Abstract:
Crampon and snowshoe combinations are disclosed, wherein the crampon or terrain-engaging cleat can be a traditional ice crampon used on a rigid and essentially unbending boot, or a soft boot cleat which engages only the front portion of the boot, forward of the heel, permitting boot flexing. The snowshoe has in a toe or ball area a registry plate configured to engage with the crampon, preferably between depending teeth or other structure of the crampon, and preferably with a self-centering feature as the crampon is lowered down onto the registry plate. Once the cleat or crampon is fully engaged down against the plate, it is substantially locked in position against relative shifting or rotation, and lifting of the boot off the back of the crampon is restricted by clips or straps, preferably flexible straps extending up from the registry plate and securable to brackets or hooks on the crampon device. Specific configurations of cleats or crampons are also disclosed, for use with or without snowshoes.

Description:
This application is a division of application Ser. No. 09/294,517, filed Apr. 20, 1999, now U.S. Pat. No. 6,256,908, which was a continuation-in-part of application Ser. No. 09/009,948, filed Jan. 21, 1998, now U.S. Pat. No. 5,901,471. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention concerns traction enhancing cleats for attachment to boots or shoes, particularly for flexible boots or shoes, functioning as a soft-boot crampon engaged under the ball of the foot but not the heel. In another aspect, the invention concerns such a terrain-engaging cleat which, when worn on a boot, can be secured to a snowshoe by stepping into the snowshoe, serving as a front cleat for the snowshoe. 
     Crampons, ice creepers and cleats for attachment to boots or shoes are very well known. For example, see U.S. Pat. Nos. 37,558, 754,577, 988,527, 1,045,565, 1,200,658, 1,230,118, 1,570,791, 1,728,783, 2,317,647, 2,358,066, 2,401,891, 2,579,143, 2,920,403, 4,005,533, 4,620,375, 4,745,692, 4,910,883, 5,787,612; French Patent No. 1,189,492 and German Patent No. DE 30 19 129 A1. 
     Conventional crampons essentially comprise rigid boot attachments which attach to the bottom of a boot sole by bales forming part of the crampons. These technical terrain-engaging devices require a substantially rigid boot, stiff like a downhill ski boot, because the crampon does not have any appreciable flexibility which could bend with the bending of a flexible boot. A crampon of this general type is shown in the above U.S. Pat. No. 4,910,883, and is also shown in the copending application Ser. No. 09/00948. The above U.S. Pat. No. 754,577 also shows an essentially rigid type of crampon device. 
     Various types of ice creepers or cleats have been proposed for use on flexible boots or shoes, as reflected in some of the patents listed above. U.S. Pat. Nos. 1,570,791, 1,728,783, 2,401,891, 2,579,143 and 4,005,533 all show such cleats or creepers which reside in the arch area of the shoe or boot, just ahead of the heel. The cleat devices of those patents are retained on the boots using straps. Some of these show angled teeth, including front teeth angled downwardly/forwardly and including teeth with faces obliquely angled so as to achieve some degree of lateral traction as well as fore/aft traction. 
     U.S. Pat. No. 988,527 shows a flexible shoe having a heel element and a separate toe element, both secured to the shoe and with a form of spikes, for use by carpenters, roofers, etc. to prevent the wearer from slipping. 
     U.S. Pat. No. 4,745,692 shows an anti-slip toe cleat device which has capability of pivoting or folding from one position to another. The hardware is permanently attached to the shoe, in the ball area. 
     U.S. Pat. No. 2,317,647 shows a strap-attachable ice creeper device which fits in the arch and ball area of the shoe or boot, with teeth positioned in the ball area of the foot. Some of the teeth are angled, and the cleat device apparently is useable on a flexible shoe or boot. 
     French Patent No. 1,189,492 discloses a simple form of ice creeper comprising a single strap that wraps around the toe area of the shoe or boot and which has, fitted onto the strap, two cleats side-by-side under the ball of the foot, each cleat having forward and rear racks of teeth. 
