Abstract:
The effective friction of a shoe is adjusted by changing the angle of a portion of the sole, relative to the shoe centerline. In one embodiment, the heel is effectively hinged and an adjustment device is spaced from the hinge axis, whereby the wearer can hold the shoe in one hand and manually adjust an actuator connected to a drive member that increases or decreases the angle of the hinge. The hinge axis can be perpendicular to the centerline, either in the front of the heel with the drive member embedded in the back of the heel, or in the back of the heel, with the drive member embedded in the front of the heel. Angulation can be effected in the foresole, about an axis perpendicular to the shoe centerline, or about an axis that is parallel to but offset from the centerline.

Description:
RELATED APPLICATION  
       [0001]     This is the regular application claiming the filing date under 35 U.S.C. § 119 (e), of U.S. Provisional App. No. 60/735,795 filed Nov. 11, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention pertains to performance footwear, especially walking and athletic shoes, and most particularly, bowling shoes.  
         [0003]     As has been recognized for a number of years, and as discussed in U.S. Pat. No. 6,907,682, experienced bowlers often desire that each of the left and right shoes exhibit different characteristics, especially with respect to sliding friction on the smooth, wooden or synthetic floors typically present in the approach region of a bowling lane. Moreover, even for one or the other of the left or right shoe, such bowler typically desires a different sliding characteristic on the foresole portion versus the heel portion of that shoe sole. In yet a further customization, the bowler may desire that the friction characteristics of each foresole and heel be adjustable depending on, for example, the surface characteristics of the bowling center in which a particular competition is staged, the day-to-day changes in temperature and humidity in the bowling center, or an increase in confidence as the bowler warms up and reaches peak performance during the course of a match.  
         [0004]     One technique for permitting a bowler to adjust the friction characteristics of one or both shoes, even during competition, is disclosed in U.S. Pat. No. 5,542,198. The concept described therein provides for replaceable foresole and heel surface elements of different configurations and performance characteristics. Although this technique has enjoyed some commercial success, it has the disadvantages of requiring a bowler to carry a kit of varying replacement pads and, even with such a variety of pads, each adjustment increment is a step change, without continuous adjustability.  
       SUMMARY OF THE INVENTION  
       [0005]     According to one aspect of the present invention, the effective friction of the shoe is adjusted by changing the angle of a portion of the sole, relative to the shoe centerline. According to another aspect, the wearer&#39;s weight distribution on the sole can be similarly adjusted.  
         [0006]     In one embodiment, the heel portion of the sole is effectively hinged and an actuating device is spaced from the hinge axis, whereby the wearer can adjust an actuator connected to a drive member that increases or decreases the angle of the hinge. The hinge axis can be perpendicular to the centerline, either in the front of the heel with the drive member embedded in the back of the heel, or in the back of the heel, with the drive member is embedded in the front of the heel.  
         [0007]     This angulation has two significant consequences that affect sliding friction. First, the angulation affects the location on the heel, of the first contact of the heel on the floor following the initial sliding of the foot on the foresole. Secondly the hinging affects the total area of the heel that contacts the floor as the bowler shifts more weight into the heel in order to stop, or brake, the slide. Both of these effects can be adjusted without the replacement of any portion of the heel, and without manipulating any exposed region of the heel relative to another exposed region.  
         [0008]     Adjustment of the sliding friction characteristics of the foresole is also of significance in bowling shoes. The invention is not limited to adjustment of the heel by a hinging action about an axis perpendicular to the shoe centerline. The foresole can likewise be angulated to adjust the sliding friction characteristics.  
         [0009]     More generally, angulation can be effected in the foresole or in the heel, about an axis perpendicular to the shoe centerline, or about an axis that is on or parallel to but offset from the centerline. In this manner, one side of the heel, or one side of the foresole, can be raised or lowered relative to the other side. This kind of lateral adjustment can affect the time dependent friction force resulting from a particular bowler&#39;s unique weight transfer in the foot bed during the course of completing the delivery of the bowling ball. As with the heel angulated about an axis perpendicular to the centerline, the lateral adjustment can affect the location of the foresole or heel that first contacts the floor, the total area of the foresole or heel in contact with the floor during the delivery, and the weight distribution over the heel or foresole.  
