US3836163A

US3836163A - Heel supporting device for a ski safety binding

Info

Publication number: US3836163A
Application number: US00305614A
Authority: US
Inventors: N Hashioka
Original assignee: Hope KK
Current assignee: Hope KK
Priority date: 1971-11-25
Filing date: 1972-11-10
Publication date: 1974-09-17
Anticipated expiration: 1991-09-17
Also published as: CH562619A5; IT971032B; FR2161069B1; JPS4858929A; AT323025B; FR2161069A1; CA964686A; DE2255976A1

Abstract

A heel supporting device which forms a part of a ski safety binding that automatically opens when an excessive force is exerted on the ski boot. The heel supporting device includes heel holding means which comprise a pin secured to a casing, a lever pivotably connected to a supporting member and adjustable spring means for pressing the lever to the pin. The lever has a notch and a curved face contiguous to the notch. The pin is engaged in the notch at a normal position of use and is disengaged from it to release the heel of the ski boot when a strong upward directed force is applied to the heel. When the skier steps down his boot to fit it with the ski binding, the pin slides along the curved face of the lever and engages in the notch without pushing the lever against the force of the spring thereby facilitating connection of the ski boot to the ski binding.

Description

United States Patent Hashioka Sept. 17, 1974 [75] Inventor: Noriyasu Hashioka, Tokyo, Japan [73] Assignee: Hope Kabushiki Kaisha, Tokyo,

Japan [22] Filed: Nov. 10, 1972 [21] Appl. No.: 305,614

[30] Foreign Application Priority Data Nov. 25, 1971 Japan 46-94132 [52] US. Cl. 280/11.35 T [51] Int. Cl. A63c 9/08 [58] Field of Search 280/1 1.35 T

[56] References Cited UNITED STATES PATENTS 3,317,217 5/1967 Poiger 280/11.35 T 3,391,944 7/1968 Shimizn 1 2530/1135 T 3,554,571 1/1971 Smolka 280/1 1.35 T

Primary Examiner-Robert R. Song Attorney, Agent, or Firm-Diller, Brown, Ramik & Wight 5 7 ABSTRACT A heel supporting device which forms a part of a ski safety binding that automatically opens when an excessive force is exerted on the ski boot. The heel supporting device includes heel holding means which comprise a pin secured to a casing, a lever pivotably connected to a supporting member and adjustable spring means for pressing the lever to the pin. The lever has a notch and a curved face contiguous to the notch. The pin is engaged in the notch at a normal position of use and is disengaged from it to release the heel of the ski boot when a strong upward directed force is applied to the heel. When the skier steps down his boot to fit it with the ski binding, the pin slides along the curved face of the lever and engages in the notch without pushing the lever against the force of the spring thereby facilitating connection of the ski boot to the ski binding.

5 Claims, 4 Drawing Figures HEEL SUPPORTING DEVICE FOR A SKI SAFETY BINDING This invention relates to a heel supporting device which forms a part of a ski safety binding, which is adapted to open automatically and release the heel of the ski boot from the ski for protecting the skiers leg when an excessive force is exerted on the ski boot due to a forward fall of the skier, an unusual operation of the ski and other causes.

Various heel supporting devices have been proposed and used which comprise a base plate attached fixedly to a ski, a supporting member provided on the base plate, a casing covering the supporting member and being pivotably connected thereto, which has a heel supporting member adapted for engaging the heel of the ski boot at the front end thereof and heel holding means which depress the casing toward the base plate at a closed position of the casing (hereinafter referred to as a normal position of use) thereby pressing the heel firmly on the ski and release the casing upwardly when a strong upwardly directed force occurs.

