SKI BOOT BINDING HEELPIECE WITH MOVABLE BODY

Abstract

Ski boot safety binding heelpiece able to occupy at least two positions, an open position and a closed position, in which latter it is suitable for the safe clamping of a ski boot for skiing purposes, the heelpiece comprising a movable body comprising a release spring to allow release of the boot by the opening of the heelpiece in the event of a force greater than a predetermined threshold, this body occupying two different positions in each of the two positions of the heelpiece, the body being movable relative to a carrier (1) about a connecting pivot, and the carrier (1) comprising a carrier base (3) and a release body comprising a release surface, in which the release surface is connected to the carrier base (3) by a first connecting means formed by the release body (4) and by a second connecting means formed by the connecting pivot connecting the carrier (1) to the movable body and at least one reinforcing arm (11).

Description

BACKGROUND OF THE INVENTION

The invention relates to a heelpiece for a “movable body” type safety binding device for a ski boot, that is to say, a device designed to keep the rear of a boot securely on a ski by exerting pressure on the heel of the boot while pressing the whole boot forwards against a front binding device, and ensuring automatic release of the rear of the boot if the skier falls forwards. It also relates to a binding device comprising a front binding device and a heelpiece of this kind, as well as to a ski on which such a heelpiece is mounted.

DESCRIPTION OF THE PRIOR ART

A first family of heelpieces, described as “fixed-body heelpieces”, relies on a fixed body comprising the heelpiece release mechanism and on a very simple separate component which is rotatable relative to this body, of lever type, comprising at its front end a jaw for gripping the heel of a boot. Rotating this “jaw lever” relative to the fixed body enables the heelpiece to occupy two positions, one closed and one open, for locking or releasing a ski boot.

The present invention relates to a second family of heelpieces, referred to as “movable-body heelpieces”, which relies on a movable body able to occupy a closed position and an open position, comprising at its front end a jaw for gripping the heel of a boot in the closed position and in its rear part a mechanism for implementing the release function which releases the rear of the boot if a large force occurs, as when the skier falls forwards. This body is usually rotatable about a carrier attached to the ski, and can occupy the closed position for skiing and the open position in which the skier can remove his or her boot.

One example of a heelpiece belonging to this second family of patents is described in document FR2507095. This solution however has the disadvantage of having a central body on which the very large movable body pivots. This creates difficulties in adjusting the pivoting of this movable body and limits the amplitude of its rotation, as it cannot reach a high enough position in the open position to make it easy to remove the boot and cannot reach a low enough position in the closed position to exert a satisfactory forward force on the boot, resulting in poor release during a twisting fall and requiring precise longitudinal positioning of the adjustment to the length of the boot. Additionally, a central body of this kind must be in metal in order to withstand the high forces which can occur in an application with a high release threshold, such as in the case of competition.

Consequently, the preceding approach has been abandoned in favor of other heelpieces of a different design belonging to this second family. Examples are described in patents EP1745827, FR2765115 and EP0893146. These texts describe a tubular cylindrical body comprising at one end a heel clamp and a cam shaft supporting a cam formed in a cylindrical part connected to two lateral arms of the carrier forming a U-shaped stirrup. The cam shaft represents the axis of rotation of the tubular cylindrical body and forms a cam suspended between two lateral arms. This tubular body provides the release function and usually comprises a helical spring working in compression between a piston which presses against the cam and a stop situated towards the end furthest from the cam. The shape of the cam is such that under spring pressure the boot, once fitted, is pressed forwards against the front binding and downwards against the ski. Only a large force will pivot the body about the cam by pushing the piston back and compressing the spring, thereby causing the heelpiece to open. These heelpieces, which are more expensive and more effective than those of the first or “fixed body” family, rely on a single body combining all the essential binding functions and have release mechanisms which release a boot under very high forces, which is particularly appropriate for competition skiing. However, one drawback with these heelpieces is their great complexity. In particular, the cam which is used is subjected to very high forces due to its position between no more than two lateral bearing points and has to be made of metal in order to withstand these forces. Also, this cam usually has a shape with a flat part, which means that stability can only be achieved in the closed position of the heelpiece and not in its open position, which creates difficulties when putting the boot into and out of the heelpiece.