         [0010]     The adjustment device is partially embedded in one or both of the heel or foresole portions of the sole and is preferably accessible as the sole faces the user&#39;s hand or tool in the user&#39;s hand. Alternatively, especially in embodiments wherein the hinge is in the heel, the adjustment device can be accessed at an upstanding exterior surface of the heel, such as at the back rim. Actuation of the device can be by any means under the control of the end-user of the shoe.  
         [0011]     The ability to adjust the angle of the heel or foresole, front to back and side to side, can also provide benefits in other performance characteristics that do not depend significantly on the user&#39;s sensitivity to sliding friction, but do depend for comfort or safety, on adjustability of the weight-bearing regions. Unlike the present invention, known comfort adjustment techniques do not rely on a hinging of the weight bearing surface of the heel or foresole in a manner that angulates the exposed weight bearing surface relative to the centerline of the shoe.  
         [0012]     In a more detailed characterization of the invention, a shoe having an adjustable weight bearing bottom surface comprises an upper supported by a sole extending generally along a longitudinal centerline, the sole having an arch, a foresole defining a first weight bearing bottom surface longitudinally forward of the arch, and a heel defining a second weight bearing bottom surface longitudinally behind the arch. Each of the first and second weight bearing surfaces has front and back regions and lateral side regions. An adjustment device angulates one of the first or second weight bearing surfaces. Preferably, the adjustment device has a drive member at least partially embedded in the sole and an actuator connected to the drive member such that adjustment of the actuator angulates one of the first or second weight bearing surfaces in relation to the centerline. It should be understood that as used herein, “region” denotes the general location of a sub-area of the outside of a heel or sole, such that, e.g., a side region of the heel can extent into the front or back of the heel.  
         [0013]     The invention can be further characterized in a preferred embodiment wherein the sole includes an exterior outsole having the bottom weight bearing surfaces and a midsole between the upper and the outsole. The drive member spans the midsole and outsole. The actuator selectively expands or contracts the drive member to push or pull the outsole away from or toward the midsole at the location where the drive member is embedded.  
         [0014]     The adjustment device can take a variety of forms. In one embodiment, one disc is embedded in a base portion of the sole, such as in the midsole, and another disc is embedded in a movable portion of the sole, with a threaded bore for receiving a worm screw or the like that has its drive end accessible at the exterior of the sole. With a screw driving device such as an Allen wrench or the like, the user can readily displace the disc in the movable portion of the sole relative to the stationary disc in the base of the sole, thereby increasing or decreasing the angulation about the hinge axis. This can be implemented for continuous adjustment, or can be ratcheted for repeatable stepwise adjustment.  
         [0015]     In another form, the adjustment device can be a disc interposed between the base portion of the sole and the movable portion of the sole, mounted for rotation with an arc of the disc accessible externally for rotation by the user. The disc has variable thickness, preferably monotonically increasing from the minimum to the maximum, whereby rotation of the disc acts a wedge which, depending on the thickness of the disc at the contact with the opposed sole surfaces, defines the hinge angle.  
         [0016]     Other adjustment techniques include an adjustable plug, jack or the like that can be pushed or extended through the footbed or mid sole, to angulate the heel or foresole. An air injection pump or other diaphragm or bladder-type member can likewise be used for this purpose. A step jack with bar analogous to one type of common car jack, or a pulled lever type device, could also be adapted for this purpose.  
         [0017]     In some embodiments, increasing the angle will produce a gap or separation between the base portion and the angulated, weight-bearing portion of the sole. Preferably, measures should be taken to compensate for this discontinuity and resulting decrease in direct weight bearing surface between the base portion and the movable portion of the sole members. This compensation can take the form of providing robust, wide components for the drive member, such as the discs mentioned above, and assuring that the discs are firmly mounted in the respective seats or other stabilizing foundation within the separable components.  