It is one of the conditions with which a heel supporting device must comply that a heel depressing spring which constitutes an element of the heel holding means should have a pressing force which is sufficient to cause the heel supporting device to press the heel of the ski boot firmly upon the ski and prevent it from releasing during ski operation except in the case where an excessive stress is applied to the ski binding due, for example, to a forward fall of the skier. For this purpose, the critical value of the pressing force which is equal to the minimum value of the excessive force which causes the heel to be released from the heel supporting device must be adjusted to a suitable value from the standpoint of safety in the event of occurence of the excessive force as well as that of firm clamping of the heel during the normal operation of the skis. The prior art heel supporting devices, however, have a problem that the stronger the pressing force of the spring, the greater is force required for stepping the ski boot down to fit it with the ski binding from a state in which the casing is pivoted upwardly and the heel supporting device is at its fully released position (hereinafter referred to as a released position). Accordingly, when the skier who has fallen on a sharp slope and had his boot removed safely from the binding tries to step his boot down to refit it with the binding while standing on the sharp slope, he finds difficulty in affording a sufficient step-down force to the binding if the pressing force of the spring is strong, such difficulty becoming greater proportionally to the magnitude of the pressing force of the spring. The reason for requiring such great force in stepping down the boot is that the release of the casing from its normal position of use at a strong upwardly directed force is effected by compressing the spring which forms an element of the heel holding means and, when the casing has reached its fully released position, the spring has stretched again to lock the casing at the fully released position. Accordingly, the step-down action of the ski boot requires pivoting of the casing against the force of the spring which has to be once compressed before the casing reaches its normal position of use. This naturally requires a substantially great provide a novel heel supporting device of a ski safety binding which has eliminated the above described disadvantage of the prior art devices.

It is another object of the invention to provide a heel supporting device which satisfies the two mutually conflicting conditions that a strong heel depressing force should be maintained for preventing an unexpected release of the boot during skiing and that connection of the ski boot to the binding should be effected at a relatively small force.

In this connection, it is an important feature of the invention that the heel holding means of the heel supporting device comprise a pin secured rigidly to a casing, a lever pivotably connected to a supporting member and adjustable spring means for pressing the lever to the pin, the lever having an end face which is pressed by the spring means, a notch formed in an end face opposite to said end face pressed by the spring means and a curved face which is formed contiguous to the notch and, at the released position, coincides substantially with an arcuate path of movement of the point of contact between the pin and the lever made by the pivotal movement of the casing between the normal position of use and the released position or lies radially inwardly of this arcuate path of movement, the pin being engaged in the notch at the normal position of use and being disengaged from the notch to release the heel of the ski boot when a strong upwardly directed force acts upon the heel, and being in contact with the curved face at a position at which the direction of the force of the spring acting upon the pin is substantially in alignment with a line connecting the axis of the pin and the axis of the pivot pin of the casing when the heel supporting device is at the released position.

According to the above described construction, when the skier steps down his boot to fit it with the ski binding or connects it manually to the binding by lifting a handle attached to the casing in a manner to be described later, the pin pivots counterclockwise about the pivot pin of the casing without causing the lever to pivot clockwise against the pressing force of the spring as is customary with the prior art heel supporting devices. Moreover, as the pin is slightly shifted from the above described aligned position by stepping down of the boot or by lifting of the handle, the counterclockwise pivoting force of the lever imparted by the pressing spring acts upon the pin to pivot it counterclockwise. Accordingly, the force required in stepping down the ski boot is mostly for pushing back springs contained in a forward pressure imparting means to be described later and the force required for pivoting the casing from the released position to the nomal position of use is relatively small.

It is another object of the invention to provide a practical heel supporting device which is of a simple and compact construction. To this end, the lever which is an element of the heel holding means has an elongated portion which is formed in its end portion with a slot for receiving the end of a ski pole which is used for pushing the lever so as to cause the lever to pivot clockwise and thereby to release the casing. Thus, the lever which functions as an element of the heel holding means serves also as a release lever with a result that space is saved and the construction of the device simplified.

lt is another object of the invention to provide a heel supporting device which has the lever enclosed by the casing except the portion in which the slot for receiving the ski pole is formed so as to prevent a casual and undesirable release of the heel supporting device due, for

example, to an accidental hitting of other skiers ski FIG. 1 is a general perspective view of the heel supporting device embodying the invention;

FIG. 2 is a sectional view of the device showing its normal state of use;

FIG. 3 is a sectional view showing a state in which the casing is at its released position; and

FIG. 4 is a sectional view of the forward pressure imparting means.

Referring first to FIG. 1, the heel supporting device includes a base plate 1 to be attached to the upper surface of a ski. The base plate 1 has

guides

2,2 along its both side edges and has at its front end a serrated raised-up face 3 in which an elongated slot 4 is formed. A pressing plate 8 is slidable on the base plate 1 in the axial direction thereof and is fixed at a suitable position to the base plate 1 by means of a screw 5 and a washer 6, the latter having a serrated face engageable with the serrated face of the raised-up face 3 on its underside. The pressing plate 8 has at its rear end two

bent portions

8a, 8a which serve as supports for two

springs

9, 9. The pressing plate 8 and the

springs

9,9 associated therewith compose forward pressure imparting means 7.

