Assembly for retaining a boot on an apparatus for gliding or walking on snow or ice

Abstract

An assembly for retaining a boot on a gliding or walking apparatus including a boot and an interface device provided to receive the boot, and to be assembled to the gliding apparatus, the device having an elongated base defining a longitudinal direction provided to support the boot and having, in its upper portion, a device for retaining the boot, and in its lower portion, a device for assembly to the gliding apparatus. The retaining device of the assembly includes retaining members, located along a direction transverse to the longitudinal direction of the base, or set back with respect to the ends of the base along a longitudinal direction, which cooperate with complementary members for attaching the boot, and the assembly device including a non-releasable release mechanism with automatic return.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an assembly for retaining a boot on an apparatus for gliding or walking on snow or ice. The invention also relates to a boot and an interface device for retaining the boot on a gliding or walking apparatus.

[0003] 2. Description of Background and Relevant Information

[0004] There are numerous gliding or walking activities that take place on snow. Among them, skiing, cross-country skiing, snowboarding, back country skiing, or snowshoeing, and walking with crampons are known. There are also other intermediate activities between these various practices. Beyond these activities, it is also necessary to enable the user to simply walk under acceptable conditions of comfort and adherence.

[0005] Generally speaking, each of these activities requires gear that includes a pair of boots, a gliding apparatus including one or two elements, as needed, and an assembly for retaining the boots on the gliding apparatus.

[0006] Each activity has so far required gear developed specifically for the activity involved. In particular, for each activity, a user must have a pair of special boots, and he/she must use different boots for each different activity. However, the activities are becoming diversified, i.e., during a single outing in the mountains, or during a single period of time, an average user might be tempted to engage in various walking or gliding activities. For each of these activities, the user must change his gear, namely, at least the boots and the gliding or walking apparatus, which proves unpractical for both the user and for the equipment lender.

[0007] Attempts have been made to allow the use of the same pair of boots for various activities. Thus, a retaining assembly for snowboards is known, for example, from the patent applications EP 712 646 and EP 719 505, which include a boot having an attachment insert beneath the sole, and a device for retaining the insert provided to be fixed on the snowboard. The retaining device enables an automatic attachment of the boot, and a lateral lever ensures its voluntary release.

[0008] This assembly, initially provided for a snowboard, has been proposed for mounting on a short ski or a snowshoe, which makes it possible to practice these activities with the same pair of boots. However, for skiing, this assembly is not provided to ensure the release of the boot in the case of an excessive force.

[0009] More recently, the patent application EP 956 886 discloses an interface device making it possible to alpine ski or snowboard with a flexible boot.

[0010] This device is adapted to cooperate with a boot having, in the sole, a longitudinal groove in which a rib is nested. The attachment of the boot is accomplished by transverse rods located in the groove of the boot, which penetrate into notches made in the rib and are retained by a latching device. Various interface devices are described for use of the boot on an alpine ski or a snowboard. For use on a ski, the interface device has retaining end-pieces of a conventional type at the front and rear, which have the same shape as the end-pieces used for traditional ski boots.

[0011] This assembly is not completely satisfactory insofar as it requires two different engaging maneuvers for skiing, namely, engaging the boot on the attachment device and engaging the interface device in the ski retaining elements. Moreover, in the case of a fall, the interface device is completely released from the ski and remains attached to the boot. Therefore, there are two possible configurations for using the boot, depending upon whether or not the interface device is attached to the boot.

[0012] Furthermore, the method for attaching the boot to the interface device imposes constructional constraints that modify the boot performances for the various gliding or walking activities for which this boot could be used.

SUMMARY OF THE INVENTION

[0013] An object of the invention is to propose an improved retaining assembly that enables the use, for skiing, of a boot allowing to practice at least one activity other than skiing, with the possibility of releasing the boot retained on the ski in the case of an excessive force.

[0014] Another object of the invention is to propose an improved retaining assembly for which the specific arrangement for attaching the boot preserves its performances as much as possible for the various activities for which it is provided.

[0015] Still another object of the invention is to propose an improved retaining assembly that simplifies the operations of adjusting the various gliding apparatuses on which it is adapted to be mounted, in particular the operations of adapting the apparatus to the size of the user's feet.

[0016] Other objects and advantages of the invention will become apparent from the description that follows.

