a  for receiving lace  23  therethrough. The second guide element  213  includes the second partial or complete aperture  207   b , also for receiving the lace  23  therethrough. As is the case with other embodiments herein, the lace pathway (not illustrated) through the first and second guide elements  211  and  213  may extend through a tunnel or may extend along a curved surface, such as a rotatable pulley, radiused recess or otherwise depending upon the desired performance and construction. 
     As illustrated in  FIG. 4C , the lace  23  enters the first aperture  207   a , extends through the first guide element  211 , and into the second guide element  213 . The adjustable guide member  199  is additionally provided with a threaded shaft  215  extending between the first and second guide elements  211  and  213 . Rotation of the threaded shaft  215  in a first direction draws the guide elements  211  and  213  towards each other, thereby shortening the distance between the lace apertures  207   a  and  207   b . Rotating the threaded shaft  215  in an opposite direction increases the axial distance between apertures  207   a  and  207   b . Specific rotational engagements between the threaded shaft  215 , guide elements  211  and  213 , to accomplish this purpose are well known in the art. A rotatable engagement structure, such as a slotted head, a hex recess or projection, or the like may be provided on one end  217  of the threaded shaft  215 . Any of a variety of alternate structures may be utilized, to permit the adjustment of the spacing between the apertures  207   a  and  207   b , as will be apparent to those of ordinary skill in the art in view of the disclosure herein. 
     The lace  23  may be formed from any of a wide variety of polymeric or metal materials or combinations thereof, which exhibit sufficient axial strength and bendability for the present application. For example, any of a wide variety of solid core wires, solid core polymers, or multi-filament wires or polymers, which may be woven, braided, twisted or otherwise oriented can be used. A solid or multi-filament metal core can be provided with a polymeric coating, such as PTFE or others known in the art, to reduce friction. In one embodiment, the lace  23  comprises a stranded cable, such as a  7  strand by  7  strand cable manufactured of stainless steel. In order to reduce friction between the lace  23  and the guide members  50 ,  52  through which the lace  23  slides, the outer surface of the lace  23  is preferably coated with a lubricous material, such as nylon or Teflon. In a preferred embodiment, the diameter of the lace  23  ranges from 0.024 inches to 0.060 inches and is preferably 0.027 inches. The lace  23  is desirably strong enough to withstand loads of at least 40 pounds and preferably at least about 90 pounds. In certain embodiments the lace is rated at least about 100 pounds up to as high as 200 pounds or more. A lace  23  of at least five feet in length is suitable for most footwear sizes, although smaller or larger lengths could be used depending upon the lacing system design. 
     The lace  23  may be formed by cutting a piece of cable to the desired length. If the lace  23  comprises a braided or stranded cable, there may be a tendency for the individual strands to separate at the ends or tips of the lace  23 , thereby making it difficult to thread the lace  23  through the openings in the guide members  50 ,  52 . As the lace  23  is fed through the guide members, the strands of the lace  23  easily catch on the curved surfaces within the lace guide members. The use of a metallic lace, in which the ends of the strands are typically extremely sharp, also increases the likelihood of the cable catching on the guide members during threading. As the tips of the strands catch on the guide members and/or the tightening mechanism, the strands separate, making it difficult or impossible for the user to continue to thread the lace  23  through the tiny holes in the guide members and/or the tightening mechanism. Unfortunately, unstranding of the cable is a problem unique to the present replaceable-lace system, where the user may be required to periodically thread the lace through the lace guide members and into the corresponding tightening mechanism. 
     With reference to  FIG. 7 , one solution to this problem is to provide the tips or ends  59  of the lace  23  with a sealed or bonded region  61  wherein the individual strands are retained together to prevent separation of the strands from one another. For clarity of illustration, the bonded region  61  is shown having an elongate length. However, the bonded region  61  may also be a bead located at just the extreme tip of the lace  23  and, in one embodiment, could be a bonded tip surface as short as 0.002 inch or less. 
     The bonded region  61  may be formed, for example, by applying a weld (e.g., solder tip, brazing, welding, or melting the strands together) to the ends  59  during formation of the lace  23  to thereby hold the strands together and prevent separation of the strands. A tip weld advantageously does not significantly increase the overall diameter of the lace  23 . Additionally, the weld may also be used to smooth the ends  59  of the lace  23  to facilitate insertion of the lace  23  into the guide members. A weld is also advantageous in that it provides a secure, permanent bond between the strands of the lace  23 . The bonded region  61  provides the ends of the lace  23  with a smooth and secure surface that greatly facilitates threading of the lace through the guide members and into the tightening mechanism. The bonded region thus makes it much easier for a user to replace the lace  23  in the system. Alternatively, adhesives or thin walled shrink wrap tubing may be used in certain embodiments. 
     After the 7×7 multistrand stainless steel cable described above has been tightened and untightened a number of times, the cable tends to kink or take a set. Kink resistance of the cable may be improved by making the cable out of a nickel titanium alloy such as nitinol. Other materials may provide desirable kink resistance, as will be appreciated by those of skill in the art in view of the disclosure herein. In one particular embodiment, a 1×7 multi-strand cable may be constructed having seven nitinol strands, each with a diameter within the range of from about 0.005 inches to about 0.015 inches woven together. In one embodiment, the strand has a diameter of about 0.010 inches, and a 1×7 cable made with that strand has an OD of about 0.030 inches. The diameter of the nitinol strands may be larger than a corresponding stainless steel embodiment due to the increased flexibility of nitinol, and a 1×7 construction and in certain embodiments a 1×3 construction may be utilized. 
     In a 1×3 construction, three strands of nitinol, each having a diameter within the range of from about 0.007 inches to about 0.025 inches, preferably about 0.015 inches are drawn and then swaged to smooth the outside. A drawn multistrand cable will have a nonround cross-section, and swaging and/or drawing makes the cross-section approximately round. Swaging and/or drawing also closes the interior space between the strands, and improves the crush resistance of the cable. Any of a variety of additives or coatings may also be utilized, such as additives to fill the interstitial space between the strands and also to add lubricity to the cable. Additives such as adhesives may help hold the strands together as well as improve the crush resistance of the cable. Suitable coatings include, among others, PTFE, as will be understood in the art. 
     In an alternate construction, the lace or cable comprises a single strand element. In one application, a single strand of a nickel titanium alloy wire such as nitinol is utilized. Advantages of the single strand nitinol wire include both the physical properties of nitinol, as well as a smooth outside diameter which reduces friction through the system. In addition, durability of the single strand wire may exceed that of a multi strand since the single strand wire does not crush and good tensile strength or load bearing capacity can be achieved using a small OD single strand wire compared to a multi strand braided cable. Compared to other metals and alloys, nitinol alloys are extremely flexible. This is useful since the nitinol laces are able to navigate fairly tight radii curves in the lace guides and also in the small reel. Stainless steel or other materials tend to kink or take a set if a single strand was used, so those materials are generally most useful in the form of a stranded cable. However, stranded cables have the disadvantage that they can crush in the spool when the lace is wound on top of itself. In addition, the stranded cables are not as strong for a given diameter as a monofilament wire because of the spaces in between the strands. Strand packing patterns in multistrand wire and the resulting interstitial spaces are well understood in the art. For a given amount of tensile strength, the multistrand cables therefore present a larger bulk than a single filament wire. Since the reel is preferably minimized in size the strongest lace for a given diameter is preferred. In addition, the stranded texture of multistrand wires create more friction in the lace guides and in the spool. The smooth exterior surface of a single strand creates a lower friction environment, better facilitating tightening, loosening and load distribution in the dynamic fit of the present invention. 
     Single strand nitinol wires having diameters within the range of from about 0.020 inches to about 0.040 inches may be utilized, depending upon the boot design and intended performance. In general, diameters which are too small may lack sufficient load capacity and diameters which are too large may lack sufficient flexibility to be conveniently threaded through the system. The optimal diameter can be determined for a given lacing system design through routine experimentation by those of skill in the art in view of the disclosure herein. In many boot embodiments, single strand nitinol wire having a diameter within the range of from about 0.025 inches to about 0.035 inches may be desirable. In one embodiment, single strand wire having a diameter of about 0.030 inches is utilized. 
     The lace may be made from wire stock, shear cut or otherwise severed to the appropriate length. In the case of shear cutting, a sharpened end may result. This sharpened end is preferably removed such as by deburring, grinding, and/or adding a solder ball or other technique for producing a blunt tip. In one embodiment, the wire is ground or coined into a tapered configuration over a length of from about ½ inch to about 4 inches and, in one embodiment, no more than about 2 inches. The terminal ball or anchor is preferably also provided as discussed below. Tapering the end of the nitinol wire facilitates feeding the wire through the lace guides and into the spool due to the increased lateral flexibility of the reduced cross section. 
     Provision of an enlarged cross sectional area structure at the end of the wire, such as by welding, swaging, coining operations or the use of a melt or solder ball, may be desirable in helping to retain the lace end within the reel as well as facilitating feeding the lace end through the lace guides and into the reel. In one embodiment of the reel, discussed elsewhere herein, the lace end is retained within the reel under compression by a set screw. While set screws may provide sufficient retention in the case of a multi strand wire, set screw compression on a single stand cable may not produce sufficient retention force because of the relative crush resistance of the single strand. The use of a solder ball or other enlarged cross sectional area structure at the end of the lace can provide an interference fit behind the set screw, to assist retention within the reel. 
     In one example, a 0.030 inch diameter single strand lace is provided with a terminal ball having a diameter within the range of from about 0.035 inches to about 0.040 inches. In addition to or as an alternative to the terminal ball or anchor, a slight angle or curve may be provided in the tip of the lace. This angle may be within the range of from about 5° to about 25°, and, in one embodiment about 15°. The angle includes approximately the distal ⅛ inch of the lace. This construction allows the lace to follow tight curves better, and may be combined with a rounded or blunted distal end which may assist navigation and locking within the reel. In one example, a single strand wire having a diameter of about 0.030 inches is provided with a terminal anchor having a diameter of at least about 0.035 inches. Just proximal to the anchor, the lace is ground to a diameter of about 0.020 inches, which tapers over a distance of about an inch in the proximal direction up to the full 0.030 inches. Although the term “diameter” is utilized to describe the terminal anchor, Applicant contemplates nonround anchors such that a true diameter is not present. In a noncircular cross-section embodiment, the closest approximation of the diameter is utilized for the present purposes. 
     As an alternative terminal anchor on the lace, a molded piece of plastic or other material may be provided on the end of each single strand. In a further variation, each cable end is provided with a detachable threading guide. The threading guide may be made from any of a variety of relatively stiff plastics like nylon, and be tapered to be easily travel around the corners of the lace guides. After the lace is threaded through the lace guides, the threading guide may be removed from the lace and discarded, and the lace may be then installed into the reel. 
     The terminal anchor on the lace may also be configured to interfit with any of a variety of connectors on the reel. Although set screws are a convenient mode of connection, the reel may be provided with a releasable mechanism to releasably receive the larger shaped end of the lace which snaps into place and is not removable from the reel unless it is released by an affirmative effort such as the release of a lock or a lateral movement of the lace within a channel. Any of a variety of releasable interference fits may be utilized between the lace and the reel, as will be apparent to those of skill in the art in view of the disclosure herein. 
     As shown in  FIG. 3 , the tightening mechanism  25  is mounted to the rear of the upper  24  by fasteners  64 . Although the tightening mechanism  25  is shown mounted to the rear of the boot  20 , it is understood that the tightening mechanism  25  could be located at any of a wide variety of locations on the boot  20 . In the case of an ice skating boot, the tightening mechanism is preferably positioned over a top portion of the tongue  36 . The tightening mechanism  25  may alternatively be located on the bottom of the heal of the boot, on the medial or the lateral sides of the upper or sole, as well as anywhere along the midline of the shoe facing forward or upward. Location of the tightening mechanism  25  may be optimized in view of a variety of considerations, such as overall boot design as well as the intended use of the boot. The shape and overall volume of the tightening mechanism  25  can be varied widely, depending upon the gear train design, and the desired end use and location on the boot. A relatively low profile tightening mechanism  25  is generally preferred. The mounted profile of the tightening mechanism  25  can be further reduced by recessing the tightening mechanism  25  into the wall or tongue of the boot. Boots for many applications have a relatively thick wall, such as due to structural support and/or thermal insulation and comfort requirements. The tightening mechanism may be recessed into the wall of the boot by as much as ¾″ or more in some locations and for some boots, or on the order of about ⅛″ or ½″ for other location and/or other boots, without adversely impacting the comfort and functionality of the boot. 
