Release device for a binding for a boot on a gliding apparatus

Abstract

A release device for a binding for a boot on a gliding board. The device includes a rotatable motor with an output shaft bearing a cam rotatable about a first axis; a lever pivotable about a second axis between a closed position and an open position, the lever having a large crank in contact with the cam, and a small crank; a tripper having at least one control tooth, which is in contact with the small crank when the lever is in the closed position, and at least one release tooth; a rod movable between a closed position and an open position, the rod being provided with a notch in which the release tooth is engaged when the rod is in the closed position. The motor can deliver a torque at its output shaft of less than 2 mN·m, or as little as less than 1 mN·m. The cam includes a plate bearing a cam groove, the cam groove including at least two distinct, contiguous portions, viz., an initial ramp and a release ramp, the initial ramp corresponding to a path of the drive finger substantially along an arc centered on the first axis and a minimal radius of close to zero.

1 . A release device for a device for binding a boot on a gliding board, the release device comprising:
 a rotatable motor having an output shaft extending along a first axis, a cam fixed on said output shaft;   a lever pivotable about a second axis between a closed position and an open position, said lever comprising a large crank in contact with said cam and a small crank;   a tripper comprising:
 at least one control tooth in contact with said small crank when said lever is in the closed position; 
 at least one release tooth; 
   a rod movable between a closed position and an open position, said rod having a notch;   said release tooth of said tripper being engaged with said notch when said rod is in the closed position.   
     
     
         2 . A release device according to  claim 1 , wherein:
 said cam includes a plate, and a cam groove is recessed within said plate, said cam groove including at least two distinct contiguous portions, said contiguous portions comprising an initial ramp and a release ramp, said initial ramp being constituted of an arc having variation in radius at the first axis of less than 20%, and occupying an angular sector greater than 90°.   
     
     
         3 . A release device according to  claim 2 , wherein:
 said arc of said initial ramp having a variation in radius at the first axis A 1  of 0%.   
     
     
         4 . A release device according to  claim 2 , wherein:
 said large crank of said lever has a drive finger engageable with said cam groove;   said initial ramp corresponds to a path of said drive finger substantially forming an angular arc having a first angle, centered on the first axis, and having a lesser radius;   said release ramp corresponds to a path of said drive finger between a first point, positioned at a lesser distance from the first axis, and a second point, positioned at a greater distance from the first axis, and occupying, in relation to the first axis, an angular sector having a second angle.   
     
     
         5 . A release device according to  claim 1 , wherein:
 said motor is a motor producing a maximum torque of less than 2 mN·m on its output shaft.   
     
     
         6 . A release device according to  claim 1 , wherein:
 said motor is a motor producing a maximum torque of less than 1 mN·m on its output shaft.   
     
     
         7 . A release device according to  claim 2 , wherein:
 said at least two distinct contiguous portions said cam groove of said plate comprises a third portion comprising a final ramp;   said final ramp shaped as an arc has a variation in radius at the first axis of less than 20%;   said final ramp is contiguous with said release ramp.   
     
     
         8 . A release device according to  claim 1 , wherein:
 said large crank has a length two times greater than a length of said small crank.   
     
     
         9 . A release device according to  claim 1 , wherein:
 said tripper is pivotable about a third axis;   a distance separating said control tooth from the third axis is more than three times greater than a distance separating said release tooth from the third axis.   
     
     
         10 . A release device according to  claim 1 , wherein:
 said tripper is pivotable about a third axis;   a distance separating said control tooth from the third axis is more than 3.7 times greater than a distance separating said release tooth from the third axis.   
     
     
         11 . A release device according to  claim 1 , further comprising:
 a pivot connection by which said tripper is pivotable about a third axis;   the pivot connection of the tripper about the third axis comprises two pins received in connecting bearings that have a radius R 52 ;   a slope of a contact surface of the tripper which comes into contact with said rod is determined such that a direction of a contact force of the rod on the tripper, which is determined in relation to the normal at the “rod/tripper” contact point by taking into account a coefficient of friction φ 2 , is outside of a circle K 1 , centered on the third axis and a radius R 1 , is the following:
     R 1= R 52×Sin φ1, 
   where φ 1  is a coefficient of friction existing between the two pins and the connecting bearings.   
     
     
         12 . A release device according to  claim 1 , further comprising:
 a pivot connection by which said lever is pivotable about the second axis;   the pivot connection of the lever about the second axis comprises a first pin received in a bearing that has a radius R 50 ;   a slope of a contact surface of the tripper which comes into contact with said lever is determined such that a direction of a contact force of the lever on the tripper, which is determined in relation to the normal at the “lever/tripper” contact point by taking into account a coefficient of friction φ 4 , is outside of a circle K 2 , centered on the second axis and a radius R 2 , is the following:
     R 2= R 50×Sin φ3, 
   where φ 3  is a coefficient of friction existing between the first pin and the bearing which receives the first pin.   
     
     
         13 . A release device according to  claim 1 , further comprising:
 a locking mechanism configured and arranged to prevent disengagement of said release tooth from said notch and to be movable alternately between a locked position and an unlocked position.   
     
     
         14 . A release device according to  claim 13 , wherein:
 said locking mechanism includes a pawl having a first stop;   said tripper includes a locking tooth;   when said locking mechanism is in the locked position, said first stop is in contact with said locking tooth of said tripper to prevent rotation of the tripper in a release direction.   
     
     
         15 . A release device according to  claim 14 , wherein:
 said pawl is mounted for rotation about a fourth axis;   said pawl includes a second stop;   said locking mechanism further comprising an abutment and a latch spring;   when said locking mechanism is in the locked position, said second stop of said pawl is maintained in contact with said abutment by means of a force applied to the pawl by said latch spring.