[0017] The assembly for retaining a boot on a gliding or walking apparatus according to the invention includes a boot and an interface device provided to receive the boot and to be assembled to the gliding apparatus, the device having an elongated base defining a longitudinal direction provided to support the boot and having, in its upper portion, a device for retaining the boot, and its lower portion, a device for assembly to the gliding apparatus.

[0018] The retaining device of the assembly includes retaining members, located along a direction transverse to the longitudinal direction of the base or set back with respect to the ends of the base along a longitudinal direction, which cooperate with complementary members for attaching the boot, and the assembly device includes a non-releasable type release mechanism with automatic return.

[0019] Thus, the boot is attached to the base along a lateral grip, or a longitudinal grip within the contour of the sole, the position of the attaching and retaining members is in the center of the boot sole. The size of the members is determined as a function of the boot of smaller size so that the attaching and retaining members are independent of the size of the boot.

[0020] Moreover, this allows much freedom as for the boot design, in particular with respect to the sole flexibility.

[0021] At the lower level, the linkage between the interface device is detachable but non-releasable. This means that in the case of a fall, the base is separated from the ski, which relieves the skier's leg of the stresses generated by the ski, but the boot is not completely released from the ski, i.e., the release mechanism maintains a linkage between the board and the base at all times. The automatic return facilitates the repositioning of the base against the ski once the skier regains control of his position and movements. Since the base remains attached to the ski in all circumstances, fitting the apparatus requires only one operation of engaging the boot.

BRIEF DESCRIPTION OF DRAWINGS

[0022] The invention will be better understood from the description that follows, with reference to the annexed drawings, in which:

[0023] FIG. 1 shows a retaining assembly according to a non-limiting example of embodiment of the invention.

[0024] FIG. 2 shows a perspective view of the arrangement for attaching the boot to the base of the interface device.

[0025] FIG. 3 schematically shows the voluntary release mechanism of the attaching arrangement.

[0026] FIG. 4 shows an alternative construction of this mechanism.

[0027] FIG. 5 shows the arrangement for retaining the base on the ski.

[0028] FIG. 6 shows the mechanism for releasing the base with respect to the ski.

[0029] FIG. 7 relates to an alternative embodiment of the invention.

[0030] FIG. 8 shows another alternative embodiment.

[0031] FIG. 9 shows another alternative embodiment.

[0032] FIG. 10 is a top view of the base of FIG. 9.

[0033] FIGS. 11-16 relate to alternative embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0034] FIG. 1 shows a portion of the ski 1 overlaid by an interface device 2 which is itself provided for a boot 3. For clarification, FIG. 1 shows the boot 3 raised in relation to the interface device.

[0035] According to the embodiment shown, the boot is a flexible boot of the snowboard boot type. Usually, such a boot includes an outer shell or envelope 4 and an inner liner not completely shown in the figure. The outer envelope is tightened around the user's foot, for example, by a lace 6 and a tightening strap 7 which passes toward the instep. In a known manner, the liner is also equipped with a tightening lace.

[0036] Possibly, the rear portion of the envelope is reinforced by a rigid or semi-rigid plate 8 that is integrated into the lining of the envelope. Such a plate is described in the published patent application No. EP 646 334.

[0037] The envelope 4 further has a sole 10. This sole is provided for walking under comfortable conditions. It is preferably flexible, with rounded front and rear edges, and its lower contact surface is provided at least locally with notches, serrations, or any other raised structures adapted to improve the adherence of the sole on the ground. For example, the sole is made of elastomer.

[0038] The boot further has an attaching member that is provided to cooperate with the retaining members of the interface device, in order to keep the boot attached to the interface device.

[0039] According to the embodiment of FIG. 1, the attaching arrangement is are located toward the center of the boot sole, on the sides. Generally, they are located on the lateral edges of the sole, in the area of the plantar arch.

[0040] It has been found that this location enables the boot to be attached, not only to an interface device provided for skiing, as the one that will be described subsequently, but also to other interface devices provided for other activities such as snowboarding, cross-country skiing, snowshoeing, etc.

[0041] Preferably, the attaching and retaining arrangements cooperate with one another so as to ensure a mutual automatic engagement.

