TOE STOP MEMBER FOR SKI SAFETY BINDINGS
United States Patent 3638959
A toe stop member of a safety ski binding comprises a frame fixable onto a ski so as to be angularly fixed against movement in the plane of the ski. First and second rearwardly extending jaws are pivotally mounted on the frame about first and second axes perpendicular to the said plane of a ski, a front end of each jaw having a camlike surface comprising a hollow. Elastic means urge first and second rollers along lines of action passing at least approximately through the first and second axes into the hollows so as to releasably hold the jaws in an operative boot-gripping position in which the jaws can fit around at least a part of the toe end of a boot placed on a ski to which the stop member may be fitted. Abutment means, such as one or more rollers or even part of the jaws, are provided to bear against the toe end of a boot thus fixed to prevent forward motion thereof in relation to the ski. Part of the frame may be hinged about an axis in the plane of the ski to enable adjustment of the height of the jaws, for example to accommodate for a layer of snow between the boot and the ski.
US Patent References:
Safety ski binder
Beyl - July 1965 - 3194574
Safety securing means for skis
Ramillon - October 1963 - 3107102
Safety binding with swivel jaw
Rehacek - October 1963 - 3105696
SECURING HEAD FOR SAFETY SKI BINDINGS
Martin - March 1971 - 3572738
SKI BINDING RELEASABLE TOE CLAMP
Khazzam - June 1971 - 3584891
Safety ski binder
Beyl - July 1965 - 3194574
Safety securing means for skis
Ramillon - October 1963 - 3107102
Safety binding with swivel jaw
Rehacek - October 1963 - 3105696
SECURING HEAD FOR SAFETY SKI BINDINGS
Martin - March 1971 - 3572738
SKI BINDING RELEASABLE TOE CLAMP
Khazzam - June 1971 - 3584891
Application Number:
05/065021
Publication Date:
02/01/1972
Filing Date:
08/19/1970
View Patent Images:
Export Citation:
Primary Class:
International Classes:
A63C9/08; A63C9/085; A63C9/00
Field of Search:
280/11.35T
Primary Examiner:
Hersh, Benjamin
Assistant Examiner:
Song, Robert R.
Claims:
What is claimed is
1. A safety ski binding comprising a frame fixable onto a ski to be angularly fixed against movement in the plane of the ski, first and second rearwardly extending jaws pivotally mounted on the frame about first and second axes perpendicular to said plane of said ski, a front end of each jaw having a hollow camlike surface, a first and second rollers, elastic means for urging said first and second rollers along lines of action passing at least approximately through said first and second axes into said hollows to releasably hold said jaws in an operative boot gripping position in which said jaws can fit around at least a part of the toe end of a ski boot, said elastic means comprising first and second levers articulated together about a common eccentric axle perpendicular to said plane of said ski, said first and second levers carrying said first and second rollers, and means for angularly adjusting the eccentric axle so as to enable adjustment of separation of said first and second rollers and the separation of said first and second jaws when in the operative position.
2. A safety ski binding, according to claim 1, in which each of said jaws is formed of a hollow pressed part having a rearward extension adapted to fit over the sole of a boot, said camlike surface being formed by two edges profiled to form said hollow, a third and fourth rollers mounted with said first and second jaws about said first and second axes form abutment means, and first and second torsion springs mounted about said first and second axes to urge said jaws towards operative position.
3. A safety ski binding, comprising a frame fixable onto a ski so as to be angularly fixed against movement in the plane of said ski, first and second rearwardly extending jaws pivotally mounted on the frame about first and second axes perpendicular to said plane of said ski, a front end of each jaw having a hollow camlike surface, a first and second rollers, elastic means for urging said first and second rollers along lines of action passing at least approximately through said first and second axes into said hollows to releasably hold said jaws in an operative boot gripping position in which said jaws can fit around at least a part of the toe end of a ski boot, each of said jaws being formed of a hollow pressed part having a rearward extension to fit over the sole of a boot, said camlike surface being formed by two edges profiled to form said hollow, a third and fourth rollers mounted with said first and second jaws about said first and second axes to form abutment means, and a first and second torsion springs mounted about said first and second axes to urge said jaws towards operative position and said elastic means comprising a first and second levers articulated together about a common axle perpendicular to said plane of said ski, said first and second levers carrying said first and second rollers, a spring urging said first and second levers, and means for adjusting the pressure of the spring.