     U.S. Pat. No. 5,687,491, owned by the assignee of the present invention, describes a contoured footbed for the front portion of a boot, the footbed being on the top surface of a front claw or cleat of a snowshoe. That patent is incorporated herein by reference. 
     In climbing or steep terrain hiking in snowy and icy conditions, the climber often needs to switch from wearing snowshoes on the boots to crampons on the boots, and back to snowshoes as fields of deeper snow are again encountered. To change from ice crampons to snowshoes, the user normally has to release the crampon&#39;s bales from front and back of the boot, remove the crampons and stow them in or on a pack, take out a pair of snowshoes from the pack, with their relatively heavy toe harness assemblies and cleats, and secure the snowshoes to the boots using several harness straps. In conditions where deep snow and ice are alternately encountered, the hiker or climber would be much better served if the crampon teeth could serve as the cleats for the snowshoes, and this is a primary object of the invention. 
     U.S. Pat. No. 4,620,375 disclosed a snowshoe wherein the user&#39;s boot was secured to a binding on an ice crampon. The crampon had toe and heel cleats which passed down through openings in toe and heel areas of the snowshoe deck when the user&#39;s boot was pivoted to the heel-down position, so that the crampon cleats served as cleats for the snowshoe. A horizontal pivot pin had to be assembled through the snowshoe frame and the crampon binding. 
     The copending application Ser. No. 09/00948 referenced above describes a snowshoe for receiving conventional crampons, the snowshoe having openings in its deck at front and rear. The snowshoe is adapted to receive a conventional crampon secured to a user&#39;s boot in a step-in arrangement which was designed to afford fast and efficient securement of the boot and crampon to the snowshoe. The crampon&#39;s teeth, both the front set and back set, then serve as snowshoe cleats. The snowshoe can quickly be removed from the boot and crampon when ice is encountered. 
     The described arrangement works well for those using rigid, full-boot crampons. However, there is also a need for a more versatile crampon or cleat, for use on a flexible boot which bends with walking of the user. In particular, there is a need for such a cleat which engages under only the ball area of the boot, using a harness which is conveniently secured to and removed from the boot. In addition, there is a need for such a soft-boot terrain-engaging cleat or crampon which has a further utility of engaging with a snowshoe having a dedicated receiving device in the front area of the snowshoe, to lock the cleat in position on the snowshoe firmly against rotation or looseness as in the system described above, and with the ability to conveniently engage the boot-attached cleat with the snowshoe and to easily remove it from the snowshoe. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention, a soft-boot cleat, serving as a toe-only crampon which engages under the ball of the foot, provides a relatively compact and lightweight terrain-engaging device which is easily attached to or removed from the boot or shoe. The terrain-engaging device or crampon has a platform including an upper surface with a footbed to receive the bottom of the front portion of a flexible boot or shoe, under the ball of the foot, such that the heel of the boot or shoe extends behind the platform. A plurality of teeth extend downwardly from edges of the platform, including left and right side teeth and at least two front teeth, the front teeth extending forward from the platform in an oblique manner such as in the front teeth of a conventional full-foot crampon. The device includes a harness assembly secured to the platform and extending laterally outwardly from forward and rear locations on the platform. This harness includes strap means for engaging over the top of a user&#39;s boot including generally over the arch region of the boot, with buckling means for engaging the strap means firmly on the boot. 
     The terrain-engaging cleat device preferably further includes a heel strap connected to the harness assembly, for extending around the back of the user&#39;s boot to connect to an opposite side of the harness, with a latch or buckle to secure the strap firmly around the boot. 
     In one preferred embodiment the platform and teeth comprise an integral stainless steel stamping, and this may include stiffener pleats in the bend areas where the platform extends down into the teeth, for added strength. 
     The harness assembly includes a web of flexible material secured to the platform, preferably to its bottom, and extending laterally outwardly and upwardly from the platform. Portions of the web at each side of the crampon extend from positions both forward of and behind the side teeth. The strap means are connected to the web. 