[0042] In the embodiment shown, the attaching arrangement includes two elements 14 and 15 projecting with respect to the lateral walls 16a, 16b, respectively, of a box 18 affixedly attached to the boot sole. The box has the general shape of a parallelepiped rectangle. It is housed in a recess of the sole located in its median portion, between the front and rear zones 11 and 12. However, the box is set back with respect to the relief of the front and rear zones. Each of the elements 14 and 15 are shaped like a sliding bolt, with a beveled lower surface that facilitates the engaging of the boot and a substantially horizontal upper surface. The width of the box 16 is close to, or preferably slightly less than, the width of the boot sole in its median portion, such that by projecting with respect to the lateral walls of the box, the sliding bolts also project with respect to the lateral edges of the sole.

[0043] The retaining members of the interface device consist of two openings 18, 19 provided in the lateral walls 20a, 20b of a transverse cradle 20 attached affixedly to the interface device. The openings have a rectangular shape, whose dimensions correspond substantially to the sectional dimensions of the sliding bolts 14 and 15.

[0044] The distance between the lateral walls corresponds to the width of the box except for the operational clearance. As shown in FIG. 2, the lateral walls 20a, 20b of the cradle can be slightly widened outwardly; moreover, they can have a trapezoidal shape narrowing toward the top which cooperates with ramps projecting with respect to the lateral walls of the box to facilitate the centering of the boot in relation to the transverse cradle and the engaging of the sliding bolts in the openings 18 and 19.

[0045] The two sliding bolts can be retracted within the box 18. As shown in FIG. 3, for example, the sliding bolts 14, 15 are guided slidingly in the lateral walls 16a and 16b of the box; a spring 25 elastically opposes their entry into the box and keeps them projecting from the box 16.

[0046] To cause the voluntary retraction of the sliding bolts 14, 15, especially to cause the voluntary release of the boot, the sliding bolts are connected by a connecting rod system to a cable 23 and finally to a lever 24 located on the rear of the boot. The rotation of the lever away from the boot causes the temporary retraction of the sliding bolts subsequent to a sliding of the cable in its sheath. It is contemplated that other constructions could also be suited for this purpose. In particular, the lever 24 could be located, not on the rear, but on the side of the boot.

[0047] FIG. 4 shows an alternative construction. The two sliding bolts are here drawn in the retracted position within the box by a traction spring 27. Two connecting rods 37 are connected to the sliding bolts, and the end of a cable 27 is secured to their common journal point. The cable is maneuvered by a knuckle joint lever 28 that is mounted on the boot upper. In the position shown in FIG. 4, the lever forces the sliding bolts to remain in projection. The boot is retained on the base with this position of the lever. If the lever is pivoted downwardly, the sliding bolts are drawn within the box by the spring. The boot is then released from the base. Other constructions are also suitable according to the invention.

[0048] The interface device 2 that is provided to cooperate with the boot includes an elongated base 30, as shown in FIGS. 1, 5, and 6. The upper surface of the base substantially has the length and width dimensions of a large sized boot. According to the embodiment shown, two cushions 31, 32 for supporting the front and rear ends of the boot are located toward the front and rear of the surface of the base 30, as shown in FIG. 1. These cushions are made of elastomer, for example. Possibly, their thickness can be varied to conform to the shape of the boot sole. By cooperating with the front and rear zones of the sole, they create an elastic suspension that facilitates the positioning of the boot and ensures a vertical backlash elimination. The transverse cradle 20 that has been described previously is fixed between the cushions.

[0049] The interface device 2 is adapted to receive boots of various sizes without it being necessary to make an adjustment with respect to the length or width of the sole.

[0050] The base 30 is connected to the ski by a linkage having a detachable but non-releasable release mechanism and, preferably, an automatic return.

[0051] In other words, in the case of excessive force, the base 30 is adapted to separate from the board 1 so as to relieve the user's leg of the stress that generated the release. However, the base is not completely released from the board, i.e., the base and the ski remain connected to one another by a linkage that is preferably retractable, i.e., which returns the ski against the base once the skier has regained control of his/her position and movements.

[0052] Such a release mechanism has been described, for example, in the patent publication FR 2 224 183 and U.S. Pat. No. 3,893,682, the disclosures of which are hereby incorporated by reference thereto in their entireties for that purpose. With respect to the invention, such a mechanism has the advantage that the complete release of the boot can occur only between the boot itself and the base. For example, the user could not walk with the base attached to the boot. Therefore, there is a certain flexibility of use. Moreover, the release mechanism makes it possible, in the case of a fall, to considerably alleviate the stresses between the user's leg and the ski, when they become substantial.

