ALPINE TOURING BINDING TOE UNIT

Abstract

This disclosure pertains to a toe unit for engaging a footwear toe of a footwear to releasably fasten the footwear toe to a snow travel aid. The toe unit comprises: a base for mounting on the snow travel aid; a slider slidably mounted on the base, the slider operably configured to resiliently slide laterally upon the base and away from a central position in response to a lateral force; opposable jaws mounted on the slider, wherein the jaws are moveable between an open and a closed position to releasably engage respective sides of the footwear toe in the closed position in order to fasten the footwear toe to the snow travel aid and to permit pivotal movement of the footwear about an axis intersecting the jaws. The opposable jaws are operable to move from the closed position to the open position independent of displacement of the slider from the central position in response to torque generated by rotation of the footwear about the footwear toe.

Claims

1. A toe unit for engaging a footwear toe of a footwear to releasably fasten the footwear toe to a snow travel aid, the toe unit comprising: a base for mounting on the snow travel aid; a slider slidably mounted on the base, the slider operably configured to resiliently slide laterally upon the base and away from a central position in response to a lateral force; opposable jaws mounted on the slider, wherein the jaws are moveable between an open and a closed position to releasably engage respective sides of the footwear toe in the closed position in order to fasten the footwear toe to the snow travel aid and to permit pivotal movement of the footwear about an axis intersecting the jaws; wherein opposable jaws are operably configured to move from the closed position to the open position in response to torque generated by rotation of the footwear about the footwear toe and independent of displacement of the slider from the central position.

2. The toe unit of claim 1, wherein the slider is operably configured to slide laterally upon the base and away from the central position along an arc curving rearward and having an apex at the central position.

3. The toe unit of claim 1, comprising slider biasing means for biasing the slider toward the central position in response to the lateral force.

4. The toe unit of claim 3, wherein the slider biasing means comprises a positioner, the positioner comprising one or more resilient members positioned in the base generally perpendicular to a forward face of the slider.

5. The toe unit of claim 4, wherein the one or more resilient members comprises one or more compression springs.

6. The toe unit of claim 4, wherein the positioner comprises a positioner follower connected to the one or more resilient members for engaging a forward cam surface on a forward face of the slider to bias the slider toward the central position.

7. The toe unit of claim 6, wherein the forward face of the slider comprises a forward face recession comprising the forward cam surface, the forward face recession operably configured to receive the positioner follower.

8. The toe unit of claim 7, wherein the positioner follower comprises a positioner follower end operably configured for reception in the forward face recession, the positioner follower end having a shape complementary to the shape of the forward face recession.

9. The toe unit of claim 4, wherein the one or more resilient elements is adjustable to adjust the force necessary to displace the slider from the central position.

10. The toe unit of claim 1, wherein the base comprises one or more lateral limiters for limiting a maximum displacement of the slider from the central position.

11. The toe unit of claim 10, wherein the one or more lateral limiters comprise opposing stoppers configured to abut the slider to limit lateral movement.

12. The toe unit of claim 1, further comprising a displacement indicator operably configured to indicate an extent of lateral displacement of the slider from the central position, wherein the displacement indicator comprises an indicator follower moveable along a longitudinal axis, and the slider comprises a rear face comprising a rear cam surface operably configured to engage a first end of the indicator follower, wherein the indicator follower is moveable from a first position proximal to the rear cam surface toward a second position distal to the rear cam surface in response to lateral movement of the slider to indicate the extent of lateral displacement of the slider from the central position.

13. The toe unit of claim 12, wherein the rear face comprises a rear face recession comprising the rear cam surface, the rear face recession operably configured to receive the first end of the indicator follower.

14. The toe unit of claim 12, wherein the displacement indicator is marked at regular intervals to facilitate quantification of slider displacement from the central position.

15. A heel unit and toe unit system for engaging a footwear to releasably fasten the footwear to a snow travel aid, the system comprising: a toe unit as defined in claim 1; and a heel unit comprising a rotating heel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

[0016] FIG. 1A is a side view of a ski, ski boot and a prior art tech binding system for alpine touring comprising toe and heel units, in downhill mode.

[0017] FIG. 1B is a side top view of the ski, ski boot and prior art tech binding system for alpine touring comprising toe and heel units shown in FIG. 1A, in downhill mode.

[0018] FIG. 2A is a side view showing the combination illustrated in FIGS. 1A and 1B in touring mode.