     In general, the tightening mechanism  25  comprises a control such as a lever, crank or knob, which can be manipulated to retract lace  23  therein. In addition, the tightening mechanism preferably comprises a release such as a button or lever, for disengaging the tightening mechanism to permit the lace  23  to be withdrawn freely therefrom. 
     The tightening mechanism  25  in the illustrated embodiment generally comprises a rectangular housing  60  and a circular knob  62  rotatably mounted thereto. The knob  62  may be rotated to wind the ends of the lace  23  into the housing  60  and thereby tension the lace  23  to reduce slack. As the slack in the lace  23  reduces, the lace  23  pulls the side guide members  50 , and thereby the flaps  32  and  34 , toward the midline of the boot to tighten the upper  24  around a foot. 
     The tightening mechanism  25  advantageously includes an internal gear mechanism to allow the wearer to easily turn the knob  62  to retract the lace  23 . Preferably, the gear mechanism is configured to incrementally pull and retain a predetermined length of lace as the knob  62  is rotated, as described in detail below. A user may thus advantageously continuously adjust the tension in the lace  23  to a desired comfort and performance level. The knob  62  may be rotated either manually or through the use of a tool or small motor attached to the knob  62 . 
     Any of a variety of known mechanical structures can be utilized to permit winding of the spool to increase tension on the lace, yet resist unwinding of the spool until desired. For example, any of a wide variety of ratchet structures can be used for this purpose. Alternatively, a Sprague clutch or similar structure will permit one-way rotation of a shaft while resisting rotation in the opposite direction. These and other structures will be well known to those of ordinary skill in the mechanical arts. 
     A release lever  63  is located along a side of the housing  60 . The release lever may be rotated to disengage the internal gear mechanism to release tension in the lace  23  and loosen the upper  23  around the wearer&#39;s foot, as described in detail below. This advantageously allows a user to quickly and easily untighten the lacing system by simply turning the release lever  63 . 
     The low friction relationship between the lace  23  and cable guides  50 ,  52  greatly facilitate tightening and untightening of the lacing system  20 . Specifically, because the lace  23  and cable guides  50  and  52  are manufactured or coated with a low friction material, the lace  23  slides easily through the cable guides without catching. The lace  23  thus automatically distributes the tension across its entire length so that tightening pressure is evenly distributed along the length of the ankle and foot. When the tension in the lace  23  is released by actuating the release lever, the lace  23  slides easily through the cable guides  50  and  52  to release tension and evenly distribute any slack among the length of the lace. The low friction tongue  36  also facilitates moving of the flaps  32 ,  34  away from each other when the lace  23  is loosened. 
       FIG. 8  is an exploded perspective view of the various components of one embodiment of the tightening mechanism  25 . As shown, the housing  60  consists of a pair of interlocking halves  64   a  and  64   b  that are mated to each other using fasteners  66 , such as screws. The housing  60  encloses a gear mechanism  70  that preferably rotatably fits within cavities  65  in the inner surfaces of the halves  64   a  and  64   b . In the illustrated embodiment, the gear mechanism  70  comprises first, second, and third gear wheels  72 ,  74 , and  76 , respectively, that rotatably engage with each other when the tightening mechanisms  25  is assembled. 
     As shown in  FIG. 8 , the first gear wheel  72  includes a shaft  78  about which the first gear wheel rotates. A first portion of the shaft  78  extends through an aperture in the housing halve  64   a . A second portion of the shaft  78  extends through an aperture in the halve  64   b . The knob  62  mounts to the shaft  78  through a mounting hole  80  in the knob  0 . 62 . A mounting pin  76  removably secures the knob  62  to the shaft  78  in a well known manner. When the tightening mechanism  25  is assembled, rotation of the knob  62  causes the first gear wheel  72  to also rotate. Actuation of the gear mechanism  70  is thus accomplished through rotation of the knob  62 . 
     Referring to  FIG. 8 , the first gear wheel  72  also includes a ratchet section  82  having a plurality of sloped teeth  83  ( FIG. 10 ) positioned circumferentially around the axis of the first gear wheel  72 . The sloped teeth  83  are configured to mate with a pawl  84  to prevent undesired backward rotation of the first gear wheel  72 , as described more fully below. Toward this end, a biasing member  86  couples to a peg  90  that extends from the pawl  84 . The biasing member  86  biases the pawl  84  against the ratchet teeth when the gear mechanism  70  is assembled. The third gear wheel  72  also includes a gear section  92  having a series of gear teeth that extend around the periphery of the third gear wheel  72 . 
     As shown in  FIG. 8 , the second gear wheel  74  includes a first gear section  94  and a stepped second gear section  96  having a diameter smaller than the first gear section  94  on a common axis of rotation. The first gear section  94  has gear teeth that are configured to mesh with the gear section  92  of the first gear wheel  72 . An aperture  97  extends centrally through the second gear wheel  74 . The aperture  97  is sized to rotatably receive a post  98  that extends from the housing halve  64   b . The second gear wheel  74  rotates about the post  98  during actuation of the assembled gear mechanism  70 . 
     Referring to  FIG. 8 , the third gear wheel  76  includes a gear section  100  that is configured to mesh with the second gear section  96  of the second gear wheel  74 . The third gear wheel also includes a spool section  102  comprising grooves  104 ,  106  that extend around the periphery of the third gear wheel  76 . The grooves  104 ,  106  are sized to receive opposite ends of the lace  23  in a winding fashion during actuation of the gear mechanism  25 . 
     The ends  107  and  108  of the lace  23  are each provided with anchors  109  that mate with seating holes  110  in a press fit fashion. The seating holes  110  are diametrically positioned on the third gear wheel  76 . When the anchors  109  are mated with the seating holes  110 , the ends  107  and  108  of the lace  23  are separately positioned within the grooves  104  and  106 , respectively. The coupling mounts  57  fit into a corresponding aperture in the housing halve  64  to maintain the distal ends  56  of the guide member  50  in a fixed position relative to the tightening mechanism. 
     Any of a variety of spool or reel designs can be utilized in the context of the present invention, as will be apparent to those of skill in the art in view of the disclosure herein. For example, only a single groove spool can be utilized. However, a dual groove spool or two side-by-side spools as illustrated has the advantage of permitting convenient simultaneous retraction of both lace ends  107  and  108 . In the illustrated embodiment, with ends  107  and  108  approaching the spool from opposite directions, the lace conveniently wraps around the spool in opposite directions using a single rotatable shaft as will be apparent from  FIG. 8 . 
     Depending upon the gearing ratio and desired performance, one end of the lace can be fixed to a guide or other portion of the boot and the other end is wound around the spool. Alternatively, both ends of the lace can be fixed to the boot, such as near the toe region and a middle section of the lace is attached to the spool. 
     Preferably, the cavity  65  is toleranced to fit closely around the outer circumference of the spool, to capture the lace. Thus, the gap between the outer flange walls surrounding each groove and the interior surface of the cavity  65  are preferably smaller than the diameter of the lace. In this manner, the risk of tangling the lace within the winding mechanism can be minimized. 
     Any of a variety of attachment structures for attaching the ends of the lace to the spool can be used. In addition to the illustrated embodiment, the lace may conveniently be attached to the spool by threading the lace through an aperture and providing a transversely oriented set screw so that the set screw can be tightened against the lace and to attach the lace to the spool. The use of set screws or other releasable clamping structures facilitates disassembly and reassembly of the device, and replacement of the lace as will be apparent to those of skill in the art. 
     In any of the embodiments disclosed herein, the lace may be rotationally coupled to the spool either at the lace ends, or at a point on the lace that is spaced apart from the ends. In addition, the attachment may either be such that the user can remove the lace with or without special tools, or such that the user is not intended to be able to remove the lace from the spool. Although the device is disclosed primarily in the context of a design in which the lace ends are attached to the spool, the lace ends may alternatively be attached elsewhere on the footwear. In this design, an intermediate point on the lace is connected to the spool such as by adhesives, welding, interference fit or other attachment technique. In one design the lace extends through an aperture which extends through a portion of the spool, such that upon rotation of the spool, the lace is wound around the spool. The lace ends may also be attached to each other, to form a continuous lace loop. 
     Rotation of the third gear wheel  76  causes the ends  107  and  108  of the lace  23  to wind around the grooves  104  and  106 , respectively, and thereby pull the length of the lace  23  into the tightening mechanism  25  and place the lace  23  in tension. It is understood that the ends  107 ,  108  of the lace  23  wind around the spool section  102  at an equal rate so that tension is evenly applied to both ends of the lace  23 . 
     The third gear wheel includes a central aperture  111  sized to rotatably receive the shaft  78  on the first gear wheel  72 . The third gear wheel  76  rotates about the shaft  78  during actuation of the gear mechanism  70 . 
     In a preferred embodiment, the third gear wheel  76  has a diameter of 0.625 inches. The second gear section  96  of the second gear wheel  74  preferably has a diameter of approximately 0.31 inches and the first gear section preferably has a diameter approximately equal to the diameter of the third gear wheel  76 . The first gear wheel  72  preferably has a diameter of approximately 0.31 inches. Such a relationship in the gear sizes provides sufficiently small adjustments in the tension of the lace  23  as the gear wheels are turned. 
       FIG. 9  illustrates a cross-sectional view of the assembled tightening mechanism  25 . As shown, the shaft  78  of the first gear wheel  72  is journaled within apertures  112  and  114  in the housing halves  64   a  and  64   b , respectively. The knob  62  is mounted over the portion of the shaft  78  extending out of the halve  64   a  through the aperture  112 . The first, second, and third gear wheels  72 ,  74 , and  76 , respectively are in meshed engagement with each other. Specifically, the gear section  92  of the first gear wheel  72  is in meshed engagement with the first gear section  94  on the second gear wheel. Likewise, the second gear section  96  on the second gear wheel  94  is in meshed engagement with the gear section  100  of the third gear wheel  76 . Accordingly, rotation of the knob  62  causes the first gear wheel  72  to rotate and thereby cause the second gear wheel to rotate in an opposite direction by means of the meshed engagement between the gear sections  92  and  94 . This in turn causes the third gear wheel  76  to rotate in the direction of knob rotation by means of the meshed engagement between the gear sections  96  and  100 . 
     As the third gear wheel  76  rotates, the ends  107  and  108  of the lace are wound within the grooves  104  and  106  respectively. Rotation of the knob  62  thus winds the lace  23  around the third gear wheel  76  to thereby tighten the boot  20 . 
     As illustrated, counterclockwise rotation (relative to  FIG. 10 ) of the knob  62  tightens the lace  23 . The tension in the lace  23  is maintained by means of a ratchet mechanism that is described with reference to  FIG. 10 . 
       FIG. 10  is a cross-sectional view of the tightening mechanism  25  taken along the line  10 - 10  of  FIG. 9 . As shown, the biasing member  86  maintains the pawl  84  in locked engagement with the sloped teeth  83  on the ratchet section  82 . The pawl  84  thus inhibits clockwise rotation of the knob  62  and loosening of the lace  23 . It will be understood that the sloped teeth  83  do not inhibit counterclockwise rotation of the knob  62  because the pawl  84  slides over the teeth  83  when the knob  64  is rotated clockwise. As the knob  62  is rotated counterclockwise, the pawl  84  automatically engages each of the teeth  83  to advantageously allow the user to incrementally adjust the amount of lace  23  that is drawn into the tightening mechanism  25 . 
     As shown in  FIG. 10 , the release lever  63  communicates with the pawl  84  through a shaft  116  that extends through the housing  60 . A lower end of the shaft  116  is provided with a cam member  118 . The release lever  63  may be rotated about the shaft  116  to cause the cam member  118  to also rotate and push the pawl  84  away from engagement with the ratchet teeth  83 . When the pawl  84  disengages from the ratchet teeth, the first gear wheel  72 , and each of the other gear wheels  74  and  76 , are free to rotate. 
     When the user actuates the release lever  63 , the tension, if any, in the lace  23  causes the lace  23  to automatically unwind from the spooling section  102 . The release lever  63  is thus used to quickly untighten the boot  20  from around the foot. It will be appreciated that the low friction relationship between the lace  23  and the guide members  50  and  52  facilitates sliding of the lace  23  within the guide members so that the lace untightens quickly and smoothly by simply turning the release lever  63  and then manually pulling the tongue  36  forward. 