     In preferred embodiments the platform has a tail extension at its rear, defining a rear attachment point located approximately at the arch of the user&#39;s shoe or boot. The web of the harness assembly, secured to the platform, has a rear portion secured to the rear attachment point on the tail extension. This provides a more secure binding to the boot, resisting rotation of the cleat relative to the boot. 
     An important aspect of the invention is a toe area terrain-engaging cleat or crampon in combination with a snowshoe which accepts the boot-worn cleat in a step-in arrangement, so that the user can quickly switch from simply using the terrain engaging cleat to wearing a snowshoe. This function and the structure which accomplishes the function are similar to the apparatus disclosed in the copending application Ser. No. 09/00948, incorporated herein by reference, and this is one form of the invention. However, the invention also encompasses another embodiment of a snowshoe/crampon combination using the soft-boot cleat or crampon described above. In this case the snowshoe does not have a deck opening in a rear area for rear crampon teeth, since the terrain-engaging cleat of the invention resides only in the toe area of the boot. The front portion of the snowshoe has a registry plate which is easily engaged by the cleat even while it is worn on the boot, without the registry apparatus being directly visible to the user. The front teeth of the terrain-engaging cleat are angled downwardly and forwardly, and these provide a tactile means for finding the associated apparatus on the snowshoe plate for correct registry. If the user fails to step into precisely the right position, this will be readily apparent because the cleat will not feel as if it is being lowered into the snowshoe for proper engagement. 
     In a preferred embodiment, the snowshoe has a pivoting front harness, which may be biased to the tail-down position of the snowshoe, the front harness including the rigid registry plate adapted to be received against the bottom of the cleat device and preferably a strap to extend over the top of the foot. The rigid plate has a specific shape designed to accommodate the pattern of teeth at the front end of the cleat device. The plate has a front portion which provides clearance at front and sides to receive teeth of the crampon down around the plate. The plate and the crampon structure are configured and sized in preferred embodiments such that the user must tip the toe of the boot and connected cleat device toe-down into the snowshoe to fit a front bar of the registry plate between teeth of the cleat; then, when the heel is rotated down, an angled tooth edge pivots under the front bar structure of the plate, the tooth structure becomes closely nested with the plate, and the front end of the cleat is thus locked in position against lifting from the plate. The configurations of the harness plate, and of the tooth structure, are such that the cleat device becomes oriented (with respect to rotation about a vertical axis) on the snowshoe as the teeth are inserted into the clearances and the heel is lowered. 
     Once the user has stepped the cleat and boot into the snowshoe as described, a single strap may be used to secure the boot down to the front harness assembly, preferably located approximately at the boot arch and extending over the top of the foot between the ankle and the ball of the foot. This strap preferably is mounted on the registry plate of the snowshoe harness. 
     It is thus among the objects of the invention to make more efficient the use of snowshoes and terrain-engaging cleats in traversing fields of ice and snow alternatively, by providing a snowshoe with a front harness plate configured to receive a terrain-engaging cleat or crampon in a step-in maneuver that enables very quick transition from ice trekking to snowshoeing. Another object is an efficiently used, lightweight terrain-engaging cleat for the ball area of the boot, with or without a snowshoe. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a snowshoe with connected boot and crampon, in accordance with the principles of the invention. 
     FIG. 2 is a perspective view showing the snowshoe alone. 
     FIG. 3 is a perspective view showing a crampon of a type for use with the snowshoe of the invention. 
     FIG. 4 is a perspective view showing the bottom side of the snowshoe&#39;s front harness assembly, with the crampon secured to the harness assembly. 
     FIG. 5 is a plan view showing the plate of the harness assembly for the snowshoe of the invention. 
     FIG. 6 is a side elevation view of a crampon as in FIG.  3 . 
