Abstract:
A device for adjusting the release threshold of a binding, comprising a threaded rod ( 2 ) and an end stop which is movable in translation on this threaded rod ( 2 ), wherein it comprises a planet wheel ( 1 ) with teeth ( 5 ) able to be activated by the corresponding teeth ( 7 ) of a tool ( 6 ) in order to move the end stop in translation along the threaded rod ( 2 ).

Description:
[0001]     The invention relates to a device for adjusting the strength of a releasable binding for a gliding board, which binding fixes a boot to a gliding board while at the same time allowing it to be released when it experiences loads above a certain threshold, for safety reasons. It also relates to a binding incorporating such an adjusting device. It is particularly suited to ski bindings.  
       DESCRIPTION OF THE PRIOR ART  
       [0002]     A conventional ski binding is made up of a heel piece and of a front end stop, which are positioned on a ski, comprising jaws that cooperate with rear and front kerbs provided on the soles of the ski boots. These jaws are connected to mechanisms, often based on a compression spring, for implementing the release functions to release the boot. The release threshold of such a binding must be adjustable in order to adapt to the characteristics of the skier, in particular his or her weight. The conventional adjusting mechanisms permit adjustment of the tensioning of the spring by changing the position of a compression end stop, for example.  
         [0003]     Document DE 8802115 U describes a binding whose adjustment is possible with the aid of a manually adjusted washer mounted directly on the adjusting screw. The advantage of this solution is that it does not necessitate the use of a tool. However, it is not suitable for bindings using considerable forces for which the compressed springs used subject the device to a very considerable force.  
         [0004]     Document FR 2778577 discloses a solution in which a heel piece of a ski binding comprises a main release mechanism, based on a main helical spring working in compression between a piston and an end stop, this end stop being mounted on a screw, permitting modification of its position and thus adjustment of the release threshold. The head of the screw has a first impression of hexagonal shape and a second cross-shaped impression in a second plane. The advantage of this binding is that its adjustment is possible with a screwdriver or wrench. However, in both cases, a considerable load is necessary for turning the screw because the compression force of this type of spring is very considerable. In particular, the bindings used in the context of competition demand extreme adjustments which engage very high forces. Moreover, the tool must necessarily be positioned in the axis of the screw, which is not always practicable.  
         [0005]     Document U.S. Pat. No. 5,671,942 describes a similar solution in which the head of the screw has a shape that facilitates the positioning of a screwdriver, since it functions even with the screwdriver slightly inclined relative to the horizontal. This solution, however, has the same disadvantages as the preceding one.  
         [0006]     One object of the present invention is therefore to propose a novel device for adjusting the binding of a boot to a gliding board which does not have the aforementioned disadvantages.  
         [0007]     More specifically, a first object of the present invention is to propose a device for adjusting a binding which does not require great effort on the part of the user to perform the adjustment.  
         [0008]     A second object of the present invention is to propose a more flexible device for adjusting a binding, allowing easier adjustment.  
       SUMMARY OF THE INVENTION  
       [0009]     The invention is based on a device for adjusting the binding of a boot to a gliding board, comprising a threaded rod and an end stop which is movable in translation on this threaded rod, characterized in that it comprises a planet wheel with teeth able to be activated by the corresponding teeth of a tool in order to move the end stop in translation along the threaded rod.  
         [0010]     The planet wheel can comprise teeth whose shape and dimensions correspond to the teeth of a standard cross-head screwdriver, their number being greater than that of the teeth of the screwdriver.  
         [0011]     According to a first embodiment, the teeth of the planet wheel are such that they can be activated by a cross-head screwdriver positioned perpendicularly with respect to the axis of the threaded rod.  
         [0012]     According to a second embodiment, the teeth of the planet wheel are such that they can be activated by a cross-head screwdriver positioned parallel to the axis of the threaded rod.  
         [0013]     According to an alternative embodiment, the planet wheel is fixed on the threaded rod on which is mounted a nut which is movable in translation and serves as an end stop for a spring of the binding.  
         [0014]     This device can be mounted in a housing intended to be fixed on a gliding board, the housing comprising an opening for insertion of a screwdriver, and an elongate slot for viewing a protruding part of the nut and for viewing the adjustment of the binding.  
         [0015]     The device can comprise two planet wheels fixed to two threaded rods to allow two nuts to abut against two springs, and the spacing between the two planet wheels is such that it permits simultaneous contact of their respective teeth with those of the same tool.  
         [0016]     According to another alternative embodiment, the planet wheel is movable in translation on the threaded rod and serves as an end stop for a spring of the device. In this case, the device for adjusting the release threshold can comprise a part moving simultaneous to the planet wheel and serving as a guide for the screwdriver and as an indicator of the adjustment.  
