FRONT UNIT COMPRISING A LOWERABLE HOLDING DEVICE

Abstract

The present invention relates to a front unit (10) for a touring binding, which front unit is to be mounted on a sliding board and has a mounting surface pointing in the direction of a sliding board surface, which mounting surface defines a sliding board plane (E), the front unit (10) being adjustable between a downhill configuration and a climbing configuration, comprising a first holding device (20) which is designed to fix a front portion of a sliding board boot for downhill travel with the touring binding, in the downhill configuration of the front unit (10), the first holding device (20) being adjustable between an active position and a passive position, and the first holding device (20) being set into the active position in the downhill configuration of the front unit (10), and being set into the passive position in the climbing configuration of the front unit (10), and a second holding device (40), which is designed to secure a toe portion of the sliding board boot for ascent with the touring binding in the climbing configuration of the front unit (10), in such a way that the sliding board boot is pivotable about a hinge pin that is substantially in parallel with the sliding board plane (E) and substantially perpendicular to a longitudinal axis (L) of the sliding board, the first holding device (20) being arranged closer to the sliding board plane (E) in the passive position than in the active position. Furthermore, the present invention relates to a touring binding comprising the front unit (10), which touring binding further comprises a heel unit and optionally a brake assembly.

Claims

1. A front unit for a touring binding, which is to be mounted on a sliding board and has a mounting surface that points in the direction of a sliding board surface and defines a sliding board plane, the front unit being adjustable between a downhill configuration and a climbing configuration, comprising: a first holding device which is configured, in the downhill configuration of the front unit, to fix a front portion of a sliding board boot to the touring binding for a descent, the first holding device being adjustable between an active position and a passive position, and the first holding device being set into the active position in the downhill configuration of the front unit and being set into the passive position in the climbing configuration of the front unit; and a second holding device which is configured to secure a toe portion of the sliding board boot, for ascent with the touring binding, in the climbing configuration of the front unit, in such a way that the sliding board boot is pivotable about a hinge pin that is substantially in parallel with the sliding board plane and substantially perpendicular to a sliding board longitudinal axis, that wherein the first holding device is arranged closer to the sliding board plane in the passive position than in the active position.

2. The front unit of claim 1, wherein the first holding device is mounted on a base of the front unit so as to be pivotable about an axis of rotation which is substantially in parallel with the sliding board plane and is substantially perpendicular to the sliding board longitudinal axis.

3. The front unit of claim 1, wherein the first holding device comprises two clamping jaws which have contact surfaces which are configured to come into contact with a front portion of the sliding board boot in order to securely hold the sliding board boot when the front unit is set into the downhill configuration and the first holding device is set into the active position.

4. The front unit of claim 1, wherein the second holding device is adjustable between an active position and a passive position and is set into the active position in the climbing configuration of the front unit and is set into the passive position in a starting configuration of the front unit.

5. The front unit according to of claim 4, wherein the first holding device comprises a tread surface for a sole portion of the sliding board boot on its side facing away from the sliding board; and wherein the front unit is configured such that, by stepping onto the tread surface of the first holding device with the sole portion of the sliding board boot, the first holding device is adjusted from the active position to the passive position, and/or the second holding device is adjusted from the passive position into the active position.

6. The front unit of claim 1, wherein the second holding device comprises two arms which are pivotably mounted on a base of the front unit and have holding means which are configured to pivotally hold the sliding board boot in the climbing configuration of the front unit; and wherein an opening angle of the arms of the second holding device relative to one another in a starting configuration of the front unit is greater than in the downhill configuration of the front unit and/or the climbing configuration of the front unit.

7. The front unit of claim 6, wherein the two arms of the second holding device are mounted on the base of the front unit so as to be pivotable about hinge pins that are substantially in parallel with the sliding board longitudinal axis or about hinge pins that are substantially in parallel with the sliding board plane and substantially perpendicular to the sliding board longitudinal axis.

8. The front unit of claim 1, wherein the first holding device is arranged further back, in a direction of travel in parallel with the sliding board longitudinal axis, than the second holding device.