         [0018]     Another advantage uniquely achievable with the present invention is the ability to effectuate a reverse inclination on either the heel or foresole. Bowling, athletic, and other performance shoes, as well as street shoes, are universally manufactured with the main weight bearing, ground contacting surface of the heel in substantially the same plane as the weight bearing, ground contacting surface of the foresole. In other words, the center of the foresole and center of the heel lie flat on a flat surface. As an example with an adjustable heel according to the invention, the neutral adjustment position can correspond to the conventional coplanar relationship between the heel and the foresole, but with positive and negative adjustment options, whereby a back region of the heel weight bearing surface can be raised above ground level, or the front weight bearing region of the heel could be raised above ground level. Similarly, the back region of the heel could be lowered relative to the foresole, or the front region of the heel could be lowered the relative to the foresole. This added capability may be attractive to some bowlers who have unusual foot shapes, approaches, or braking tendencies. When combined with the further option of the exposed surface of the adjustable heel comprising two or more different materials, even greater customization of performance may be achieved.  
         [0019]     It should thus be understood that important an aspect of the invention is that the exposed surface of the sole, i.e., one or both of the heel or foresole, is angulated. There is no adjustment of the footbed or other shoe component that conforms to the wearer&#39;s foot. The purpose of the angle adjustment is to increase or decrease the surface area of the sole that contacts the ground or floor. The footbed remains in the same relation to the shoe centerline, but the exposed surface of the adjusted sole portion changes its angular relation to the shoe centerline. This adjustment can affect the timing of when certain portions of the sole contact the ground, which of multiple materials contact the ground and in what sequence, and how the weight of the wearer is distributed on various portions of the foresole and heel. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     Various embodiments of the invention will be described with reference to the accompanying drawing, in which:  
         [0021]      FIG. 1  is a schematic longitudinal section view of a shoe incorporating one embodiment of the invention;  
         [0022]      FIG. 2A  is a schematic detail view of the heel where a representative adjustment device is in a neutral position,  FIG. 2B  is similar to  FIG. 2A , but with the adjustment device in a different configuration, producing an angulation in the heel about a hinge axis at the front of the heel, and  FIG. 2C  is a view similar to  FIG. 2B , but for an alternative embodiment in which the hinge axis is at the back of the heel;  
         [0023]      FIG. 3  is a schematic representation of another embodiment of an adjustment device for angulating the heel;  
         [0024]      FIG. 4  is a schematic representation of yet another adjustment device for angulating the heel;  
         [0025]      FIG. 5  is a schematic representation of an actuation device for angulating the heel about a different axis;  
         [0026]      FIG. 6  is an elevation view of the medial heel portion of a left bowling shoe incorporating an embodiment of the invention analogous to that shown of  FIG. 1 ;  
         [0027]      FIG. 7  is a bottom plan view of the heel shown in  FIG. 6 ;  
         [0028]      FIG. 8  is a section view along line  8 - 8  of  FIG. 7 ;  
         [0029]      FIG. 9  is a section view along line  9 - 9  of  FIG. 7 ;  
         [0030]      FIGS. 10A , B, and C schematically illustrate one of many possible techniques for including a ratchet feature with the adjustment device;  
         [0031]      FIG. 11  is a schematic of another embodiment wherein two adjustment devices are situated in the back portion of the heel, on either side of the shoe centerline;  
         [0032]      FIG. 12  is a schematic of another embodiment, wherein two adjustment device are situated in the heel, on the same lateral side of the shoe centerline; and  
         [0033]      FIG. 13  is a section view of one embodiment for implementing the invention in the foresole of a shoe, with the adjustment device situated laterally of the shoe centerline. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]      FIGS. 1 and 2  show a schematic representation of one embodiment of the invention as implemented in a left bowling shoe. The representative bowling shoe  10 , has an upper  12  supported by a sole  14  having a foresole with associated flat slide surface  16  and heel  20  defining a nominally flat brake surface  18 . The sole can have one or more layers. An angulation adjustment device  22  is situated in the heel  20  for changing the angle between the surface  18  and the surface  16 , thereby changing the area of the heel surface  18  in contact with the, e.g., bowling lane approach, when the foresole is sliding flat on the approach and the bowler transfers weight into the heel to control braking. For purposes of the present description the term “sole” refers to the entire bottom structure of the shoe, which for exemplary purposes, can conveniently comprise a foresole associated with surface  16 , a heel associated with surface  18 , and an arch (often but not necessarily recessed) situated therebetween.  
