Toepiece Which Releases a Boot Automatically as a Result of Twisting

Abstract

A toepiece of a binding to secure a boot to a gliding board includes two rigid jaws pivotable about respective horizontal axes oriented in a longitudinal direction. A releasing system for automatically releasing the boot by twisting the boot, associated with tilting of jaws. Tilting of at least one jaw causes the toepiece to take up a closed configuration, a releasing configuration for releasing the boot as a result of twisting of the boot, or a fitting configuration. The releasing system includes an elastic return for the jaws in the closed configuration and releasing configuration of the toepiece. Connection between a jaw and the elastic return includes at least one transmission link articulated to the jaw about a hinge axis oriented in the longitudinal direction so the jaw and transmission link form a knuckle joint that deforms in the plane corresponding to the transverse direction and vertical direction of the toepiece.

1 . A toepiece of a binding device for securing a boot to a gliding board, comprising two rigid jaws that are mounted so as to pivot about respective substantially horizontal axes that are oriented in a substantially longitudinal direction of the toepiece, comprising a releasing system for automatically releasing the boot as a result of twisting of the boot, associated with tilting of the jaws, said toepiece being configured such that, by tilting of at least one jaw, it takes up:
 a closed configuration in which retaining elements carried by the jaws can engage with the boot,   a releasing configuration for releasing the boot as a result of twisting of the boot, said releasing configuration being different from the closed configuration, in order to automatically free the boot by actuation of the releasing system,   a fitting configuration, different from the closed configuration, in particular different from the releasing configuration, and allowing the boot to be fitted in the toepiece between the retaining elements,   
       the releasing system for automatically releasing the boot as a result of twisting of the boot comprising an elastic return means for the jaws in the closed configuration and in the releasing configuration of the toepiece, wherein, in said toepiece, the connection between a jaw and the elastic return means comprises at least one transmission link articulated to the jaw about a first hinge axis that is oriented in the longitudinal direction such that the jaw and its transmission link form a knuckle joint that deforms in the plane corresponding to the transverse direction and vertical direction of the toepiece. 
     
     
         2 . The toepiece as claimed in  claim 1 , wherein the constituent parts of the elastic return means exhibit movements and/or elastic deformations generally in a plane that is oriented in the longitudinal and transverse directions of the toepiece, during the passage from the closed configuration to the releasing configuration and to the fitting configuration. 
     
     
         3 . The toepiece as claimed in  claim 1 , wherein the transmission link is articulated to the elastic return means about a second hinge axis that is oriented in the longitudinal direction. 
     
     
         4 . The toepiece as claimed in  claim 1 , wherein the elastic return means of the releasing system comprises at least one elastically deformable strip. 
     
     
         5 . The toepiece as claimed in  claim 1 , wherein the elastic return means comprises at least one spring and two lever arms that are articulated and/or elastically deformable. 
     
     
         6 . The toepiece as claimed in  claim 5 , wherein the lever arms are arranged such that each lever arm makes the connection between one end of said spring that is oriented in the transverse direction and the transmission link connected to one of the jaws. 
     
     
         7 . The toepiece as claimed in  claim 5 , wherein the elastic return means comprises two transfer links and a tie bar that is oriented and slides in the longitudinal direction of the toepiece so as to stress said spring that is oriented in the longitudinal direction, each transfer link making the connection between the tie rod and one of the lever arms. 
     
     
         8 . The toepiece as claimed in  claim 7 , wherein the spring is disposed in a fixed housing with respect to a base of the toepiece that is intended to be fixed to the gliding board. 
     
     
         9 . The toepiece as claimed in  claim 7 , wherein the spring is disposed in a housing that is able to move in the longitudinal direction with respect to a base of the toepiece that is intended to be fixed to the gliding board, such that the housing moves at the same time as the tie bar and the spring during the passage from the closed configuration to the fitting configuration and vice versa, and such that the housing remains fixed with respect to the base during the passage from the closed configuration to the releasing configuration and vice versa. 
     
     
         10 . The toepiece as claimed in  claim 5 , wherein the elastic return means comprises connecting elements between the two lever arms, allowing the two jaws to move continuously in a synchronous and symmetrical manner with respect to a plane oriented in the longitudinal and vertical directions. 
     
     
         11 . The toepiece as claimed in  claim 5 , wherein the transmission link connected to the jaw is articulated by its second hinge axis directly to the lever arm by way of a contact between two spherical surfaces that are respectively carried by the transmission link and by the lever arm. 
     
     
         12 . The toepiece as claimed in  claim 5 , wherein the elastic return means comprises an offsetting link interposed between each lever arm and the transmission link connected to the jaw, the offsetting link being mounted so as to pivot on the lever arm and on the transmission link and optionally on a base of the toepiece that is intended to be fixed to the gliding board. 
     
     
         13 . The toepiece as claimed in  claim 1 , wherein the angular tilting travel of a jaw between the closed configuration of the toepiece and the releasing configuration of the toepiece is greater than the angular tilting travel thereof between the closed configuration and the fitting configuration. 
     
     
         14 . The toepiece as claimed in  claim 1 , which comprises an actuating lever that is accessible to the user from outside the toepiece and may take up:
 a fitting position in which the toepiece is placed in the fitting configuration,   a downhill position in which the toepiece is placed in the closed configuration,   and an uphill position in which the releasing system is blocked so as to block the toepiece in the closed configuration by preventing any possibility of it passing into the fitting configuration and/or into the releasing configuration.   
     
     
         15 . The toepiece as claimed in  claim 14 , which comprises a fitting stop that engages with the actuating lever so as to take up an active position in which it forms a support for the boot in the longitudinal direction when the actuating lever is in its fitting position. 
     
     
         16 . The toepiece as claimed in  claim 1 , wherein the releasing system comprises means for separating the overall tilting travel of the jaw between the closed configuration and the releasing configuration, into first and second angular sectors that are separated by an intermediate neutral-point position of the jaw corresponding to a hard point of inflection of the jaw under the action of the elastic return means. 
     
     
         17 . A binding device for securing a boot to a gliding board, comprising a toepiece as claimed in  claim 1  which is intended to secure the front part of the boot, and also a heel piece which is intended to secure a rear part of the boot to the gliding board, the heel piece being designed to release the boot only in the case of a forward fail of the skier, the boot being released from the binding device in the case of a twisting fall only by way of the toepiece. 
     
     
         18 . A gliding board, in particular a touring ski, comprising a toepiece as claimed in  claim 1 . 
     
     
         19 . A gliding board, in particular a touring ski, comprising a binding device as claimed in  claim 17 . 
     
     
         20 . A gliding board, in particular a touring ski, comprising a toepiece as claimed in  claim 1  and comprising a binding device for securing a boot to a gliding board, comprising a toepiece as claimed in  claim 1  which is intended to secure the front part of the boot, and also a heel piece which is intended to secure a rear part of the boot to the gliding board, the heel piece being designed to release the boot only in the case of a forward fall of the skier, the boot being released from the binding device in the case of a twisting fall only by way of the toepiece.