Safety Binding For Releasably Securing A Boot To A Ski

Abstract

A safety binding for a ski has a vertical post 4 over which a plate 5 having front and rear boot engaging ridges 32, 33 is rotatably mounted. The post has a rear transverse groove 15 which accomodates a spring piston biased half-axle 16. A retention lever 18 is secured to the half-axle and extends forward over the post to engage and urge downwardly a transverse pin 23 mounted in a recess 29 in the bottom of a boot. The binding is operated by a pivoted cam lever 38 which withdraws the piston 10 and allows spring 26 in the center of the post to push the lever 18 upwards about the half-axle. Quick release in case of accident is facilitated by the rocking of the boot about the toe or heel whereby pin 23 is forced up and out from under the lever 18.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a safety binding for releasably securing a boot to a ski.

2. Prior Art

The standard safety bindings comprise a relatively large number of parts, more particularly two sets of parts designed to secure the heel and the front end of the boot. These bindings have to be mounted on the ski with great care to adapt them exactly to the boot and the weight of the skier etc., and, in practice, the safety of the standard bindings leaves much to be desired.

SUMMARY OF THE INVENTION

The present invention is designed to obviate the above disadvantages. The safety binding according to the invention is characterized in that it comprises a base plate integral with the ski and a vertical axle on which pivots a rotating plate. Arranged at the front and rear of the rotating plate are two catches engaged in two transverse grooves in the sole of the boot. This sole is characterized in that it is provided with a recess in which is arranged a retaining element pressed towards the rotating plate by another retaining element governed by the pressure of a spring mounted on the rotating plate. These elements are capable of being disengaged from each other at random to detach the boot from the ski and to release themselves automatically in the event of an accident.

An embodiment of the binding according to the invention is represented by way of example in the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of the binding substantially along the line I--I of FIG. 2,

FIG. 2 is a horizontal sectional view of the binding substantially along the line II--II of FIG. 1,

FIGS. 3 and 4 are vertical sectional views corresponding to FIG. 1 but showing the positions of the device in the event of a forward fall and a backward fall,

FIG. 5 is a horizontal sectional view corresponding to FIG. 2 but showing the position of the device in the event of a sharp twist,

FIG. 6 is a vertical sectional view of a rear part of the device showing a lever in position for removal of the boot.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The binding shown comprises a base plate 1 integral with the ski 2 on which it is secured by way of the screws 3, only one of which is shown. A vertical pivot post 4 is integral with the base plate 1 and acts as a pivot for a rotating plate 5 on which a boot 6 is secured. The base plate 1 is provided on its upper surface with a sliding zone 7, for example, a "Teflon" coating, to reduce friction between the two plates 1 and 5. The upper surface of the rotating plate 5 is provided with a groove 8 in which is embedded the base of a housing 9 containing a piston 10 with its shaft 11 enclosed by a dish-shaped compression spring washer commonly known as a "Belleville." The housing 9 is integral with the rotating plate 5 to which it is secured by way of screws 13, only one of which is shown.

The vertical pivot post 4 which acts as a pivot for the rotating plate 5 and the housing 9, is provided with a peripheral groove 14 and a rear, transverse groove 15 in which is housed a part of a transverse axle 16, the ends of which are integral with the two opposite walls 17 of a retention lever 18 having a U-shaped profile. The transverse axle 16 is provided with a groove 19 in which the front part of the piston 10 engages. The base 20 of the groove 19 is flat and forms an acute .alpha. angle with the front plane 21 of the piston 10. As a result, the force of the spring tends to cause the axle 16 to pivot with the lever 18 in the directions of the arrow 22, keeping the lever 18 on a retention axle 23 integral with the boot 6. The vertical pivot post 4 is provided with a central hole 24, in which slides a piston 25, which, under the action of a small spring 26 tends to push back the lever 18 in the opposite direction to the arrow 22. This is only possible when the spring 12 is decompressed. The hole 24 is plugged at the bottom by a threaded stopper 27.

