FR2605889A1 - BACKGROUND SKI WITH ITS SHOE FIXING DEVICE - Google Patents

Abstract

1. Cross-country ski equipped with a device for fixing the boot, this fixing device comprising means for indirect articulation of the boot, characterised - in that the upper part (2) of the body of the ski has two transverse recesses (19), which are symmetrical in relation of the medial longitudinal axis of the ski, extending along a defined section (L) of the ski starting under the point intended for the point of the boot and continuing in the direction of the tip, these two recesses (19) giving to this upper part (2) and this section (L) of the ski two vertical lateral sides (20) which between them allow the vertical passage of two first longitudinal arms (18), this vertical passage occurring by means of the rotation of these two arms around their higher ends, each of which is articulated to one of the two ends of a transverse shaft (6) which crosses these lateral sides approximately under the point intended for the point of the boot, - in that the lower ends of these two arms provide articulation for the lower ends (24, 25) of two second longitudinal arms (17), each placed above the first linked arm (18), in the same vertical plane and so as to form an acute angle (a) with this first arm (18), - and in that the higher sections of these two arms serve to attach the boot-fixing device (7) directly to them, the first arms being lowered when the back of the boot is lifted on striding, whilst at the same time the angle (a) between each first and second arm increases and the point of the boot moves forward, on the upper part (3) of the ski, the means (17, 16) being in addition provided on the rotating structure formed by the transverse shaft (6) and the four longitudinal arms (17, 18) to return automatically the back of the foot to its starting position after the stride.

Description

! "Cross-country skiing with its shoe attachment device" La

  The present invention relates to a cross-country ski equipped with a device for fastening the boot, this fixing device comprising

  means for the indirect articulation of the shoe.

  Whether the cross-country skiing is done using the alternative step technique or the skating step technique, there is always, at each stride, lifting of the back part of the shoe, which tends to turn around. from its tip while the ski remains on the ground. The lifting of the back of the shoe is much more important in the

  case of the alternative step than in that of the skater's step.

  With the bindings currently known, the tip of the shoe does not remain fixed in position during the stride, but, compared to the upper part of the ski, it lifts and advances at a time. The lifting of the tip of the shoe causes a parasitic effort for the skier oriented towards

the top, called lifting effort.

  The invention aims to favor the advancement of the tip of the boot relative to its lifting, to minimize the parasitic lifting effort, and lengthen the stride accordingly. For this

  - The upper part of the body of the ski has two decro-

  transverse formations, symmetrical with respect to the longitudinal axis of the ski, extending over a defined portion of the ski going under the tip of the boot and going towards the spatula; these two recesses confer, at this upper part and on this portion of ski, vertical lateral faces which allow against them the vertical deflection of two first longitudinal arms. This vertical deflection is effected by rotation of these two arms around their upstream ends, which are articulated each respectively on one of the two ends of a transverse axis which passes through these vertical side faces under the tip of the shoe. - The downstream ends of these two arms serve as articulation to

  downstream ends of two second longitudinal arms, placed respectively

  each above the first associated arm, in the same plane

  vertical and so as to form an acute angle with the first arm.

  - The upstream parts of these second arms are used for their

  directly connect the attachment device of the shoe.

  - The first arms are lowered when the back of the shoe is raised during a stride, while simultaneously the angle between each

  first and second arm increases and the tip of the shoe advances.

  This rotational assembly formed by the transverse axis and the four longitudinal arms is arranged to automatically return the rear of the

  shoe in starting position after the stride.

  The invention will be well understood, and its advantages as well as others

  characteristics will emerge, in the course of the following description of a

  nonlimiting embodiment, with reference to the accompanying schematic drawings in which - Figure 1 is a perspective view of the device of the invention; - Figure 2 is a simplified side view of this device; - Figure 3 is a view similar to Figure 2, with the stirrup tilted forward during a stride; - Figure 4 is an enlarged side view, partially cut, of this device; - Figure 5 is a cross section along the line V-V of Figure 4; - Figure 6 is a perspective view of a variant of this device. In Figure 1 is partially shown a cross-country ski 1 which has a longitudinal rib 2 limited by an upper face 3 and two inclined side faces 4 which connect this upper face to two edges 5 of reduced height. The rib 2 is traversed by a transverse axis 6 located below its upper face 3 and serving for the indirect articulation of the shoe. The shoe, not shown here, comprises, along the entire length of its sole, a complementary groove

of the rib 2 of the ski.

  On the axis 6 is articulated the attachment of the shoe, generally designated 7. This comprises, in a manner known per se, a stirrup 8 in the shape of an inverted U, whose two branches extend from one side to the other. other of the rib 2 and are joined by a cross member 9 located above this rib. The stirrup 8 is shaped for the interlocking of a complementary part, not shown here, formed at the front of the shoe, and it is equipped with means ensuring the immobilization and locking of the front of the shoe on stirrup. In this example, these means include a

  lever 10, also inverted U-shaped, which is outside the stirrup 8.