9. The front unit of claim 6, further comprising: a lever assembly which comprises an opening lever which has an actuating portion, and a deflection mechanism; wherein the opening lever is adjustable by means of the actuating portion between a downhill position, a starting position, and a climbing position; and wherein the lever assembly is configured to adjust the front unit between the downhill configuration, a starting configuration, and the climbing configuration by means of an adjustment of the opening lever between the downhill position, the starting position and the climbing position.

10. The front unit of claim 9, wherein the opening lever is pivotably mounted about a swivel pin; and wherein the pivot angle of the opening lever is at least approximately 90?.

11. The front unit of claim 9, wherein the lever assembly is further configured to block the first holding device in the active position, in the downhill position of the opening lever.

12. The front unit of claim 9, wherein the deflection mechanism comprises: a locking lever, which is formed in one piece with the opening lever or is immovable relative to the opening lever; an adjusting lever which is connected to the opening lever and/or the locking lever and which is configured to transmit an adjusting movement of the opening lever to the second holding device in order to effect a movement of the arms of the second holding device relative to one another to modify the opening angle of the arms; wherein one end of the locking lever has a latching portion which is configured to engage with a complementary latching portion provided on a base of the front unit in the climbing position of the opening lever, in order to lock the second holding device in the active position, in the climbing position of the front unit; and wherein the opening lever is pivotably mounted about a swivel pin in such a way that the latching portion is able to pivot in front of and behind the complementary latching portion in relation to a direction in parallel with the sliding board longitudinal axis.

13. The front unit of claim 1, wherein the first holding device comprises a release mechanism having at least one resilient element; and wherein the release mechanism is configured to bias the first holding device into a holding position in which the first holding device securely holds the front portion of the sliding board boot, and, when a predetermined release force acting on the first holding device is exceeded, to bring the first holding device into a release position in which the front portion of the sliding board boot is released.

14. The front unit of claim 1 wherein, the second holding device comprises a clamping mechanism having at least one resilient element; and wherein the clamping mechanism being designed is configured to bias the second holding device into the active position and/or into the passive position.

15. The front unit according to of claim 1, further comprising: a tread portion having a tread plate for a sole portion of the sliding board boot, wherein the tread portion is mounted on a base of the front unit or on the sliding board and is designed configured to support the sole portion of the sliding board boot on the tread plate at a predetermined height above the sliding board plane.

16. The front unit of claim 15, wherein the tread plate is height-adjustable in such a way that a distance between the tread plate and the sliding board plane can be changed.

17. A touring binding comprising: a heel unit; and a front unit mounted on a sliding board and having a mounting surface that points in the direction of a sliding board surface to define a sliding board plane, the front unit being adjustable between a downhill configuration and a climbing configuration, wherein the front unit further comprises: a first holding device configured, in the downhill configuration of the front unit, to fix a front portion of a sliding board boot to the touring binding for a descent, the first holding device being adjustable between an active position and a passive position, and the first holding device being set into the active position in the downhill configuration of the front unit and being set into the passive position in the climbing configuration of the front unit; and a second holding device configured to secure a toe portion of the sliding board boot, for ascent with the touring binding, in the climbing configuration of the front unit, in such a way that the sliding board boot is pivotable about a hinge pin that is substantially in parallel with the sliding board plane and substantially perpendicular to a sliding board longitudinal axis, wherein the first holding device is arranged closer to the sliding board plane in the passive position than in the active position.

18. The touring binding claim 17, further comprising a brake assembly.

19. The front unit of claim 9, wherein the opening lever is pivotably mounted about a swivel pin, and the pivot angle of the opening lever is at least approximately 150?.

20. The front unit of claim 15, wherein the tread plate is configured to move in a direction that is substantially in parallel with the sliding board plane and substantially perpendicular to the sliding board longitudinal axis, in case of a lateral release of the first holding device.