     It is contemplated that a limit on the expansion of portions of the boot due to the sliding of the lace  23  could be accomplished such as through one or more straps that extend transversely across the boot  20  at locations where an expansion limit or increased tightness or support are desired. For instance, a strap could extend across the instep portion  30  from one side of the boot  20  to another side of the boot. A second or lone strap could also extend around the ankle portion  29 . 
     With reference to  FIG. 11 , an expansion limiting strap  220  is located on the ankle portion of the boot  20  to supplement the closure provided by the lace  23  and provide a customizable limit on expansion due to the dynamic fit achieved by the lacing system of the present invention. The limit strap  220  may also prevent or inhibit the wearer&#39;s foot from unintentionally exiting the boot  20  if the lace  20  is unlocked or severed or the reel fails. In the illustrated embodiment, the strap  220  extends around the ankle of the wearer. The location of the limit strap  220  can be varied depending upon boot design and the types of forces encountered by the boot in a particular athletic activity. 
     For example, in the illustrated embodiment, the limit strap  220  defines an expansion limiting plane which extends generally horizontally and transverse to the wearer&#39;s ankle or lower leg. The inside diameter or cross section of the footwear thus cannot exceed a certain valve in the expansion limiting plane, despite forces imparted by the wearer and the otherwise dynamic fit. The illustrated location tends to limit the dynamic opening of the top of the boot as the wearer bends forward at the ankle. The function of the limit strap  220  may be accomplished by one or more straps, wires, laces or other structures which encircle the ankle, or which are coupled to other boot components such that the limit strap in combination with the adjacent boot components provide an expansion limiting plane. In one embodiment the expansion limiting strap surrounds the ankle as illustrated in  FIG. 11 . The anterior aspect of the strap is provided with an aperture for receiving the reel assembly therethrough. This allows the use of the expansion limiting strap in an embodiment having a front mounted reel, and may be particularly useful where the reel is provided with a quick mount release such the bayonet mount described in connection with  FIG. 27A , discussed below. 
     In an alternative design, the expansion limiting plane is positioned in a generally vertical orientation, such as by positioning the limit strap  220  across the top of the foot anterior of the ankle, to achieve a different limit on dynamic fit. In this location, the expansion limiting strap  220  may encircle the foot inside or outside of the adjacent shoe components, or may connect to the sole or other component of the shoe to provide the same net force effect as though the strap encircled the foot. 
     The limit strap  220  may also create a force limiting plane which resides at an angle in between the vertical and horizontal embodiments discussed above, such as in an embodiment where the force limiting plane inclines upwardly from the posterior to the anterior within the range of from about 25° to about 75° from the plane on which the sole of the boot resides. Positioning the limit strap  220  along an inclined force limiting plane which extends approximately through the ankle can conveniently provide both a limit on upward movement of the foot within the boot, as well as provide a controllable limit on the anterior flexing of the leg at the ankle with respect to the boot. 
     The strap  220  preferably includes a fastener  222  that could be used to adjust and maintain the tightness of the strap  220 . Preferably, the fastener  222  is capable of quick attachment and release, so that the wearer can adjust the limit strap  220  without complication. Any of a variety of fasteners such as corresponding hook and loop (e.g., Velcro) surfaces, snaps, clamps, cam locks, laces with knots and the like may be utilized, as will be apparent to those of skill in the art in view of the disclosure herein. 
     The strap  220  is particularly useful in the present low-friction system. Because the lace  23  slides easily through the guide members, the tension in the lace may suddenly release if the lace is severed or the reel fails. This would cause the boot to suddenly and completely open which could cause injury to the wearer of the boot, especially if they were involved in an active sport at the time of failure. This problem is not present in traditional lacing systems, where the relatively high friction in the lace, combined with the tendency of the lace to wedge with the traditional eyelets on the shoe, eliminates the possibility of the lace suddenly and completely loosening. 
     The low-friction characteristics of the present system also provides the shoe with a dynamic fit around the wearer&#39;s foot. The wearer&#39;s foot tends to constantly move and change orientation during use, especially during active sports. This shifting causes the tongue and flaps of the shoe to shift in response to the movement of the foot. This is facilitated by the low-friction lacing system, which easily equilibrates the tension in the lace in response to shifting of the wearer&#39;s foot. The strap  220  allows the user to regulate the amount of dynamic fit provided by the boot by establishing an outer limit on the expansion which would otherwise have occurred due to the tension balancing automatically accomplished by the readjustment of the lace throughout the lace guide system. 
     For example, if the wearer of the boot in  FIG. 11  did not have the ankle strap  220 , when he flexed his ankle forward during skating, the increased forward force at the top of the boot would cause the tongue to move out slightly while the laces lower in the boot would tighten. As the wearer straightened his ankle out again, closure force would equalize and the tongue would stay tight against his ankle. If the strap  220  were wrapped around his ankle however, it would prevent or reduce this forward movement of the ankle and tongue reducing the dynamic fit characteristics of the boot in the plane of the strap  220  and providing a very different fit and feel of the boot. Thus, the strap provides an effective means for regulating the amount of dynamic fit inherent in the low friction closure system. Since traditional lacing systems have so much friction in them, they do not provide this dynamic fit and consequently would not benefit from the strap in the same way. 
     Similar straps are commonly used in conjunction with traditional lacing systems but for entirely different reasons. They are used to provide additional closure force and leverage to supplement shoelaces but are not needed for safety and are not used to regulate dynamic fit. 
     The footwear lacing system  20  described herein advantageously allows a user to incrementally tighten the boot  20  around the user&#39;s foot. The low friction lace  23  combined with the low friction guide members  50 ,  52  produce easy sliding of lace  23  within the guide members  50  and  52 . The low friction tongue  36  facilitates opening and closure of the flaps  32  and  34  as the lace is tightened. The lace  23  equilibrates tension along its length so that the lacing system  23  provides an even distribution of tightening pressure across the foot. The tightening pressure may be incrementally adjusted by turning the knob on the tightening mechanism  25 . A user may quickly untighten the boot  20  by simply turning the release lever  63  or lifting or pressing the knob or operating any alternative release mechanism to automatically release the lace  23  from the tightening mechanism  25 . 
     As illustrated in  FIG. 12 , at least one anti-abrasion member  224  is disposed adjacent the tongue  36  and between the flaps  32 ,  34 . As best shown in  FIGS. 13 , the anti-abrasion member  224  comprises a flat disc-like structure having a pair of internal channels or lumen  127   a,b  arranged in a crossing pattern so as to define a crossing point  230 . The lumen  127   a,b  are sized to receive the lace  23  therethrough. As shown in the cross-sectional view of  FIG. 14 , the lumen  127   a,b  are arranged to prevent contact between adjacent sections of the lace  23  at the crossing point  230 . The anti-abrasion member  224  thereby prevents chafing of the lace  23  at the crossing point  230 . The anti-abrasion member  224  also shields the lace  23  from the tongue  36  to inhibit the lace  23  from chafing or abrading the tongue  36 . 
     The anti-abrasion member  224  may alternatively take the form of a knife edge or apex for minimizing the contact area between the lace  23  and the anti-abrasion member  224  For example, at a crossing point where lace  23  crosses tongue  36 , an axially extending (e.g. along the midline of the foot or ankle) ridge or edge may be provided in-between the boot tongue  36  and the lace  23 . This anti-abrasion member  224  is preferably molded or otherwise formed from a lubricious plastic such as PTFE, or other material as can be determined through routine experimentation. The lace  23  crosses the apex so that crossing friction would be limited to a small contact area and over a lubricious surface rather than along the softer tongue material or through the length of a channel or lumen as in previous embodiments. Tapered sides of the anti-abrasion member  224  would ensure that the anti-abrasion member  224  stayed reasonably flexible as well as help distribute the downward load evenly laterally across the foot. The length along the midline of the foot would vary depending upon the boot design. It may be as short as one inch long or less and placed on the tongue just where the lace crossing are, or it may extend along the entire length of the tongue with the raised ridge or crossing edge more prominent in the areas where the lace crosses and less prominent where more flexibility is desired. The anti-abrasion member  224  may be formed integrally with or attached to the tongue or could float on top of the tongue as in previously described disks. 
     In one embodiment, the anti-abrasion member  224  is fixedly mounted on the tongue  36  using any of a wide variety of well known fasteners, such as rivets, screws, snaps, stitching, glue, etc. In another embodiment, the anti-abrasion member  224  is not attached to the tongue  36 , but rather freely floats atop the tongue  36  and is held in place through its engagement with the lace  23 . Alternatively, the anti-abrasion member  224  is integrally formed with the tongue  36 , such as by threading a first portion of the lace  23  through the tongue, and the second, crossing portion of lace  23  over the outside surface of the tongue. 
     Alternatively, one or more of the sections of lace  23  which extend between the flaps  32  and  34  may slideably extend through a tubular protective sleeve. Referring to  FIG. 12 , three crossover points are illustrated, each crossover point including a first and a second crossing segments of the lace  23 . A tubular protective sleeve may be provided on each of the first segments or on both the first and second segments at each of the crossover points. Alternatively, the short tubular protective sheaths may be provided on one or both of the segments of lace  23  at the central crossover point which, in  FIG. 12 , is illustrated as carrying the anti-abrasion member  24 . Optimizing the precise number and location of the protective tubular segments may be routinely accomplished, by those of skill in the art observing wear patterns of the lacing system in a particular shoe design. 
     The tubular protective element may comprise any of a variety of tubular structures. Lengths of polymeric or metal tubing may be utilized. However, such tubular supports generally have a fixed axial length. Since the distance between the opposing flaps  32  and  34  will vary depending upon the size of the wearer&#39;s foot, the protective tubular sleeves should not be of such a great length that will inhibit tightening of the lacing system. The tubular protective sheaths may also have a variable axial length, to accommodate tightening and loosening of the lacing system. This may be accomplished, for example, by providing a tubular protective sheath which includes a slightly stretched spring coil wall. During tightening of the system, when each of the opposing flaps  32  and  34  are brought towards each other, the axial length of the spring guide may be compressed to accommodate various sizes. A further alternative comprises a tubular bellows-like structure having alternating smaller-diameter and larger-diameter sections, that may also be axially compressed or stretched to accommodate varying foot sizes. A variety of specific accordion structures, having pleats or other folds, will be apparent to those of skill in the art in view of the disclosure herein. As a further alternative, a telescoping tubular sleeve may be utilized. In this embodiment, at least a first tubular sleeve having a first diameter is carried by the lace  23 . At least a second tubular sleeve having a second, greater diameter is also carried by the lace  23 . The first tubular sleeve is axially slideably advanceable within the second tubular sleeve. Two or three or four or more telescoping tubes may be provided, for allowing the axial adjustability described above. 
       FIG. 15  schematically illustrates a top view of the insole region of the boot  20 . At least one lace locking member  232  (shown schematically) is disposed along the pathway of the lace  23 . Each locking member  232  is configured to engage the lace  23  and prevent a predetermined portion of the lace from moving axially, such as toward the tightening mechanism  25  to thereby limit the tension of the lace in a predetermined region. For example, a pair of locking members  232   a  are located at points “a” along the lace pathway near the toe region of the flaps  32 ,  34 . After tension has been applied to the lace  23  via the tightening mechanism  25 , the locking members  232   a  may be engaged with the lace  23  to prevent movement of the lace in region “a”. Once engaged, the locking members  232   a  secure the tension in the lace  23  in region “a” by locking the position of the lace  23  at points “a” with respect to the tightening mechanism  25 . The lace tension in region “a” is thereby maintained even if the tension applied to the lace  23  by the tightening mechanism  25  is released or actuated. Thereafter, the tightening mechanism  25  may be released or actuated to apply a different level of tension or tightness in the lace outside of lace region “a”. 
     With reference to  FIG. 15 , locking members  232  may be disposed at any of a wide variety of locations along the lace pathway, such as locations “b”, and “c” to create various lace locking zones. By alternately locking and unlocking the locking members  232  and varying the tension in the lace  23 , a user may provide zones of varied tightness along the lace pathway. 