  The lateral branches of this lever 10 are joined, near their articulation axes 11, 12, by a shaft or transverse axis 13 which can move in two circular arcuate slots 14 pierced in the two branches of the stirrup 8 concentrically to the hinge pin 11, 12 of the lever 10 on this yoke. When the fastener is locked by raising the lever 10, the front of the boot is pinched between the movable transverse axis 13 of the outer lever 10 and the fixed crosspiece 9 of the stirrup-8. Means are provided to hold the stirrup 8 and the lever 10 of the fastener in the locked position: the upper face of the crosspiece 9 is provided with a groove, while the lever 10 has a latching pallet 15 in this groove , this pallet being a toggle pallet associated with an elastic return device of the pallet in the latching position. Furthermore, the bases of each of the branches of the inner yoke 8 are joined by a cross member 16, offset in the direction of the shoe, and profiled so as to closely match the contour of the rib 2 on which it comes to rest, and to be married by the groove of the sole of the shoe. This type of fastener, which does not form the subject of the invention, is described in the French applications N 85 18723 and 86 10119, filed by the applicant, respectively December 5, 1985 and June 30, 1986, both under the heading "device for attaching a shoe to

a cross-country ski ".

  As best seen in Figure 4, the attachment 7, which could be of a type other than that shown, is reported on a set

  rotational axis formed by the transverse axis 6 and two pairs of longitudinal arms

  dinices 17,18 placed one on the other and joined by their downstream ends. These two pairs of longitudinal arms are placed on either side of the groove 2, which is shaped to allow simultaneous vertical movement of these two pairs of arms, by rotation about their common hinge axis 6. For this, the rib 2 has, on at least the length of the arms 17,18, two transverse recesses 19, symmetrical with respect to the longitudinal axis of the ski, which leave under the tip of the

  shoe to stop slightly downstream of the arms 17,18. These declines

  19 give to the rib 2, on a portion defined by their length L, vertical side faces 20 against which can be

  to debate the arms vertically 17,18.

  The two arms 17 are made of an elastic material, such as an elastomer. They each comprise an insert 21 consisting of a small metal plate pierced with two holes which pass on the one hand to a screw 22 for securing the arm 17 and the base of the stirrup 8, and on the other hand to a positioning pin 23 which is secured to the stirrup 8. The whole of the

  fastening 7 is thus reported on the two elastic arms 17.

  The downstream ends 24,25 of the elastic arms 17 are secured, by means of a cross member 26 passing above the ski and two screws 27,28, at the downstream ends of the longitudinal arms 18, which are rigid arms. The

  cross member 26 and the two arms 18 are for example molded in one piece.

  In the rest position, as in FIGS. 1, 2 and 4, the arms 17 are pressed onto the arms 18. Moreover, the rigid arms 18 are hinged to

  upstream about the axis 6 which passes through the groove 2. A trans-

  versale 29 secured to the stirrup 8 at its downstream base is in contact with the

upper part of the ski.

  The operation of this binding is as follows The starting position, just before the stride, is that of Figure 2. the rear cross member 16 rests on the groove 2 of the ski, if only because the shoe presses on it, and the front cross member 26 is substantially above the upper face 3 of the groove 2. The acute angle between the two arms 17 and 18 has a zero value. The distance between axis 6 and

the axis 12 is then d.

  During the stride, the skier raises his heel and tends to tiptoe forward. The position taken by the attachment is then that of FIG. 3: the rotational assembly 17, 18 rotates in the clockwise direction, the crossbar 26 is lowered, the bar 29 advances by sliding on the upper part 3 of the ski, the elastic arms 17 deviate from the rigid arms 18 as if they were pivoting about their downstream ends 24,25, so that the angle α between the arms 17 and 18 increases. At the end of the stride, the crossbar 26 is lowered to come into contact with the groove 2. By these conjugate movements, the attachment 7 advance on the ski, but does not rise practically. The distance between the axis 6 and the axis 12 has become D. During the stride, the front of the shoe has advanced Dd, and the lifting effort, parasitic for the skier, isprertiquemment removed by the fact that the bar

  29 advance by sliding on the upper part 3 of the ski.

  After the stride, the shoe returns flat on the ski, pressing it crosses 16. The elasticity of the arms 17 closes the angle a, so that the arms 17 return to be pressed on the arms 18. L rotational assembly 6,17,18 thus resumes its starting position of FIG. 2. A stop 30 fixedly located in the housing 20 prevents the arms 18 from pivoting counterclockwise to limit the loss of rear balance.

of the skier.