It is an object of the present invention to provide a simpler and less expensive movable-body heelpiece.

The invention achieves this object by providing an overall heelpiece structure that offers good resistance to the cam forces, is suited to a wide range of operation up to high release thresholds, and allows easy insertion and removal of the boot and satisfactory forward pressure on the boot.

SUMMARY OF THE INVENTION

More specifically, the invention relies on a ski boot safety binding heelpiece able to occupy at least two positions, an open position and a closed position, in which latter it is suitable for the safe clamping of a ski boot for skiing purposes, the heelpiece comprising a movable body comprising a release spring to allow release of the boot by the opening of the heelpiece in the event of a force greater than a predetermined threshold, this body occupying two different positions in each of the two positions of the heelpiece, the body being movable relative to a carrier about a connecting pivot, and the carrier comprising a carrier base or foot and a release body comprising a release surface, in which the release surface is connected to the carrier base by a first connecting means formed by the release body and by a second connecting means formed by the connecting pivot connecting the carrier to the movable body and at least one reinforcing arm.

The release body can thus be connected to the connecting pivot connecting the carrier to the movable body and the release surface may act on a piston of the movable body.

At least that part of the release body which comprises the release surface may be made of plastic or of fiber-reinforced plastic.

The release body may be a one-piece body made of plastic or fiber-reinforced plastic.

The movable body may have a downwardly open region between the jaw of its forward end and a piston acted upon by the release surface of the carrier.

The release body may be a central body extending from the carrier base to the upper part of the carrier.

Additionally, the safety binding heelpiece may comprise two lateral arms arranged on either side of the release body. These lateral arms may define a space between the release body and themselves in such a way as to be able to accommodate a part of the movable body.

The release body may comprise an essentially cylindrical upper part oriented transversely relative to the heelpiece, comprising a transverse tubular opening designed to accommodate the pivot connecting it to the movable body, this upper part comprising the release surface.

The release body may comprise a lower part connecting its upper part to the carrier base, this lower part comprising a narrow part whose dimension measured in the longitudinal direction is between 8 and 14 millimeters.

The movable body may have an amplitude of rotation of more than 70° between its two positions.

The release body and the arm or arms may comprise openings to accommodate the pivot connecting them to the movable body.

In one advantageous embodiment, the release surface may be a ramp.

The invention also relates to a device for binding a ski boot to a ski, comprising a front binding to accommodate the front part of a ski boot, and a heelpiece as described above to accommodate the rear part of the ski boot.

Finally, the invention also relates to a ski comprising a ski boot safety binding heelpiece as described above.

DESCRIPTION OF THE DRAWINGS

These objects, features and advantages of the present invention will be explained in detail in the following description of one particular embodiment offered without implying any limitation with reference to the attached figures, in which:

FIG. 1 is a perspective view of a heelpiece having a movable body in the closed position according to one embodiment of the invention;

FIG. 2 is a perspective view of a heelpiece having a movable body in the open position according to the embodiment of the invention;

FIG. 3 is a cross section on a longitudinal central plane through the heelpiece in the closed position according to the embodiment of the invention;

FIG. 4 is a cross section on a longitudinal central plane through the heelpiece in the open position according to the embodiment of the invention;

FIG. 5 is a perspective side view of the central body of the carrier of the heelpiece having a movable body according to the embodiment of the invention;

FIG. 6 is a perspective side view of the carrier of the heelpiece having a movable body according to the embodiment of the invention;

FIG. 7 is a rear perspective view of the carrier of the heelpiece having a movable body according to the embodiment of the invention;

FIG. 8 is a rear view of the carrier of the heelpiece having a movable body according to the embodiment of the invention; and

FIG. 9 is a bottom perspective view of the movable body of the heelpiece according to the embodiment of the invention.