4. A safety ski binding, comprising a frame fixable onto a ski to be angularly fixed against movement in the plane of said ski, first and second rearwardly extending jaws pivotally mounted on said frame about a first and second axes perpendicular to said plane of said ski, each of said jaws having a hollow camlike surface at its front end, a first and second rollers, elastic means urging said first and second rollers along lines of action passing at least approximately through said first and second axes into the hollows of said camlike surfaces to releasably hold said jaws in an operative boot gripping position in which said jaws can fit around at least a part of the toe end of a ski boot, said frame comprising a baseplate fixable in said plane of said ski, a part hinged to said baseplate, and means for angularly adjusting said part in relation to said baseplate, whereby an angular displacement of said part causes a raising or lowering of said jaws in relation to the plane of said ski.
5. A safety ski binding according to claim 4, in which said means for angularly adjusting said part comprises a screw mounted perpendicularly on said baseplate, a nut having a flange threadably engaging said screw, said part having an aperture engaged by said flange, a cylindrical body passing through said aperture, a head, a compression spring acting between said head and said part to urge said part towards said flange, whereby said jaws can be adjusted to a height suitable for a particular boot but can be raised from the adjusted position to accommodate for an effective increase in the thickness of the sole of the boot.
1. A safety ski binding comprising a frame fixable onto a ski to be angularly fixed against movement in the plane of the ski, first and second rearwardly extending jaws pivotally mounted on the frame about first and second axes perpendicular to said plane of said ski, a front end of each jaw having a hollow camlike surface, a first and second rollers, elastic means for urging said first and second rollers along lines of action passing at least approximately through said first and second axes into said hollows to releasably hold said jaws in an operative boot gripping position in which said jaws can fit around at least a part of the toe end of a ski boot, said elastic means comprising first and second levers articulated together about a common eccentric axle perpendicular to said plane of said ski, said first and second levers carrying said first and second rollers, and means for angularly adjusting the eccentric axle so as to enable adjustment of separation of said first and second rollers and the separation of said first and second jaws when in the operative position.
2. A safety ski binding, according to claim 1, in which each of said jaws is formed of a hollow pressed part having a rearward extension adapted to fit over the sole of a boot, said camlike surface being formed by two edges profiled to form said hollow, a third and fourth rollers mounted with said first and second jaws about said first and second axes form abutment means, and first and second torsion springs mounted about said first and second axes to urge said jaws towards operative position.
3. A safety ski binding, comprising a frame fixable onto a ski so as to be angularly fixed against movement in the plane of said ski, first and second rearwardly extending jaws pivotally mounted on the frame about first and second axes perpendicular to said plane of said ski, a front end of each jaw having a hollow camlike surface, a first and second rollers, elastic means for urging said first and second rollers along lines of action passing at least approximately through said first and second axes into said hollows to releasably hold said jaws in an operative boot gripping position in which said jaws can fit around at least a part of the toe end of a ski boot, each of said jaws being formed of a hollow pressed part having a rearward extension to fit over the sole of a boot, said camlike surface being formed by two edges profiled to form said hollow, a third and fourth rollers mounted with said first and second jaws about said first and second axes to form abutment means, and a first and second torsion springs mounted about said first and second axes to urge said jaws towards operative position and said elastic means comprising a first and second levers articulated together about a common axle perpendicular to said plane of said ski, said first and second levers carrying said first and second rollers, a spring urging said first and second levers, and means for adjusting the pressure of the spring.
4. A safety ski binding, comprising a frame fixable onto a ski to be angularly fixed against movement in the plane of said ski, first and second rearwardly extending jaws pivotally mounted on said frame about a first and second axes perpendicular to said plane of said ski, each of said jaws having a hollow camlike surface at its front end, a first and second rollers, elastic means urging said first and second rollers along lines of action passing at least approximately through said first and second axes into the hollows of said camlike surfaces to releasably hold said jaws in an operative boot gripping position in which said jaws can fit around at least a part of the toe end of a ski boot, said frame comprising a baseplate fixable in said plane of said ski, a part hinged to said baseplate, and means for angularly adjusting said part in relation to said baseplate, whereby an angular displacement of said part causes a raising or lowering of said jaws in relation to the plane of said ski.