A supporting member 10 is disposed on the pressing plate 8 with the lower side edge portions thereof projecting outwardly to slidably engage in the guides 2. The supporting member 10 has an opening 10a in its lower portion for receiving the springs 9, as is shown in FIG. 2. Thus, the supporting member 10 is arranged to be pushed forward by the forward pressure imparting means 7 when the device is in the state of normal use so as to hold the ski boot tightly in cooperation with a toe piece (not shown) of the ski binding.

A casing 11 is mounted over the supporting member 10 and is pivotably connected thereto by means of a pivot pin 12. The casing 11 is provided on its front end with heel supporting members which include a heel depressing member 13 and a sole engaging plate 14.

The heel holding means employed in the device according to the invention comprise a pin 15 secured rigidly to the casing 11 and projecting horizontally across the base plate 1, a lever 16 pivotably connected to the supporting member by means of a pivot 24 and adjustable spring means generally designated by reference numeral 17. The spring means 17 consist of a spring 18, an adjusting screw 19 for adjusting the force of the spring l8 and a guide cap 20. The lever 16 has an end face 21 which is in abutting engagement with the guide cap of the spring means 17 and is constantly subject to the resilient force of the spring 19. The lever 16 also has a notch 22 formed in an end face opposite to the end face pressed by the spring 19 and a curved face 23 formed contiguous to the notch 22. At the released position, the curved face 23 coincides substantially with an arcuate path of movement of the point of contact between the pin 15 and the lever 16 made by the pivotal movement of the casing between the normal position of use and the released position or lies radially inwardly of this arcuate path of movement.

The lever 16 has an elongated portion 27 which is formed in its end portion with a slot 26 for receiving the end of a ski pole. The lever 16 further has a notch 25 formed at the root of the elongated portion 27 in such a manner that the pivot pin 12 is engaged in it when the device is at the released position. The lever 16 is enclosed by the casing 11 except the end portion in which the slot 26 is formed and the top portion adjacent thereto. It will be understood that this construction is effective for preventing the lever 16 from being accidentally pivoted to release the heel supporting device when, for example, other skiers ski strikes against his binding.

The casing 11 is provided at the rear end thereof with a handle or grip portion 28 which enables the skier to move the casing manually from the released position to the normal position of use. The lower surface of the rear end portion of the casing 11 is in abutting contact with the upper end surface of the lever 16.

Referring to FIGS. 2 and 3, the operation of the heel supporting device according to the invention will be described. In FIG. 2, the device is at the normal position of use. The

heel supporting members

13, 14 hold the heel of the ski boot and press it forwardly due to the action of the forward pressure imparting means 7. The pin 15 is engaged in the notch 22 of the lever 6 and prevents the casing 11 from being pivoted during the normal state of use. When a strong upward directed force acts on the heel due, for example, to a forward fall of the skier, the pin 15 tends to move upwardly and causes the lever 16 to pivot clockwise about the pivot 24 against the force of the spring 18. Accordingly, the pin 15 is disengaged from the notch 24 and moves upwardly along its arcuate path of movement about the pivot pin 12. As a result, the casing 11 to which the pin 15 is secured is pivoted clockwise and the boot heel is released. The release of the boot can also be effected voluntarily by inserting the end of a ski pole into the slot 26 and pushing down the lever 27. The position of the pin 15 is so arranged that when it is at the released position shown in FIG. 3 it is in contact with the curved face 23 of the lever 16 at a position at which the direction of the force of the spring 18 acting upon the pin 15 is substantially in alignment with a line connecting the axis of the pin 15 with the axis of the pivot pin 12. At this released position the pivot pin 12 is brought into abutting engagement with the notch 25 and further clockwise pivotal movement of both the lever 16 and the casing 11 is prevented. At the released position the lever 16 holds the spring 18 in a compressed state and therefore is subject to the force of the spring 18. However, the pin 15 remains stationary at the released position because the direction of the force acting upon the pin 15 is substantially in alignment with the line connecting the axis of the pin 15 with the axis of the pivot pin 12 as described above.