     FIG. 7 is a perspective view showing a base portion of a terrain-engaging cleat or crampon according to another embodiment of the invention, for engaging only under the ball portion of the foot. 
     FIG. 8 is a perspective view showing a crampon assembly which includes the base portion shown in FIG. 7, along with a harness. 
     FIG. 9 is a perspective view showing the crampon of FIG. 8 as attached to a user&#39;s boot, and engaged in a snowshoe designed to receive the crampon. 
     FIG. 10 is a perspective view showing the snowshoe of FIG. 8, without the crampon. 
     FIGS. 11A and 11B are plan and perspective views showing a registry plate which forms a part of the snowshoe of FIGS. 9 and 10. 
     FIG. 12 is a bottom perspective view showing engagement between the registry plate of FIG.  11  and the cleat or crampon. 
     FIGS. 13A-15B are developed plan views and perspective views showing three additional types of registry plates which can be used in lieu of the plate shown in FIGS. 9-12. 
     FIG. 16 is a perspective view showing another modified form of terrain-engaging cleat or crampon according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a snowshoe  10  having a frame  12  and deck portions  14 ,  16  and  18 , in a first embodiment of a snowshoe/crampon combination. A boot  20  with an attached crampon or terrain-engaging cleat  22  is secured to the snowshoe by a front harness assembly of the snowshoe, generally identified by  24 . As can be seen in the drawing, the snowshoe deck portions  16  and  18  have relatively large openings  26  and  28 , and these accommodate rear and front groups of crampon teeth, as further explained below. 
     FIG. 2 shows the snowshoe  10  alone. The decking areas  14 ,  16  and  18  in this preferred embodiment are retained to the snowshoe frame  12  by sections of decking material which extend around the frame and are riveted together to the main body of decking, as at  30 , for example, and as shown in U.S. Pat. No. 5,440,827. The snowshoe&#39;s decking can be comprised of fewer pieces if desired. 
     As FIG. 2 reveals, the snowshoe  10  has a front harness assembly  24 , preferably pivotable about a horizontal axis which can be provided by one or more resilient straps  32  wrapped around the frame and retaining the harness assembly preferably in a toe-down biased position, as shown in U.S. Pat. Nos. 5,253,437, 5,440,827, 5,699,630 and 5,687,491. However, the front harness and pivot assembly is without a front claw or cleat, nor does the snowshoe have any rear cleat. Instead, the open areas  28  and  26  provide space for a user wearing a boot and a crampon such as the crampon  22  to step into the snowshoe and lock the crampon to the snowshoe, after which the teeth of the crampon can be used as front and rear cleats for the snowshoe. 
     FIGS. 3 and 6 show a crampon or terrain-engaging cleat  22  which is configured for use with the snowshoe of the invention. Important features of the cleat device  22  are that its rear group  34  of teeth is positioned to pass through the rear, generally heel-located opening  26  of the snowshoe, that its front group  36  of teeth is positioned to pass through the opening  28  at the front of the snowshoe, and that the front group  36  of teeth be configured to straddle over and engage with a front harness plate or registry plate  38  which is an important feature of the snowshoe. As seen in FIGS. 2 and 3, the crampon  22  can be attached to the snowshoe via the harness mounting plate  38 , by simply stepping into the snowshoe in a toe-down position when the crampon is worn on the user&#39;s boot. With the strap assembly  24  in a loosened or released position, the user inclines the boot with the toe downward, at a steeper angle than the orientation of the mounting plate  38  itself, inserting a pair of opposed, left and right side teeth  40  (the left tooth  40  is visible in FIGS. 3 and 6) down through a clearance  42  provided at each side of a front portion of the mounting plate  38 . The opposed crampon teeth  40  have inclined front surfaces so as to extend under tip structure  44  at each side of the front end of the mounting plate, the tip structures comprising a front bar across the front end of the plate  38 . 