[0053] According to the embodiment shown, the base 30 rests on the gliding board via two blocks 33a and 33b located on its lower surface. It is connected to the board of the ski 1 by a cable 34. The front and rear ends 34a, 34b of the cable are attached to front and rear abutments 35 and 36 assembled affixedly to the ski. Two recesses 38 and 39 in the lower portion of the base are used to house the front and rear abutments. The housings open up transversely to enable the base to displace laterally with respect to the abutments.

[0054] Preferably, the front abutment 35 includes a turret 35a rotating about a vertical axis, and the cable emerges from the base in the horizontal plane of the turret. The base has a cable return on the rear, and the end of the cable emerges vertically above the abutment.

[0055] Within the base, the cable 34 circulates between successive returns. The returns are mounted on two loosely mounted facing supports 41, 42. A set of springs 44 elastically oppose the coming together of the supports 41 and 42.

[0056] In the case of an excessive force, the stresses are transmitted to the cable 34 and to the set of springs 44. The coming together of the two supports enables the cable to unwind out of the base, at the front and/or the rear; the base can then move away from the ski relative to the abutments, in the direction along which it is driven by the stress.

[0057] FIG. 6 schematically shows the base carrying the boot separated from the ski along a substantially perpendicular direction. However, this is not limiting, and other spacing directions are also possible as a function of the direction of the stress that generated the release.

[0058] As soon as the force diminishes, the supports retract the cable by moving away from one another, which brings the base back in the centered position on the ski.

[0059] The release mechanism that has just been described is not limiting, and there are other possible constructions according to the invention. In particular, the supports and the set of springs have a linear or quasi-linear release characteristic. One could adopt other mechanisms for unwinding the cable, where the force necessary for unwinding the cable diminishes as the cable unwinds, by playing on the lever arms, as has been described in FR 2 224 183 and U.S. Pat. No. 3,893,682.

[0060] Furthermore, the front abutment could cooperate with the base via support surfaces so as to create a meshing effect in the case of a lateral force.

[0061] FIG. 7 shows an alternative embodiment of the invention.

[0062] According to this variation, the boot sole is equipped with two attachment members of different types.

[0063] On the front, a transverse rod 51 affixedly assembled to the sole is located in a recess 50 of the sole. The rod is provided to engage on a hook 52 located on the upper surface of the base 49.

[0064] On the rear, the sole is equipped with a box 53 similar to the previously described box, with its retractable sliding bolts 54 provided to engage in the boring 55 of a transverse cradle 56 assembled affixedly to the upper surface of the base.

[0065] The main difference with the previous embodiment is that the engaging of the boot occurs in two steps; in a first step, the rod 51 is engaged in the hook 52, the boot sole being slightly oblique with respect to the base. In a second step, the sliding bolts are engaged in the openings of the cradle 56. Preferably, the distance between the rod 52 and the box 53 is constant so that boots of different sizes can be mounted on the base without a need to make an adjustment relative to the length of the boot.

[0066] At the lower level, the base is connected to the ski by a detachable but non-releasable release mechanism, as previously described.

[0067] This embodiment is interesting insofar as the front rod 52 can be used alone as a member for hooking the boot with, for example, a cross-country ski binding where the boot sole is connected to the ski via a journal located on the front.

[0068] In the case of such an activity, the rear sliding bolts would remain inactive.

[0069] Conversely, one could provide that the rod 52 be inactive for skiing, and that the retaining of the boot on the base only be ensured by the sliding bolts for this activity.

[0070] FIG. 8 shows the assembly of the invention as more particularly adapted for an activity such as back country skiing or off-trail cross-country skiing.

[0071] The boot is of the same type as the preceding boot, with a transverse rod 60 housed in a recess 61 at the front of the sole. A retaining element such as a cross-country ski binding 62 is assembled to the upper surface of the base 59. In a known manner, this element includes a sliding hook 63 provided to confine the rod 60 while allowing the rotation of the sole about the axis which it defines, and an elastomeric block 64 provided to be compressed by the front of the boot during the rotation of the sole.