       FIGS. 16 and 17  show one embodiment of a locking member  232  that is coupled to the boot flap  32 . The locking member  232  comprises an actuator  234  having an elongate arm  235  that extends outwardly from an enlarged cam portion  236  having a rounded bottom edge  240 . The lace  23  is interposed between the rounded edge  240  of the cam portion  236  and the flap  32 . The enlarged cam portion  236  of the actuator  234  is rotatably mounted to the flap  32 , such as through a rotatable pin connector  242 . As shown in  FIG. 16 , the actuator  234  may be moved to first or engaged position wherein the rounded edge  240  engages the lace  23  and applies a tightening force to secure the lace against the flap  32 . The locking member  232  thereby prevents movement of the lace  23  relative to the shoe flap  32 . 
     With reference to  FIG. 17 , the actuator  234  may also be moved to a second, non-engaged orientation wherein the rounded edge  240  of the cam portion  236  is removed from engagement with the lace  23  to thereby allow movement of the lace  23  relative to the flap  32 . 
       FIG. 18  shows another embodiment of a lace locking member  312  comprised of a multi-piece structure including a first member  314  and a second member  322  coupled thereto. As best shown in the cross-sectional view of  FIG. 19 , the first member has a pair of shafts  316  extending therethrough. A pair of bore holes  315  ( FIG. 18 ) in the first member  314  communicate with the shafts  316 . An elongate tubular compression clamp  320  is located within each of the shafts  316 . The shafts  316  and the compression clamps  320  are sized to receive the lace  23  therethrough, as shown in  FIG. 19 . 
     The second member  322  is movably coupled to the first member  314 . The second member  322  includes a pair of pegs  324  that extend into the bore holes  315  in the first member  314 . A screw  326  is coupled to the first member  314  and the second member  322 . The second member  322  may be incrementally moved toward the first member  314  by turning the screw  326 . As the screw  326  is turned, the pegs  324  incrementally slide into the lace shafts  316  and pinch or compress the compression clamps  320 . When the lace is disposed within the compression clamps  320 , the compression coupling between the pegs  324  and the compression clamps  320  is transferred to the lace  23  to inhibit the lace  23  from moving. The user may adjust the screw  326  to vary the level of compression that the pegs  324  apply to the lace  23 . 
     The compression clamps  320  are preferably made of a soft, deformable material that will deform when the pegs  324  apply pressure thereto. Advantageously, the soft compression clamps  320  exert sufficient compression to the lace  23  with reduced risk of deformation to the lace  23 . The locking member  312  may be disposed at various locations along the lace pathway to allow the user to create zones of varying tightness, as described previously. 
     As mentioned, the locking members  232  may be located at any of a wide variety of locations along the lace pathway to allow the user to fix the position of the lace  23  at any of these locations. Other mechanical or structural designs may be used to lock the lace relative to the tightening mechanism. For example, the entryways of the guide members may be fitted with a collect to engage the lace  23 . 
       FIG. 20  is a front view of the instep portion of the boot  20 . In the embodiment shown in  FIG. 20 , the tubular guide members  50  and  52  are mounted directly within the flaps  32 ,  34 , such as within or between single or multiple layers of material. Preferably, the tips  150  of each of the guide member  50 ,  52  protrude outwardly from an inner edge  152  of each of the flaps  32 ,  34 . As best shown in  FIG. 21 , a set of stitches  154  surrounds each guide member  50  and  52 . The stitches  154  are preferably positioned immediately adjacent the guide members  50 ,  52  to create a gap  156  therebetween. For ease of illustration, the gap  156  is shown-having a relatively large size with respect to the diameter of the guide members  50 ,  52 . However, the distance between each guide member  50 ,  52  and the respective stitches  154  is preferably small. 
     Preferably, each set of stitches  154  forms a pattern that closely matches the shape of the respective guide members so that the guide members  50 ,  52  fit snug within the flaps  32 ,  34 . The stitches  154  thereby inhibit deformation of the guide members  50 ,  52 , particularly the internal radius thereof, when the lace is tightened. Advantageously, the stitches  154  also function as anchors that inhibit the guide members  50 ,  52  from moving or shifting relative to the flaps  32 ,  34  during tightening of the lace. 
     The gap  156  may be partially or entirely filled with a material, such as glue, that is configured to stabilize the position of the guide members  50 ,  52  relative to the flaps  32 ,  34 . The material is selected to further inhibit the guide members  50 ,  52  from moving within the gap  156 . As shown in  FIG. 22 , the guide members may also be equipped with anchoring members, such as tabs  160  of various shape, that are disposed at various locations thereon and that are configured to further inhibit the guide members  50 ,  52  from moving or deforming relative to the flap  32 . The anchoring members may also comprise notches or grooves on the guide members  50 ,  52  that generate friction when the guide members  50 ,  52  begin to move and thereby inhibit further movement. The grooves may be formed using various methods, such as sanding, sandblasting, etching, etc. 
     Axial movement of the guide tubes  50  or  52  may also be limited through the use of any of a variety of guide tube stops such as that illustrated in  FIG. 22A . The guide tube stop includes a tubular body having an opening  51  which provides access to a central lumen  53  extending therethrough. The stop may also be provided with one or more fastening tabs  160 , for sewing or gluing to the shoe, as has been discussed. Tabs  160 , once stitched or otherwise secured into place, resist axial movement of the device along its longitudinal pathway. 
     The central lumen  53  extends to a radially outwardly extending step  57 , producing a chamber  55  having a greater inside diameter than the lumen  53  at the opening  51 . Chamber  55  is dimensioned to slideably receive an end of a guide tube  50  or  52  therein. The annular step  57  inhibits movement of the guide tube in the direction of opening  51 . The stop may be manufactured in accordance with any of a variety of techniques, such as injection molding or machining from suitable materials including plastics and metal. In one embodiment, the guide tube  52  comprises plastic, and the stop comprises plastic. The end of the guide tube may be secured within chamber  55  using any of a variety of adhesives, solvent bonding, thermal bonding, interference fit or other techniques known in the art, or simply held in place by tension on the lace. In one embodiment, the tube  50  is bonded within the stop using adhesive. 
     In any of the embodiments discussed elsewhere herein, the exit point on the lace guide or other structure may be made from a harder, more durable material than the rest of the lace guide. In the case of a tubular lace guide, the lace guide is often preferably flexible so that it can flex with the boot. Most of the wear takes place at the exit point of the cable, where reinforcement may be desirable. In addition, the tube stop can be made completely of metal or other high durometer material while the corresponding tubular lace guides are more flexible. This may be accomplished in a variety of ways, such as using metal or high durometer plastic ring inserts or attachments or coatings at the lace exit point as will be apparent to those of skill in the art in view of the disclosure herein. 
     By providing a stop on each end of a guide tube  50  or  52 , movement of the guide tube  50  or  52  along its longitudinal axis under normal use conditions can be prevented. 
     In any of the foregoing embodiments, the external opening to the lace guide is subject to wear by the cable advancing in and out as the product is used. The durability of the lace guide may be improved by including an annular ring of a harder durometer material at the lace guide opening. Alternatively, a metal ring can be attached at each lace guide opening, using any of a variety of attachment techniques known in the art, including insert molding, adhesive bonding, threaded engagement and others known in the art. As a further alternative, a portion of the lumen extending through the lace guide may be lined using a metal tube such as an appropriately sized hypodermic needle tubing, taking into account the diameter of the lace. The tubing can extend slightly beyond the opening to the central lumen in the plastic-molded or formed part. 
     With reference to  FIGS. 23 and 24 , an alternative guide member  250  comprises a thin, single-piece structure having an internal lumen  252  for passage of the lace  23  therethrough. The guide member  250  includes a main portion  254  that defines a substantially straight inner edge  256  of the guide member. A flange portion  260  extends peripherally around one side of the main portion  254 . As best shown in  FIG. 22 , the flange portion  260  comprises a region of reduced thickness with respect to the main portion  254 . An elongate slot  265  comprised of a second region of reduced thickness is located on the upper surface  266   a  of the guide member  250 . 
     A pair of lace exit holes  262  extend through a side surface of the lace guide member  250  and communicate with the lumen  252 . The lace exit holes  262  may have an oblong shape to allow the lace  23  to exit therefrom at a variety of exit angles. 
     With reference to  FIGS. 23 and 24 , a series of upper and lower channels  264   a ,  264   b , respectively, extend through upper and lower surfaces  266   a ,  266   b , respectively, of the lace guide member  250 . The channels  264  are arranged to extend along the pathway of the lumen  252  and communicate therewith. The location of each of the upper channels  264   a  preferably successively alternates with the location of each of the lower channels  264   b  along the lumen pathway so that the upper channels  264   a  are offset with respect to the lower channels  264   b.    
     With respect to  FIGS. 25 and 26 , the lace guide member  250  is mounted to the flaps  32 ,  34  by inserting the flange region  260  directly within the flaps  32 ,  34 , such as within or between single or multiple layers  255  ( FIG. 26 ) of material. The layers  255  may be filled with a filler material  257  to maintain a constant thickness in the flaps  32 ,  34 . 
     The lace guide member  250  may be secured to the flaps  32 ,  34 , for example, by stitching a thread through the flap  32 ,  34  and through the lace guide member  250  to form a stitch pattern  251 . The thread is preferably stitched through the reduced thickness regions of the flange portion  260  and the elongate slot  265 . Preferably, the flaps  32 ,  34  are cut so that the main portion  254  of the guide member  250  is exposed on the flap  32 ,  34  when the lace guide member  250  is mounted thereon. 
     With respect to  FIG. 26 , the upper surface  266   a  of the main portion of the guide member  250  is preferably maintained flush with the upper surface of the flaps  32 ,  34  to maintain a smooth and continuous appearance and to eliminate discontinuities on the flaps  32 ,  34 . Advantageously, because the flange region  260  has a reduced thickness, the lace guide member  250  is configured to provide very little increase in the thickness of the flaps  32 ,  34 , and preferably no increase in the thickness of the flaps. The lace guide member  250  therefore does not create any lumps in the flaps  32 ,  34  when the guide member  250  is mounted therein. 
     As mentioned, a series of upper and lower offset channels  264   a,b  extend through the lace guide member  250  and communicate with the lumen  252 . The offset arrangement of the channels advantageously facilitates manufacturing of the guide members  250  as a single structure, such as by using shut-offs in an injection mold process. 
     The shape of the lumen may be approximately defined by an ellipse. In one embodiment, the ellipse has a major axis of about 0.970 inches and a minor axis of about 0.351 inches. 
       FIG. 27  is a side view of an alternative tightening mechanism  270 . The tightening mechanism  270  includes an outer housing  272  having a control mechanism, such as a rotatable knob  274 , mechanically coupled thereto. The rotatable knob  274  is slideably movable along an axis A between two positions with respect to the outer housing  272 . In a first, or engaged, position, the knob  274  is mechanically engaged with an internal gear mechanism located within the outer housing  272 , as described more fully below. In a second, or disengaged, position (shown in phantom) the knob is disposed upwardly with respect to the first position and is mechanically disengaged from the gear mechanism. A bottom plate  273  is disposed at a bottom end of the outer housing  272 . A set of mounting arms  275  extends radially outwardly from the bottom plate  273 , to removably engage a mounting structure discussed below. 
       FIG. 28  is a cross-sectional view of the tightening mechanism  270 . A gear mechanism  276  (shown schematically) is disposed within a lower region of the outer housing  272  and is mechanically coupled to the rotatable knob  274  via a shaft  280 . The shaft  280  is mechanically coupled to the knob, such as through a spline interface. 
     A lace wind-up spool  282  is interposed between the gear mechanism  276  and the control knob  274 . The shaft  280  is journaled through the spool  282 . The spool  282  is mechanically coupled to the gear mechanism  276 . The spool  282  includes a pair of annular grooves  284   a,b  that are sized to receive the wound lace  23 . The spool  282  rotates about the axis of the shaft  280  in response to rotation of the control knob  274 . 
     The control knob  274  is configured to be incrementally rotated in a forward rotational direction, i.e., in a rotational direction that causes the lace  23  to wind around the spool  282 . Toward this end, the control knob  274  preferably includes a series of integrally-mounted pawls  277  that engage corresponding series of ratchets on the outer housing  272 . See  FIGS. 31-32 . The pawls  277  are preferably permanently engaged with the ratchets  279  when the control knob  274  is in the coupled or uncoupled position. The ratchet/pawl engagement prevents the knob  274  and the spool  282  from being rotated in a backwards direction (i.e., in a rotational direction opposite the rotational direction that winds the lace  23  around the spool  282 ) when the knob  274  is in the coupled position. This configuration prevents the user from inadvertently winding the control knob  274  backwards, which could cause the lace  23  to kink or tangle in the spool  282 . The risk of tangling is especially high where a large length of lace  23  is wound around the spool, such as in the present case, where from about six inches up to about 2 feet of cable length (one half on each end) is wound around the spool  282 . 