     The crampon teeth  40  each comprise a part of a side protrusion  46 , which may also include another tooth  48  just behind the tooth  40 , and which has a width W (FIG. 6) at its upper end, near a deck or frame  50  of the crampon, which is matched to the length of the clearance  42  in the harness plate  38 . The forward side of the tooth  40 , that is, of each side protrusion  46 , is inclined forwardly/downwardly as shown, so that it engages under the structure  44  of the plate  38  and then locks the crampon in place after the crampon has been rotated such that its back end  52  is downward and the front portion  54 , with the front group  36  of teeth, is in contact with the surface of the harness plate  38 . FIG. 6 shows the crampon  22  in side view, with bales  56  and  58  removed (shown in FIG.  3 ). The illustrated crampon is of a known configuration, marketed as the Sabre Tooth crampon by Black Diamond Equipt. Ltd. of Salt Lake City, Utah. 
     FIG. 5 shows in plan, developed view the harness registry plate  38  which cooperates with the crampon  22 . The clearance  42  at each side of the front end of the harness plate is shown as formed between the tip structure  44  and a wing extension  60  at each side, spaced back from the tips  44 . The harness plate  38  in this embodiment is further configured to provide adequate spaces  61  for a further posterior pair of crampon teeth  62 , still in the forward set  36  of teeth, as seen in FIGS. 3 and 6. Another pair of teeth  64 , the most posterior of the forward set of teeth  36 , are received in clearances  66  of the harness plate as shown in FIG.  5 . 
     At the rear end of the harness plate  38  are a pair of arms  68 , each of which has a tab  69  at its end, to be bent upward approximately at right angles along a line indicated by dashes  70  in FIG.  5 . These tabs, as seen in FIG. 2, provide a mounting for the strap assembly  24  which extends over the user&#39;s boot after the user steps into the snowshoe with the crampon. The strap assembly  24  is adjustable, and preferably has a ratchet-type buckle known as a ladder lock buckle, of the type that tightens a strap by one or more notches in a rack of notches with each pivot stroke of a buckle lever, and which allows easy release by lifting the lever to a full-back position. 
     FIG. 4, a bottom view of the snowshoe with the crampon attached, illustrates the engagement of the front end of the crampon with the snowshoe&#39;s harness assembly, and particularly with the harness plate  38 . FIG. 4 reveals that the side protrusion  46  at each side of the crampon has been closely engaged within the clearance  42  at each side of the mounting plate  38 . Also, the drawing shows the other pairs of teeth  62  and  64  as residing in the side clearances  61  and  66  of the harness plate. In this position the frame or deck  50  of the crampon is against the upper surface of the harness plate  38 . The crampon teeth generally surround the plate  38 , by which is meant that teeth extend down alongside the plate at least at front and sides. 
     As can be appreciated from FIG. 4, the act of stepping into the front harness of the snowshoe with the crampon teeth  40  engaging as discussed above and shown in the drawings, locates the crampon precisely relative to the harness assembly and the snowshoe, establishing proper rotational orientation between the crampon and the snowshoe, such that the snowshoe is firmly secured to the crampon against left or right rotation. For this purpose, as shown in FIG.  5  and also seen in FIG. 4, the mounting and registry plate  38  has angled surfaces  72  just aft of the tips  44 , so that when the crampon teeth are inserted into and under the tips  44 , these obliquely angled surfaces  72  guide the crampon into the precise position, particularly when the heel is rotated down to closely engage the crampon&#39;s side protrusions in the clearances  42 . 
     FIGS. 7-12 show another form of terrain-engaging cleat or crampon  80  which can be used on a boot for enhancing traction such as in icy or semi-icy conditions, or in combination with a snowshoe wherein the device  80  provides a cleat for the snowshoe, as illustrated. 