[0072] On the rear, the attachment of the boot is done by means of sliding bolts, as has been described previously. However, a two-position lever 66 located on the rear or the side of the boot upper makes it possible to selectively disengage or engage the sliding bolts. In the disengaged position, the sliding bolts are retracted within the box, they are inactive. This position is the climbing position where the rear of the boot is free to be raised.

[0073] In the engaged position, the sliding bolts project, and they ensure the retention of the boot when they are engaged in the openings of the cradle. This position corresponds to the descending position.

[0074] According to the embodiment shown, the base is connected to the ski by a detachable but non-releasable release mechanism, similar to that described previously.

[0075] FIGS. 9 and 10 relate to a retaining assembly more particularly adapted for snowboarding.

[0076] According to the embodiment shown, the boot attaching members are of the same type as that which has been described in the first embodiment. They include retractable sliding bolts 71 mounted in a box 70, which is itself affixedly attached beneath the boot sole. The base 73 has a transverse cradle 75 with openings 76 in which the sliding bolts can engage. The base rests on the sliding board via blocks 78 and 79 located at the lower surface of the base.

[0077] A central block 80 is provided to be affixedly attached to the board. Preferably, the central block has two steps connected affixedly to one another by a screw. The lower step 80a is fixed to the board, the upper step 80b is adjustable in orientation with respect to the lower step. Possibly, notches or any other construction can be provided between the two steps to ensure their cohesion once the orientation has been adjusted.

[0078] A cable 81 connects the base and the central block, in the manner of that which has been described previously. The cable reel is located either toward the front and rear ends of the base, or in the central block. The fastening points of the cable are located along the longitudinal axis define by the boot. They could also be oriented differently.

[0079] The attaching and retaining members of the boot that have been described are not limiting. In particular, rather than being attached to the boot, the lever or member that enables the release of the boot could be associated with the base. To illustrate this, FIG. 11 schematically shows a boot having, in its median portion, two pins 83 projecting with respect to the lateral edges of the sole. These pins are, for example, the ends of a transverse rod nested in the sole. In this case, the retaining elements of the base include a U-shaped cradle whose flanges 84 have notches 85 provided to receive the pins. Self-closing cams 86 are located at the inlet of the notches. They are movably mounted about a transverse axle, and are returned in the closure position, for example, by a spring. A lever (not shown) makes it possible to voluntarily pivot the cams to clear the openings of the notches.

[0080] FIG. 12 shows an alternative embodiment. The boot includes two series of transverse pins 90 and 91 projecting with respect to the lateral edges of the sole. The pins are located toward the front and the rear of the sole; however, their distance is constant for the various boot sizes.

[0081] The retaining members are two cradles 92 and 93 with flanges provided with notches and self-closing cams. The opening of the cams can be synchronized.

[0082] According to FIG. 13, the boot includes, on each side and toward the middle of the sole, two hollow recesses 98 which each cooperate with a finger 99 hingedly mounted with respect to the base. The finger 99 penetrates into the recess 98 in the manner of a gear tooth, and a locking mechanism, not shown, locks the finger in its closed position where it retains the boot.

[0083] According to FIG. 14, the boot attaching members are no longer on the lateral edges of the sole but beneath the sole, within its contour. These members include, on the front of the sole, a small plate 101 attached affixedly to the sole with a finger 102 projecting on the front, and on the rear, a transverse small bar 104 with a U-shaped cutout. The finger and the small bar are cleared from the boot sole; for example, the sole has a recess toward these elements.

[0084] On the base, a bridge-like element is provided toward the front as a member for retaining the finger, and on the rear, a tilting finger 107 engages the small bar 104 to ensure its locking toward the top. These two elements are substantially set back with respect to the ends of the base. A lever 108 located on the edge of the base enables the tilting of the finger 107 so that it releases the small bar 104. Upon engagement of the boot, the central portion of the small bar is inclined and acts as a ramp on the finger so as to cause its automatic engagement.

[0085] Such attachment methods are known in the field of snowboarding. One of their advantages is that they enable the automatic engaging of the boot. Another advantage is that they do not require any particular adjustment with respect to the boot size.

[0086] The cable release mechanism that has been described is not limiting, and other mechanisms could be used.

[0087] To illustrate this, FIGS. 15 and 16 show a base 115 that is pivotally mounted about a vertical pivot 116 affixedly connected to the ski.