[0019] FIG. 2B is a top view showing the combination illustrated in FIGS. 1A and 1B in touring mode.

[0020] FIG. 3 is a perspective view of a tech binding toe unit according to an embodiment of the invention.

[0021] FIG. 4 is an exploded view of components of the toe unit according to the embodiment featured in FIG. 3.

[0022] FIG. 5 is top cross-sectional view of the toe unit according to the embodiment featured in FIG. 3 showing features of the positioner and the displacement indicator.

[0023] FIG. 6 is perspective view of the toe unit according to the embodiment featured in FIG. 3 showing features of the positioner.

[0024] FIG. 7 is perspective view of the toe unit according to the embodiment featured in FIG. 3 showing features of the displacement indicator.

Definitions

[0025] The term snow travel aid as contemplated herein are devices that support a user and are adapted to slide on a snow surface. They have a longitudinal axis which generally corresponds to the direction of travel. Examples include skis, and other snow sliding devices similar in shape to a ski. This includes devices known as split-boards (which are snowboards that can be separated longitudinally into at least two portions, the two portions then functioning in a manner similar to a pair of skis). Examples of such other such devices include ski blades, snow blades, ski boards, and sliding or gliding snowshoes.

[0026] The term footwear herein typically means a boot such as a ski boot with a sole extending between a toe and a heel.

[0027] The term resilient element herein refers to an element that when pre-loaded by a compression or tension force, exerts a biasing force on an object or objects that are in contact or are coupled to the resilient element. The biasing force is opposite in direction to the pre-load force. Thus, a resilient element may be elastic or compressible and in either case, may comprise a spring or spring set.

[0028] Unless otherwise clear, terms herein such as vertical, upward, and downward are relative to where the upper surface of a snow travel aid would be when the heel unit is mounted thereon. Other terms such as above, below, lowered and beneath refer to relative positions of objects but unless otherwise clear, the overall context is always the proper orientation of such objects relative to a snow travel aid upper surface. Unless otherwise clear, the context of terms herein such as transverse, horizontal, side, front, in front, forward(ly), rear, rearward(ly) and behind is the proper orientation of footwear and the heel unit relative to the longitudinal axis or direction of travel of the snow travel aid. Thus, with regard to components of a heel unit, the term forward (or front) relates to a direction towards the footwear and rearward (or rear) relates to the opposite direction. However, unless accompanied by precise terminology, the aforementioned terms as well as terms such as longitudinal,parallel and perpendicular shall be construed as being qualified by the word generally and are not to be considered absolute. For example, while the terms forward (or front) and rearward (or rear) relate to a direction along or parallel to the longitudinal axis of a snow travel aid, they would also refer to any direction that is at an angle of less than 45 degrees to the longitudinal axis.

[0029] In this specification, reference to generally vertical is intended to indicate a general direction upwards or downwards from a reference but does not require perpendicularity to such reference. Conversely, the term generally horizontal would include directions that are perpendicular to those which are generally vertical but are not limited to situations involving a line or a plane parallel to the reference. The latter two terms also include lines or planes that are curved relative to the reference and extend in generally vertical or horizontal directions from the reference. In addition, the terms generally horizontal and generally parallel include lines or planes that are parallel to a reference as well as those which form an angle of less than 45 degrees with the reference or which are curved and follow a direction that is generally parallel to the reference. The term generally perpendicular is not limited to a 90 degree orientation but includes orientations that form an angle to a reference of greater than 45 degrees and less than 135 degrees. The term generally spherical includes any shape comprising one or more portions of a surface of a sphere.

DETAILED DESCRIPTION

[0030] FIGS. 1A and 1B show a prior art binding system, including a tech binding toe unit 4 and tech binding heel unit 10 mounted on the upper surface of ski 1. The toe unit is an example of one which is configured to releasably secure a footwear toe on a snow travel aid and to permit pivotal movement of the footwear about a transverse axis at the toe unit, when walking. The toe unit comprises jaws 5 that pivot to engage pins with cavities in special fittings (not shown) embedded in opposite sides of the toe of ski boot 2. Body 6 of the heel unit contains forward connectors, which as illustrated are a pair of pins 8 that engage cavities in the most rearward surface of the boot heel 3. The heel unit also comprises a base 7 which supports the body and is fixed to the ski surface by multiple fasteners 9.

