Locking and adjustment device particularly for ski boots
BACKGROUND OF THE INVENTION 
     The present invention relates to a locking and adjustment device particularly usable for ski boots of the rear-entry type. 
     Among known devices, suitable for example for fastening the quarters of a ski boot, U.S. Pat. No. 4,433,456 filed by the same Assignee discloses a closure device comprising a box-like body associated with a first boot portion and provided with a knob actuating a spool for winding at least one cable associated with another boot portion to be loosened or tightened relatively to the first boot portion. 
     The device furthermore comprises ratchet-gear means controlled by said knob, adapted to lock the spool in any position during the rotation of the knob in one direction and to unlock said spool upon the rotation of the knob in the opposite direction. 
     To reduce the locking effort, a reduction ratio is provided, while the stroke limit for winding the cable is obtained by means of a particular arrangement of the teeth. 
     Though said device is undoubtedly valid, it has some disadvantages, being structurally rather complicated, therefore constructively onerous, the range of transmission ratio being furthermore reduced since it is limited by dimensional requirements due to the particular structure of said device. 
     As a partial solution to these disadvantages, European Pat. No. 0 132 744, filed by the same Assignee, discloses a device for actuating a foot instep presser alone composed of an actuation element comprising a spool for winding a cable rigidly associated in rotation with a knob supported, with the possibility of rotation and axial translatory motion, by a fixed body associated with the shell. 
     Though said device is structurally simpler than the preceding one, it has a direct transmission which makes it suitable practically only for securing the foot presser, great efforts not intervening in this operation. 
     The device furthermore provides a stroke limit constituted by a tooth protruding from the knob, which interacts with an abutment on the fixed part of the support: this configuration however allows only one rotation of 360 degrees. 
     The same Assignee filed a U.S. Pat. No. 4,620,379 disclosing a closure device which allows the simultaneous locking of the quarters and of the foot. 
     This device, however, also has a disadvantage, the locking being the same both for the quarters and for the foot, this not being optimum since the two require separate adjustments. 
     A French patent application, No. 2570257 filed on Sept. 14, 1984, is also known, wherein a circular device is illustrated which effects a locking on the foot instep and of the quarters, said device winding a single cable acting thereon. 
     Among the disadvantages observable in said known type of device, it is noted that the locking occurs without differentiations between the foot instep and the quarters, furthermore, there is an insufficient rear support since, during the extension of the leg, the cable exerts a greater pressure on the foot instep and, vice versa, it tends to slacken the pressure when the skier flexes his or her leg, thus being ineffective in the conditions of actual stress. 
     The device furthermore provides the unlocking of the cable by means of a ratchet lever actuatable by the skier: however, when said lever is subject to high loads, that is to say for very tight lockings, the skier has to exert quite an effort and, furthermore, only the rapid unwinding of the cable is possible. 
     SUMMARY OF THE INVENTION 
     The aim of the present application is to eliminate the disadvantages described above in known types by providing a device allowing the simultaneous locking of the quarters and/or of pressers located, for example, at the instep and at the heel of the foot, in a rapid, simple manner and with modest efforts on the part of the skier. 
     Within the scope of the above described aim, another important object is to provide a device which allows to differentiate the degree of locking of the quarters and/or of the pressers. 
     A further object is to provide a device which allows to achieve an optimum grip of the boot for backward movements of the leg, keeping the locking of the quarters and/or of the presser in optimum conditions. 
     Still another object is to provide a device which allows to slacken the quarters and/or the pressers in a rapid and/or gradual manner according to the contingent requirements. 
     Not least object is to provide a device which associates with the preceding characteristics that of being structurally simple, scarcely bulky, reliable in use, and having modest costs. 
     The aim and the objects mentioned above, as well as others which will become apparent hereinafter, are achieved by a locking and adjustment device, particularly for ski boots, comprising a box-like body, associable with a ski boot, a first knob actuatable by the skier being rotatably associable to said body, the device further comprising a first and a second winding spool, for at least one traction element, pivoted freely to said box-like body and interacting with mechanical reduction means univocally controlled by said knob, means being provided for a fine adjustment of the tensioning of at least one of said traction elements. 
     Conveniently said first winding spool has means adapted to prevent the accidental winding thereon of said one or more traction elements beyond the point of maximum unwinding. 