     Referring to  FIG. 30 , the knob  274  is illustrated to show moveability between two positions, a coupled position (left side of drawing) and an uncoupled position (right side of drawing). The pawls  277  on the knob  274  are slideably engaged with the ratchets on the case so they are engaged in either position so the knob can never be rotated backwards. In the engaged position, the spline teeth on the knob are coupled to the spline teeth on the shaft  280  which effectively couples the ratchet/pawl system to the gear train and spool  282  so the lace  23  cannot unwind. The only way to unwind the lace  23  from the spool  282  is to pull the knob  274  out into the uncoupled position which uncouples the splines allowing the spool to spin freely in either direction. The lace is then pulled off the spool manually. A deflectable indent washer mounted onto the shaft presses against the knob  274  and falls into one of two indents in the knob. This holds the knob by friction in either the coupled or uncoupled position. Although in this embodiment, the permanently engaged ratchet/pawl assembly is uncoupled from the spool by pulling out the knob, this uncoupling could be accomplished in several different ways by someone skilled in the art. 
     With reference to  FIG. 28 , a pair of lace entry holes  296   a,b  are disposed on the side of the outer housing  272  of the tightening mechanism  270 . The lace entry holes  296   a,b  communicate with the annular grooves  284   a,b , respectively, in the spool  282 . A pair of lace retention holes  300   a,b  are disposed in the spool within the grooves  284   a,b . respectively. Each of the lace retention holes  300   a,b  comprises a cylindrical bore that extends radially into the spool  282 . The lace retention holes  300   a,b  are sized to receive the end of lace  23  therein. A pair of counterbores  302  extend downwardly through the spool  282  and communicate with the lace retention holes  300   a,b . An attachment device, such as set screw  304 , is disposed within each of the counterbores  302 . The set screws  304  may be rotated to incrementally project bottom ends thereof into the lace retention holes  300   a,b.    
     The spool  282  may be rotated so that each of the lace retention holes  300   a,b  aligns with a corresponding lace entry hole  296   a,b , respectively, as shown in  FIG. 28 . Toward this end, an alignment hole  301  is located in the spool  282  and a corresponding alignment hole  303  is located in the outer housing  272 . The two alignment holes  301 ,  303  may be aligned through rotation of the spool  282 . Preferably, when the holes  301 ,  303  are aligned, the lace retention holes  300  are also aligned with the lace entry holes  296 . The user may thereby quickly and easily align the lace retention holes  300  with the lace entry holes  296  by aligning the alignment holes  301 ,  303  and then inserting a pin therein to fix the position of the spool  282  with respect to the outer housing  272 . 
     The lace  23  is installed onto the tightening mechanism  270  by first rotating the spool  282  so that the lace retention holes  300   a,b  align with the corresponding lace entry holes  296   a,b , as described above. The ends of the lace  23  are then each inserted into separate lace entry holes  296   a,b  until the lace ends abut an inner surface of the lace retention holes  300   a,b . The set screws  304  are then individually rotated so that the bottom ends of the set screws  304  engaged or pinch the lace ends to thereby secures the lace  23  within the retention holes  300   a,b . The control knob  274  may be rotated in the forward direction to wind the lace  23  around the spool  282 . The lace  23  may be removed from the spool  282  by loosening the set screws  304  to disengage the set screws  304  from the lace end and then pulling the lace  23  from the spool  282 . 
     As mentioned, the lace entry holes  296   a,b  should be aligned with the corresponding lace retention holes  300   a,b  when inserting the lace ends into the entry holes  296   a,b . As shown in  FIG. 29 , the lace end will not enter the retention hole  300  but will rather abut the inner surface of the spool  282  if the holes  296 ,  300  are not correctly aligned. The user will then not be able to engage the set screw with the lace  23 . The ends of the lace  23  preferably each include a marker or indicator  310  to assist the user in installing the lace  23  into the lace retention hole  300   a,b . The indicator  310  is located a preselected distance from the end of the lace  23 , which is preferably substantially equal to the distance D between the inner surface of the lace retention hole  300  and the location of lace entry hole  296 . 
     If the lace entry hole  296  and the lace retention hole  300  are misaligned during installation of the lace  23 , the indicator  310  will be clearly visible to the user, as shown in  FIG. 29 . However, if the lace  23  is correctly positioned within the lace retention hole  300 , the indicator  310  will be flush with the entry point of the lace entry hole  296 . Advantageously, the user can confirm the that lace is correctly positioned within the lace retention hole  300  when the indicator on the lace is aligned with the entry point of the lace entry hole  296 . 
     The tightening mechanism  270  may be removably mounted to the front, back, top or sides of the boot. In the illustrated embodiment, the tightening mechanism is mounted to the tongue  36  of the boot  20  between the flaps  32 ,  34 . In one embodiment, a bayonet-type mounting system is used to mount the tightening mechanism  270  to the tongue  36 . The tongue  36  may include a sheet of flexible material, such as plastic, mounted therein or thereover. The material may include die-cut hole that mates with a corresponding bayonet structure on the bottom plate  273  ( FIG. 27 ) of the tightening mechanism  270 . The die cut hole may be, for example, key-shaped so that the bayonet structure may be inserted therein and twisted to lock the bayonet structure within the hole. 
     The base for one bayonet mounting system is illustrated in  FIG. 27A . The mounting ring  330  comprises an attachment structure  332  for attachment to the boot. In the illustrated embodiment, the attachment structure  332 , comprises a radially outwardly extending flange suitable for attachment to the tongue or other portion of the boot by sewing, adhesive bonding, grommets or other fastening techniques known in the art. The mounting ring  330  is provided with a central aperture  334  for removably receiving the base of a reel. One or more axially extending recesses  336  are provided, to slideably receive one or more mounting arms  275  therethrough. When the base of the reel has been advanced into the aperture  334  such that the mounting tab  275  has advanced through the length of the groove  336 , the base of the reel may be rotated to offset the mounting tab  275  from the groove  336  thereby locking the reel in place. In the illustrated embodiment, four grooves  336  are illustrated to accommodate four mounting tabs  275 . Preferably, two or more corresponding  336  and mounting tabs  275  will be utilized to provide secure retention. 
     A releasable lock  338  may also be provided. The lock  338  preferably resists rotation of the base such that the base can become separated from the mounting ring  330 . In the illustrated embodiment, the lock  338  comprises a flexible arm  340  having a radially inwardly extending engagement surface  342  such as on a tooth. Once the base has been advanced through the aperture  334  and rotated to provide an interference fit, the engagement surface  342  advances under the spring bias supplied by arm  340  into a corresponding recess on the base. By rounding the edges of the tooth, and dimensioning the recess, the engagement provided by lock  338  can be sufficient to resist detachment under normal use conditions. However, when removal of the spool is desired, the spool may be forced to rotate by overcoming the resistance provided by lock  338  as will be appreciated by those of skill in the art in view of the disclosure herein. Advantageously, such a design allows the tightening mechanism to be quickly and easily mounted and dismounted from the boot  20  without the use of tools. Alternatively, it may be desirable to prevent removal of the reel from the bayonet without the use of a special tool. This latter construction will minimize accidental removal of the reel. Any of a variety of locking structures, which may be released using a special screw driver or other tool may be readily incorporated into the present design. Alternatively, a small aperture in the reel may be provided, into which a wire such as a paper clip size pin is inserted to advance a release mechanism to release the reel to bayonet. 
     Certain functional advantages of embodiments of the present invention can be further illustrated in connection with  FIGS. 30 through 32 . In particular, the closure system includes a rotatable spool for receiving a lace. The spool is rotatable in a first direction to take up lace and a second direction to release lace. A knob is connected to the spool such that the spool can be rotated in the first direction to take up lace only in response to rotation of the knob. A releasable lock is provided for preventing rotation of the spool in the second direction. One convenient lock mechanism is released by pulling the knob axially away from the boot, thereby enabling the spool to rotate in the second direction to unwind lace. However, the spool rotates in the second direction only in response to traction on the lace. The spool is not rotatable in the second direction in response to rotation of the knob. This prevents tangling of the lace in or around the spool, which could occur if reverse rotation on the knob could cause the lace to loosen in the absence of a commensurate traction on the lace. 
     Thus, referring to  FIG. 30 , a knob  274  is shown split down the middle such that the left half of the figure illustrates the knob in the coupled position and the right half of the figure illustrates the knob in the uncoupled position. In the coupled position, rotation of the knob in the forward direction winds lace around the reel. Unwinding of the lace is prevented, despite the tension in the tightened system. In the uncoupled position, traction on the lace causes the reel to unwind. However, the reel is not windable in the reverse direction by rotating the knob. 
     One manner of accomplishing the foregoing is to provide a spline  314  on the shaft, for engagement with a spline  312  on the knob when the knob is in the coupled position. As illustrated, when the knob  274  is in the uncoupled position, the spline  314  on the shaft is disengaged from the spline  312  on the knob, thereby enabling the reel to be wound in a reverse direction in response to traction on the lace. A radially moveable indent washer  316  is slideably moveable between an uncoupled recess  318  and a coupled recess  320 . Any of a wide variety of structures can be utilized to accomplish this result as will be apparent to those of skill in the art in view of the disclosure herein. The indent washer  316  both inhibits accidental movement of the knob  274  from the coupled position to the uncoupled position, and also provides tactile feedback to the user so that the knob will snap into the coupled position or the uncoupled position as desired. A stabilizing washer  322  or other spacer may also be provided, to prevent wobbling of the knob  274 . 
     Detailed views shown in  FIGS. 31A and 31B  and  32  illustrate, for example, a plurality of integrally molded pawls  277  on the knob  274 . The pawls  277  are sufficiently axially elongated that they engage the housing in both the coupled position and the uncoupled position to prevent reverse rotation of the knob  274 . The corresponding ratchet teeth  279  on the case are illustrated in  FIG. 32 . 
     In the foregoing embodiments, the wearer must pull a sufficient length of cable from the spool to enable the wearer&#39;s foot to enter or exit the footwear. The resulting slack cable requires a number of turns of the reel to wind in before the boot begins to tighten. An optional feature in accordance with the present invention is the provision of a spring drive or bias within the spool that automatically winds in the slack cable, similar to the mechanism in a self biased automatically winding tape measure. The spring bias in the spool is generally not sufficiently strong to tighten the boot but is sufficient to wind in the slack. The wearer would then engage the knob and manually tighten the system to the desired tension. 
     The self winding spring may also be utilized to limit the amount of cable which can be accepted by the spool. This may be accomplished by calibrating the length of the spring so that following engagement of the knob and tightening of the boot, the knob can only be rotated a preset additional number of turns before the spring bottoms out and the knob is no longer able to be turned. This limits how much lace cable could be wound onto the spool. Without a limit such as this, if a cable is used which is too long, the wearer may accidentally wind in the lace cable until it jams tightly against the reel housing and cannot be pulled back out. 
     With reference to  FIGS. 33-35 , alternative embodiments of a lacing system  22  have an outer housing  400  comprising a base member  402  and a knob  404 . The outer housing is preferably injection molded out of any suitable material, as discussed above, but in one embodiment, is formed of nylon. Of course, any suitable manufacturing process that produces mating parts fitting within the design tolerances is suitable for the manufacture of the components disclosed herein. 
     The base member  402  is generally a hollow cylinder further having a relatively thin and flat mounting flange  406  that extends generally radially from around about half of the base member  402  circumference. In some embodiments, the mounting flange  406  extends from approximately the bottom surface  410  of the base member, while in other embodiments, the mounting flange  406  extends from about midway between the top edge  412  and the bottom surface of the base member. The mounting flange  406 , as described above, is configured to be attached to the footwear in any acceptable manner. In one preferred embodiment, the mounting flange  406  is stitched onto the footwear during manufacture. As discussed above, it may be securely attached by any suitable method, such as, for example, by adhesives, rivets, threaded fasteners, and the like. Alternatively, the mounting flange  406  may be removably attached, such as by a releasable mechanical bonding structure in the form of cooperating hook and loop structure, for example. 