5. A safety ski binding according to claim 4, in which said means for angularly adjusting said part comprises a screw mounted perpendicularly on said baseplate, a nut having a flange threadably engaging said screw, said part having an aperture engaged by said flange, a cylindrical body passing through said aperture, a head, a compression spring acting between said head and said part to urge said part towards said flange, whereby said jaws can be adjusted to a height suitable for a particular boot but can be raised from the adjusted position to accommodate for an effective increase in the thickness of the sole of the boot.
Description:
BACKGROUND OF THE INVENTION
This invention relates to toe stops for ski safety bindings which are designed to releasably hold a boot to a ski, release taking place when a stress on the boot exceeds a given value.
Toe stops are generally pivotally mounted about an axis perpendicular to the ski, a locking device comprising a ball urged by a spring being provided to releasably hold the stop in its normal operational position. With such stops, it has additionally been proposed to use jaws pivoted about axes perpendicular to the ski. These types have however not given entire satisfaction since they have generally been of complicated construction while not operating reliably.
One particular type has a main body pivotally mounted about an axis perpendicular to the ski and a spring-loaded ball to releasably hold the body in an aligned position. A pair of boot-gripping jaws are freely pivoted to the body but are prevented from pivoting by a boot held therein when the body is aligned. When a certain torsional stress acts on the boot, if the binding is correctly adjusted, the body pivots whereupon one of the jaws pivots to release the boot. However, adjustment of these bindings is complicated and the freely pivoted jaws, whose main purpose is to enable use with different sized boots, often contribute to release of the boot in an unwanted manner.
SUMMARY OF THE INVENTION
It is an aim of the present invention to provide a safety toe stop which is robust, of reliable operation and having few parts which enables manufacture at low cost.
According to the invention, a toe stop member of a safety ski binding comprises a frame fixable onto a ski so as to be angularly fixed against movement in the plane of the ski. First and second rearwardly extending jaws are pivotally mounted on the frame about first and second axes perpendicular to the said plane of a ski, a front end of each jaw having a camlike surface comprising a hollow. Elastic means urge first and second rollers along lines of action passing at least approximately through the first and second axes into the hollows so as to releasably hold the jaws in an operative boot-gripping position in which the jaws can fit around at least a part of the toe end of a boot placed on a ski to which the stop member may be fitted. Abutment means are provided to bear against the toe end of a boot thus fixed to prevent forward motion thereof in relation to the ski.
The abutment means advantageously consist of one or more rollers mounted to the frame or to the jaws about axes perpendicular to the plane of the ski, but could alternatively be formed by a surface of the jaws.
DESIGNATION OF THE DRAWINGS
The accompanying drawings show, by way of example, several embodiments of the toe stop according to the invention.
FiG. 1 is a plan view, partly in cross section, of a first embodiment.
FIG. 2 is a view similar to FIG. 1 for a second embodiment.
FIG. 3 is a cross section through a third embodiment.
FIg. 4 is a cross section through a fourth embodiment.
FIG. 5 is a cross section taken along line A--A of FIg. 4.
FIG. 6 is a cross section taken along line B--B of FIG. 4.
FIG. 7 is a schematic plan view of a variant of FIG. 4.
FIG. 8 is a view similar to FIG. 7 of another variant.
DESCRIPTION OF PREFERRED EMBODIMENTS
The safety toe stop member shown in FIG. 1 comprises a frame 1 on which are mounted two rearwardly extending jaws intended to cooperate with the toe of a boot 4. The frame 1 is fixed to a ski (not shown) by means of screws 5.
Each jaw 2 and 3 is pivotally mounted about an axle 6 and 7 respectively which are fixed to the frame 1 and perpendicular to the ski. A spring device holds each of the jaws 2 and 3 in the illustrated boot-locking position. For this purpose, each jaw is formed of a block the front end of which has a cam surface comprising a hollow 8 in which a roller 9 is elastically urged. A piston 10, carrying a yoke 11 supporting the roller 9, is urged by a compression spring 12 mounted in a cylinder 13. The compression of the spring 12 is adjustable by means of a screw 14 accessible at the front end of the cylinder 13.