Description

[0028] The invention is explained in more detail below on the basis of a preferred embodiment and with reference to the accompanying drawings. In the drawings, in detail:

[0029] FIG. 1 shows a perspective view of a front unit according to the preferred embodiment, in a downhill configuration,

[0030] FIG. 2 shows a plan view of the front unit according to the preferred embodiment in the downhill configuration,

[0031] FIG. 3 shows a plan view of the front unit according to the preferred embodiment in a starting configuration,

[0032] FIG. 4 shows a plan view of the front unit according to the preferred embodiment in a climbing configuration,

[0033] FIG. 5 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the downhill configuration, along the line A-A in FIG. 2,

[0034] FIG. 6 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the starting configuration, along the line B-B in FIG. 3,

[0035] FIG. 7 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the climbing configuration, along the line C-C in FIG. 4,

[0036] FIG. 8 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the downhill configuration, along the line D-D in FIG. 2,

[0037] FIG. 9 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the climbing configuration, along the line E-E in FIG. 4,

[0038] FIG. 10 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the starting configuration, along the line F-F in FIG. 3, and

[0039] FIG. 11 shows a sectional view of the front unit according to the preferred embodiment of the present invention in the downhill configuration, along the line G-G in FIG. 2.

[0040] With reference to FIG. 1, a front unit for a touring binding is generally denoted by 10. FIG. 1 is a perspective view of the front unit in a downhill configuration. A mounting surface of the front unit 10 which points in the direction of a sliding board surface of a sliding board, on which the front unit 10 is to be mounted, defines a sliding board plane E. Furthermore, a X-axis (sliding board longitudinal direction or x-direction) extending along a sliding board longitudinal axis L, which is oriented in the direction of travel of the sliding board, a Y-axis (sliding board transverse direction or y-direction) extending orthogonally to the X-axis and in parallel with the sliding board plane E, and a Z-axis extending orthogonally to the sliding board plane E (vertical direction or z-direction) are defined hereby.

[0041] In particular, the front unit 10 can comprise a base 12, the underside of which defines the sliding board plane E. In the embodiment described, the base 12 can in particular be in the form of a carriage 12 which can be displaced in the longitudinal direction of the sliding board by means of overlap portions 14 on a base plate (not shown), in order to adjust the length of the touring binding and thus to be able to adapt to different sole lengths, the base plate being able to be fixedly mounted on the sliding board, for example by means of binding screws.

[0042] The front unit 10 is adjustable between the downhill configuration shown in FIG. 1 (see for example also FIG. 2) and a climbing configuration (see for example FIG. 4), and comprises a first holding device 20 and a second holding device 40.

[0043] The first holding device 20 is designed, in the downhill configuration of the front unit 10, to fix a front portion of a sliding board boot to the touring binding for a descent. In addition, the first holding device 20 is adjustable between an active position and a passive position, the first holding device 20 being set into the active position in the downhill configuration of the front unit 10, and being set into the passive position in the climbing configuration of the front unit 10. In this case, an essential concept of the invention is that the first holding device 20 is arranged closer to the sliding board plane E in the passive position than in the active position, i.e., is arranged lower, in relation to a direction perpendicular to the sliding board plane E, in the climbing configuration of the front unit 10 than in the downhill configuration of the front unit 10. In the present embodiment, this can be achieved in that the first holding device 20 can be mounted so as to be pivotable about a hinge pin S1 that is substantially in parallel with the sliding board plane E 20) and substantially perpendicular to the sliding board longitudinal axis L, in particular on the base or the carriage 12 of the front unit 10, such that the first holding device can be lowered by a pivoting movement about this horizontal hinge pin S1 and thus can be adjustable from the active position into the passive position.

[0044] With reference to FIGS. 2 to 4, which are plan views of the front unit 10 in the downhill configuration (FIG. 2), a starting configuration (FIG. 3) and the climbing configuration (FIG. 4), the first holding device 20 can comprise two clamping jaws 22a, 22b having contact surfaces 24a, 24b which are designed to come into contact with a front portion of the sliding board boot in order to retain the sliding board boot when the front unit 10 is set into the downhill configuration and the first holding device 20 is set into the active position. In particular, a left-hand clamping jaw 22a in the direction of travel x can be mounted on the first holding device 20 so as to be pivotable about a swivel pin S2 that is substantially perpendicular to the sliding board plane E, and a right-hand clamping jaw 22b in the direction of travel x can be mounted on the first holding device 20 so as to be pivotable about a swivel pin S3 that is substantially perpendicular to the sliding board plane E. With reference to FIG. 11, which will be described in more detail later, the clamping jaws 22a, 22b can be biased by at least one spring 30a, 30b in such a way that they securely hold the sliding board boot.