     The mounting flange  406  may be disposed between layers of the footwear upper, or may be disposed on top of, or underneath, the footwear upper material. The method and location of attachment of the base member  402  is dictated primarily by fashion design, and hence, could conceivably be mounted in any of a number of locations and by any suitable method. 
     The base member  402  cylindrical portion includes sloped teeth  414  formed into its inner surface. The base member teeth  414  may be formed during the molding process, or may be subsequently cut therein, and each defines a sloped portion  416  and a substantially radial surface  418 . In one embodiment, the sloped portion  416  of each tooth  414  allows relative clockwise rotation of a cooperating pawl, while inhibiting relative counterclockwise rotation of an engaging pawl. Of course, the teeth direction could be reversed as desired. The number and spacing of teeth  414  controls the fineness of adjustment possible, and the specific number and spacing can be designed to suit the intended purpose by one of skill in the art in light of this disclosure. However, in many applications, it is desirable to have a fine adjustment of the lace tension, and the inventors hereof have found that approximately 20 to 40 teeth  414  are sufficient to provide an adequately fine adjustment of the lace tension. 
     The base member  402  additionally contains a pair of lace entry holes  420  ( FIG. 40 ) for allowing each end of a lace to enter therein. As discussed above, the base member  402  lace entry holes  420  may be made more robust by the addition of higher durometer materials either as inserts or coatings to reduce the wear caused by the laces abrading against the base member  402  entry holes  420 . Additionally, the site of the entry hole can be rounded or chamfered to provide a larger area of contact with the lace to further reduce the pressure abrasion effects of the lace rubbing on the base unit. 
     A lace guide  422  can be formed integrally with the base member and can be configured depending upon the specific application of the lacing system  22 . For example, in a traditional lacing application where the laces zigzag across the tongue of the boot or shoe, the laces may extend in a lacing path that enters the base member from directions that are diametrically opposed. For this application, the lace guides  422  may extend substantially radially from the base member  402 , as discussed above. Alternatively, in applications where the lace path results in substantially parallel laces entering the base member, a pair of lace guides  422  can be integrally molded into the base unit to receive the laces and direct them to opposing sides of the spool for subsequent winding and collection. 
     It is preferable that the inner bottom surface  424  of the base member is highly lubricious to allow mating components an efficient sliding engagement therewith. Accordingly, in one embodiment, a washer or bushing  426  is disposed within the cylindrical portion of the base member  402 , and may be formed of any suitable lubricious polymer, such as PTFE, for example, or may be formed of a lubricious metal. Alternatively, the inner bottom surface  424  of the base member  402  may be coated with any of a number of coatings designed to reduce its coefficient of friction and thereby allow any components sharing surface contact therewith to easily slide. 
     With additional reference to  FIG. 36 , a spool  426  is configured to reside within the cylindrical portion of the base member and is configured with sloped teeth  428 , such as those found on a ratchet, as has been described herein above in great detail. In one preferred embodiment, the spool  426  is formed of metal, such as aluminum, by any standard chip producing, material removal machining operation. Alternatively, the spool  426  may be cast or molded, and may be formed of any suitable polymer. In another preferred embodiment, the spool is formed of nylon and may optionally have a metal plate insert. 
     In cooperating with the washer or bushing  426  disposed on the inner bottom surface  424  of the base member  402 , the lower surface of the spool  426  is likewise configured for efficient sliding engagement. Accordingly, a second washer  430  formed of highly lubricious material may be provided, or alternatively, the lower surface of the spool  426  may be configured to reduce its coefficient of friction such that the spool  426  easily spins within the base member  402 . In the illustrated embodiment, this is accomplished by providing a lip  431  that offers a small surface area that contacts the bottom surface  424  of the base member  402 . 
     The spool  426  has one or more grooves  433  formed therein to receive the lace  435 . As described in detail above, there may be one or more grooves that are configured to receive the wound up lace. In one embodiment, the lace passes through holes  437  formed in the spool base member  432  and are securely held in the spool. In one embodiment, the lace  435  has two ends that are tied together. In this particular embodiment, the spool  426  can be configured with a recess  438  ( FIG. 40 ) to accompany the knot formed by the lace ends. 
     The spool base  432  is preferably circular in shape and is configured to reside within the base member  402 . In order to inhibit contact between the outer spool surface and the inner periphery of the base member  402 , an axle  434  is provided that extends through the central axis of the spool  426  to maintain the spool  426  in the center of the base member  402 . 
     In one preferred embodiment, the axle  434  is a metallic hollow tube, such as a brass tube, that fits down through the center axis of the spool  426 . The axle  434  may be configured with bored ends, or may be threaded, for receiving threaded fasteners. In one embodiment, a screw passes through the knob  404 , through the axle  434 , and threads into a threaded insert provided in the base member  402 . Alternatively, a screw passes through the bottom of the outer housing and is threaded into one end of the axle  434 . The spool  426  is installed onto the axle  434 , and the knob  404  is attached to the axle  434  by a second threaded fastener. In either case, the base member  402  and knob  404  are interconnected by the axle  434 , which provides an axis of rotation for the spool  426 . 
     Additionally, the spool  426  may contain a bushing, bearing, or other form of friction reducing device along its central axis to allow it to easily revolve around the axle  434 . The axle  434  can additionally carry a washer  430  disposed between the reel and the washer or bushing  426  disposed in the base member  402  to further reduce rotational friction of the spool  426 . This type of rotatable connection maintains the spool  426  at the center of the base member  402  and thereby inhibits friction caused by the outer periphery of the spool  426  contacting the inner periphery of the base member  402 , while still allowing the spool  426  to freely spin within the base member  402 . Accordingly, without any interference from other components, the rotatable connection of the spool  426  allows it to freely rotate in either direction. 
     With reference to  FIG. 36 , the spool  426  is additionally configured with one or more sloped teeth  428  disposed generally above the spool base  432 . The spool teeth  428  are preferably configured to allow relative counterclockwise rotation, while inhibiting relative clockwise rotation of a corresponding pawl. 
     As discussed above, it is preferable that the laces are attached to the spool  426  at substantially diametrically opposed locations to provide a simultaneous and equivalent tension to each lace as a winding force is imparted to the spool  426 . Moreover, the preferred lace attachment configuration applies balanced forces to the spool  426  to protect the spool  426  from transverse bending forces that could cause the journal connection to prematurely wear. For example, if the laces engaged the spool  426  from directions forming a ninety degree angle, the forces imparted by the tension in the wound laces would apply a shear force to the axle  434  of the spool  426 . If, however, the laces were diametrically attached to the spool  426 , the resultant force on the spool  426  from the equivalent opposing tension forces would be zero, thus protecting the spool  426  and its journaled connection from wear resulting from transverse forces. 
     The spool  426  further comprises one or more annular grooves, as described above, configured to receive the wound up lace. The groove is preferably configured to contain the full length of the lace while minimizing any tendency for the lace to become loose within the housing  400  and potentially becoming jammed, or interfering with additional components contained within the outer housing  400 . In some preferred embodiments, two annular grooves separated by an annular ridge are provided to segregate each end of the lace to reduce the likelihood of jamming or binding the mechanism. The lace grooves are preferably located below the spool teeth  428  and spool base, but could optionally be located above the spool teeth  428 . 
     As illustrated in  FIGS. 37   a  and  37   b , a pawl spring  440  comprises a central horizontally flat circular section  442  attached to two diametrical arm sections  444 . In the illustrated embodiment, each arm section  444  is attached to the circular section  442  by a corresponding bridge  446 , and may be attached in any suitable manner, such as by welding, or may be formed integrally therewith. The arm sections  444  are generally disposed below the central flat circular section  442  and are flat in a vertical plane. 
     Extending in a counterclockwise direction from each arm section is an outer pawl  450 . Each outer pawl  450  is configured to terminate outside the periphery of the spool base  432 , as described later below, and is configured to contact the base member sloped teeth  416 . Therefore, when turning one direction, the outer pawls  450  are free to rotate relative to the base member  402 , while the base member  402  sloped teeth inhibit relative movement in the opposite direction. 
     Extending in a clockwise direction from each arm section is a spool pawl  452 . The spool pawl  452  is configured to terminate within the periphery of the spool base  432 , as described later, and is configured to contact the sloped teeth  428  of the spool  426 . Therefore, while turning one direction, the spool pawls  452  interfere with the sloped teeth  428  of the spool  426 , and cause the spool  426  to turn concurrently with the pawl spring  442 . However, if the spool pawls  452  are removed from contact with the spool sloped teeth  428 , the spool  426  is free to rotate. Of course, it should be understood that the illustrated components could be reversed such that the tightening and loosening directions are opposite from those described. However, for clarity, the reel will primarily be discussed by utilizing a design in which a clockwise rotation tightens the lace, while a counterclockwise rotation allows the lace to unwind. 
     In one preferred embodiment, the pawl spring  442 , arms sections  444 , and pawls  450 ,  452  are formed unitarily from a high temper sheet metal. The entire spring  442  may be stamped out of a single sheet of high temper sheet metal, such as, for example, spring steel or stainless steel, and then the arm sections  444  can be plastically bent to be orthogonal to the original plane of the flat material. Additionally, the spool pawls  452  and outer pawls  450  can be permanently bent relative to the arm sections  444 . This may be done either prior or subsequent to the arm sections receiving a bend. 
     The residual stresses formed in the spring  440  may optionally be compensated for such as by heat working to allow the relieve the residual stresses caused by plastic deformation. In other embodiments, the residual stresses are beneficial as they add to the resiliency of the spring  440 . For example, the spool pawl  452  is configured to be biased inwardly; however, the residual stresses created by bending the spool pawl  452  with respect to the arm section  444  will tend to force the spool pawl  452  outward. To compensate for this stress, which could ultimately cause the spool pawl  452  to lose its desired bias, the spool pawl  452  may be bent to a more acute angle than necessary and then bent back to its desired angle. By bending the spool pawl  452  beyond the desired angle and then plastically returning it to its desired angle, the residual stresses now naturally bias the spool pawl  452  in an inward direction. 
     Those of ordinary skill in the art will readily realize that several types of springs and/or spring-loaded devices will provide an equivalent structure and equivalent function to that of the disclosed pawl spring  440 . However, the applicants believe the disclosed method is a suitably quick and efficient construction. 
     Returning to  FIGS. 33-35 , a knob  404  is configured to fit over and close the open end of the base member  402  and generally circumscribe the outer periphery thereof. The knob  404  can be securely attached to the spool  426  or axle by a screw, as described above. In this way, the outer housing  400  is complete with the base member  402  and the knob  404  both securely attached to the spool  426 . Of course, the knob  404  may be attached through alternative structure. For example, the knob  404  and base member  402  can have a cooperating annular ridge and annular groove designed to provide a secure connection therebetween. In this type of connection, the annular ridge can be configured on either the knob  404  or the base member  402 , with the corresponding annular groove being formed on the other component. Furthermore, to provide additional support to the spool  426 , the knob  404  can contain an integral axle configured to extend down into the spool  426  for providing a rotational connection. The knob  404  may be subsequently removed by prying the knob  404  from the lower unit, with the required force determined by the specific configuration of the cooperating annular groove and ridge. In either disclosed embodiment, the spool  426  is journaled for rotational movement within the outer housing  400 . 
     The pawl spring  440  is constrained to rotate with the knob  404  in at least one direction, such as a winding direction, which is some embodiments is clockwise. This may be accomplished in any of a number of ways, one of which is by forming protrusions on the underside of the knob  404  that contact the pawl spring  440  as the knob  404  is rotated, thereby imparting a rotational force to the pawl spring  440 . With reference to  FIGS. 38 and 39 , a portion of the underside of the knob  404  has a pair of protrusions  454  extending therefrom. Each protrusion  454  contains an interfering surface  456  that contacts the bridge  446  of the pawl spring  440  and causes it to rotate concurrently therewith. Additionally, each protrusion contains a ramp  458 , as will be discussed in greater detail below. 
     An alternative structure that allows the knob  404  to impart a rotational force to the pawl spring  440  comprises a recess formed into the underside of the knob  404  that corresponds generally with the shape of the pawl spring  440  such that when the outer housing  400  and its internal components are assembled, the pawl spring  440  center section  442  and bridge sections  446  securely reside within the recess in the underside of the knob  404 . Of course, the pawl spring  440  may be constrained for concurrent rotation in one or both directions with the knob  404  by any suitable method, such as alternative interfering structure, adhesives, clips, snaps, mechanical bonding, chemical bonding, heat bonding, or any such suitable interaction. 