         [0035]      FIG. 2  shows a representative construction of the heel portion of a shoe incorporating embodiments of the present invention. The sole construction can include insole  26  and outsole  28  as shown in  FIG. 2A . Similarly, the heel  20  includes a base portion  30  attached to midsole  26  or extension of outsole component  28 , and an active portion  32 . The adjustment mechanism or device  22  is partially embedded in the heel, leaving an exposed actuation surface or component  24 , and spans the base portion  30  and active portion  32 . In this context, “spans” means the device remains in contact with the spanned components. In shoes having a recessed arch, the base portion  30  and active portion  32  of the heel are analogous to the midsole  26  and outsole  28  of the foresole, in that these are the two layers closest to the ground when the shoe is worn.  
         [0036]     The effect of manipulating the adjustment mechanism  22  from a nominal condition in  FIG. 2A , whereby active heel portion  32  fully abuts the base portion  30 , is shown in an exaggerated condition in  FIG. 2B , where the active portion  32  pivots about a hinge axis  33  at the front edge or rim of the heel, and has in part separated from the base portion  30  at the back edge or rim. The mechanism  22  has a first disc  34  embedded in the base  30 , and a second disc  36  embedded in the active portion  32 , with a worm screw  38  fixed at one end  40  to disc  34  and engaging a threaded bore in disc  36 . The other end  24  has a slot or socket for rotating the screw.  
         [0037]     Upon rotation of the screw, the disc  36  is displaced relative to disc  34 , thereby separating active portion  32  from base portion  30 , creating a gap  44 . This also creates an angle  46  relative to the horizontal (such as a flat floor)  42 .  
         [0038]     The material at or along hinge or pivot  33  can be glued or sewn relatively tightly, and the interface between the periphery of the base  30  and active portion  32  can be sewn loosely (not shown), especially adjacent the location of gap  44 , to assure that the hinging occurs at the desired hinge axis and that the base and active portions are separable but to a limited extent at gap  44 . Also, a region (preferably about 50%) of different material than the remainder of the active portion  32  of the heel can be provided to produce a coefficient of friction at exposed surface  18 ′ on one side of the actuation device  22  that is different from the coefficient of friction on the remainder of the surface  18 ″.  
         [0039]      FIG. 2C  shows an alternative in which the hinge axis  33 ′ is at the back edge of the heel and the gap  44 ′ opens at the front edge of the heel, whereby the angle  46 ′ is created between heel surface  18  and the ground  42 .  
         [0040]      FIG. 3  is a schematic of another embodiment in which wedge disc  48  is shown between heel portions  30  and  32 . The disc  48  is situated in the space between (i.e., spans) the base  30  and active portion  32  with the center of the disc having an opening through which shaft  56  passes. The shaft has one end fixed to support member  52 , which is in turn fixed within base  30 , and another end fixed to support  54 , which is fixed within active member  32 . The disc has a varying thickness such that, upon rotation by the user, the selected thickness of the disc will bridge the base and active portion  30 ,  32  thereby define the gap and thus the angle that is established between members  30  and  32 . An arc segment of the disc projects from the exterior surface of the heel, preferably at the back, thereby serving as a thumb wheel, which directly angulates the heel. The disc  48  functions as both the actuator and the drive member of the adjustment device.  
         [0041]      FIG. 4  depicts another embodiment wherein the adjustment mechanism  58  comprises a thumb wheel  60  that is exposed at the rear of the base portion  30 , for the user to rotate screw  64  which in turn advances or retracts a disc or the like  62  embedded in portion  32 , along with portion  32 .  
         [0042]     The same concept can be utilized to change the angle of the active portion  32  relative to horizontal  42 , laterally as suggested by arrow  74  in  FIG. 5 .  FIG. 5  is a view from the back of the shoe, in the direction of arrow V as shown in  FIG. 1 . In this embodiment, the adjustment device is situated adjacent either the medial or lateral exterior surface of the heel, thereby permitting the adjustment of the pronation angle of the heel. Any of the adjustment devices previously described may be utilized for this embodiment. A device  66  analogous that shown in  FIG. 2  is shown in  FIG. 5 . A first disc  68  is embedded in the base portion  30  and a second disc  70  is embedded in active portion  32 , with an adjustment screw  72  extending between the discs and exposed to a bottom surface of the heel for access by the user. The active and base portions  32 ,  30  can be separated or brought closer together, with an effective pivot or hinging axis at  76 , running parallel to but offset below the shoe centerline. This raises or lowers one side of the exposed surface of the heel, relative to ground the  42 , as shown at  74 .  