[0045] In FIGS. 2 to 4, it can also be seen that the first holding device 20 in the present embodiment can be arranged further back than the second holding device 40 in a direction of travel x in parallel with the sliding board longitudinal axis L. That is to say that the first holding device 20 can be arranged closer to a heel unit (not shown) of the touring binding than the second holding device 40. The distances between the first holding device 20, the second holding device 40, and the heel unit (not shown) can in particular be fixed in such a way that a heel portion of the sliding board boot can be coupled to the heel unit in the downhill configuration of the front unit 10 during a descent with the touring binding and, when climbing with the touring binding in the climbing configuration of the front unit 10, is not disturbed by the heel unit.

[0046] The second holding device 40 is designed to secure a toe portion of the sliding board boot, for ascent with the touring binding, in the climbing configuration of the front unit 10 in such a way that the sliding board boot can be pivoted about a hinge pin that is substantially in parallel with the sliding board plane E and substantially perpendicular to the sliding board longitudinal axis L. FIGS. 5, 6 and 7 show that the second holding device 40 can also be adjustable between an active position and a passive position, it being set into the active position in the climbing configuration of the front unit 10 and being set into the passive position in the step-in configuration of the front unit 10. By means of the step-in configuration of the front unit 10, it is possible for a user to couple their boot to the second holding device 40. FIG. 5 is a sectional view along the line A-A in FIG. 2, i.e., the front unit 10 is shown in the downhill configuration, FIG. 6 is a sectional view along the line B-B in FIG. 3, i.e., the front unit 10 is shown in the step-in configuration, and FIG. 7 is a sectional view along the line C-C in FIG. 4, i.e., the front unit 10 is shown in the climbing position.

[0047] The second holding device 40 can comprise two arms 42a, 42b that are pivotably mounted on the base 12. In the described embodiment, the two arms 42a, 42b can be mounted about hinge pins S4, S5 that are substantially in parallel with the sliding board longitudinal axis L, but alternatively it would also be conceivable for the two arms 42a, 42b to be mounted on the base 12 of the front unit 10 so as to be pivotable about hinge pins that are substantially in parallel with the sliding board plane E and substantially perpendicular to the sliding board longitudinal axis L, or that only one of the arms is pivotably mounted and the other is rigidly connected to the base 12 or is integrally formed thereon.

[0048] The pivotable mounting of the arms 42a, 42b can advantageously ensure that the two arms 42a, 42b of the second holding device 40 can be moved between a closed position and an open position in order to couple and decouple the sliding board boot. The closed position and the open position are described in more detail later with reference to FIGS. 8 to 10.

[0049] A left-hand arm 42a of the two arms 42a, 42b in the direction of travel x can have a left-hand holding means 44a, and a right-hand arm 42b of the two arms 42a, 42b in the direction of travel x can have a right-hand holding means 44b. These holding means 44a, 44b can in particular be projections 44a, 44b which are designed to engage in receptacles provided on the sliding board boot. Conversely, it would also be conceivable for the holding means to be receptacles which are designed to be engaged by projections provided on the sliding board boot. In the present embodiment, the holding means 44a, 44b can in particular be designed as bearing journals 44a, 44b having conically tapered tips, which engage in corresponding opposite lateral bearing recesses of a sliding board boot. The front unit 10 can then be used in the climbing configuration when the sliding board boot is held on the bearing pin, and can be used in the downhill configuration when the first holding device 20 immovably fixes the front portion of the sliding board boot. In the downhill configuration, the bearing journals 44a, 44b are then in particular not in engagement with the bearing recesses of the sliding board boot. Accordingly, the described holding means 44a, 44b can pivotably hold the sliding board boot in the climbing configuration of the front unit 10.

[0050] FIGS. 5, 6 and 7 are sectional views of the front unit 10, FIG. 5 being a sectional view along the line A-A in FIG. 2, FIG. 6 being a sectional view along the line B-B in FIG. 3, and FIG. 7 being a sectional view along the line C-C in FIG. 4. Accordingly, the front unit is set into the downhill configuration in FIG. 5, set into the starting configuration in FIG. 6, and set into the climbing configuration in FIG. 7.