  The invention is obviously not limited to the example of.

  realization which has just been described, and is likely to be realized from

multiple equivalent ways.

  For example, the superposed arms 17, 18 could both be elastic, and even made in one piece, the axis 6 can then be locked in rotation. Conversely, the arms 17, 18 could both be rigid, articulated one on the other at their downstream ends by means of a hinge pin, and recalled in position after the stride by means of a spring. traction for example, this spring being stretched between their upstream ends. The axis 6 may be an axis locked in angular position, taken from the mass of the ski for example, but be constituted by a torsion bar, forming both articulation and return spring. Equivalently, this axis 6 can be fixed in rotation and in torsion, and the upstream ends of the arms 18 can be hinged to it by means of a spiral spring of

reminder, etc ...

  In another example, the superimposed arms 17-18, also both elastic, could be in a state of prestressing when the attachment is in the rest position, the angle a is then no longer zero. This

  prestressing would increase the value of the elastic return of the fastener.

  In another example, shown schematically in FIG. 6, this attachment principle can be adapted to a cross-country ski conventionally of rectangular section. For this, the upper part of the ski has on at least the length of the arms 17-18 two transverse recesses 19 symmetrical with respect to the median longitudinal axis of the ski which leave under the tip of

  the shoe to stop slightly downstream of the arms 17-18. These declines

  19 give to the upper part of the ski on a portion defined by their length L, vertical lateral forces 20 against which

  can struggle vertically 17-18 arms.

  As it should be, the invention is applicable whatever the

  different possible positions of the axis 6 in height in the decree-

  19, to obtain a prestressing of the elastic arms, the differences

  the respective lengths of the arms 17-18 which will determine d, to adjust the advance of the front of the shoe during the stride, the different densities of the plastic material retained to achieve the arms 17-18, to increase or decrease the value of the elastic return of the attachment, so that the return energy of the attachment can be adapted to the needs of the

  skier, especially his weight and his type of evolution on the snow.

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Claims (9)

  1. Cross-country ski equipped with a device for fixing the boot, this fixing device comprising means for the indirect articulation of the boot, characterized in that the upper part (2) of the body of the ski has two   transverse recesses (19), symmetrical with respect to the axis. longitu-   dinal median of the ski, extending over a defined portion (L) of the ski leaving under the tip of the shoe and going towards the spatula, these two recesses (19) conferring, at this upper part (2) and on this portion (L) of the ski, lateral faces (20) which vertical vertical against vertical movement of two first longitudinal arms (18), this vertical movement being effected by rotation of these two arms around their upstream ends, which are each articulated respectively on one of the two ends of a transverse axis (6) which passes through these vertical lateral faces (20) under the tip of the boot, - in that the downstream ends of these two arms serve   at the downstream ends (24,25) of two second long arms   dinals (17), respectively placed respectively above the first associated arm (18), in the same vertical plane and so as to form an acute angle (a) with this first arm (18), and in that the upstream parts of these second arms are used to directly connect the attachment device (7) of the shoe, - the first arms lowering when the rear of the shoe is raised during a stride, while simultaneously the angle (a) between each first and second arm increases and that the tip of the shoe advances, on the upper part 3 of the ski, means (17,16Y being also provided on the rotational assembly formed by the transverse axis (6 ) and the four arms   (17,18) to automatically return the back of the shoe.   sure in starting position after the stride.   2. Cross-country ski with a fastening device according to claim 1, characterized in that at least one of the longitudinal arms (17) is in one elastic material.   3. cross-country ski with binding according to claim 1 or claim 2, characterized in that the downstream ends of the longitudinal arms (17, 18) are joined by a cross member (26) passing over the skiing (1).   Cross-country ski with binding according to one of claims 1 to 3,   characterized in that the superposed longitudinal arms (17, 18) are made   in one piece in an elastic material.   Cross-country ski with binding according to one of claims 1 to 4,   characterized in that the axis (6) passing through the vertical side faces (20) is a torsion axis which is locked in rotation.   6. Cross-country ski with binding according to one of claims 1 to 4,   characterized in that the axis (6) passing through the vertical side faces (20) is locked in rotation and is connected to the first longitudinal arms (18)   by a return spring connection.   Cross-country ski with binding according to one of claims 1 to 4,   characterized in that the adjustment of the elastic return is obtained by using resilient arms (17, 18) of plastics material of different hardnesses for   increase or decrease the value of the elastic return of the fixation.   8. Cross-country ski with binding according to one of claims I to 4,   characterized in that the axis 6 can be at different heights in the   lateral faces 20 to obtain a prestressing of the elastic arms.   9. Cross-country ski with binding according to one of claims 1 to 4,   characterized in that the length of the arms 17-18 is variable relative to each other to adjust the advancement of the front of the shoe during from the stride.