The two cylinders 13 are mounted about a common pivoting axle 15 located near the front of frame 1 and perpendicular to the ski. This arrangement enables adjustment of the separation of the jaws 2 and 3. To enable the cylinders to be locked in an adjusted position, each cylinder 13 comprises a foot 16 having a slot 17 for a locking screw 18 which can be screwed into a threaded hole in the frame 1.
The two jaws 2 and 3 each have at their rear part a bearing surface 19 to cooperate with the toe end of the sole of boot 4. A recess 20 is provided in the block of each jaw to accommodate the sole, the upper part 21 of the block thus forming a gripping edge for the sole.
The described stop member operates as follows:
The toe of the boot 4 is pushed forwards to abut against the bearing surface 19 of the jaws by a heel-gripping member, cable, or any other means. When a lateral torsional stress exceeding a given value is exerted on the boot, one of the jaws 2 or 3 is pivoted about its axle and forces the roller 9 out of the hollow 8 against the action of the spring 12. When this roller 9 has passed the nose 8', the jaw disengages and turns about its axle to free the boot. Contrary to what generally happens in known safety toe stops, the frame 1 and elastic locking devices as described do not turn about an axis perpendicular to the ski upon release of the stop. The shape of each jaw 2 and 3 and in particular the configuration of the front end of the jaw having a cam surface enables a complete release of the boot without it being necessary for the frame 1 of the stop to also be pivotally mounted.
To reset the stop, it suffices to push the two jaws back to the illustrated position, forcing the roller 9 in question against the action of the spring 12 over the 8' and into the hollow 8.
In the embodiment illustrated in FIG. 2, the same reference numerals designate the same parts as in the first embodiment. The jaws 22 and 23 are also each formed of a block and are respectively pivotable about axles 6 and 7 perpendicular to the ski and fixed on a frame, not shown. The elastic locking device of each jaw is similar to that of the first embodiment. To adjust the separation of the jaws, each cylinder 13 has a rear foot 24 bore with a threaded hole to receive a left and right handed screw 25.
A fixed bearing part 26 is mounted on a central nonthreaded part of the screw 25 between the two jaws 21 and 23, this part 26 being able to engage with and abut against the toe end of the boot to prevent forward motion thereof in relation to the ski. Instead of a fixed part, it would be possible to provide abutment means comprising at least one roller for contacting the part of the sole.
The operation of this embodiment is identical to that of the embodiment shown in FIG. 1 except for adjustment of the separation of the jaws 22 and 23. In this case, this adjustment is achieved simply by turning the screws 25 in one direction or the other so as to bring together or separate the cylinders 13. In separating the cylinders 13, the jaws are brought together by the action of the rollers 9 in the hollows 8 of the front cam surfaces of the jaws.
In the embodiment of FIG. 3, each jaw is formed of a block 26, 27 respectively pivoted about axles 6, 7 perpendicular to the ski and carrying arms 28, 29 respectively fixed onto a lateral surface by means of screws 30, 31.
Rollers 32, 33 are mounted on the axles 6 and 7 and act as an abutment surface for the front of the sole of the boot 4. These rollers can freely turn on their respective axles. The arms 29 are slightly curved at their rear ends in a manner to be able to press against the upper edge of the sole.
The forwardly facing surface of each block 26 and 27 has a cam surface with a hollow 8 able to accommodate a roller 9 elastically urged by a spring 12.
In the embodiments of FIGS. 4 to 6, jaws 34 and 35 pivotally mounted about axles 34 and 35 respectively are formed by hollow U-shaped pressed pieces having rearwardly projecting extensions 36, 34 able to engage with the upper edge of the sole by the intermediary of a piece in plastics material, 36', 37' respectively, embedded in the respective jaw.
At the front, each jaw terminates in two edges 38, 39 (FIG. 5) cut away in a manner to have a hollow 40 able to accommodate an upper support roller 41, another lower roller 42 being mounted about the same axle 43 to engage with the lower edge 39. The rollers 41, 42 are able to turn freely about their common axle 43.