[0088] On the front and rear, the pivot 116 has two flat portions 116a and 116b.

[0089] Pistons 117 and 118 housed and guided in recesses 119 and 120 of the base are in support against the flat portions, under the thrust of two sets of springs 121 and 122. Screws 123 and 124 make it possible to adjust the initial stress of the springs.

[0090] At rest, the base 115 is maintained in the axis of the ski. In the case of a torsional bias whose moment applied to the base is greater than the return moment induced by the springs, the base pivots about the pivot. When the torsional bias is reduced, the springs bring the plate back in its resting position aligned on the ski.

[0091] Alternative constructions could be adopted. For example, the springs could be housed in a fixed box on the ski, and the pivot could be affixed to the base.

[0092] Other modes of construction of the release mechanism could also be used.

[0093] Finally, the object of the invention is to associate these attaching and retaining elements to an interface device with the ski, which is disengageable, non-releasable, and has an automatic reengagement. The advantage of such a system is to enable the separation and offset of the base and the ski in certain cases of excessive biases. However, the base is capable of repositioning itself on the ski without the skier having to maneuver a lever or other mechanism.

[0094] Furthermore, the boot that has been described in its various embodiments can be associated with other interface devices, which have retaining members provided to cooperate with the boot hooking members, and which are not equipped with a release mechanism such as that which has been described. This means that the same boot involved can be used for various activities, each of them using a different interface device, but with retaining members that are compatible with the boot hooking members. The interface device that has been described with its release mechanism is more particularly adapted to skiing, or to the practice of a walking or gliding activity where the boot is required to be capable of separating temporarily from the gliding apparatus without being released in the case of excessive bias.

[0095] The present description is provided for guidance only, and other embodiments of the invention could be adopted without leaving the scope thereof.

[0096] In particular, the boot attaching members could be rods or pins, or could have any other appropriate cross section capable of enabling hooking of the boot. Instead of the two members being retractable, only one being movable could be sufficient. Both attaching members could also be fixed, and at least one of the retaining members of the base could be retractable.

[0097] The instant application is based upon French Patent Application No. 00 01266, filed Jan. 28, 2000, the disclosure of which is hereby incorporated by reference thereto in its entirety, and the priority of which is hereby claimed under 35 U.S.C. §119.

Claims

1. An assembly for retaining a boot on a gliding or walking apparatus, said assembly comprising: a boot; and an interface device adapted to receive the boot and to be assembled to the gliding or walking apparatus, the device including an elongated base, extending in a longitudinal direction, said base being adapted to support said boot and comprising, in an upper portion, a device for retaining the boot and, in a lower portion, a device for assembly to the gliding apparatus, said retaining device comprising retaining members, located along a direction transverse to said longitudinal direction of said base, or set back with respect to the ends of the base along a longitudinal direction, said retaining members being structured to cooperate with complementary members for attaching said boot, said assembly device including a non-releasable release mechanism with automatic return.

2. An assembly according to claim 1, wherein: said assembly device includes at least one cable connecting said base to the ski, said cable unwinds against the return force of a spring.

3. An assembly according to claim 1, wherein: a transverse cradle is affixedly attached to said base; and said cradle has lateral flanks that carry said retaining members of said boot.

4. An assembly according to claim 1, wherein: said boot comprises a sole and has a second attaching member on a front of said sole; and said base has, on the front, a second retaining member provided to cooperate with the second attaching member.

5. An assembly according to claim 1, wherein: said boot attaching members include two sliding bolts or rods or pins that are movable between a projecting position with respect to edges of a sole of said boot and a retracted position.

6. An assembly according to claim 5, wherein: a spring is provided to draw the sliding bolts, rods or pins in the retracted position; and a lever maintains the sliding bolts, rods or pins in a projecting stable position.

7. An interface device for the assembly for retaining a boot on a gliding or walking apparatus as defined in claim 1, said interface device comprising: a base provided to receive said boot, said base having, in an upper portion, attaching members oriented transversely provided to cooperate with said boot and, in a lower portion, a device for assembly to the ski with a detachable but non-releasable release mechanism and with automatic return.

8. An interface device according to claim 7, wherein: said base is pivotally mounted on a pivot provided with two flat portions against which springs are in support.