[0031] The arrangement shown in FIGS. 1A and 1B is the downhill mode with both the toe and heel of the boot engaged by the binding system. It should be noted that pins 8 are visible in the downhill mode in a gap between boot heel 3 and a forward surface of body 6. The area on the boot heel indicated by reference numeral 3 is a ledge that is common to many ski boots and is the normal location where the heel retainer of an alpine downhill binding would press down on the boot heel to hold the heel against a ski.

[0032] FIGS. 2A and 2B show the prior art Tech-type binding system in touring mode. The toe of the boot remains engaged to toe unit 4 which permits pivotal movement of the footwear about a transverse axis at the toe unit when walking. The heel is free to move up and down relative to the ski because body 6 of the heel unit has been rotated relative to base 7 so that the pins 8 face away from the boot heel.

Lateral Movement of Jaws on Slider

[0033] Referring to FIG. 3 to FIG. 7, a tech binding toe unit according to one embodiment of the disclosure is shown generally at 100. Toe unit 100 includes a base 102 for mounting the toe unit on the top surface of a snow travel aid (now shown). The toe unit further includes a slider 104 mounted on the base. Slider 104 is operably configured to slide laterally upon base 102 and away from a central resting position (i.e. at a longitudinal midline of the toe piece) on a path generally along a transverse axis. In the presently illustrated embodiment, base 102 comprises a track 106 for receiving slider 104 therein, wherein the slider is slidable laterally upon the base in the track within a sliding zone (i.e. the operable range of lateral movement of the slider on the base). In the presently illustrated embodiment, track 106 effectively defines the path along which slider 104 may move. As discussed in more detail below, slider 104 is operably configured to resiliently slide away from the central position along the path in response to the lateral force. That is, slider 104 is biased to return to the central resting position upon later displacement.

[0034] In various embodiments, the path along which the slider is slidable is an arc-shaped path that curves rearward with its apex at the central position.

[0035] Toe unit 100 further comprises opposable jaws 108 mounted on slider 104. Opposable jaws 108 are moveable between an open position, in which a toe of a footwear can be positioned between the jaws, and a closed position in which the jaws rotatably engage respective sides of the toe of the footwear. In this way, the jaws are able to cooperate to releasably engage the respective sides of the toe of the footwear to fasten it to the snow travel aid and permit rotation of the toe relative to the toe unit about a transverse axis when in touring mode.

[0036] In the presently illustrated embodiment, opposable jaws 108 include opposable pins 110 for reception in respective cavities (not shown) on opposite sides of the toe of the footwear. This permits the footwear to rotate on the pins about the transverse axis when the heel of the footwear is not secured to the snow travel aid by a heel unit (i.e. when the toe and heel assembly are in walk mode).

[0037] In the presently illustrated embodiment, opposable jaws 108 are each rotatably mounted on slider 104 about a longitudinal axis that is parallel to the longitudinal axis of the snow travel aid. In the presently illustrated embodiment, each jaw 108 is rotatably coupled to slider 104 between a respective pair of slider shoulders 112 on the lateral ends of slider 104 by a jaw pivot 114 (e.g. a pin or a bolt).

[0038] The jaws 108 of the presently illustrated embodiment use an over-center mechanism as is well known to a skilled person to retain the jaws in either an open or a closed position. Jaws 108 are pivotally coupled to each other via respective cooperating jaw couplers 116 that connect generally at a midline between the jaws. Respective jaw couplers 116 may be connected by a coupler pivot. For example, respective cooperating jaw couplers may have complementary hinge portions, and the coupler pivot may include a pin extending through the complementary hinge portions. Alternatively, respective jaw couplers may be connected by a living hinge, in which case the respective couplings may be formed together as a single integral unit. Yet alternatively, one of the cooperating jaw couplers may comprise a sleeve for receiving a complementary end of its respective cooperating jaw coupler.

[0039] Each jaw 108 is connected to its respective jaw coupler 116 via one or more resilient elements 118 operably configured to resist compression. Resilient elements 118 may comprise any number or type of springs (e.g., coil springs) and their equivalents (e.g., elastic bands).

[0040] In each of the open and closed positions, jaw couplers 116 are coupled in an over-center position, such that the resilient elements 118 bias the jaws towards either the fully opened or the fully closed positions. As toe unit 100 moves between the open and closed position, resilient elements 118 are compressed, and reach a maximum compression when couplers 116 are in a center position. Once couplers 116 have moved beyond the center position (i.e. over-center), resilient elements 118 expand to apply a force to jaws 108 to rotate them about jaw pivots 114 to either fully open or fully close the jaws as the case may be.