     FIG. 7 shows a cleat plate or base plate  82  which is a principal component of the terrain-engaging cleat or crampon  80  shown in FIG.  8 . The base  82  has a generally flat platform  84 , a pair of front end teeth  86  integrally formed with and extending downwardly/forwardly from the platform  84 , and further pairs of teeth  88  and  90 . The two teeth  88  are angled teeth in this preferred embodiment, just aft of the two frontal teeth  86  as shown. The angled teeth  88  are angled relative to the forward/aft direction of movement of the crampon and relative to the transverse direction of the cleat device  82 . Thus, these teeth  88  provide traction for the crampon in both the forward/back directions and in lateral directions. 
     The additional teeth  90  are side teeth, further aft on the crampon or terrain-engaging cleat. The base member also preferably includes a tail extension  92 , defining a rear attachment point  94  for a part of the harness assembly  96  shown in FIG.  8 . 
     The cleat base  82  in a preferred embodiment is formed as a stainless steel stamping. As shown, the teeth  86 ,  88  and  90  bend downwardly from edges of the platform  84 , in bends  98 ,  100  and  102 . Each of these bends may include a stiffener pleat  104 , comprising an indentation formed into the metal for stiffening the teeth at each of these bends. Stiffener pleats are also shown at  105  in the platform  84 . 
     The frontal teeth  86  are tapered, generally triangular as shown and are angled down about 45° in the embodiment shown. This angle preferably is between about 40° and 50°, or more broadly, between about 35° and 55°. 
     FIG. 7 also shows various holes through the deck or platform portion of the stamping  82 , four of which identified as  106  are used for attaching a footbed  110  and the harness assembly  96  to the base  82 . This can be a contoured footbed as in U.S. Pat. No. 5,687,491. 
     As also seen in FIGS. 7 and 8, each of the angled teeth  88  and the side teeth  90  comprises a relatively narrow neck  112 , which extends from the platform  84  down through the bend  102 , into a flat area  113 ,  114  of the tooth, substantially wider than the neck portion. The flat face area  113 ,  114  of the tooth, with its larger width, provides good gripping traction in penetrable terrain. As seen in the drawings, the maximum width of this flat face area, in each tooth  88  and  90 , preferably is at least 50% wider than the narrower neck  112 . 
     The drawings also show that each tooth  88 ,  90  defines a point  116  at its bottom, for engaging ice when encountered. Importantly, these ice points  116  are substantially directly beneath the stiffener pleats  104 , so that if the terrain-engaging device  80  is used on rigid ice, the stress of supporting the weight of the user through the bends  100 ,  102  in the base portion is efficiently resisted by the stiffeners. 
     The assembled terrain-engaging cleat device or crampon  80  as shown in FIG. 8 has a harness assembly  96  which can be similar to those produced by Atlas Snow-Shoe Company and incorporated as the front harness assembly of a snowshoe, such as on Atlas Models Nos. 1022 and 1033. The harness includes a web which has a central, bottom section or harness shell  120  that is secured to the metal platform  84 , preferably being positioned beneath the platform  84  as shown. With reference to all of FIGS. 7-12, this harness  96  has forward harness legs  122  and rear harness legs  124  extending up and outwardly from the harness shell  120 , as shown. These discrete legs of the harness web are positioned to extend over the ball of the foot, or essentially between the toe area and the ball area, with the legs  122 ; and from the arch area or slightly forward of the arch area, over the top of the foot generally as seen in FIG.  9 . Straps  126 ,  127  extend between the webs to closely retain the web and the crampon device  80  on the foot. These straps  126  and  127 , in a preferred embodiment, can comprise a single strap connected in a “Z” type arrangement as described in copending application Ser. No. 10,199, filed Jan. 21, 1998 and incorporated herein by reference. As in that copending application, the strap arrangement employed in the crampon device  80  provides for easy adjustment and quick and easy attachment of the crampon or cleat device  80  to the shoe or boot. 
     In addition, there is preferably included a heel strap  130  for increased stability and torsion resistance, this strap preferably extending from rear extensions  132  of the harness web  96 . 
     As seen in the drawings, the tail extension  92  and rear attachment point  94  of the main base member  82  (FIG. 7) is important in providing an attachment point as far back on the crampon device  80  as needed for good binding and stability. That rear attachment point  94  is located in the arch area of the boot, slightly forward of the heel, as can be seen in FIG.  9 . 