         [0043]     It should thus be understood that the front-to-back angulation represented by α in  FIG. 1  and the side-to-side angulation represented by arrow  74  in  FIG. 5  can each be considered as changing the relationship of a weight bearing surface to the longitudinal centerline of the shoe or sole  
         [0044]      FIGS. 6 through 9  show additional details for implementing a variation of the embodiment shown generally in  FIGS. 1 and 2 . In this embodiment, the adjustment device is situated in the forward region of the heel, with the hinge axis situated toward the back of the heel, in contrast to the embodiment shown in  FIG. 1 , where the adjustment device is centered or toward the back of the heel, and the hinge axis is relatively forward in the heel.  
         [0045]      FIG. 6  is an elevation view of a bowling shoe  100 , rearward of the arch. In this view the adjustable, active portion of the heel is shown at  112 , adapted for contacting the ground. The base portion  114  of the heel rests on the active portion  112 , and a riser portion  116  of the shoe upper is connected to the base portion  114 . In this context, base portion  114  can be considered a midsole component in relation to the active portion  112 , which can be considered the outsole component.  
         [0046]      FIG. 7  shows the same portion  100  of the shoe depicted in  FIG. 6 . The adjustment device  118  is situated in the front or forward portion of the heel, substantially vertically beneath the shoe centerline CL. Only the adjustment screw  120  is visible and accessible from the bottom of the heel. The adjustment screw  120  can carry a structural or applied marker for selective alignment with visible discreet indicia  122  carried on the surrounding surface of the heel. In this manner, the user can reproduce a particular angular adjustment by realigning the marker with a particular one of the indicia. Preferably, the adjustment device includes a ratchet or similar discrete action, corresponding to the discreet indicia.  
         [0047]     In this embodiment, the adjustable portion  112  and the base portion  114  of the heel converge  124  at the rearward portion of the arch, where a gap is formed which increases or decrease in size according to the position of the adjustment device. At the back of the heel, a fulcrum or pivot line is effectively formed by the overlap of the base  114  relative to the active portion  112 , as shown at  126 ,  128 . The overlap  126  serves as a curtain, camouflaging the pivoting and therefore avoiding any detrimental aesthetic appearance in the shoe. Alternatively, an accordion type covering can be provided.  
         [0048]      FIG. 8  is a section view through line  8 - 8  of  FIG. 7  and  FIG. 9  is a section view through line  9 - 9  of  FIG. 7 . The base  114  serves as the mid sole and the adjustable portion  112  serves as the outsole. In this particular embodiment, the risers  116  forming part of the upper are connected to the base  114 , such that the inner surface of the riser and the upper surface of the base portion merge to form foot bed  130 ′,  130 ″. The side portion of the base  114  can also provide an overlap or curtain  132  relative to the sidewall  134  of the active member  112 . The exposed bottom surface of the active member  112  can have recesses or other patterns  136  (not shown in  FIG. 7 ) in a well-known manner, for both aesthetic and functional purposes, but the overall boundary of the bottom surface is substantially flat. Within the active portion  112 , one or more cavities  138  can be formed for weight savings and comfort.  
         [0049]     In the illustrated embodiment, a substantially circular rim  140  provides a support wall and is upstanding to the extent of close or contact relation with the underside of the base portion  114 . A cavity  142  is established within the support wall  140 , for containing the main components of the actuating device. In this embodiment, the active disc  144  rests on transverse support surface  146  at the bottom of the support wall  140 . This can be cemented in place, or rotationally restrained by lugs or the like (not shown) engaging the support wall  140 . Another disc  148  is seated for rotation at  150  at the underside of the base member  114 . An Allen screw or the like  120  spans these discs and is fixed with respect to disc  148 , but cooperates with the active disc  144  as in a worm gear. In this manner, rotation of the screw forces the active disc  144  to move away from or toward the stationary disc  148 . As the active disc  144  separates and moves away from the fixed disc  148 , it acts on the support surface  146  to cause separation of the active portion  112  of the heel from the base portion  114  of the heel along interface  152 . As a result, much of the weight of the bowler after release of the ball and into the follow-through shifts to the heel and is ultimately transmitted from the fixed disc  148 , through screw  120 , to the active disc  144 . Accordingly, the screw threads and the mating threads in the active disc  144  will be sufficiently robust to accommodate this weight. Furthermore, inasmuch as the heel  112  has separated from the base  114  the weight will not be transmitted to the active portion  112  at the sidewalls through the interface  152 . The active disc  144  should be of sufficient width or diameter, or include other stabilizer structure (not shown) to enable the user to maintain proper balance during desired or inadvertent lateral weight shift within the foot bed  130 .  