[0051] As shown, the clamping jaw 22b can have a contact roller 26 and/or a holding projection 25 in addition to the contact surface 24b or as a contact surface. This also applies in the same way to the clamping jaw 22a, which is not shown in the sectional views from FIGS. 5 to 7. In the downhill configuration of the front unit 10, in the active position of the first holding device 20, the holding projection 25 can overlap or hold down a front portion of the sliding board boot, in order to be able to hold the sliding board boot even more securely in the downhill configuration. The contact roller is designed for contact with a front portion of the sliding board boot, and supports a relative movement between the sliding board boot and the clamping jaws during a release of the sliding board boot in the event of a fall release. The contact roller(s) 26 can thus provide for a reduction in friction in the contact region between the sliding board boot and the front unit 10.

[0052] On its side facing away from the sliding board, the first holding device 20 can comprise a tread surface 27 for a sole portion of the sliding board boot. A user can adjust the first holding device 20 from the active position (see FIGS. 5 and 6) into the passive position (see FIG. 7) by stepping onto the tread surface 27 with a sole portion of the sliding board boot. In addition, by stepping onto the tread surface 27 of the first holding device 20, the second holding device 40 can also be adjusted from the passive position (FIG. 6) into the active position (FIG. 7). It is thereby possible for the user to only have to step with the sole portion of the sliding board boot onto the tread surface 27 of the first holding device 20, in order to bring the sliding board boot and the second holding device 40 into engagement. In the embodiment described, the first holding device 20 can in particular be provided in the manner of a housing 20 which can be pivoted about the hinge pin S1 and in which a toggle lever system 62 (described below) is accommodated and on which the clamping jaws 22a, 22b are pivotably mounted about the hinge pins S2, S3.

[0053] It can be clearly seen in FIG. 7 that the first holding device 20 is arranged significantly lower in its passive position than in its active position shown in FIGS. 5 and 6. It is thereby possible to couple the sliding board boot to the second holding device 40, in particular to the bearing means 44a, 44b of the arms 42a, 42b, without the first holding device 20 causing disruption.

[0054] The toggle lever system 62 already mentioned above can be part of a lever assembly 60, 62, as a deflection mechanism 62, which assembly further comprises an opening lever 60 which has an in particular exposed actuating portion 61. The opening lever 60 can in particular be pivotable about a lever axis H which is in parallel with the sliding board plane E and perpendicular to the sliding board longitudinal axis L, and can be adjustable by a pivoting movement about the lever axis H between a downhill position (FIG. 5), a step-in position (FIG. 6) and a climbing position (FIG. 7). By adjusting the opening lever 60 between the downhill position, the step-in position and the climbing position, by operating the actuating portion 61, the front unit 10 can be adjusted between the downhill configuration, the step-in configuration and the climbing configuration. As can be seen, in the present embodiment in FIG. 5, the opening lever 60 is located in the downhill configuration, in a position approximated to the first holding device 20, in FIG. 6 in the step-in configuration, in a position that is approximated to the sliding board, and in FIG. 7 in the climbing configuration, in an upwardly projecting position, but other lever positions are also conceivable for the different configurations. In particular, the opening lever 60 can be pivoted about the swivel pin H at an angle of more than 90?, preferably more than 120?, or even more than 150?, in order to be able to provide the above-described angular positions of the opening lever 60.

[0055] By means of the toggle lever system 62, an adjusting movement of the opening lever 60 via a clamping mechanism 50a, 50b, 52a, 52b (described below) can in particular be transmitted via an adjusting lever 64 to the arms 42a, 42b of the second holding device 40, so that an opening angle of the arms 42a, 42b relative to one another is greater in the step-in configuration than in the downhill configuration and the climbing configuration (see also FIGS. 8 to 10). For this purpose, the adjusting lever 64 can comprise an end-side fork portion 65 which encompasses spring stops 52a, 52b of the clamping mechanism. A more detailed mode of operation will be described later with reference to FIGS. 8 to 10.