[0041] Starting in an open position where jaw couplers 116 are above the center position, a user of the snow travel aid may place the toe of the footwear between open jaws 108 and step down over jaw couplers 116. The force of stepping down moves jaw couplers 116 toward the center position and compresses the resilient elements 118. When jaw couplers 116 pass over-center, resilient elements 118 expand to apply a force to jaws 108 to rotate them upward about jaw pivots 114 and into the closed position where they are held firmly. To open jaws 108 while the snow travel aid is in motion, a sufficient force must be applied to jaws, i.e. either a lateral force imparted by lateral movement of the toe or a torsional force imparted by rotation of the footwear about the toe (e.g. upon release of the heel from the heel unit), to rotate the jaws downward to move jaw couplers 116 toward the center position and compress resilient elements 118. When jaw couplers 116 pass over-center, resilient elements 118 expand again to apply a force to jaw couplers 116 to move them upward to put the toe unit in the open position where it is held firmly.

[0042] As illustrated in the current embodiment, toe unit 100 may include a control lever 120 pivotally connected to a fulcrum 122 on base 102 located forward of jaws 108 and slider 104. Control lever 120 is coupled to jaw couplers 116 by control lever coupling 124. Control lever 120 further comprises an actuator 126 located forward of fulcrum 122. When toe unit 100 is in the closed position, a downward force may be applied to actuator 126 to rotate control lever 120 to apply an upward force to jaw couplers 116 to move them upward toward the center position. This in turn causes jaws 108 to rotate downward toward the open position. Movement of jaw couplers 116 toward the center position also compresses resilient elements 118. When jaw couplers 116 pass over-center, resilient elements 118 expand to apply a force to jaw couplers 116 to move them upward to put the toe unit in the open position and hold it there firmly.

[0043] When toe unit 100 is in the closed position, control lever 120 can also be locked to prevent rotation of the control lever which, in turn, precludes movement of jaw couplers 116 toward the center position regardless of any lateral or torsion forces applied to jaws 108 by the toe of the footwear.

Slider Positioning

[0044] As indicated previously, movement of the slider according to embodiments of the present disclosure is biased toward a central resting position. As illustrated in FIG. 4 to FIG. 6, toe unit 100 further comprises slider-biasing means for biasing slider 104 toward the central resting position in response to lateral forces that work to displace the slider from said central resting position. In various embodiments, the slider-biasing means comprise a positioner that is operably configured to bias the slider toward the central resting position in opposition to the lateral forces that displace the slider from the central position.

[0045] Referring to FIG. 4 and FIG. 5, a positioner for biasing the slider toward the central position is shown generally at 128. Positioner 128 comprises a positioner follower 130 disposed within a positioner channel 132 in base 102 located frontward of slider 104 along a longitudinal axis that intersects the central resting position. Positioner follower 130 is resiliently moveable in channel 132 along the longitudinal axis in response to lateral movement of slider 104. More particularly, positioner follower 130 comprises a first follower end 133 proximal to slider 104 and having positioner follower faces 134 operably configured to contact slider 104 in a recession 136 on a front face 138 of the slider. Recession 136 is shaped such that the recession surfaces 140 of the slider within the recession are configured to operate as cam surfaces in contact with positioner follower faces 134 of positioner follower 130. Thus, the front face of slider 104 functions as a wedge cam that translates lateral movement of slider 104 into linear movement of positioner follower 130 within positioner channel 132.

[0046] The recession (i.e. providing the cam surface(s)) may have a shape that is complementary to the shape of the end of the positioner follower with which it makes contact. In the presently described embodiment, the first positioner follower end 133 has a generally triangular shape that is received within complementary-shaped recession 136 in front face 138 of slider 104 providing cam surfaces 140.

[0047] Starting from the central resting position in which first positioner follower end 133 is positioned at the rearward extremity of recession 136 in which positioner follower faces 134 are both in contact with respective cam surfaces 140, lateral movement of slider 104 in track 106 applies a force to positioner follower 130 to move it forward in channel 132.

[0048] As indicated above, positioner follower 130 is resiliently movable in channel 132 in response to lateral movement of slider 104. Positioner 128 further comprises at least one resilient positioner element connected to second positioner follower end 135 of positioner follower 130 that is distal to slider 104. The at least one resilient positioner element is operably configured to resist compression so as to resist forward movement of positioner follower 130 in positioner channel 132. The at least one resilient positioner element is intended to be pre-loaded under compression to provide a biasing force that permits, but resists, forward movement of positioner follower 130 in positioner channel 132.