The axles 34' and 35' of the jaws 34, 35 each carry a roller 32, 33 respectively, able to engage the front end of the sole as in the embodiment of FIG. 3. A torsion spring 44 is additionally mounted upon each of the pivoting axles of the jaws, these springs urging the jaws towards their initial position.
The elastic locking device for the jaws 34, 35 comprises two angle levers 45, 46 articulated together by means of an eccentric axle 47 perpendicular to the ski (FIG. 6) and subjected to the action of a leaf spring 48. The tension of this spring is adjustable by means of a block 12' threadably engaging with and movable by a screw. By turning the eccentric axle 47, it is possible to modify the horizontal separation of the rollers 41, 42 which enables the jaws 34 and 35 to be moved apart or together to adjust to the size of the end of the boot 4.
The frame of this embodiment of stop member is designated in a general manner by reference numeral 49 and is pivotally mounted on a transversal axle 50. A screw 51 perpendicular to the ski is supported in a baseplate 52 and enables adjustment of the height of the jaws 34, 35 by causing the frame 49 to tip by a small amount about the axle 50. A spring 53 is located between a nut 54 screwed onto the screw 51 and the frame 49 to enable taking up of an excess thickness of the sole, due for example to a layer of snow or ice under the sole.
In the variant shown in FIG. 7, the support piece for the sole of the boot comprises two rollers 55 mounted on the frame between the pivotable jaws 56 and 57, as in the embodiment of FIG. 2. This arrangement has the advantage of facilitating disengagement of the boot when it is urged by a torsional stress exceeding a fixed limit. As can be seen schematically, by passing from the position of the jaws 56, 57 shown by a continuous line to the position shown in a dotted-dashed line, the sole of the boot 4 rolls on the roller 55.
Instead of two rollers, the support piece could comprise only one roller 58 of a greater diameter located between the jaws, as shown in FIG. 8.
In all of the described embodiments it will be remarked that the line of action of the force exerted on the rollers 9, 41, 42 to urge them into the hollows of the cam surface of the front end of the jaws passes at least approximately through the axis of pivoting of these jaws. Hence, when, under the effect of a torsional stress of a value which can be supported by the leg of a skier, the boot causes one of the jaws to slightly pivot, a couple tending to return the jaw to its original position is set up, which avoids an abrupt release of the jaw.
It is understood that the term "roller" generically includes any equivalent means; for example, the roller 9 of FIG. 1 could be replaced by a ball.
This invention relates to toe stops for ski safety bindings which are designed to releasably hold a boot to a ski, release taking place when a stress on the boot exceeds a given value.
Toe stops are generally pivotally mounted about an axis perpendicular to the ski, a locking device comprising a ball urged by a spring being provided to releasably hold the stop in its normal operational position. With such stops, it has additionally been proposed to use jaws pivoted about axes perpendicular to the ski. These types have however not given entire satisfaction since they have generally been of complicated construction while not operating reliably.
One particular type has a main body pivotally mounted about an axis perpendicular to the ski and a spring-loaded ball to releasably hold the body in an aligned position. A pair of boot-gripping jaws are freely pivoted to the body but are prevented from pivoting by a boot held therein when the body is aligned. When a certain torsional stress acts on the boot, if the binding is correctly adjusted, the body pivots whereupon one of the jaws pivots to release the boot. However, adjustment of these bindings is complicated and the freely pivoted jaws, whose main purpose is to enable use with different sized boots, often contribute to release of the boot in an unwanted manner.
SUMMARY OF THE INVENTION
It is an aim of the present invention to provide a safety toe stop which is robust, of reliable operation and having few parts which enables manufacture at low cost.
According to the invention, a toe stop member of a safety ski binding comprises a frame fixable onto a ski so as to be angularly fixed against movement in the plane of the ski. First and second rearwardly extending jaws are pivotally mounted on the frame about first and second axes perpendicular to the said plane of a ski, a front end of each jaw having a camlike surface comprising a hollow. Elastic means urge first and second rollers along lines of action passing at least approximately through the first and second axes into the hollows so as to releasably hold the jaws in an operative boot-gripping position in which the jaws can fit around at least a part of the toe end of a boot placed on a ski to which the stop member may be fitted. Abutment means are provided to bear against the toe end of a boot thus fixed to prevent forward motion thereof in relation to the ski.