     As indicated in the drawings, the footbed  110  can be secured to the base member  82  by rivets  134 , but also by gluing. The rivets  134  also serve to secure the harness shell  120  to the platform  84  of the metal base member  82 . 
     FIG. 9 shows the user&#39;s shoe or boot  136 , wearing the crampon device  80  of the invention, and also engaged in a snowshoe  140 . As also seen in FIG. 10, the snowshoe has decking  142  which preferably includes a rear cleat at  144  (the cleat actually extends below the decking), and the snowshoe has a front boot binding assembly  146  that includes a registry plate  148  for the crampon, which may be supported on tensioned straps  150  that afford a biased pivoting movement of the toe, and which includes a single strap  152  for extending over the top of the foot area of the boot, but which does not include a front cleat. See also FIGS. 11A-12. The terrain-engaging cleat or crampon  80  of the invention supplies the front cleat, since the teeth  86 ,  88  and  90  extend down and around the registry plate  148 . This is similar to the registry of the front portion  54  of the full-foot crampon  22  into a snowshoe in the earlier described embodiment. 
     FIGS. 9-12 show one form of registry plate  148  for use with the crampon device  80  in this embodiment of the invention. FIGS. 13-15 show alternatives, described below. The registry plate  148  has a front bar  155  which extends across a forward end  156  of the plate and has extending tips  158  at left and right. These, as seen in FIGS. 9 and 12, are to be engaged between back sides of the front end teeth  86  and forward edges  159  of the angled teeth  88  that serve as protrusions similar to the protrusions  46  in FIGS. 3 and 4. Since the teeth  88  themselves are angled preferably downwardly and outwardly at an angle relative to the lateral and straight-ahead directions, this inclined forward edge  159  has a forward component to its orientation, so that when the front bar  155  is in place under the crampon, with the tips  158  between the teeth  86  and the inclined edges  159 , the crampon cannot be lifted straight up at its front end, being confined by the front bar  155  interacting with the inclined edge  159 . Thus, when the user wearing the crampon device  80  steps into the snowshoe, this must be done with the toe tipped downwardly, until the frontal bar  155  of the registry plate is correctly in position between the teeth  86  and the teeth  88 . At that point, the user can pivot the foot downwardly onto the plate, then attach a pair of straps  161  to the harness via securing hooks  163 , as seen particularly in FIGS. 8,  9  and  10 . This is one preferred system for holding the boot down against the plate. The straps  161  can be of an elastic polymer that flexes somewhat but exerts enough force to keep the boot against the plate. By this arrangement the user can conveniently pull up on the two straps  161  and hook them on the hooks  163 , avoiding additional straps over the top of the foot. 
     The registry plate  148  shown in FIGS. 11A and 11B, as well as in FIGS. 9,  10  and  12 , has side stabilizers formed as projections  160  on each side, somewhat aft of the middle of the plate. These are bent downwardly (FIGS. 11B and 12) and positioned to engage against inner sides of the side teeth  90 , and they are preferably located so as to engage between the stiffener pleats  104  on the base cleat device  82  shown in FIG.  7 . When the user engages the front bar  155  in place, with the toe of the boot and crampon tipped down, and positions the front bar correctly between the crampon teeth  86  and  88 , then rotates the foot downwardly, these side stabilizers  160  then engage inside surfaces of the teeth  90  to lock the cleat in place on the registry plate  148 . 
     From FIGS.  10  and  11 A-B can be seen one preferred method of securement of the registry plate  148  to the snowshoe. The plate has holes  164  through which rivets pass to secure the plate to the snowshoe&#39;s tensioned front straps  150 , as in FIG.  10 . The tensioned straps  150  in this embodiment are spaced apart sufficiently to allow the side teeth  90  of the crampon device (FIGS. 7 and 8) to pass down between the straps, one such tooth at each side of the registry plate  148 . This is best seen in the bottom view of FIG. 12, which also reveals the side stabilizers  160  as engaging against inside surfaces of the side teeth  190 . This tight engagement is made as the wearer rotates the cleat down onto the registry plate  148 . 