The sole 28 of the boot 6 is provided at the lower part with a recess 29, in the front part of which a retention axle 23 is located. The retention lever 18 normally exerts pressure on the retention axle 23 thereby pressing the sole 28 on the rotating plate 5. The sole is also provided with two transverse grooves 30 and 31 in which are engaged two transverse catches 32 and 33 having a partially cylindrical profile. These catches are arranged at the front end and rear end of the rotating plate 5.

The rear end of the spring 12 which is lodged in the housing 9 abuts against a sliding head 34 of a screw 35 provided with a regulating screw 36 which the spring 12 pushes against a cam 37 formed by two parallel walls of a lever 38 for the attachment and removal of the boots. The lever 38 pivots about a transverse axle 39 provided at the lower end of the housing 9. The cam 37 has two support surfaces 40 and 41. These are arranged at different distances from the axle 39. In the position for attaching the boot (FIGS. 1-5), the surface 40, which is a relatively large distance from the axle 39 is in contact with the screw 36. As a result, the spring 12 is compressed and keeps the retention lever 18 in its normal position (FIGS. 1 and 2). It is obvious that the force of compression depends on the position of the regulating screw 36. In the position for removing the boot (FIG. 6), the surface 41, which is a relatively short distance from the axle 39, is in contact with the screw 36. Consequently, the spring 12 is decompressed and no longer keeps the retention lever 18 on the retention axle 23 and it is then possible to readily detach the boot from the rotating plate 5. This is facilitated by the action of the piston 25, which, under the action of the small spring 26, pushes the retention lever 18 upwards.

With reference to FIGS. 3-5, the operation of the device in the event of an accident will now be described. In FIGS. 3-5, the vertical axis is shown as a main axle, the piston 25 and the spring 26 having no particular role as far as safety is concerned.

When a forward fall occurs, the sole 28 begins to pivot about the front catch 32 until its forward end touches the ski 2, as shown by the continuous lines in FIG. 3. The retention lever 18 was raised when the spring 12 was compressed and it will be noticed that the angle .alpha. has grown larger. As soon as the front end of the sole 28 touches the ski, the sole then continues to pivot on the ski, as shown at 28' by the line of dots and dashes, so that the boot is then completely detached from the securing device. The fact that the boot pivots from 28 to 28' on the end of the sole has no particular role in the securing operation. In fact, due to the play between the parts, the force on the axle 23 is lower in this position.

FIG. 4 shows what happens in the case of a backward fall. The sole 28 first pivots on the rear catch 33 and then on its rear edge which, at the level of the recess 29 enters into contact with the housing 9 as shown at 28', until the sole is completely detached from the rotating plate 5. In the position of the sole 28 represented in continuous lines, the skier may possibly still return to a normal position after beginning to fall. It will be noted that the movement of the boot is fairly appreciable and consequently the effort on the part of the leg of the skier relatively small.

When a violent frontal impact on the ski occurs -- which in any event will be followed by a forward fall-- the sole 28 can slide forwards on the plate 25 by passing over the two catches 32 and 33, thereby disengaging very rapidly the retention axle 23 from the retention lever 18 without necessitating any pivoting.

FIG. 5 illustrates the case of a strong torsional force acting between the ski and the boot 6. The rotating plate 5 and the housing 9 pivot about the vertical axle 4 so that the transverse axle 16 tends to leave the transverse groove 15 of the vertical axle 4, pivoting at the intersection 42 of this groove 15 with the peripheral grove 14. As a result, the retention lever 18 is pushed backwards disengaging the retention axle 23 against the force of the spring 12, which tends to prevent the return movement of the piston 10. In the position shown in FIG. 3, the retention axle 23 is not yet completely disengaged but it is obvious that if the plate 5 rotates a little further, or if the torsional movement is followed -- as it generally is -- by a forward or backward fall, the retention lever 18 will completely release the retention axle 23.