[0049] Referring to FIG. 5 and FIG. 6, in the presently illustrated embodiment, the at least one resilient positioner element comprises two parallel positioner springs 142 contacting second positioner follower end 135 of positioner follower 130. In the illustrated embodiment, positioner springs 142 may be compression springs. Second positioner follower end 135 comprises opposing follower pegs 144 for reception within first positioner spring ends 146. Positioner 128 further comprises an adjuster screw 148 extending through forward opening 150 in base 102 for adjusting the pre-load on positioner springs 142. More particularly, adjuster screw 148 cooperates with a base plate 152 or shim located between the adjuster screw and positioner springs 142 to preload the positioner springs. In the present embodiment, base plate 152 comprises opposing base plate pegs 154 operably configured to be received in respective second positioner spring ends 156 of positioner springs 142 that are distal to slider 104.

[0050] In operation, when preloaded under compression, positioner springs 142 urge positioner follower 130 rearward to cause positioner follower face 134 to press against cam surface(s) 140 to resist lateral displacement of slider 104 from the central resting position in track 106.

[0051] Thus, starting from the central resting position in which first positioner follower end 133 is positioned at the rearward extremity of recession 136 in which positioner follower face 134 is in contact with both cam surfaces 140, lateral displacement of slider 104 in track 106 may apply a force to positioner follower 130 that is sufficient to exceed the resistive force applied to the positioner follower by positioner springs 142 to move the positioner follower forward in positioner channel 132 and compress positioner springs. As the lateral force displacing slider 104 from the central resting position subsides, positioner springs 142 expand to press first positioner follower end against one or the other front cam surface 140 to urge the slider back toward the central resting position in track 106.

[0052] Again, the resistance provided by the positioner springs is user-adjustable by means of the adjuster screw 148 and provides for variable levels of resistance to displacement of the slider from the central resting position. Thus, a user of the snow travel aid can tune the resistance of the positioner to displacement depending on their weight or the amount of energy that they wish for the toe piece to absorb. Thus, the user can tune the slider positioner as they prefer to improve the feel of their binding.

[0053] In the presently illustrated embodiment, the at least one resilient positioner element comprises a pair of springs. However, the skilled person understands that the at least one resilient positioner element could comprise a number or type of springs (e.g., coil springs) and their equivalents (e.g., elastic bands).

[0054] The skilled person further understands that while the slide positioner in the illustrated embodiment is positioned forward of the slider 104, the positioner could be positioned rearward of the jaws with the positioner follower operably configured to extend forward to contact a cam surface on a rear face of the slider.

[0055] The skilled person further understands that, while the positioner in the illustrated embodiment is located in a central position of the toe unit, the positioner could be positioned off-center. The skilled person yet further understands that while the illustrated embodiment includes a single slide positioner, multiple slide positioners could be used, e.g. in parallel.

Slider Displacement Limitation

[0056] Referring again to FIG. 5, the toe unit according to the present disclosure may also include means for limiting the maximum displacement of the slider from the central position (thereby defining the sliding zone). Such means may include one or more displacement limiters. In the presently illustrated embodiment, base 102 comprises a pair of opposing displacement limiters, i.e. opposing stoppers 160, positioned at least partially in track 106 on the rearward side of the track to abut a portion of slider 104 to stop its lateral displacement along the path. In this embodiment, slider 104 comprises necks 162 extending rearward to contact a rearward wall 164 of track 106. Stoppers 160 are operably configured to abut respective lateral sides 166 of necks 162 to stop the lateral movement of slider 104.

[0057] While the presently illustrated embodiment features multiple stoppers positioned at least partially in the track external to the slider, the skilled person understands that several possibilities exist for displacement limiters. For example, the displacement limiter could feature one or more stoppers received within respective internal slots formed within the slider along the axis of lateral displacement. Alternatively, the displacement limiter could feature a single stopper positioned in the central position on the rearward side of the track and operable to abut opposing necks extending rearward from the slider to contact the rearward wall of the track.

[0058] The skilled person further understands that while the stoppers in the illustrated embodiment are positioned on a rearward side of track 106, the toe unit could be designed with the stoppers positioned on a forward side of the track.