     Referring to  FIG. 40 , the interaction and operation of the components is illustrated. As the knob  404  and concomitant spring  440  are rotated in a clockwise direction, the outer pawls  450  slide past the base member  402  sloped teeth. Simultaneously, the spool pawls  452  contact and interfere with the spool teeth  428 , also referred to herein as ratchet teeth, thereby imparting a rotating force to the spool  426 . Thus, as the knob  404  turns clockwise, the spool  426  also turns clockwise, thereby winding the lace about the spool  426 . 
     Moreover, as the outer pawls  450  slide past the base member teeth  416  and are repeatedly deflected by the high slope of the teeth  416  and resiliently spring outwardly to contact the low slope of the teeth  416 , an audible and tactile feedback is provided to the user to indicate incremental winding and tightening of the lace about the spool  426 . 
     The spacing of the base member  402  sloped teeth controls the precision of incremental adjustment. For example, if only two or three base member teeth  416  are present, the knob  404  must be wound either one half or one third revolutions, respectively, to reach the next increment. Otherwise, the tension in the lace will cause the spool  426  to unwind until the outer pawls  450  contact the base member  402  teeth. Accordingly, while the number and spacing of the base member teeth  416  is not critical to practice the invention, those of ordinary skill will realize that an appropriate number of base member teeth  416  should be provided to provide acceptable adjustment increments, such as, for example, 20 to 40 or more teeth. 
     As the lace becomes wound about the spool  426 , its tension increases and thereby imparts a rotation force to the spool  426  in an unwinding direction. This unwinding force is counteracted by the interference between the spool pawls  452  and the spool teeth  428  in combination with the interference between the outer pawls  450  and base member  402  teeth. 
     For example, during initial turning of the knob  404  and pawl spring  440  in a clockwise direction, the spool pawls  452  resiliently fall down the slope of the spool teeth  428  and contact the substantially radial tooth face  462  of the adjacent tooth. Further rotation of the knob  404  and pawl spring  440  in a winding direction  464  imparts a torque, or winding force, to the spool  426  which rotates and thereby winds the lace about the spool  426 . When the winding force is removed, any tension in the lace will impart a torque in an unwinding direction  466 , or unwinding force, to the spool  426  and cause it to rotate in a counterclockwise direction. Consequently, as the spool  426  attempts to turn in a counterclockwise direction, the interaction between the radial tooth face  462  and the spool pawl  452  cause the pawl spring  440  to rotate counterclockwise with the spool  426 . As such, the outer pawls  450  contact the substantially radial face  468  of the base member  402  teeth and thereby prevent further unwinding of the spool  426 . 
     In order to effectuate unwinding of the spool  426 , it must become free of the spool pawls  452 . In the illustrated embodiment, this is accomplished by rotating the knob  404  and pawl spring  440  in a counterclockwise direction through predetermined angular displacement, which in one embodiment, is about one quarter turn. As the knob  404  and pawl spring  440  are rotated counterclockwise, structure on the knob  404  will contact the spool pawls  452  which deflect outwardly in response thereto, thus freeing the spool  426  for rotation. 
     More specifically, one or more ramps  456  ( FIGS. 38 and 39 ) are formed on the underside of the knob  404 . The ramps  456  are configured such that counterclockwise rotation of the knob  404  causes the ramps  456  to contact the spool pawls  452 , which slide up the ramps  456  and thereby deflect outwardly away from the spool teeth  428 . Once the spool pawls  452  extend up the ramp a sufficient distance, the spool pawls  452  are clear of the spool teeth  428 . Accordingly, the spool pawls  452  will be deflected a sufficient distance to become free from the spool  426 , thereby allowing the spool  426  to freewheel spin in response to the unwinding force applied by the tensioned lace. In this embodiment, the knob  404  must be held in its releasing position until the spool  426  unwinds, otherwise, the spool pawl  452  will resiliently return to its unbiased position and interfere with continued unwinding of the spool  426 . 
     Of course, other suitable methods and structure could be used to effectuate unwinding of the spool  426 . For example, a push button (not shown) located on top of the knob  404  could be coupled to the spool pawls  452  in such as way that depression of the push button forces the spool pawls  452  resiliently outward, thus allowing free rotation of the spool  426 . Other structure causing the spool pawls  452  to deflect outwardly will be readily apparent to those of skill in the art in light of the present disclosure. 
     Accordingly, in the described embodiments, as the illustrated spool pawl  452  deflects outwardly, its interfering contact with the spool  426  is released, which is then free to rotate. As such, the spool  426  unwinds in response to the unwinding force imparted by the lace tension, thereby loosing the tension in the lace and releasing the closing force of the footwear about the wearer&#39;s foot. The lace is preferably maintained within the reel such that it cannot escape once loosened. 
     An important realization is that it may be possible for the knob  404  to become inadvertently twisted during use, such as by impact with another object like another shoe, sporting implement, or the ground, for example, thereby resulting in unintentional or accidental unwinding of the laces. This could have unfortunate results, especially during strenuous physical activity when strict fit and control of the footwear is critical. Accordingly, the reel or knob  404  can be configured with a safety mechanism for preventing unintentional and accidental unwinding. 
     In one embodiment, as illustrated in  FIGS. 40 and 41 , the safety mechanism comprises a lever  470  or button that must be depressed in order to rotate the knob  404  in a counterclockwise direction. The lever is hingedly connected to the base member  402  in any suitable manner. However, in one embodiment, a pair of apertures  472  are provided for receiving a pair of pins  474  extending from connecting arms  476  of the lever  470 . Additionally, it is preferable that the lever  470  is biased in an upward direction, and accordingly, a spring can be provided underneath the lever  470  to give the desired bias. As illustrated, the base member  402  includes a lever flange  480  that defines the lever travel limit in a depressed direction and further contains a boss (not shown) for holding a coil spring (not shown) between the lever flange  480  and lever  470 . Accordingly, as the lever  470  is depressed, the coil spring becomes compressed, thereby imparting a restoring force to bias the lever in an upward direction. 
     The lever interacts with the knob  404  to prevent unintentional counterclockwise rotation. In one embodiment, this is accomplished by providing lock teeth  482  on the lever  470  that cooperate with knob teeth  484  (of  FIG. 39 ) to prevent relative rotation of the knob  404 . The lever  470  is biased upwardly, thus biasing the lock teeth  482  against the knob teeth  484 , which interfere with one another to inhibit counterclockwise rotation of the knob  404  relative to the lever  470 . The knob teeth  482  can be strategically spaced around the knob  404  to coincide with the winding increments of the reel. As such, for each winding increment, there is a corresponding locking position that allows the lever teeth  482  to lock the knob  404  at that particular location. However, such a correspondence between the winding increments and the locking increments is not crucial to the present invention. 
     The lock teeth  482  and knob teeth  484  are preferably configured to allow rotation of the knob  404  in a tightening direction without interference between the respective teeth  482 ,  484 . However, the teeth  482 ,  484  are configured to inhibit rotation of the knob  404  in a loosening direction by interference between the lock teeth  482  and knob teeth  484 . Thus, in order to rotate the knob  404  in a counterclockwise direction and release the spool  426 , the lever  470  must be depressed, thereby separating the lock teeth  182  and knob teeth  484 . Only then can the knob  404  be rotated counterclockwise to release the spool  426 , as described above. 
     With particular reference to  FIG. 38  and additionally to  FIG. 35 , an alternative embodiment comprises a knob  404  configured with a knob insert, or rotatable actuator  460 , that rotates independently of the knob  404 . For example, the knob  404  is configured with one or more arc grooves  480  configured to receive the protrusions  454  of the rotatable actuator. The arc grooves  480  and protrusions  454  can cooperate to securely attach the actuator  460  to the knob  404 , yet still allow relative rotation therebetween. The actuator  460  is configured with one or more upwardly extending tabs  482  that allow a user to grip and rotate the actuator  460  independently of the knob  404 . Moreover, the rotatable actuator  460  carries one or more ramps  456  on its lower surface, as discussed above, that interact with the pawl spring  440  to effectuate a release of the spool pawls  452  from the spool teeth  428 , as also described above. One or more alignment holes  484  may be provided through the actuator  460  to allow a user to visually verify the locked or unlocked status of the spool. For example, holes  484  can be located through the actuator  460  and the knob  404  can be configured with a visual indicator, such as one or more colored dots  485 . The colored dots  485  are preferably located such that when the actuator  460  is positioned to lock the spool  426  one color is viewable through the holes  484 , and when the actuator  460  is positioned to unlock the spool  426  a different color is viewable through the holes  484 . 
     In order to release the spool  426  and unwind the laces, a user simply rotates either the knob  404  or actuator, depending on the particular embodiment, in a counterclockwise direction thus causing the ramps  456  to engage and deflect the spool pawls  452  outwardly, thereby allowing the spool  426  to unwind the tensioned laces. Thus, a safety mechanism is provided that inhibits unintentional and accidental loosing of the reel and lace. Of course, it is to be understood that a counterclockwise rotation is not the only direction of rotation that can release the spool. In some embodiments, a right reel is tightened by rotating the knob in a clockwise direction and the spool is released by rotating the knob in a counterclockwise direction; and a left reel is tightened by rotating the knob in a counterclockwise direction and the spool is released by rotating the knob in a clockwise direction. 
     Therefore, a right reel and a left reel can be configured for opposite directional rotation to allow a user to more naturally grip and manipulate the reel. It is currently believed that an overhand motion, e.g. a clockwise rotation with a person&#39;s right hand, is a more natural motion and can provide a greater torque to tighten the reel. Therefore, by configuring a right and left reel for opposite rotation, each reel is configured to be tightened with an overhand motion by tightening the right reel with the right hand, and tightening the left reel with the left hand. 
     In several of the above described embodiments, the lace includes two free ends that can be inserted and fixed within the spool  426 . One particular advantage of these embodiments is that the lace can be removed and replaced, such as by threading through the guide members and inserted and affixed into the spool  426 , as necessary, without having to replace any ancillary components. However, other embodiments provide a closed loop lace which is permanently engaged with the spool  426 . In these embodiments, a removable spool and lace unit allows replacement of the spool and lace assembly as a unit. Such a replaceable spool and lace does not require subsequent threading of the lace through the guide members or the outer housing, and further does not require steps to secure the lace within the spool  426 , thus making lace replacement a fast and efficient process. However, in order to effectuate such a replacement, a closed loop lace must be able to enter the guide members without having a free end to thread through a tubular guide member. 
     To this end,  FIGS. 42   a  and  42   b  illustrate one embodiment of a guide member  490  especially suited to accept a closed loop lace. When referring to the term “closed loop lace,” it should be interpreted to mean a lace that enters the spool  426  at two or more locations, whether it has two free ends affixed within the spool  426 , or is a truly continuous lace having no ends. 
     In this embodiment of a guide member  490 , rather than having a tubular lace guide, the guide members comprise a lace guide  491  defining an open channel  492  having, for example, a semicircular, “C” shaped, or “U” shaped cross section. The guide member  490  is preferably mounted on the boot or shoe such that the channel opening  494  faces away from the midline of the boot, so that a lace under tension will be retained therein. One or more retention strips, stitches or flaps may be provided for “closing” the channel opening  494  to prevent the lace from escaping when tension on the lace is released. The axial length of the channel can be preformed in a generally U configuration. Moreover, practically any axial configuration of the guide member  490  is possible, and is mainly dictated by fashion, and only partly by function. 
     Several guide members  490  may be molded as a single piece, such as several lace guides  491  molded to a common backing support strip which can be adhered or stitched to the shoe. Thus, a right lace guide member and a left lace guide member can be secured to opposing portions of the top or sides of the shoe to provide a right set of guide channels  492  and a left set of guide channels  492 . When referring to “right” and “left” guide members, this should not be construed as suggesting a mounting location of the retainer strips. For example, the guide members  490  can be located on a single side of the shoe, such as in a shoe having a vamp that extends generally from one side of the shoe, across the midline of the foot, and is secured by laces on the opposing side of the shoe. In this type of shoe, the guide members  490  are actually disposed vertically with respect to one another, and hence, a left and right guide member merely refers to the fact that the guide members  490  have openings that face one another, as illustrated in  FIG. 44 . 