The binding arrangement described is extremely simple and efficient. It has less parts than the normal binding devices comprising a number of different parts which have to be separately rendered integral with the ski.

In particular, it should be noted that to regulate the detachment of the boot in case of a forward fall, a backward fall or a torsional movement, only one regulating operation is required, that of regulating the spring 12 by means of the screw 36.

To carry out the regulating operation, taking into account as usual a vertical force V (FIG.1) acting on the rear part of the boot 6 and a horizontal force H (FIG. 5) acting on the front part of the boot and being capable of detaching the boot, the parts of the present binding device are dimensioned so that the ratio H:V is between 1:3 and 1:4. In view of the fact that the base plate 1 is very short and more particularly is shorter than the sole 28, the operation of the binding device is practically completely independent of the bending and torsional movements of the ski 2. It is no longer necessary to carry out delicate regulating operations to adapt the binding device to the boot-- these regulating operations often being carried out without due attention. The binding device can be mounted on the ski by the ski manufacturer. The sliding zone 7 prevents uncontrollable sliding friction which renders illusory the regulation of the torsional force of disengagement in the case of the known devices. It should also be noted that the housing 9 which contains lubricating oil, is practically seal-tight so that the axles 4 and 16, the piston 10 and the spring 12 are always in perfect operating condition. The catches 32 and 33 may possibly be arranged on the rotating plate 5 in such a manner as to be displaceable on this plate in a regulatable manner in the longitudinal direction.

Claims

What is claimed is:

1. A safety binding assembly for releasably securing a boot to a ski, comprising:

a. a base plate (1) integral with a ski,

b. a vertical axle post (4) upstanding from the base plate and having a transverse groove (15),

c. a rotating plate (5) pivoted about the axle and having front and rear catches (32, 33)thereon,

d. a boot (6) having two transverse grooves (30, 31) in its sole (28) adapted to engage the front and rear catches, and a transverse pin (23) mounted in a recess (29) in the sole,

e. a transverse axle (16) partially lodged in the transverse groove of the vertical axle and having a surface (20),

f. a lever (18) integral with the transverse axle for engaging the transverse pin and urging it toward the rotating plate,

g. a housing (9) integral with the rotating plate,

h. a sliding piston (10) mounted in the housing and having a front surface (21) bearing against the surface of the transverse axle and forming an acute angel (.alpha.) therewith, and

i. a spring (12) mounted in the housing for urging the piston against the transverse axle and the lever against the transverse pin, the transverse pin and the lever being capable of manual disengagement from each other to detach the boot from the ski, and automatic disengagement in the event of an accident.

2. A safety binding assembly according to claim 1, characterized in that the state of compression of said spring (12) depends on the position of a cam lever (38) for the attachment and detachment of the boot forming a cam (37) having two positions, the one for the attachment of a boot and the other for removal of a boot.

3. A safety binding assembly according to claim 2, characterized in that the cam (37) acts on a regulating nut (36) disposed on a screw (35) against which abuts an end of said spring (12).

4. A safety binding assembly according to claim 2, characterized in that the vertical axle (4) is provided with a central hole (24) in which are disposed a piston (25) and a spring (26) pushing said piston against said lever (18) to move it away from the transverse pin (23) when the cam lever (38) is in position for removal of the boot.

5. A safety binding assembly according to claim 1, characterized in that, in the event of a forward or backward fall, the sole pivots about the front catch or the rear catch (32 and 33 respectively), the transverse pin (23) raising the lever (18).

6. A safety binding assembly according to claim 1, characterized in that, in the case of a torsional movement between the boot and the ski, the transverse axle (16) partially leaves the transverse groove (15) of the verticle axle (4), pivoting at an intersection (42) of this groove (15) with a peripheral groove (14) of the verticle axle (4) and consequently displacing the lever (18) is a rearward direction.

7. A safety binding assembly according to claim 1 characterized in that a sliding zone (7) is disposed between the base plate (1) and the rotating plate (5).