To facilitate an understanding of the rest of the description, the longitudinal direction x is here defined as the horizontal direction extending from the rear to the front of the heelpiece, the transverse direction y and the horizontal direction perpendicular to the direction x, and the vertical direction z, directed upwards, as perpendicular to the horizontal plane defined by the axes x and y.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The heelpiece according to the embodiment of the invention comprises a tubular body 21 which is movable about a carrier 1 designed for attachment to a ski by means of rails 2 formed on the lateral parts of the lower base or base 3 of the carrier to enable its longitudinal position to be adjusted on a ski to adapt it to different sizes of boots. The movable tubular body 21 comprises at its forward end a jaw or “heel clamp” 22 designed to grip the standardized rear lip of a ski boot.

The movable body 21 which can be seen more particularly in FIGS. 3, 4 and 9, comprises within itself a release mechanism which allows the heelpiece to move automatically from the closed configuration for skiing, shown in FIG. 1, to the open configuration shown in FIG. 2, in which the ski boot can escape from the heelpiece. This release happens automatically if the skier falls and produces a force on the jaw greater than a predefined threshold. The movable body 21 moves from the closed configuration to the open configuration by a rotational movement relative to the carrier 1, about a pivot 10. To implement the release function, the movable body comprises various components in its internal volume, including a compression spring 23 pressing against the stop 25 at the rear top end of the body 21 and against a piston 24 at its other end. This piston 24 is acted upon by a release surface formed on the carrier 1, detailed below. The release threshold can be modified in a known manner by modifying the degree of compression of the spring 23 using an adjustment screw 26 at the rear end of the movable body 21 for moving the stop 25. In this solution, the movable body 21 thus has the feature of presenting a large downwardly open region 29 between its jaw 22 and the release piston 24. This region is intended to accommodate the release surface of the carrier, as will be detailed later.

The concept of the invention consists in reinforcing the release surface or cam which supports the forces of the movable body by connecting it by two complementary connecting means to the base of the carrier, including at least one reinforcing arm and the body which carries the cam. This means that the principal structure of the release surface which receives the greatest forces can be made of plastic, within a fixed body 4, which will be referred to here as the “fixed release body” 4. The fixed release body is of an optimized volume representing a compromise between the volume that is great enough in total to offer a strong enough structure in an inexpensive material, such as a simple plastic for example, optionally reinforced with glass fibers or any equivalent, and a minimized volume to allow satisfactory pivoting of the movable body, easy insertion of the base, and satisfactory forward thrusting of a boot. This concept is less expensive than prior art concepts which require the use of a metal part.

In the embodiment illustrated, the carrier 1, which can be seen in particularly in FIGS. 5-8, comprises a fixed release body 4 that takes the form of a monolithic central portion, in a single body, extending from the base 3 of the carrier near the surface of the ski to the highest part of the carrier, and across a large width of the carrier measured in the y direction. This fixed central body 4 comprises an essentially cylindrical upper part 5 oriented transversely relative to the heelpiece and comprising a transverse tubular opening 6 designed to take the pivot 10 which connects it to the movable body 21. The upper part 5 comprises at its rear end a region that departs from the cylindrical form to form a ramp 7 which performs the release function by acting on the piston 24 of the tubular body 21, as will be detailed later. The ramp 7 extends transversely across the full width of the central body 4, parallel to the transverse opening 6 in the y direction, and is roughly triangular in cross section, having a vertex 8 between an upper slope 9 and a lower slope 9′. This upper part 5 is directly connected to the carrier base 3 by a lower part of the fixed body 4 that extends across the full width of the upper part 5 and has a relatively narrow region of small dimension in the longitudinal direction x. As a result, the body 4 represents a first means of connection and support for the surface of the ramp 7. In the embodiment, this narrower region comprises a minimal dimension L of around 11 millimeters, illustrated in FIG. 5. The use of a release body 4 that is narrow in the lower part beneath the release ramp 7 is advantageous because it saves space, facilitating the placing in movement of the movable body 21 and allowing the definition of the release ramp that facilitates the engagement and disengagement of the boot in the heelpiece while providing an effective release function. More generally, a minimal dimension of this body in the longitudinal direction x of between 8 and 14 millimeters is advantageous. With such a geometry, the movable body achieves an amplitude of rotation of more than 70°. When it is in its closed position shown in FIG. 1, it has a high position in which the axis of symmetry of the spring 23 is at an angle of about 65° above a horizontal plane, containing the rotary pivot 10, which allows the jaw 22 to exert a large forward thrust on the inserted ski boot to ensure release by rotation of the front stop in the event of a twisting fall by the skier. When it is in its open position shown in FIG. 2, it has a low position in which the axis of symmetry of the spring 23 is at an angle of about 8° below the horizontal plane containing the rotary pivot 10, which allows the jaw 22 to reach an upward orientation suitable for easy insertion of a ski boot. In the embodiment depicted, the movable body thus has an amplitude of rotation of 73° between its two extreme positions. In a variant, a reinforcing rib (not shown) may be provided between the lower slope 9′ of the ramp 7 and the narrow part of the lower part of the fixed body 4.