Slider Displacement Indication

[0059] Aspects of the disclosure further relate to means for indicating the extent of magnitude of lateral displacement of the slider from the central resting position. Referring again to FIG. 5, the illustrated toe piece 100 further comprises a displacement indicator shown generally at 170. Displacement indicator 170 comprises an indicator follower 172 disposed within an indicator channel 174 in base 102 that extends rearward along a longitudinal axis from a rear wall opening 176 in the rear wall 164 of track 106 through to a rear base opening 178 in rear wall 180 of the base 102. Indicator follower 172 is moveable in indicator channel 174 along the longitudinal axis in response to lateral movement of slider 104. More particularly, indicator follower 172 comprises a first indicator follower end 182 proximal to the rear side of slider 104 and having indicator follower faces 184 operably configured to contact slider 104 in an indicator recession 186 on the rear side of the slider. Indicator recession 186 is shaped such that indicator recession surfaces 188 of the slider 104 within the indicator recession are configured to operate as a cam surface in contact with indicator follower faces 184. Thus, the rear face of slider 104 acts as a wedge cam that translates lateral movement of the slider into linear movement of indicator follower 172 within indicator channel 174.

[0060] The indicator recession (i.e. providing the indicator recession surface) may have a shape that is complementary to the shape of the first indicator follower end 182. In the presently described embodiment, the first indicator follower end 182 has a generally triangular shape that is received within a complementary-shaped indicator recession 186 in the rear side of the slider providing cam surfaces 188.

[0061] Starting from a displacement indicator resting position in which first indicator follower end 182 is positioned at the frontward extremity of indicator recession 186 wherein indicator follower faces 184 are both in contact with respective indicator recession surfaces 188, lateral movement of slider 104 in track 106 applies a force to first indicator follower end 182 to move indicator follower 172 rearward in indicator channel 174. The distance that indicator follower 172 moves rearward in indicator channel 174 depends on the magnitude of lateral displacement of slider 104 from the central resting position on base 102. Indicator follower 172 is operably configured to extend through rear base opening 178 to provide an indication of the magnitude of lateral displacement of the slider 104 from the central resting position. Referring to FIG. 7, indicator follower 172 may include regularly spaced markings 192 toward second indicator follower end 194 that function as a ruler to quantify the displacement of slider 104 from the central resting position.

[0062] In the illustrated embodiment, indicator follower 172 is not resiliently movable in indicator channel 174 in response to lateral movement of slider 104. Rather, indicator follower 172, once moved rearward in indicator channel 174, will remain in a particular position until it is either moved further rearward in response to a greater magnitude of displacement of slider 104 from the central position, or it is manually returned to the resting position by the user (e.g. by applying a force to the indicator follower at second indicator follower end 194 to move it back through indicator channel 174 toward the displacement indicator rest position).

[0063] Accordingly, the skilled person understands that the distance that indicator follower 172 has moved within channel 174 from the displacement indicator rest position is indicative of a maximum displacement of slider 104 from the central resting position while the snow travel aid has been moving (i.e. between successive returns of indicator follower 172 to the displacement indicator resting position by a user).

[0064] Thus, the displacement indicator allows a user to observe the magnitude of lateral displacement of the slider from the central position while using the snow travel aid and, if desired, to adjust the tension on the slider positioner. For example, the displacement indicator may be operably configured to indicate whether the slider has been displaced to the limits of the sliding zone (e.g. lateral displacement has been stopped by the stoppers). In such case, the user may wish to increase the tension on the slider positioner to maintain displacement of the slider within the sliding zone.

[0065] While the illustrated embodiment provides the displacement indicator in a position at the rear of the toe unit, such that it is under the toe of the footwear when the travel aid is in use, the skilled person understands that the displacement indicator could be positioned forward of the slider and jaws with the indicator follower configured to extend rearward to contact a cam surface(s) on a forward face of the slider. This might allow the user to observe the magnitude of lateral displacement of the slider while the snow travel aid is in use and/or without removal of the footwear from the snow travel aid. The skilled person further understands that while the displacement indicator in the illustrated embodiment is located in a central position of the toe unit, it could be positioned off-center.

[0066] While the presently described displacement indicator has been illustrated in combination with the specifically described combination of slider, jaws, and slider positioner (i.e. in which movement of the jaws from the open to the closed position is not dependent on displacement of the slider from the central position), the skilled person will readily appreciate that the presently described means of indicating lateral displacement of a slider could be more generally used in combination with other toe units employing laterally moveable sliders.