     FIGS. 13-15 show alternative configurations of registry plates  170 ,  180  and  190 . In FIGS. 13 and 13A, the registry plate  170  is quite similar to the plate  148 , except at the front end. There, a front finger  172  extends forwardly and is formed into a somewhat downwardly dipping hook, in position to be engaged in a V notch  173  between the front teeth  86  of the crampon, as seen particularly in FIG.  7 . This helps the user place the crampon correctly on the registry plate, since the registry plate is not visible beneath the foot and boot. With the central hooked finger  172  extending forward as a tactile guide, the user can feel it between the frontal crampon teeth  86 , in the notch  173 , then step down with the toe, causing the hooked finger  122  to shift the cleat&#39;s frontal teeth  86  left or right as needed and back against the front to position the front of the cleat correctly. Again, side stabilizers  160  center the aft parts of the cleat or crampon by engagement between the structure of the side teeth  90  as the foot is rotated down. Although not shown in FIGS. 13A-13B, the plate  170  can have a front bar similar to the front bar  155  of FIGS. 11-12, in addition to the hook  172 . 
     FIGS. 14A-B again show a registry plate  180  which is similar to the plates  148  and  170 , except at the front end. Here, a slot  182  is formed by front end structure  184 , and this slot is positioned to receive the frontal crampon teeth  86 . Again, this gives a tactile indicator for the user to locate the front of the pleat or crampon correctly, prior to rotating the arch of the foot downwardly to engage the crampon with the outboard side stabilizers  160 . In this case, the user again preferably tips the crampon down slightly, to best insert the frontal teeth  86  down through the slot  182 , prior to rotating the arch downward. As indicated, the front end structure  184  on this plate  180  preferably is angled upwardly somewhat, to better catch the frontal teeth  86 . If the user is off-center with the crampon, the tapered outside edges of the teeth guide the crampon to the correct position. 
     FIGS. 15A-B show a registry plate  190  which is again similar to the other plates described above in many respects. At the front of the registry plate  190  is a tapering frontal apex  192  with a raised disk  194  similar to a rivet head, spaced upwardly by a narrow neck  195  from the surface of the frontal apex  192 . The frontal apex  192  is angled downwardly from a bend  193 . Again, a tactile indicator is provided for the user in placing the toe end of the cleat or crampon  80  correctly. The frontal teeth  86  of the crampon are moved downwardly and forwardly against the neck of the rivet head or locator disk  194 , such that the neck  195  of the disk becomes positioned in the V notch  173  between the frontal teeth  86 . As in the last described embodiment, even if the user holds the foot laterally left or right to some extent, the downward engagement of the frontal teeth  86  will become self-centering of the crampon relative to the registry plate  190 . 
     FIG. 16 shows another embodiment of a terrain engaging cleat or crampon  200  according to the invention. This cleat or crampon  200  is similar in many respects to the previously described crampon  80 , but employs a different cleat base  202 , not specifically designed to engage with a snowshoe. The simpler cleat base  202  has a rack of front teeth  204 , positioned at the bottom of a downwardly/forwardly angled frontal bend  206 , and has a pair of side teeth  208 . Its harness  210  may be essentially the same as described previously, but in this embodiment the crampon omits the tail extension  92  (FIG. 7) of the earlier embodiment, thus providing a less bulky terrain-engaging cleat or crampon. The crampon device  200  includes a rear strap  210  for extending around the back of the user&#39;s boot or shoe. Again, a footbed  212 , which may be a flexible, rubbery footbed and which may be contoured as in U.S. Pat. No. 5,687,491, is secured down to the platform of the cleat base  202 . 
     The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to this preferred embodiment will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention.