Abstract:
A binding, comprises a pair of jaws ( 7,8 ) which can be moved apart from one another laterally while pushing back a cam ( 13 ) acted on by springs ( 19 ) and additional holding means, such as a jaw ( 21 ) located in front of or behind the lateral jaws and capable of tilting, preferably about a swivel, s against the action of the springs. The binding is intended to receive a part ( 2 ) integrated with the sole of the boot. The binding further comprises a lever for intentional boot release ( 24 ).

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a releasable binding for a gliding board, comprising a part secured to a boot and a part intended to be fixed on a gliding board, in which the part intended to be fixed to the gliding board comprises a pair of jaws which can be moved apart from one another and an elastic means opposing this movement apart, and in which the jaws and the part secured to the boot are designed so as to make it possible for the jaws to be moved apart, by the part secured to the boot when the boot is being fitted in the binding and upon release and to hold the boot on the gliding board after the boot has been fitted. 
     Such a binding is known from Patent FR 2 409 064. In this binding, the sole of the boot is fitted with a plate retained between the two jaws of the binding, the lateral sides of this plate having a hollow cutout in order to provide longitudinal holding of the boot. Each of these jaws is mounted at the end of an arm capable of pivoting about a vertical axis. 
     Bindings of the same type are described in Patents U.S. Pat. No. 4,143,886 and U.S. Pat. No. 5,799,966, the contents of which are incorporated by reference. These bindings also include a pair of jaws and are characterized by the presence of rods for transmitting the forces from the spring to the jaws articulated about a vertical axis. 
     Still further, U.S. Pat. No. 3,647,235, the content of which is incorporated herein by reference, and French Patent 2553671 describe such an invention. However, in both cases, it is necessary that both bindings swivel in order to insert a boot 
     Some of the prior art bindings have the advantage, on the one hand, of responding well to a twisting movement of the leg because of their position in the central part of the boot and, on the other, of being capable of being used for boots of different lengths without the need for adjustment. In such bindings, it is certainly easy to ensure good lateral gripping of the sole of the boot or of the metal plate fixed to this sole, by the jaws. However, the same is not true as regards the holding of the boot along a determined axis of the gliding board. This is because, even though the shape of the jaws is perfectly matched to the shape of the plate of the boot the spring which holds the jaws would need to be excessively powerful in order to prevent any rotational movement about a vertical axis. Further, wear on the jaws and the plate of the boot increases the possibility of rotation, which, even if very limited, equates to play for the user, which play makes control of the gliding board inaccurate and creates a feeling of insecurity. A similar play also appears when the skier presses on the rear of the boot. 
     Keeping the idea of retaining the boot by a pair of jaws which are located in the central region of the sole of the boot, what is needed is an in invention which avoids the drawbacks of the bindings according to the prior art, that is to say to produce a binding with lateral jaws which provide improved holding of the boot in its longitudinal direction. 
     SUMMARY OF THE INVENTION 
     A binding is provided wherein the boot is reed by a pair of jaws which are located in the central region of the sole of the boot, in which the binding has lateral jaws providing improved holding of the boot in its longitudinal direction. 
     The binding further comprises additional holding means, retained elastically, opposing at least a twisting movement about an at least approximately vertical axis of the part secured to the boot these additional means being preferably located in front of the jaws, relative to the heel of the boot. 
     Hence, even in the presence of angular play of the boot in the jaws, the additional holding of this boot neutralizes this angular play. 
     As explained above, the angular play is produced both dug slight twisting movements and because of wear. 
     The additional holding means could also retain the boot against wrenching, that is to say like conventional toe pieces. 
     The additional holding means preferably consist of a jaw articulated by a swivel joint and of a slide held bearing against the lower part of said jaw by said elastic means, so as to hold the jaw elastically in a determined position. 
     The swivel joint allows the jaw to pivot in all directions in the space above the binding. The boot can hence come out of the jaw both in the event of twisting and in the event of falling forward or backwards. 
     According to a preferred embodiment of the invention, the elastic means retaining the jaw pair is mounted between the pair of jaws and the jaw of the additional holding means, so as simultaneously to provide retention of the jaw of the additional holding means. 
     A binding of this type is therefore no builder than the bindings according to the prior art. The elastic means is covered by the sole of the boot and extends over a length substantially shorter than the length of the boot. 
     The jaws of the pair of jaws are in the form of a lever of the first class whose axis is parallel to the longitudinal axis of the binding, and they bear on a horizontally and axially sliding V-shaped cam retained by the elastic means. 
     The common elastic means, mounted between the V-shaped cam and the slide on which the jaw of the additional holding means bears, consists, for example, of one or two springs working in compression or of at least one leaf working in buckling mode. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The appended drawing represents, by way of example, one embodiment of the invention as well as a slightly modified embodiment. 
     FIG. 1 is a first perspective view of the part of the binding intended to be fixed to the gliding board. 
     FIG. 2 is a second perspective view of the same part. 
     FIG. 3 is a side view of the boot sole intended to be fixed to the binding. 
     FIG. 4 is a bottom view of the boot sole represented in FIG.  3 . 
     FIG. 5 is a view in section on V—V of FIG.  4 . 
     FIG. 6 is a top view of the part represented in FIGS. 1 and 2. 
     FIG. 7 is a view in longitudinal axial section on VII—VII of FIG.  5 . of the binding fitted with the boot sole, not sectioned. 
     FIG. 8 is a view ill section on VIII—VIII of FIG. 7 without the boot sole. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The binding represented consists essentially of a part  1  (FIG. 1) intended to be fitted to a gliding board, for example a ski, and of a part  2  (FIGS. 3 and 4) integrated with a boot sole and intended to connect to the part  1 . 
     The part  1  comprises a base  3  having four holes for fastening it to the ski and whose central part is formed as a rail  4 . Over a part of its length, the base  3  has a longitudinal central groove  5 . Across the groove  5 , the base further has a transverse rib  6  which, with the neighboring end of the rail  4 , defines two recesses in which two lateral jaws  7  and  8 , respectively articulated about a pin  9 ,  10  extending parallel to the longitudinal axis of the base, are mounted. At their upper end, on their inner side, these jaws  7  and have a chamfer  11 ,  12 , respectively, of an engagement ramp for fitting the boot. The ramps  11  and  12  are also oriented obliquely relative to the longitudinal axis of the binding so as to converge in the direction of the rear of the binding. As can be seen in FIG. 8, the jaws  7  and  8  are in the form of a lever of the first class articulated about pins  9  and  10 . The lower arms  7   a ,  8   a , respectively, of these levers have, in plan view, a rounded side via which they bear on a cam  13 , or more precisely on the two sides  14  and of a V-shape constituting the cam proper (FIGS.  2  and  6 ). The cam  13  is mounted so as to slide in the rail  4 . The upper arms of the jaws  7  and  8  have a projection  7   b ,  8   b , respectively, intended to be attached onto the part  2  secured to the boot. 
     The cam  13  has a threaded axial hole with a longitudinal screw  16  that is engaged partially in the groove  5  and whose opposite end from the screw slot  17  is journalled in a support piece  18  guided in the rail  4 . This support piece  18  bears on a pair of parallel springs  19  working in compression between the support piece  18  and the slide  20 . The thrust exerted by the springs  19  on the cam  13  has the effect of holding the jaws  7  and  8  in the position represented. As can be seen in FIG. 8, the jaws butt against the sides of the base  3 , so a they are held in a vertical position. 
     A front jaw  21 , against which the slide  20  comes to bear, is mounted facing the other end of the rail  4 . As can be seen in FIGS. 6 and 7, the jaw is retained on the base  3  by a swivel joint  22 , so that the jaw  21  can pivot in all directions in the space above the base  3  in vertical axial section, as represented in FIG. 7, the front jaw  21  has a C-shape whose lower part  21   a  bears against the slide  20  which, when at rest, holds the jaw  21  in a vertical position. The upper part of the jaw  21  extends parallel to the base  3  and has an open V-shaped notch  23 . As can be seen in FIGS. 1 and 6, the lower part  21   a  of the jaw  21  extends over only a part of the width of the jaw and over only a part of the width of the slide  20 , which has a plane front face perpendicular to the longitudinal a of the base, against which the part  21   a  bears. The springs  19  work in compression between the support piece  18  and the slide  20 , and it is hence the same springs tat retain the lateral jaws  7  and  8  and the front jaw  21 . The precompression of the springs  19 , that is to say the hardness upon release of the binding, is adjusted by means of the screw  16 , which makes it possible to move the support piece  18  by bearing an the cam  13 . 
     Further, a lever  24  is articulated on the base  3  about a transverse pin  25 . The lower arm  24   a  of the lever  24  bears against a bar  26  mounted so as to slide in the groove  5  and itself bearing against the cam  13 . The lever  24 , pushed back by the bar  26 , is retained by a pair of stops  38 , The effect of pressure on the lever  24  is to push back the cam  13  by means of the bar  26 , and consequently to allow the jaws  7  and  8  to tilt outward while moving away from one another. 
     The part  2 , represented in FIGS. 3 and 4, is integrated with the sole  27  of a boot. It comprises a cylindrical stud  28  fitted with a head  29 , also cylindrical, with a diameter larger than the diameter of the stud  28  and whose lower edges have two chamfers  30  and  31  arranged symmetrically relative to the longitudinal axis of the sole and whose upper edge also has two chamfers  35  and  36  which are symmetrical relative to the longitudinal axis of the sole and which penetrate into the stud  28  to form indentations, as can be seen in FIG.  5 . The front end of the part  2  has a projecting part in the form of an arc of a circle  33 , under which a rectangular projecting part  34 , juxtaposed with the part  33  and extending laterally beyond the latter so as to form two plane support surfaces  34   a  on either side of the part  33 . 
     It can be seen in FIG. 4 that the part  2  extends over only a part of the length of the sole, which, in front of the part  2 , has a step structure  39  separated from the part  2  by a space making it possible to obtain an intermediate zone  40  having a degree of flexibility to make it easier to walk. 
     The rail  4  has two lateral windows  32  which face the support piece  18  and whose edge is graduated in order to display the setting of the precompression of the springs  19 . 
     In order to fit the boot in the binding, the support surfaces  34   a  of the part  2  are engaged under the jaw  21  so that the rounded part  33  comes to bear in the V-shaped notch  23 . The head  29  of the stud  28  comes to lie in front of the lateral jaws  7  and  8 , the lower chamfers  30  and  31  coming to bear on the top of the chamfers  11  and  12  of tho jaws. Under the pressure exerted by the heel, the head  29  moves the jaws  7  and  8  apart by sliding over their chamfers  11  and  12  while compressing the Gags  19 . The jaws  7  and then re-close over the chamfers  35  and  36 , pressing the sole onto the binding. The effect of the oblique orientation of the chamfers  11  and  12  of the jaws is to push the sole forward and apply the rounded front part  33  of is the part  2  into the V-shaped notch  23  of the front jaw  21 . The boot is hence securely held both transversely and longitudinally. 
     In the event of falling forward, the head  29  of the boot moves the lateral jaws  7  and  8  apart, compressing the springs  19 . The front jaw  21  pivots on its swivel  22 , pushing the slide  20  back slightly. The boot can hence come out of the binding. 
     In the event of falling backward, the tilt of the front jaw  21  and the movement apart of the lateral jaws  7  and  8  also take place simultaneously. 
     Under twisting, the stud  28  can tun between the lateral jaws  7  and  8 , and the boot escapes first from the front jaw  21 , and then the jaws  7  and  8 , the springs  19  being compressed only by the front jaw  21 . 
     As already mentioned above, intentional boot release is carried out by pressure on the lever  24 , which frees the lateral jaws  7  and  8  and makes it possible to take the boot out of these jaws. The boot can then be taken out of the font jaw  21 , as in the case of a conventional toe piece. 
     The binding which has been described provides stable fastening of the boot at three points. The same result could be obtained by placing the jaw  21  behind the lateral jaws  7  and  8 , it being possible for the latter to be placed further forward relative to the heel of the boot. In particular, the jaw  21  could retain the heel of a boot having a rear ridge. In this case, the fitting of the boot would start by engaging the heel under its retaining jaw. 
     The lateral jaws could have some other shape matched to the shape of the sole of the boot. 
     The coil springs  19  could be replaced by one or more leaves working in buckling mode. 
     The part  2  could be without the support surfaces  34 . In this case, the jaw  21  would provide only horizontal retention, under twisting. 
     It should be pointed out that the diameter of the head of the stud  28  could be equal to or less than the diameter of the stud, that is to say formed by a channel into which the jaws penetrate. 
     The boot could instead be pushed forward by engagement ramps on the part  2 , against which ramps the jaws would come to bear. 
     Although illustrative embodiments of the invention have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.