         [0017]     Finally, the invention also relates to a device for binding a sports boot to a gliding board, comprising a device for adjusting the threshold of its release as has been described above. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0018]     These objects, characteristics and advantages of the present invention will be set out in detail in the following description of particular embodiments given by way of nonlimiting examples in conjunction with the attached figures, where:  
         [0019]      FIG. 1  depicts a simplified view of the device for adjusting a binding according to a first embodiment of the invention;  
         [0020]      FIG. 2  depicts an enlarged view of details of the device from  FIG. 1 ;  
         [0021]      FIG. 3  depicts a perspective view from above of the device in its first embodiment incorporated in its housing;  
         [0022]      FIG. 4  depicts a perspective view from below of the device of the first embodiment incorporated in its housing;  
         [0023]      FIG. 5  depicts a simplified view of a second embodiment of the invention;  
         [0024]      FIG. 6  depicts a simplified view of a third embodiment of the invention;  
         [0025]      FIG. 7  depicts a simplified view of a fourth embodiment of the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     The embodiment shown in  FIG. 1  is based on a planet wheel  1  mounted in a fixed manner on a threaded rod  2 , permitting translation of a nut  3  serving as an end stop for the spring  4  of the mechanism for release of the binding. The planet wheel comprises teeth  5  whose dimensions correspond to those of a standard cross-head screwdriver  6 . By engaging the teeth  7  of such a screwdriver in those of the planet wheel  1 , by positioning of the screwdriver perpendicularly with respect to the threaded rod  2 , the rotation of the screwdriver causes the rotation of the planet wheel  1  and permits translation of the nut  3  in order to adjust the compression of the spring  4  for release of the binding.  
         [0027]     According to the inventive concept, the number of teeth  5  of the planet wheel is greater than the number of teeth  7  of the cross-head screwdriver, equal to 4, by which means it is possible to gear down the necessary force: to obtain a turn of the threaded rod  2 , it is necessary to execute a number of turns with the screwdriver equal to the number of teeth  5  of the planet wheel divided by 4. For example, in the case of a planet wheel with  12  teeth, one turn of the screwdriver induces a rotation of 120 degrees of the threaded rod  2 , and three turns of the screwdriver are needed to obtain a rotation of 360 degrees of the threaded rod. Thus, for a given displacement of the nut  3 , the manual force needed to turn the screwdriver is less than that which would be necessary for an equivalent displacement with a solution of the prior art, where one turn of the screwdriver corresponds to one turn of the threaded rod. The number of teeth of the planet wheel  1  can be defined by varying the diameter of the planet wheel.  
         [0028]     As is illustrated in  FIGS. 3 and 4 , the preceding device is placed in a housing  10  intended to be fixed on a gliding board. The housing comprises a lateral opening  11  permitting insertion of the screwdriver  6  and positioning of its teeth  7  in contact with the teeth  5  of the planet wheel  1 . The housing comprises an elongate slot  12  on its upper face, in which slot a projection  13  of the nut  3  moves in a visible manner. This indicates visually to the user the level of adjustment of the binding. A scale is advantageously inscribed on the lateral parts of the slot  13 .  
         [0029]      FIG. 5  illustrates a second embodiment of the invention in which the planet wheel  1  is movable in translation on the threaded rod  2  and serves as an end stop for a spring  4 . A part  8  serving as a guide for the placement of the screwdriver  6  also moves in translation simultaneously with the planet wheel. This part  8  can also fulfill the second function of visually indicating the adjustment obtained.  
         [0030]      FIG. 6  illustrates a third embodiment of the invention in which the teeth  5  of the planet wheel are such that they mesh with those of a cross-head screwdriver  6  positioned parallel to the axis of the threaded rod  2 .  
         [0031]      FIG. 7  illustrates a fourth embodiment of the invention in which the screwdriver  6  can be inserted perpendicularly with respect to two threaded rods placed in the same axis and supporting two planet wheels  1  and  1 ′ which are mounted in a fixed state and position opposite one another, their spacing being such that their teeth  5  and  5 ′ can come simultaneously into contact with the teeth  7  of the screwdriver in such a way as to obtain their simultaneous rotation. These planet wheels  1  and  1 ′ drive in translation two nuts  3  and  3 ′ serving as end stops for two springs  4  and  4 ′. With this embodiment, it is possible to choose two nonidentical threads for the threaded rods and to obtain different simultaneous adjustments of the springs  4  and  4 ′, which affords additional mechanical combinations. This solution could be used to simultaneously adjust the front and rear bindings of the compact binding devices.  
         [0032]     The above embodiments have been advantageously implemented with a standard cross-head screwdriver. However, the same concept could be applied with different tools, even specific ones.  
         [0033]     Finally, the solution according to the invention effectively meets the desired object and has the following advantages: 
        it permits a reduction in the force needed to adjust the binding;     it can function with a standard tool;     it entails virtually no modification to the existing mechanisms and takes up a negligible amount of space. It is easily applied to the standard front and rear binding devices, and to the more compact devices, arranged under the boot for example, such as that described in patent FR 2794028;     it is flexible because access to the adjustment can be provided in different locations, and in particular laterally, which permits adjustment even in the presence of a boot in the binding irrespective of the form of the binding.