Abstract:
Automatic snowboard binding holding the boot via its sides and having an automatic locking mechanism ( 11, 14 ), retention mechanism ( 6 ), and a boot-release lever ( 16 ) whose operation results in unlocking of the retention mechanism. The boot-release lever is kinematically independent of the locking mechanism ( 11, 14 ) in such a manner that it remains stationary when the boot is clipped into the binding.

Description:
FIELD OF THE INVENTION 
     The invention relates to an automatic snowboard binding comprising a base carrying at least one retention means for holding a boot via at least one of its sides, shaped so as to engage with the retention means, comprising automatic means for locking the retention means, and a boot-release lever whose operation unlocks the retention means, this boot-release lever being articulated about a pin transverse to the base. 
     BACKGROUND OF THE INVENTION 
     Such a binding is known from patent application U.S. Pat. No. 6,105,996, the content of which is incorporated by reference. In this binding, the boot is equipped with two lateral studs which engage in guides into which they are inserted by elastically separating rotatably mounted cams which then lock the studs in the guides. The boot is released by means of a boot-release lever whose operation separates the cams so as to release the boot studs. The boot-release lever is linked kinematically to the cams in such a manner that it is moved by the cams when the boot is clipped (i.e., inserted) into the binding. Thus, on every such occasion, the boot-release lever is unexpectedly raised. This untimely activation of the boot-release lever gives rise to unnecessary wear of the latter and may constitute a source of irritation to the user. 
     Automatic snowboard bindings are, furthermore, known from patents FR 2 758 994, 2 736 274, 2 758 091, EP 0 778 055, U.S. Pat. No. 5,871,226, U.S. Pat. No. 5,954,358, the content of the US patents being incorporated by reference and also patent application U.S. Pat. No. 5,520,406, the content of which is incorporated by reference in all these constructions the boot-release lever is caused to move when the boot is clipped into the binding. 
     Patent FR 2 745 192 furthermore discloses a binding whose locking means comprise a rotary disk equipped with a locking notch and with a ratchet serration interacting with a catch which acts simultaneously as a boot-release lever. The boot-release lever is thus not only caused to move when the boot is clipped into the binding, but gives rise to noise when the boot is clipped into the binding by jumping over the teeth of the serration. 
     In U.S. Pat. No. 6,523,852, in the name of the applicant; automatic snowboard bindings are furthermore described which comprise two opposing cam jaws which are equipped with a movement arm intended to be moved by the boot, the cam-shaped part interacting with a blocking element which is movable in a guide in such a manner that a blocking of the jaw is ensured for various positions of the jaw. In these bindings, also, the boot-release lever is moved when the boot is clipped into the binding. 
     SUMMARY OF THE INVENTION 
     An aim of the present invention is to prevent movement of the boot-release lever when the boot is clipped into the binding. 
     To this end, the binding according to the invention is defined in that the boot-release lever is kinematically independent of the locking means in such a manner that it remains stationary when the boot is clipped into the binding, for example in a position in which it is lowered along the side of the base. 
     According to a preferred embodiment of the invention, the retention device is a jaw pivoting about a horizontal axis and integral with an movement arm intended to be moved by the boot during insertion of the boot into the binding this jaw having a part in the form of a cam interacting with a blocking element which is movable in a guide and urged by an elastic means in the blocking direction, the boot-release lever having a part shaped and positioned so as to move the blocking element unidirectionally in the direction of unlocking during raising of the boot-release lever. 
     The binding preferably comprises two symmetrical, opposed retention devices intended for holding the boot via its two sides, and the blocking elements are connected kinematically together by a bar. The boot-release lever has a lateral arm or tab engaged under said bar for the movement of this bar in the unlocking direction during raising of the boot-release lever. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The appended drawing represents, by way of example, an embodiment of the binding according to the invention. 
     FIG. 1 shows a side, break-away view in perspective, with no boot in the binding. 
     FIG. 2 is a detail view showing one of the jaws of the binding in the open position when the boot is out of the binding. 
     FIG. 3 shows the jaw of FIG. 2 in the position in which the boot is clipped into the binding. 
     FIG. 4 shows the action of the boot-release lever at the start of the unlocking action. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The binding comprises a base  1  of general rectangular shape intended to be fixed on a snowboard. This base  1  carries two identical, opposite binding elements  2  and  3  intended to hold a boot via its two sides, as described in patent application FR 99 14696. As the binding elements are identical, the element  2  only will be described. 
     The binding element  2  comprises a frame  4  in which a stirrup, oriented vertically, is mounted, in which stirrup a jaw  6  is mounted, capable of pivoting about a pin  7  transverse to the stirrup against the action of a spring tending to hold the jaw in the open position, as shown in FIG.  2 . The jaw is equipped with a pedal  8  for its movement by the boot when the boot is clipped into the binding. The stirrup  5  has two apertures  9  and  10  located facing one another and oriented substantially vertically. These apertures  9  and  10  serve for guiding a blocking finger or wedge  11  urged elastically downward by a bar  12  mechanically and kinematically connecting this blocking finger  11  to the blocking finger of the binding element  3 , passing through the base  1 . Such a binding is described in U.S. Pat. No. 6,523,852. More precisely, the outer side of the guide apertures  9  and  10  is slightly rounded, and the blocking fingers, such as the finger  11 , are connected to the bar  12  by means of a linking piece  13  in such a manner as to constitute a kind of crank, it being possible for the piece  13  to turn freely on the U-shaped bar  12 . 
     A torsional spring  20  biases the bar  12  downwardly. An end of the spring  20  is fixed in a vertical hole  26  (shown in phantom lines in FIG. 3) in the base  1 . The other end of the spring  20  reacts against the portion of the bar  12  which enters into the linking member  13 . The mid-portion of the spring  20  wraps around the bar  12 . Note that a linking member cover portion  22  and a bar cover portion  24  of the base  1  cover and obscure each linking member  13  and the bar  12  so that its operation docs not interfere with the boot of the operator. 
     The jaw  6  has a part  14  in the form of a cam engaged in the stirrup  5 , between the guide apertures  9  and  10 . The upper part of the jaw  6  has a planar face  15  on which the blocking finger  11  bears when the boot is out of the binding. The binding is furthermore equipped with a boot-release lever  16  mounted pivotably on the frame  4  about a pin  17  parallel with and transverse to the base  1 . More precisely, as shown in FIG. 2, the boot-release lever  16  is equipped with a hub  18  in the form of a drum containing a return spring which tends to hold the lever  16  in the lowered position. The hub  18  is equipped with an arm or tab  19  which extends transversely to the lever  16 , parallel to the pin  17  and engaged under the bar  12 . 
     FIG. 3 shows the binding element in the position in which the boot is clipped into the binding. The pedal  8  has been moved downward by the boot and the jaw  6  is engaged in a lateral housing of the boot. The blocking finger  11  has left the planar face  15  and has descended in the guide apertures  9  and  10  in order to block the cam part  14  of the jaw. 
     In order to remove the boot from the binding, the boot-release lever  16  is raised into the position  16 ′ shown in dot-dash lines in FIG.  1 . During this raising movement, the arm  19  of the boot-release lever raises the bar  12  which moves the blocking finger  11  upward. When this finger  11  arrives at the top of the apertures  9  and  10 , the jaw  6  is able to rise in order to return to the position shown in FIG.  2 . The lever  16 , now released, returns to the lowered position shown in solid lines in FIG.  1 .