The abutment means advantageously consist of one or more rollers mounted to the frame or to the jaws about axes perpendicular to the plane of the ski, but could alternatively be formed by a surface of the jaws.
DESIGNATION OF THE DRAWINGS
The accompanying drawings show, by way of example, several embodiments of the toe stop according to the invention.
FiG. 1 is a plan view, partly in cross section, of a first embodiment.
FIG. 2 is a view similar to FIG. 1 for a second embodiment.
FIG. 3 is a cross section through a third embodiment.
FIg. 4 is a cross section through a fourth embodiment.
FIG. 5 is a cross section taken along line A--A of FIg. 4.
FIG. 6 is a cross section taken along line B--B of FIG. 4.
FIG. 7 is a schematic plan view of a variant of FIG. 4.
FIG. 8 is a view similar to FIG. 7 of another variant.
DESCRIPTION OF PREFERRED EMBODIMENTS
The safety toe stop member shown in FIG. 1 comprises a frame 1 on which are mounted two rearwardly extending jaws intended to cooperate with the toe of a boot 4. The frame 1 is fixed to a ski (not shown) by means of screws 5.
Each jaw 2 and 3 is pivotally mounted about an axle 6 and 7 respectively which are fixed to the frame 1 and perpendicular to the ski. A spring device holds each of the jaws 2 and 3 in the illustrated boot-locking position. For this purpose, each jaw is formed of a block the front end of which has a cam surface comprising a hollow 8 in which a roller 9 is elastically urged. A piston 10, carrying a yoke 11 supporting the roller 9, is urged by a compression spring 12 mounted in a cylinder 13. The compression of the spring 12 is adjustable by means of a screw 14 accessible at the front end of the cylinder 13.
The two cylinders 13 are mounted about a common pivoting axle 15 located near the front of frame 1 and perpendicular to the ski. This arrangement enables adjustment of the separation of the jaws 2 and 3. To enable the cylinders to be locked in an adjusted position, each cylinder 13 comprises a foot 16 having a slot 17 for a locking screw 18 which can be screwed into a threaded hole in the frame 1.
The two jaws 2 and 3 each have at their rear part a bearing surface 19 to cooperate with the toe end of the sole of boot 4. A recess 20 is provided in the block of each jaw to accommodate the sole, the upper part 21 of the block thus forming a gripping edge for the sole.
The described stop member operates as follows:
The toe of the boot 4 is pushed forwards to abut against the bearing surface 19 of the jaws by a heel-gripping member, cable, or any other means. When a lateral torsional stress exceeding a given value is exerted on the boot, one of the jaws 2 or 3 is pivoted about its axle and forces the roller 9 out of the hollow 8 against the action of the spring 12. When this roller 9 has passed the nose 8', the jaw disengages and turns about its axle to free the boot. Contrary to what generally happens in known safety toe stops, the frame 1 and elastic locking devices as described do not turn about an axis perpendicular to the ski upon release of the stop. The shape of each jaw 2 and 3 and in particular the configuration of the front end of the jaw having a cam surface enables a complete release of the boot without it being necessary for the frame 1 of the stop to also be pivotally mounted.
To reset the stop, it suffices to push the two jaws back to the illustrated position, forcing the roller 9 in question against the action of the spring 12 over the 8' and into the hollow 8.
In the embodiment illustrated in FIG. 2, the same reference numerals designate the same parts as in the first embodiment. The jaws 22 and 23 are also each formed of a block and are respectively pivotable about axles 6 and 7 perpendicular to the ski and fixed on a frame, not shown. The elastic locking device of each jaw is similar to that of the first embodiment. To adjust the separation of the jaws, each cylinder 13 has a rear foot 24 bore with a threaded hole to receive a left and right handed screw 25.
A fixed bearing part 26 is mounted on a central nonthreaded part of the screw 25 between the two jaws 21 and 23, this part 26 being able to engage with and abut against the toe end of the boot to prevent forward motion thereof in relation to the ski. Instead of a fixed part, it would be possible to provide abutment means comprising at least one roller for contacting the part of the sole.