For bringing the released condition of the device shown in FIG. 3 back into the normal state of use shown in FIG. 2, the skier has only to step his boot heel lightly down onto the sole engaging plate 14 as in the conventional manner, or otherwise he may hold the handle portion 28 of the casing 16 by hand and lift it,

whereby the pin is caused to pivot counterclockwise to the normal position of use. It is to be noted that the curved face 23 substantially coincides with the arcuate path of movement of the point of contact between the pin 15 and the lever 16 or lies radially inwardly of this arcuate path of movement. Consequently, the pin 15 smoothly slides down along the curved face 23 into the notch 22 without causing the lever 16 to pivot clockwise and thereby pushing back the spring 18. Thus, this operation only requires application of a relatively small force and the skier can set the device at ease by lightly stepping down his boot or manually bringing the device to the normal use position even in an extremely unfavourable situation such as on a sharp slope.

What is claimed is:

1. In a heel supporting device for a ski safety binding comprising a base plate attached fixedly to a ski, a supporting member provided on said base plate, a casing covering said supporting member and being pivotably connected thereto by means of a first pivot extending horizontally across the axis of the ski, heel supporting members fixedly secured to said casing and adapted for fit-ting with the heel of a ski boot at the front end thereof and heel holding means for pressing said casing downwardly toward said base plate at a normal position of use and releasing said casing upwardly when a strong upwardly directed force is exerted on said casing, the improvement wherein said heel holding means comprise a pin secured rigidly to said casing and extending horizontally across the axis of the ski, a lever pivotably connected to said supporting member below said first pivot by means of a second pivot extending horizontally across the axis of the ski and adjustable spring means for pressing said lever to said pin, said lever having a rearward end face being pressed by said spring means, a notch formed in a forward end face opposite to said rearward end face being pressed by said spring means and a curved face which is formed contiguous to said notch and, at the released position, coincides substantially with an arcuate path of movement of the point of contact between said pin and said lever made by the pivotal movement of said casing between the normal position of use and the released position or lies radially inwardly of this arcuate path of movement, said pin being engaged in said notch at the normal position of use and being disengaged from said notch to release the heel of the ski boot when a strong upwardly directed force acts upon the heel, and, at the released position being in contact with said curved face at a position at which the line of action of the rotational force caused by the force of the spring acting at the point of contact between said pin and said curved face is substantially collinear with a line connecting the axis of said pin and the axis of said first pivot of said casing.

2. A heel supporting device as defined in claim 1 wherein said lever has an elongated portion which is provided in the end portion thereof with a slot for re ceiving the end of a ski pole.

3. A heel supporting device as defined in claim 2 wherein said lever is enclosed by said casing except the portion in which said slot for receiving the end of the ski pole is formed.

4. A heel supporting device as defined in claim 1 wherein said casing is provided at the rear end thereof with a handle for manually pivoting said casing from the released position to the normal position of use and from the normal position of use to the released position.

5. A heel supporting device as defined in claim 1 wherein said lever has another notch in which the pivot of said casing is in abutting engagement at the released position of the device.

Claims

1. In a heel supporting device for a ski safety binding comprising a base plate attached fixedly to a ski, a supporting member provided on said base plate, a casing covering said supporting member and being pivotably connected thereto by means of a first pivot extending horizontally across the axis of the ski, heel supporting members fixedly secured to said casing and adapted for fitting with the heel of a ski boot at the front end thereof and heel holding means for pressing said casing downwardly toward said base plate at a normal position of use and releasing said casing upwardly when a strong upwardly directed force is exerted on said casing, the improvement wherein said heel holding means comprise a pin secured rigidly to said casing and extending horizontally across the axis of the ski, a lever pivotably connected to said supporting member below said first pivot by means of a second pivot extending horizontally across the axis of the ski and adjustable spring means for pressing said lever to said pin, said lever having a rearward end face being pressed by said spring means, a notch formed in a forward end face opposite to said rearward end face being pressed by said spring means and a curved face which is formed contiguous to said notch and, at the released position, coincides substantially with an arcuate path of movement of the point of contact between said pin and said lever made by the pivotal movement of said casing between the normal position of use and the released position or lies radially inwardly of this arcuate path of movement, said pin being engaged in said notch at the normal position of use and being disengaged from said notch to release the heel of the ski boot when a strong upwardly directed force acts upon the heel, and, at the released position being in contact with said curved face at a position at which the line of action of the rotational force caused by the force of the spring acting at the point of contact between said pin and said curved face is substantially collinear with a line connecting the axis of said pin and the axis of said first pivot of said casing.

2. A heel supporting device as defined in claim 1 wherein said lever has an elongated portion which is provided in the end portion thereof with a slot for receiving the end of a ski pole.