EMBODIMENTS

[0067] 1. A toe unit for engaging a footwear toe of a footwear to releasably fasten the footwear toe to a snow travel aid, the toe unit comprising: a base for mounting on the snow travel aid; a slider slidably mounted on the base, the slider operably configured to resiliently slide laterally upon the base and away from a central position in response to a lateral force; opposable jaws mounted on the slider, wherein the jaws are moveable between an open and a closed position to releasably engage respective sides of the footwear toe in the closed position in order to fasten the footwear toe to the snow travel aid and to permit pivotal movement of the footwear about an axis intersecting the jaws; wherein the opposable jaws are operably configured to move from the closed position to the open position in response to torque generated by rotation of the footwear about the footwear toe and independent of displacement of the slider from the central position.

[0068] 2. The toe unit of embodiment 1 or 2, wherein the slider is operably configured to slide laterally upon the base and away from the central position along an arc curving rearward and having an apex at the central position.

[0069] 3. The toe unit of embodiment 1 or 2, comprising slider biasing means for biasing the slider toward the central position in response to the lateral force.

[0070] 4. The toe unit of embodiment 3, wherein the slider biasing means comprises a positioner.

[0071] 5. The toe unit of embodiment 4, wherein the positioner comprises one or more resilient members positioned in the base generally perpendicular to a forward face of the slider.

[0072] 6. The toe unit of embodiment 5, wherein the one or more resilient members comprises one or more compression springs.

[0073] 7. The toe unit of embodiment 5 or 6, wherein the positioner comprises a positioner follower connected to the one or more resilient members for engaging a forward cam surface on a forward face of the slider to bias the slider toward the central position.

[0074] 8. The toe unit of embodiment 7, wherein the forward face of the slider comprises a forward face recession comprising the forward cam surface, the forward face recession operably configured to receive the positioner follower.

[0075] 9. The toe unit of embodiment 8, wherein the positioner follower comprises a positioner follower end operably configured for reception in the forward face recession, the positioner follower end having a shape complementary to the shape of the forward face recession.

[0076] 10. The toe unit of embodiment 9, wherein the shape of the positioner follower end is generally triangular.

[0077] 11. The toe unit of any one of embodiments 5 to 10, wherein the one or more resilient elements is adjustable to adjust the force necessary to displace the slider from the central position.

[0078] 12. The toe unit of any one of embodiments 1 to 11, wherein the base comprises one or more lateral limiters for limiting a maximum displacement of the slider from the central position.

[0079] 13. The toe unit of embodiment 12, wherein the one or more lateral limiters comprise opposing stoppers configured to abut the slider to limit lateral movement.

[0080] 14. The toe unit of embodiment 13, wherein the opposing stoppers are operable to abut a projection of the slider.

[0081] 15. The toe unit of embodiment 13, wherein the one or more lateral limiters comprise one or more stoppers, wherein the slider comprises one or more slots for receiving respective one or more stoppers, each of the one or more slots comprising first and second ends, wherein the one or more stoppers are configured to abut the slider at the first and second ends.

[0082] 16. The toe unit of any one of embodiments 1 to 15, further comprising a displacement indicator operably configured to indicate an extent of lateral displacement of the slider from the central position.

[0083] 17. The toe unit of embodiment 16, wherein the displacement indicator comprises an indicator follower moveable along a longitudinal axis, and the slider comprises a rear face comprising a rear cam surface operably configured to engage a first end of the indicator follower, wherein the indicator follower is moveable from a first position proximal to the rear cam surface toward a second position distal to the rear cam surface in response to lateral movement of the slider to indicate the extent of lateral displacement of the slider from the central position.

[0084] 18. The toe unit of embodiment 17, wherein the indicator follower is operably configured to remain in the second position until returned to the first position by a user of the toe unit.

[0085] 19. The toe unit of embodiment 17 or 18, wherein the rear face comprises a rear face recession comprising the rear cam surface, the rear face recession operably configured to receive the first end of the indicator follower.

[0086] 20. The toe unit of embodiment 19, wherein a shape of the indicator follower is complementary to the shape of the rear face recession.

[0087] 21. The toe unit of embodiment 19 or 20, wherein the shape of the first end of indicator follower is generally triangular.

[0088] 22. The toe unit of any one of embodiments 16 to 21, wherein the displacement indicator is marked at regular intervals to facilitate quantification of slider displacement from the central position.