Two lateral arms 11 are additionally attached to the carrier 1. At the top of these are openings 12 to take the connecting pivot 10 which extends transversely from one arm to the other through the opening 6 formed in the fixed central body 4 and through openings 27 formed in two lower lateral wings 28 of the movable body 21, as can be seen in FIG. 9, which fit into the space 13 between the arms 11 and the central body 4 of the carrier 1. By means of this construction, some of the release forces applied to the ramp 7 of the central body 4 are transmitted through the connecting pivot 10 to the lateral arms 11. The latter thus reinforce the whole structure and represent a second ramp 7 linking and supporting means, allowing the heelpiece to function at very high release levels, greater than 12 in the unit of values defined by the ISO standard for competition alpine bindings. These attached arms 11 may be made of the same material as the body 4, in plastic, optionally reinforced with fibers or metal parts. As a variant, the arms 11 may be made entirely of metal. They are screwed at the bottom to the base 3 of the carrier 1. As a variant, any fixing means may be suitable, such as clips, adhesive bonding or the like. In yet another variant, the arms could be molded integrally with the carrier base and/or with the release body.

The way the heelpiece works can be seen particularly in FIGS. 3 and 4. In FIG. 3 the heelpiece is in the closed configuration with the piston 24 pressing down on the upper slope 9 of the ramp 7 in a stable position. If a force greater than the predefined threshold is exerted by the boot on the jaw 22 of the heelpiece, as for example if the skier falls forward, the piston 24 is driven back until it reaches the vertex 8 of the ramp 7 before finally pivoting around onto the lower slope 9′ of the ramp 7, into the second more open stable position shown in FIG. 4.

The release surface on the carrier has been depicted by way of a ramp 7, which offers an advantageous release behavior. However, this surface could be different and in a variant could be more generally in the form of any cam surface. Moreover, this release surface could be of any size and thus could for example occupy less than the full width of the release surface.

Further, this surface has moreover been illustrated as extending across the full width of a central body of the carrier between two attached arms. As a variant, the release body comprising the release surface could be of any other geometry, including not being a central body. However, this body has a shape that allows a direct connection between the release surface positioned at its upper end to the carrier base by a connecting means separate from the connecting pivot 10 and/or the attached arms. The release body could occupy more than half the width of the heelpiece to have a volume such that it can have great strength. Moreover the release body will advantageously be a one-piece component so that it can be injection-molded or shaped in a plastic and the release surface will occupy a large surface area in order to have sufficient strength. This body may be made of any rigid plastic, such as polyamide, optionally reinforced by a fiber-based structure. In a variant, the release body may be an assembly of a number of separate components, optionally made of different materials. For example, this body may comprise a top part made of plastic comprising the release surface, and a bottom part underneath this release surface to connect it directly to the carrier base, which bottom part may be made of any material.

Lastly, the shape of the attached arms may also be different. For example, the arms may be positioned in contact with the central fixed body and not define a space 13 as in the embodiment depicted, in which case the movable body would be positioned on the outside of these attached arms. Alternatively, a single attached arm may be sufficient. In this case, this arm could be centered and could pass through an opening in the release body, for example. This arm or these arms take the form of a component connected to the carrier base and separate from the release body, so as to form a reinforcement of this release body while supporting some of the forces acting on the release surface and transmitted by the pivot of the movable body. The arm or arms may be of any shape and size to allow this function to be performed.