         [0050]     As described above, during adjustment, the active portion  112  will separate to some extent form the base portion  114 , as a result of the displacement of the active disc  144  relative to the fixed disc  148 . While the wearer applies weight on the foot bed  130 , these members  112 ,  114  are urged toward each other. However, during a bowler&#39;s stride or at other times when the shoe is above the ground without support from below, the active portion  112  would have a tendency to separate from the base portion  114 . This is prevented by the gluing and/or stitching described above with reference to  FIG. 2 . Alternatively, or in addition, other embodiments of the adjustment device itself can include structure that is fixed with respect to the base  114 , such as described below with respect to  FIG. 10 .  
         [0051]      FIGS. 10A , B and C show one embodiment for including a ratchet mechanism or similar step-wise, incremental setting of the degree of adjustment. This is especially helpful in conjunction with the indicia previously described, for precisely returning the adjustment to a known setting that is to be reproduced. The active portion of the heel  112 ′ includes stationary but rotatable disc  140  with rigidly projecting adjustment screw  142 . A ratchet type mechanism  144  is also located in base portion  114 ′, spring loaded toward to circumference of the disc  140 , which has a saw toothed or similar rim  140 ′. The members  146 ,  148  are threaded to screw  142  and, as the screw is rotated, the members are displaced along the screw, thereby moving active heel portion  112 ′ either toward or away from base portion  114 ′. The ratchet-type or similar detent mechanism retains the screw in a selected rotational position upon completion of the adjustment. Such movement is preferably accompanied by a sequential clicking sound generated between the ratchet  144  and rim  140 ′.  
         [0052]     In a preferred implementation in which a single adjustment device is on the shoe centerline at the back of the heel, the movable disc has a diameter of at least about 50 mm for providing sufficient stability. The ratchet has at least seven stop positions, with eight being ideal, e.g., +4 to 0 (neutral whereby the heel and foresole are substantially coplanar) to −4. Each turn of the screw through 180 degrees, advances the moveable disc and active portion of the heel, about 0.5 mm.  
         [0053]      FIG. 11  shows another embodiment  200 , in which two actuation devices  202 ,  204  are situated in the rearward region of the heel, thereby hinging the heel about an axis  206  in the forward portion of the heel, transverse to the centerline.  
         [0054]      FIG. 12  discloses another embodiment  300  wherein two actuation devices  302 ,  304  are both situated on one lateral region of the centerline of the heel in a manner that effectuates a lateral adjustment about a hinge axis at  306  that is parallel to but offset from the shoe centerline.  
         [0055]      FIG. 13  shows another embodiment  400 , implemented in the foresole along one lateral side of the shoe centerline  402  whereby a lateral adjustment can be made by actuating the adjustment device  404  to angulate the outsole  406  relative to the midsole  408  about a hinge axis  410  that is parallel to but laterally offset from the shoe centerline.  
         [0056]      FIG. 13  also shows schematically within the phantom lines  412 , that other types of adjustment devices can be located for access through the footbed  414 , to angulate not only the foresole, but alternatively the heel, either front to back or laterally.  
         [0057]     From the foregoing detailed examples, one of ordinary skill in this field can also implement a hinge adjustment in the foresole about an axis transverse to the centerline, thereby lifting or lowering the forward or back portion of the foresole, in a manner analogous to that described with respect to the heel.  
         [0058]     It should be appreciated that the foregoing embodiments can be implemented with only one adjustment device, but two devices enhance stability and offer greater precision, especially for the lateral adjustment. Two or more can be used in combination, for fore/aft and lateral angulation. The invention can be used in other types of performance shoes, including but not limited to shoes used in court games, such as basketball or tennis, and walking shoes, driving shoes, etc.