[0089] 23. A toe unit for engaging a footwear toe of a footwear to releasably fasten the footwear to a snow travel aid, the toe unit comprising: a base for mounting on the snow travel aid; a slider slidably mounted on the base, the slider configured to resiliently slide laterally upon the base and away from a central position in response to a lateral force; and a displacement indicator operably configured to indicate an extent of lateral displacement of the slider from the central position.

[0090] 24. The toe unit of embodiment 23, wherein the displacement indicator comprises an indicator follower moveable along a longitudinal axis, and the slider comprises a rear face comprising a rear cam surface operably configured to engage a first end of the indicator follower, wherein the indicator follower is moveable from a first position proximal to the rear cam surface toward a second position distal to the rear cam surface in response to lateral movement of the slider to indicate the extent of lateral the lateral displacement of the slider from the central position.

[0091] 25. The toe unit of embodiment 24, wherein the indicator follower is operably configured to remain in the second position until returned to the first position by a user of the toe unit.

[0092] 26. The toe unit of embodiment 24 or 25, wherein the rear face comprises a rear face recession comprising the rear cam surface, the rear face recession operably configured to receive the first end of the indicator follower.

[0093] 27. The toe unit of embodiment 26, wherein a shape of the indicator follower is complementary to the shape of the rear face recession.

[0094] 28. The toe unit of embodiment 26 or 27, wherein the shape of the first end of indicator follower is generally triangular.

[0095] 29. The toe unit of any one of embodiments 24 to 28, wherein the displacement indicator is marked at regular intervals to facilitate quantification of slider displacement from the central position.

[0096] 30. The toe unit of any one of embodiments 24 to 29, wherein the slider is operably configured to slide laterally upon the base and away from the central position along an arc curving rearward and having an apex at the central position.

[0097] 31. The toe toe unit of any one of embodiments 24 to 30, comprising slider biasing means for biasing the slider toward the central position in response to the lateral force.

[0098] 32. The toe unit of embodiment 31, wherein the slider biasing means comprises a positioner.

[0099] 33. The toe unit of embodiment 32, wherein the positioner comprises one or more resilient members positioned in the base generally perpendicular to a forward face of the slider.

[0100] 34. The toe unit of embodiment 33, wherein the one or more resilient members comprises one or more compression springs.

[0101] 35. The toe unit of embodiment 33 or 34, wherein the positioner comprises a positioner follower connected to the one or more resilient members for engaging a forward cam surface on a forward face of the slider to bias the slider toward the central position.

[0102] 36. The toe unit of embodiment 35, wherein the forward face of the slider comprises a forward face recession comprising the forward cam surface, the forward face recession operably configured to receive the positioner follower.

[0103] 37. The toe unit of embodiment 36, wherein the positioner follower comprises a positioner follower end operably configured for reception in the forward face recession, the positioner follower end having a shape complementary to the shape of the forward face recession.

[0104] 38. The toe unit of embodiment 37, wherein the shape of the positioner follower end is generally triangular.

[0105] 39. The toe unit of any one of embodiments 33 to 39, wherein the one or more resilient elements is adjustable to adjust the force necessary to displace the slider from the central position.

[0106] 40. The toe unit of any one of embodiments 23 to 39, wherein the base comprises one or more lateral limiters for limiting a maximum displacement of the slider from the central position.

[0107] 41. The toe unit of embodiment 40, wherein the one or more lateral limiters comprise opposing stoppers configured to abut the slider to limit lateral movement.

[0108] 42. The toe unit of embodiment 41, wherein the opposing stoppers are operable to abut a projection of the slider.

[0109] 43. The toe unit of embodiment 41, wherein the one or more lateral limiters comprise one or more stoppers, wherein the slider comprises one or more slots for receiving respective one or more stoppers, each of the one or more slots comprising first and second ends, wherein the one or more stoppers are configured to abut the slider at the first and second ends.

[0110] 44. A heel unit and toe unit system for engaging a footwear to releasably fasten the footwear to a snow travel aid, the system comprising: a toe unit as defined in any one of embodiments 1 to 43; and a heel unit comprising a rotating heel.

[0111] Although the invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of skill in the art in light of the teachings of this specification that changes and modifications may be made thereto without departing from the spirit and scope of the invention as recited in the appended claims. All patents, patent applications or other publications referred to herein are hereby incorporated by reference.