     When changing a worn or broken lace, a user simply removes the knob  404 , such as by removing an axial mounting screw extending through the knob  404  and into the spool  426 . Additionally, a screw extending through the base member  402  and into the spool  426  may also require removal before the spool  426  can be removed. Once the appropriate fasteners are removed, the entire spool  426  with concomitant lace can be removed and a new spool  426  and lace unit can be inserted in place. In order to accommodate this type of closed loop lace, not only must the guide members be open channeled, but the guides of the outer housing  400  must likewise comprise open channels to allow removal and insertion of a closed loop lace. 
     With returning reference to  FIGS. 33 and 34 , the base member  402  incorporates lace guides  422  having an open channel. The base member  402  has a generally C-shaped channel into which the lace may be inserted or removed. As described above, the channel  492  may selectively be closed by a flap or other closure device for maintaining the lace within the channel when not under tension. A tension applied to the lace will maintain it within the channel. 
     As described above, the base member  402  may contain a mounting  406  flange adapted for fastening to a shoe or boot. The mounting flange  406  can be configured with ridges  496  or grooves to offer increased frictional holding between the flange portion and connected material. Moreover, grooves can offer a decreased thickness to facilitate puncture, such as for stitching, yet offer an increased thickness to inhibit pull through of the stitching. Ridges or ribs can function in a similar manner to provide an area of increased thickness to increase the flange resistance to stitching pull through pressures. Of course, the base member  402  can be mounted to the footwear in any suitable manner, such as through adhesives, fasteners, mechanical or chemical bonding, mechanical structure, and the like. 
     While the function of the embodiments disclosed in relation to  FIGS. 33 and 34  is substantially similar, it should be apparent to one of ordinary skill in the art that great artistic license can be taken with the design of the outer housing to appease the whims of the fashion conscious. 
       FIGS. 43 and 44  illustrate examplary embodiments and mounting configurations of the present footwear-lacing system. For example, a plurality of guide members  490  can be located in lieu of traditional shoe eyelet strips, as described above. Typically, the guide members  490  are installed as opposing pairs, with the guide members formed integrally with the reel  498  typically comprising one of the guide members. The term “reel” will be used hereinafter to refer to the various embodiments including the complete structure of the outer housing and its internal components, unless otherwise specified. Thus, in some embodiments, there are 2, 4, 6, or 8 or more cooperating guide members  490  installed to define a lace path. Moreover, a non-paired guide member  490  can be installed, such as toward the toe of the shoe and positioned transverse to the midline and having its lace openings directed toward the heel of the shoe. This configuration, in addition to applying tightening forces between the lateral and medial sides of the shoe, would also apply a lace tension force along the midline of the shoe. Of course, other numbers and arrangements of guide members can be provided and this application and its claims should not be limited to only configurations utilizing opposing or even paired guide members. 
       FIG. 43  shows an embodiment in which the reel  498  is located on the lateral quarter panel of the shoe. Of course, the reel  498  can be located practically anywhere on the shoe and only some of the preferred locations are described herein. Moreover, the illustrated reel can be any reel embodiment suitable for practicing the present invention, and should not be limited to one particular embodiment. The illustrated embodiment provides three guide members  490  spaced along the gap between the medial quarter panel  500  and lateral quarter panels  502  of the shoe and thus creates a lace path that zigzags across the tongue  504  . While the reel  498  is illustrated as being disposed on the lateral quarter  502  panel near the ankle, it may also be disposed on the medial quarter panel  500  of the shoe. In some embodiments, the reel  498  is disposed on the same quarter panel of each shoe, for example, the reel can be mounted on the lateral quarter panel  502  of each shoe, or in alternative embodiments, the reel can be disposed on the lateral quarter panel  502  of one shoe, and on the medial quarter panel  500  of the other shoe. 
     Notably, this particular embodiment has a lace path that forms an acute angle a as it enters the outer housing. As discussed above, a lace guide member can be integrally formed into the outer housing to direct the lace to approach and interact with the reel from substantially diametrical directions. Thus, the summation of tension forces applied to the reel are substantially cancelled. 
       FIG. 44  shows an alternative embodiment of a shoe incorporating a vamp closure structure. In this particular embodiment, the reel  498  can be disposed on the vamp  506 , as illustrated, or can be disposed on the lateral quarter panel, or even in the heel, as disclosed above. Similar to  FIG. 43 , the reel illustrated in this  FIG. 44  should not be limited to one specific embodiment, but should be understood to be any suitable embodiment of a reel for use with the disclosed invention. In the illustrated embodiment, three lace guides  490  are affixed to the shoe; two on the lateral quarter panel  502 , and one on the vamp  506  cooperating with the guide members integrally formed with the reel  498  to define a lace path between the lateral quarter panel  502  and the vamp  506 . Those of ordinary skill will appreciate that the guide members can be spaced appropriately to result in various tightening strategies. 
     For example, the opposing guide members  490  can be spaced a greater distance apart to allow a greater range of tightening. More specifically, by further separating the opposing guide members  490 , there is a greater distance that can be used to effectuate tightening before the guide members  490  bottom out. This embodiment offers the additional advantage of extending the lace  23  over a substantially planar portion of the shoe, rather than across a portion of the shoe having a convex curvature thereto. 
       FIG. 45  illustrates an alternative arrangement of a shoe incorporating a vamp closing structure and having a reel and a non-looping lace. In this particular embodiment, an open ended lace can be attached directly to a portion of the shoe. As illustrated, a reel  498  is mounted on the lateral quarter panel  502  of the shoe. The shoe has one or more lace guides  490  strategically positioned thereon. As illustrated, one lace guide  490  is mounted on the vamp  506  while a second lace guide  498  is mounted on the lateral quarter panel  502 . A lace has one end connected to a spool within the reel  498  and extends from the reel  498 , through the lace guides  490  and is attached directly to the shoe by any suitable connection  512 . One suitable location for attaching the lace is on the vamp toward the toe for those embodiments in which the reel  498  is mounted on the lateral quarter panel  502 . 
     The connection  512  may be a permanent connection or may be releasable to allow the lace to be removed and replaced as necessary. The connection is preferably a suitable releasable mechanical connection, such as a clip, clamp, or screw, for example. Other types of mechanical connections, adhesive bonding, or chemical bonding may also be used to attach a lace end to the shoe. 
     While the illustrated embodiment shows the reel  498  attached to the lateral quarter panel  502 , it should be apparent that the reel  498  could readily be attached to the vamp  506  and still provide the beneficial features disclosed herein. Additionally, the lace could optionally be attached to the shoe on the lateral quarter panel  502  rather than the vamp  506 . The reel  498  and lace could be attached to a common portion of the shoe, or may be attached to different portions of the shoe, as illustrated. In any case, as the lace is tightened around the spool, the lace tension draws the guide members toward each other and tightens the footwear around a wearer&#39;s foot. 
     A shoe is typically curved across the midline to accommodate the dorsal anatomy of a human foot. Therefore, in an embodiment in which the laces zigzag across the midline of the shoe, the further the lace guides  490  are spaced, the closer the laces  23  are to the sole  510  of the shoe. Consequently, as the laces  23  tighten, a straight line between the lace guides  490  is obstructed by the midline of the shoe, which can result in a substantial pressure to the tongue of the shoe and further result in discomfort to the wearer and increased chaffing and wearing of the tongue. Therefore, by locating the laces  23  across a substantially flat surface on either the lateral or medial portion of the shoe, as illustrated, the laces  23  can be increasingly tightened without imparting pressure to other portions of the shoe. 
     It is contemplated that some embodiments of the lacing system  22  discussed herein will be incorporated into athletic footwear and other sports gear that is prone to impact. Such examples include bicycle shoes, ski or snowboard boots, and protective athletic equipment, among others. Accordingly, it is preferable to protect the reel from inadvertent releasing of the spool and lace by impact with external objects. 
       FIGS. 46 and 47  illustrate a lacing system  22  further having a protective element to protect the reel from impact from external objects. In one embodiment, the protective element is a shield  514  comprised of one or more raised ridges  516  or ramps configured to extend away from the mounting flange  406  a distance sufficiently high to protect the otherwise exposed reel. In the illustrated embodiment, the shield  514  is configured to slope toward the reel thus presenting an oblique surface to any objects it may contact to deflect the objects away from the reel. The shield  514  is positioned around the reel circumferentially and slopes radially toward the reel and may encircle the reel, or may be positioned around half the reel, a quarter of the reel, or any suitable portion or portions of the reel. 
     The shield  514  may be integrally formed with the mounting flange  406 , such as during molding, or may be formed as a separate piece and subsequently attached to the lacing system  22  such as by adhesives or other suitable bonding techniques. It is preferable that the shield  514  is formed of a material exhibiting a sufficient hardness to withstand repeated impacts without plastically deforming or showing undue signs of wear. 
     Another embodiment of a protective element is shown in  FIG. 48 . In this embodiment, a shield  514  is in the form of a raised lip  517  that encircles a portion of the circumference of the knob (not shown). The lip  517  can be of sufficient height to exceed the top of the knob, or can extend to just below the height of the knob to allow a user to still grasp the knob above the lip  517 , or the lip  517  can be formed with varying heights. The lip  517  is preferably designed to withstand impact from various objects to thereby protect the knob from being inadvertently rotated and/or displaced axially. 
     The lip  517  can be integrally molded with the mounting flange, or can be a separate piece. In addition, the lip  517  can take on various shapes and dimensions to satisfy aesthetic tastes while still providing the protective function it has been designed for. For example, it can be formed with various draft angles, heights, bottom fillets, of varying materials and the like. In the illustrated embodiment, the lip  517  extends substantially around the entire circumference of the knob  498 , except at holds  521  where the lip  517  recedes sufficiently to allow a user to grasp a large portion of the knob&#39;s height to be able to displace the knob axially by lifting it away from the housing. The illustrated embodiment additionally shows that the lip  517  extends outward to protect a substantial portion of the knob&#39;s height. While the lip  517  is illustrated as extending around a particular portion of the knob&#39;s circumference, it can of course extend around more or less of the knob&#39;s circumference. Certain preferred embodiments integrate a continuous shield  514  extending around between a quarter and a half of the knob circumference, while other embodiments incorporate a shield  514  comprising one or more discrete portions that combine to cover any appropriate range about the circumference of the knob. Of course, other protective elements or shields  514  could be incorporated to protect the reel, such as a protective covering or cap to cover the reel, a cage structure that fits over the reel, and the like. 
     As discussed above, the lace  23  is preferably a highly lubricious cable or fiber having a low modulus of elasticity and a high tensile strength. While any suitable lace may be used, certain preferred embodiments utilize a lace formed from extended chain, high modulus polyethylene fibers. One example of a suitable lace material is sold under the trade name SPECTRA™, manufactured by Honeywell of Morris Township, N.J. The extended chain, high modulus polyethylene fibers advantageously have a high strength to weight ratio, are cut resistant, and have very low elasticity. One preferred lace made of this material is tightly woven. The tight weave provides added stiffness to the completed lace. The additional stiffness provided by the weave offers enhanced pushability, such that the lace is easily threaded through the lace guides, and into the reel and spool. 
     The lace made of high modulus polyethylene fibers is additionally preferred for its strength to diameter ratio. A small lace diameter allows for a small reel. In some embodiments, the lace has a diameter within the range of from about 0.010″ to about 0.050″, or preferably from about 0.020″ to about 0.030″, and in one embodiment, has a diameter of 0.025″. Of course, other types of laces, including those formed of textile, polymeric, or metallic materials, may be suitable for use with the present footwear lacing system as will be appreciated by those of skill in the art in light of the disclosure herein. 
     Another preferred lace is formed of a high modulus polyethylene fiber, nylon or other synthetic material and has a rectangular cross-section. This cross-sectional shape can be formed by weaving the lace material as a flat ribbon, a tube, or other suitable configuration. In any case the lace will substantially flatten and present a larger surface area than a cable or other similar lace and will thereby reduce wear and abrasion against the lace guides and other footwear hardware. In addition, there is a sufficient amount of cross-sectional material to provide an adequate tension strength, while still allowing the lace to maintain a sufficiently thin profile to be efficiently wound around a spool. The thin profile of the lace advantageously allows the spool to remain small while still providing the capacity to receive a sufficient length of lace. Of course, the laces disclosed herein are only exemplary of any of a wide number of different types and configurations of laces that are suitable to be used with the lacing system described herein. 
     Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.