The operation of this embodiment is identical to that of the embodiment shown in FIG. 1 except for adjustment of the separation of the jaws 22 and 23. In this case, this adjustment is achieved simply by turning the screws 25 in one direction or the other so as to bring together or separate the cylinders 13. In separating the cylinders 13, the jaws are brought together by the action of the rollers 9 in the hollows 8 of the front cam surfaces of the jaws.
In the embodiment of FIG. 3, each jaw is formed of a block 26, 27 respectively pivoted about axles 6, 7 perpendicular to the ski and carrying arms 28, 29 respectively fixed onto a lateral surface by means of screws 30, 31.
Rollers 32, 33 are mounted on the axles 6 and 7 and act as an abutment surface for the front of the sole of the boot 4. These rollers can freely turn on their respective axles. The arms 29 are slightly curved at their rear ends in a manner to be able to press against the upper edge of the sole.
The forwardly facing surface of each block 26 and 27 has a cam surface with a hollow 8 able to accommodate a roller 9 elastically urged by a spring 12.
In the embodiments of FIGS. 4 to 6, jaws 34 and 35 pivotally mounted about axles 34 and 35 respectively are formed by hollow U-shaped pressed pieces having rearwardly projecting extensions 36, 34 able to engage with the upper edge of the sole by the intermediary of a piece in plastics material, 36', 37' respectively, embedded in the respective jaw.
At the front, each jaw terminates in two edges 38, 39 (FIG. 5) cut away in a manner to have a hollow 40 able to accommodate an upper support roller 41, another lower roller 42 being mounted about the same axle 43 to engage with the lower edge 39. The rollers 41, 42 are able to turn freely about their common axle 43.
The axles 34' and 35' of the jaws 34, 35 each carry a roller 32, 33 respectively, able to engage the front end of the sole as in the embodiment of FIG. 3. A torsion spring 44 is additionally mounted upon each of the pivoting axles of the jaws, these springs urging the jaws towards their initial position.
The elastic locking device for the jaws 34, 35 comprises two angle levers 45, 46 articulated together by means of an eccentric axle 47 perpendicular to the ski (FIG. 6) and subjected to the action of a leaf spring 48. The tension of this spring is adjustable by means of a block 12' threadably engaging with and movable by a screw. By turning the eccentric axle 47, it is possible to modify the horizontal separation of the rollers 41, 42 which enables the jaws 34 and 35 to be moved apart or together to adjust to the size of the end of the boot 4.
The frame of this embodiment of stop member is designated in a general manner by reference numeral 49 and is pivotally mounted on a transversal axle 50. A screw 51 perpendicular to the ski is supported in a baseplate 52 and enables adjustment of the height of the jaws 34, 35 by causing the frame 49 to tip by a small amount about the axle 50. A spring 53 is located between a nut 54 screwed onto the screw 51 and the frame 49 to enable taking up of an excess thickness of the sole, due for example to a layer of snow or ice under the sole.
In the variant shown in FIG. 7, the support piece for the sole of the boot comprises two rollers 55 mounted on the frame between the pivotable jaws 56 and 57, as in the embodiment of FIG. 2. This arrangement has the advantage of facilitating disengagement of the boot when it is urged by a torsional stress exceeding a fixed limit. As can be seen schematically, by passing from the position of the jaws 56, 57 shown by a continuous line to the position shown in a dotted-dashed line, the sole of the boot 4 rolls on the roller 55.
Instead of two rollers, the support piece could comprise only one roller 58 of a greater diameter located between the jaws, as shown in FIG. 8.
In all of the described embodiments it will be remarked that the line of action of the force exerted on the rollers 9, 41, 42 to urge them into the hollows of the cam surface of the front end of the jaws passes at least approximately through the axis of pivoting of these jaws. Hence, when, under the effect of a torsional stress of a value which can be supported by the leg of a skier, the boot causes one of the jaws to slightly pivot, a couple tending to return the jaw to its original position is set up, which avoids an abrupt release of the jaw.
It is understood that the term "roller" generically includes any equivalent means; for example, the roller 9 of FIG. 1 could be replaced by a ball.