[0056] The lever assembly 60, 62 can furthermore be designed to block the first holding device 20 in the active position, in the downhill position of the opening lever 60, in order to stabilize said holding device in the active position. For this purpose, the toggle lever system 62 can comprise a locking lever 66 which has a latching recess 68. The locking lever 66 can be formed integrally with the opening lever 60, as a locking portion 66 of the opening lever 60 on an end of the opening lever 60 opposite the actuating portion 61. Alternatively, the locking lever 66 can be rigidly connected to or immovable in relation to the opening lever 60, as a separate component. A latching projection 18 formed complementarily to the latching recess 68 can be provided on an inside portion of the first holding device 20, designed in particular as a pivotable housing, and can engage with the latching recess 68 in the downhill configuration of the front unit 10 and the downhill position of the opening lever 60, in order to lock the first holding device 20 or to block it in its active position (see FIG. 5).

[0057] The deflection mechanism 62 can in particular be designed such that the latching portion 68 can pivot in front of and behind the complementary latching portion 18 in relation to the direction x, in parallel with the sliding board longitudinal axis L, so that it can pivot in both directions beyond the latched position with the latching portion 18 on the base 12.

[0058] In the preferred embodiment of the present invention, an adjustment of the opening lever 60 from the step-in position into the downhill position takes place in such a way that the latching portion 68 of the locking lever 66, starting from the climbing position, pivots beyond the complementary latching portion 18 on the base 12. As mentioned above, the adjusting movement of the opening lever 60 is transmitted to the second holding device 40 in order to effect a movement of the arms 42a, 42b of the second holding device 40 relative to one another, in particular in order to change the opening angle of the arms 42a, 42b. As a result, the distance between the holding means 44a, 44b provided in each case on the arms 42a, 42b also changes. In the step-in position of the opening lever 60, this distance is greater than a width of the sliding board boot at the point to be coupled, such that the boot can be guided between the holding means 44a, 44b. In the climbing position of the opening lever 60, the distance between the holding means 44a, 44b is somewhat smaller than the boot width at the point to be coupled, so that the sliding board boot is clamped firmly. In the downhill configuration of the front unit 10 and the downhill position of the opening lever 60, as can be seen in FIG. 11 the distance between the holding means 44a, 44b can be set so small, by the continued movement of the opening lever 60 beyond the latching position, that the sliding board boot cannot be coupled to the second holding device 40, but only to the first holding device 20, which is intended for the descent.

[0059] Furthermore, a latching projection 18 which is designed in a manner complementary to the latching recess 68 can also be formed on the base 12, which latching projection can engage with the latching recess 68 in the climbing configuration of the front unit 10 and the climbing position of the opening lever 60, in order to lock the second holding device 40 or to block it in its active position (see FIG. 7).

[0060] FIGS. 5 to 7 furthermore show a tread portion 70 which has a tread plate 72 for a sole portion of the sliding board boot. The tread portion 70 can be mounted on the base 12 or on the sliding board and can support the sole portion of the sliding board boot on the tread plate 72 at a predetermined height above the sliding board plane E. In particular, the tread plate 70 can be designed to move in a direction y, that is substantially in parallel with the sliding board plane E and substantially perpendicular to the sliding board longitudinal axis L, in the case of a lateral release of the first holding device 20. As a result, in the event of a lateral release (Mz release), less friction occurs between the sole portion of the sliding board boot and the portion of the front unit 10 on which the sole portion of the sliding board boot is supported. For example, the tread plate 72 can be height-adjustable by an adjusting screw 74, such that a distance between the tread plate 72 and the sliding board plane E can be changed. A variable distance between the sliding board plane E and the tread plate 72 of the tread portion 70 makes it possible for the front unit 10 to be adapted for different sole profiles or sole thicknesses. An adjustment of the height of the tread plate 72 above the sliding board plane E can take place in a relatively simple manner, for example by means of the adjusting screw 74, the height of the tread plate 72 being able to be changed by a rotation of the screw 74.

[0061] In addition, a frozen snow lug 90 can be fastened to the tread portion 70 or to the sliding board itself, for example by means of screws, for receiving frozen snow.