The concept of the invention can thus be summarized as the use of a carrier for receiving a movable body of a heelpiece in the second family referred to in the preamble, this carrier comprising a construction in which a base forms its bottom part, suitable for connection to a ski, and in which the release surface is not only directly connected by the release body to this base, by a first connecting means, but is also connected in parallel to the base by at least one reinforcing arm, through the mounting pivot of the movable body of the heelpiece, by a second connecting means, the release surface and the reinforcing arm both being connected to the connecting pivot of the movable body of the heelpiece.

Claims

1. A ski boot safety binding heelpiece able to occupy at least two positions, an open position and a closed position, in which latter it is suitable for the safe binding of a ski boot for skiing purposes, the heelpiece comprising a movable body (21) comprising a release spring (23) to allow release of the boot by the opening of the heelpiece in the event of a force greater than a predetermined threshold, this body (21) occupying two different positions in each of the two positions of the heelpiece, the body (21) being movable relative to a carrier (1) about a connecting pivot (10), and the carrier (1) comprising a carrier base (3) and a release body (4) comprising a release surface, wherein the release surface is connected to the carrier base (3) by a first connecting means formed by the release body (4) and by a second connecting means formed by the connecting pivot (10) connecting the carrier (1) to the movable body (21) and at least one reinforcing arm (11).

2. The ski boot safety binding heelpiece as claimed in claim 1, in which the release body (4) is also directly connected to the connecting pivot (10) connecting the carrier (1) to the movable body (21) and in which the release surface acts on a piston (24) of the movable body (21).

3. The ski boot safety binding heelpiece as claimed in claim 2, in which at least that part of the release body (4) which comprises the release surface is made of plastic or of fiber-reinforced plastic.

4. The ski boot safety binding heelpiece as claimed in claim 3, in which the release body (4) is a one-piece body made of plastic or fiber-reinforced plastic.

5. The ski boot safety binding heelpiece as claimed in claim 1, in which the movable body (21) has a downwardly open region (29) between the jaw (22) of its forward end and a piston (24) acted upon by the release surface of the carrier (1).

6. The ski boot safety binding heelpiece as claimed in claim 1, in which the release body (4) is a central body extending from the carrier base (3) to the upper part (5) of the carrier.

7. The ski boot safety binding heelpiece as claimed in claim 6, comprising two lateral arms (11) arranged on either side of the release body (4).

8. The ski boot safety binding heelpiece as claimed in claim 7, in which the lateral arms (11) define a space (13) between the release body (4) and themselves in such a way as to be able to accommodate a part (28) of the movable body (21).

9. The ski boot safety binding heelpiece as claimed in claims 6, in which the release body (4) comprises an essentially cylindrical upper part (5) oriented transversely relative to the heelpiece, comprising a transverse tubular opening (6) designed to accommodate the pivot (10) connecting it to the movable body (21), this upper part (5) comprising the release surface.

10. The ski boot safety binding heelpiece as claimed in claim 9, in which the release body (4) comprises a lower part connecting its upper part (5) to the carrier base (3), this lower part comprising a narrow part whose dimension measured in the longitudinal direction is between 8 and 14 millimeters.

11. The ski boot safety binding heelpiece as claimed in claim 1, in which the movable body (21) has an amplitude of rotation of more than 70° between its two positions.

12. The ski boot safety binding heelpiece as claimed in claim 1, in which the release body (4) and the arm or arms (11) comprise openings (6, 12) to accommodate the pivot (10) connecting them to the movable body (21).

13. The ski boot safety binding heelpiece as claimed in claim 1, in which the release surface is a ramp (7).

14. A device for binding a ski boot to a ski, comprising a front binding to accommodate the front part of a ski boot, and wherein it comprises a heelpiece as claimed in claim 1 to accommodate the rear part of the ski boot.

15. A ski comprising a ski boot safety binding heelpiece as claimed in claim 1.