Abstract:
This fastener notably for sports boot comprises an indented strap secured to one portion of the boot and a rack associated with the strap for nipping the latter with the assistance of a yoke. The rack is engageable by a transverse element carried by one end of an arm pivoted to a tightening lever mounted on the other portion of the boot.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a sports boot fastener, notably for ski boots, of the type comprising a toothed anchoring rack adapted to be fastened to a first portion of the boot and a tightening lever pivoted to a yoke adapted to be secured to another portion of the boot which is to be firmly assembled with the first portion, said yoke being provided with a hooking member matching said anchoring rack and adapted releasably to engage this rack. 
     THE PRIOR ART 
     A device of this type is disclosed in the Swiss Pat. No. 615,811, which shows an anchoring rack secured directly to one of the boot portions by means of one or two rivets. The tightening lever is connected to a hooking buckle by means of a threaded rod and a nut-forming buckle support for permitting the fine adjustment of the fastener closing force. However, the range of permissible adjustment of the fastener closing force is subordinate essentially by the number of teeth of the rack. Under these conditions, if one wished to increase this adjustment range, one would be compelled to increase the rack length and also the buckle length, but this would not be feasible in actual practice for lack of space, not to mention the undesired increment in the boot weight. On the other hand, the fine adjustment of the fastener by means of a threaded rod is attended by several inconveniences; thus, if the user unscrews almost completely the buckle support so that the rod is retained only by one or two threads, the support is most likely to be stripped off when an excessive tension is exerted thereon; furthermore, the user runs the risk of unscrewing completely the buckle support, or loosing it and in any case experiencing have some difficulties when attempting to refit this support in place. 
     SUMMARY OF THE INVENTION 
     This invention is directed to avoid these various inconveniences by providing a sports boot fastener in which the anchoring rack is connected to the first boot portion by means of a strap having an indented or toothed inner surface, this rack being pivoted to a yoke provided with at least one tooth adapted to engage at least one notch of the indented face of the strap, said anchoring rack further comprising about its pivot axis a portion eccentric in relation to this axis and adapted to nip said strap between this eccentric portion and the yoke, when the anchoring rack is moved to its fastener closing position, i.e. towards the strap, a gap being left between the tightening lever and its supporting yoke to permit the passage of said indented strap therethrough. 
     The device of this invention is attended by several advantageous features with respect to the prior art: in fact, there is no limit to the length of the indented strap, which determines the total length of the permissible fastener adjustment range. Consequently, the anchoring rack may be extremely short, and with a short rack it is possible to use a likewise shorter hooking member, buckle or the like. Moreover, the device is free of any threaded or tapped component elements, which are expensive, difficult to handle and prone to jam. The rack movement from one point to another of the indented strap may take place very rapidly, since it is only necessary to raise the rack, cause same to slide along the indented strap and fold it down at the selected position. The movable parts of the device may be of simple, sturdy construction. The overall dimensions are relatively small since the indented strap is inserted through the yokes of the two portions of the device. 
     In a preferred form of embodiment of the present invention the rack comprises a longitudinal median slot and the hooking member pivoted to the tightening lever consists of an intermediate arm engaging the rack slot and comprises a cross member for releasably engaging the rack teeth. This construction is particularly sturdy and compact. 
     Two exemplary forms of embodiment of the invention will now be described by way of example with reference to the accompanying drawings. 
    
    
     THE DRAWINGS 
     FIG. 1 is a plane view of one portion of the indented strap associated with the anchoring rack; 
     FIG. 2 is a side elevational view of the same portion of the indented strap portion with the anchoring rack; 
     FIG. 3 is another side elevational view showing the same component elements, showing the rack in its raised position; 
     FIG. 4 is a side elevational view showing the tightening device in its open position; 
     FIG. 5 is a side elevational view showing the complete fastener in its closed position, and 
     FIG. 6 is a plane view showing the fastener of FIG. 6 in the same position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The indented strap 1 consists of a suitable plastic material having a relatively high resistance to abrasion. This strap 1 is manufactured by injection molding, and its lower surface has transverse notches 2 formed therein. 
     The anchoring rack 3 is pivotally mounted in a yoke 4 about a transverse pivot pin 5 having its ends riveted externally of the yoke wings 4a and 4b. About this pin 5 the rack 3 is formed with an eccentric portion 6. The base interconnecting the yoke wings 4a and 4b comprises two edges 7,8 bent upwards like these wings to form a pair of teeth engageable into spaced notches 2 of the indented strap 1. Furthermore, the anchoring rack 3 has formed therein three oblique notches 9 and a longitudinal median slot 10 extending substantially from one end to the portion thereof receiving the pivot pin 5 therethrough. When the rack 3 is raised (FIG. 3) its eccentric portion 6 moves away from the indented strap 1, so that the yoke 4 can slide freely along the strap. When the rack 3 is folded back towards strap 1 (FIG. 2) its eccentric portion 6 acts as a nipper and wedges or clamps the indented strap 1 between the rack and the teeth 7 and 8 of yoke 4. Thus, if the rack is pulled in a direction parallel to the indented strap this wedging action is unaffected. 
     The tightening device comprises a lever 11 fulcrumed by means of a pivot pin 12 between the spaced wings 13 and 14 of another yoke having its base plate 15 secured to one portion 16 of the boot (not shown) by means of a pair of rivets 17 and 18 (FIG. 5). A slot 19 aligned with the slot 10 of anchoring rack 3 is formed in lever 11 and engaged by a hooking arm 20 pivoted to said lever 11 about a pivot pin 21. The end of arm 20 carries a transverse rod 22 adapted releasably to engage one of the notches of rack 3. The pivot pin 21 is surrounded by a calliper spring 23 exerting an elastic pressure on the one hand against the hub of lever 11 and on the other hand against an extension of arm 20, whereby this spring 23 constantly urges the arm 20 to the position in which the latter engages the pivot pin 12. In the position illustrated in FIG. 4 the arm 20 is thus assumed to be lifted by a force F. The spring 23 is relatively weak, so that the arm 20 can be raised very easily. 
     FIG. 5 also illustrates the fixing of one end of strap 1 to the second portion 24 of the boot by means of a rivet 25. This Figure further shows that a sufficient gap is provided between the bottom or base of yoke 15 and the hub of lever 11 to permit the passage of the indented strap 1. Since the folding-down movement of arm 20 is limited by the presence of pivot pin 12, it is also possible to easily insert at any time the free end of strap 1 between the end of arm 20 and the base 15 of the tightener yoke. In the closed position shown in FIGS. 5 and 6 the arm 20 engages the slot 10 of rack 3, so that the height of the device is further decreased. 
     However, it would not constitute a departure from the basic principles of the present invention to substitute a rectangular buckle or a plate having a hook-forming curved end for the arm 20 constituting the hooking member proper. 
     The use of an indented strap is attended by several advantages: it permits on the one hand, independently of the distance between the two boot portions to be assembled, of positioning the hooking rack in close vicinity of the tightening device, and on the other hand of adapting the length of the indented strap to the specific application contemplated, without inasmuch reducing the intrinsic quality of the fastener. This last-mentioned feature is particularly valuable in the case of ski boots which require a uniform tightening force. To this end, the indented strap may extend from the boot sole and surround the upper portion of the foot. 
     The use of the fastener of this invention is particularly convenient. The user can modify in a trice the fine adjustment, i.e. the rack position, under any circumstance and without using any tool. It is only necessary to raise the rack and cause same to slide along the indented strap.