[0062] The mode of operation of the second holding device 40 is described in more detail below with reference to FIGS. 8, 9 and 10. FIG. 8 is a sectional view of the front unit 10 in the downhill configuration, along the line D-D in FIG. 2, FIG. 9 is a sectional view of the front unit 10 in the climbing configuration, along the line E-E in FIG. 4, and FIG. 10 is a sectional view of the front unit 10 in the step-in configuration, along the line F-F in FIG. 3.

[0063] The second holding device 40 can comprise a clamping mechanism 42a, 42b, 50a, 50b, 52a, 52b, which can be formed from the two arms 42a, 42b, a resilient element, for each arm 42a, 42b, in each case, in the form of compression springs 50a, 50b, and a spring stop in each case for each spring 50a, 50b. The clamping mechanism 42a, 42b, 50a, 50b, 52a, 52b biases the second holding device 40 into the active position and/or into the passive position, it being possible in particular for a dead centre to be passed through during the adjustment between the active position and the passive position, so that the second holding device 40 is always biased by the clamping mechanism, either into the active position (see for example FIG. 9) or into the passive position (see FIG. 10). As mentioned above, in this case an opening angle of the arms 42a, 42b relative to one another is greater in the step-in configuration of the front unit 10 (FIG. 10) than in the downhill configuration of the front unit 10 (FIG. 8) and the climbing configuration of the front unit 10 (FIG. 9).

[0064] The compression springs 50a, 50b can be wound around end portions of the arms 42a, 42b facing one another and can press against the spring stops 52a, 52b at one spring end, and press at the respectively opposite spring ends against a stepped portion of the arms 42a, 42b in each case, in order to bias the second holding device 40 or the arms 42a, 42b. During an adjustment from the climbing configuration (active positionFIG. 9) into the step-in configuration (passive positionFIG. 10), a dead centre is passed through in a substantially horizontal position of the mutually facing arm end portions, in which dead centre the clamping forces of the clamping mechanism are substantially cancelled, so that the second holding device 40 can be biased, both in the passive position and in the active position, into this position in each case. For the adjustment between the active position and the passive position of the second holding device 40 or the arms 42a, 42b by means of the opening lever 60, as described above an end-side fork portion 65 of the adjusting lever 64 of the toggle lever system 62 of the lever assembly 60, 62 can surround the spring stops 52a, 52b of the clamping mechanism of the second holding device 40. A pivoting movement of the opening lever 60 about the lever axis H can thereby be converted into a substantially vertical movement, upwards and downwards, of the spring stops 52a, 52b, and thus into a pivoting movement of the arms 42a, 42b about the hinge pins S4, S5, in order to adjust the second holding device 40 between the active position and the passive position.

[0065] With reference to FIG. 11, a release mechanism of the first holding device 20 of the front unit 10 according to the present embodiment is described below. FIG. 11 is a sectional view of the front unit 10 in the downhill configuration, along the line G-G in FIG. 2.

[0066] The first holding device 20 can comprise a release mechanism 22a, 22b, 30a, 30b, 32a, 32b, 34 having at least one resilient element 30a, 30b. In the present embodiment, two compression springs 30a, 30b can be provided as a resilient element, which press against spring guides 32a, 32b and the spring bias of which can be changed, for example by means of an adjusting screw 34, in order to be able to adjust a release force.

[0067] The release mechanism 22a, 22b, 30a, 30b, 32a, 32b, 34 biases the first holding device 20 in a holding position, in that the spring force of the springs 30a, 30b is transmitted to the clamping jaws 22a, 22b in such a way that these are biased in one direction, relative to one another. In the holding position, the first holding device 20 holds the front portion of the sliding board boot firmly by means of the clamping jaws 22a, 22b and, when a predetermined release force acting on the contact surfaces 24a, 24b of the clamping jaws 22a, 22b, which can be set by a change in the bias of the springs 30a, 30b, is exceeded, the first holding device 20 is brought into a release position, in which the front portion of the sliding board boot is released, in particular by the contact surfaces 24a, 24b of the clamping jaws 22a, 22b being pivoted away from one another about the hinge pins S2, S3. In the present embodiment, the release mechanism 22a, 22b, 30a, 30b, 32a, 32b, 34 can in particular be a Mz release mechanism.