     Advantageously said second winding spool has a toothed ring interacting with ratchet-gear means controlled by means selectively actuatable by the skier and adapted to lock and unlock said second spool during the rotation of said knob in one direction and in the opposite direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the invention will become apparent from the detailed description of a particular but not exclusive embodiment, illustrated only by way of non-limitative example in the accompanying drawings, wherein: 
     FIG. 1 is a front view of the device; 
     FIG. 2 is a view according to a longitudinal middle sectional plane wherein, for the sake of clarity, the spools have not been sectioned; 
     FIG. 3 is a partially sectioned front view of the means adapted to prevent the accidental winding on the first spool of the traction elements beyond the point of maximum unwinding; 
     FIG. 4 is a partially sectioned side view of the device illustrating the ratchet-gear means; 
     FIG. 5 is a view, similar to that of FIG. 1, of the device in partial cross section; 
     FIG. 6 is a side view, sectioned according to a longitudinal middle plane of a device according to another aspect of the invention; 
     FIG. 7 is a partially sectioned front view of the device of FIG. 6; 
     FIG. 8 is an exploded perspective view of the stop end assembly of the device of FIGS. 6 and 7. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1-5, the locking and adjustment device, generally indicated by the reference numeral 1, comprises a box-like body 2, associable with a ski boot, from which protrudes a ring 3, axially perforated and externally threaded, with which a first knob 4 is rotatably associated. 
     A stem 5, having at the end internal to said box-like body 2 a first toothed wheel 6, is coaxially associated to the knob 4 so as to rotate integrally therewith. 
     The toothed wheel 6 interacts with a second toothed wheel 7 keyed at a first pivot 8 freely pivoted internally to the box-like body 2, axially offset with respect to said stem 5. 
     The second toothed wheel 7 has a diameter preferably greater than that of said first toothed wheel 6. 
     To said first pivot 8 there is furthermore keyed a third toothed wheel 9 having a diameter smaller than that of said second toothed wheel 7 and being arranged at an adapted cavity 10 provided internally to the box-like body 2. 
     Said third toothed wheel 9 interacts simultaneously with a fourth and with a fifth toothed wheel indicated respectively by the numerals 11 and 12. 
     Said fourth toothed wheel 11 is keyed to a first winding spool constituted by a first pulley 13 freely pivoted internally to the cavity 10 of the box-like body 2. 
     An end of a traction element, such as for example a first cable 14 adapted for example to interact with an adapted presser placed internally to the boot at the foot instep and/or heel regions, is arrangeable inside said first pulley 13. 
     The other end of said first cable interacts with means for the fine adjustment of the tensioning thereof, said means being constituted by a threaded rod 15, rotatably associated with said box-like body 2 proximate to the end thereof from which the first cable 14 protrudes, with said threaded rod there being associated a complementarily threaded first pawl 16 whereto is freely pivoted a second pulley 17 around which the end of the first cable 14 not associated with the first pulley 13 is caused to pass. 
     The rotation is impartable to the threaded rod 15 by means of an adapted second knob 18 protruding externally to the box-like body 2. 
     With the first winding spool there is furthermore associated, on the opposite side with respect to the first knob 4, a flange 19, rigidly associated in rotation with the fourth toothed wheel 11, whereon a seat 20 having a helical configuration is provided. 
     A second pawl 21 is slideably accommodated within said seat 20 and is also slideable at the other end, within an adapted guide 22 provided at the box-like body 2 radially to said flange 19. 
     A second winding spool is keyed to the fifth toothed wheel 12 and is constituted by a pair of third pulleys 23 at each whereof there is associated the end of a traction element such as second cables 24a and 24b the other ends whereof are associated at the quarters of the boot. 
     On the opposite side with respect to said third pulleys 23, a ring 25 is associated with said fifth toothed wheel 12; the ring 25 has a front set of teeth interacting with the tooth 26 of a ratchet 27 pivoted to the box-like body 2 along an axis perpendicular to that of said fifth toothed wheel 12. 
     Said ratchet 27 has, at the end opposite to the one having the tooth 26, a lug 28 an end whereof interacts with the perimetral edge of the first knob 4 and the other with an elastically deformable element constituted by a spring 29 interposed between the same and the box-like body 2. 
     The lug 28 allows, by rotating the first knob 4, to disengage the tooth 26 from the ring 25. 
     To allow the rapid uncoupling between the ratchet 27 and the ring 25, a lever 30 is provided, pivoted internally to the box-like body 2 along an axis approximately parallel to the pivoting axis of said ratchet 27. The lever 30 has at one end a pushbutton 31 accessible to the skier, and at the other end a tab 32 interacting with the ratchet 27 and adapted to disengage the tooth 26 thereof from the ring 25 once the pushbutton 31 is pressed. 
     Naturally the ratchet 27 and the ring 25 have sets of teeth adapted to allow the rotation of said first knob 4 in the direction of winding for the first pulley 13 and third pulleys 23, but preventing the rotation thereof in the direction of unwinding. 
     The use of the device is thus as follows: the skier, by imposing a rotation to the first knob 4 in the direction of winding of the first and of the second cables 14 and 24, imposes simultaneously the locking of the quarters and of pressers arranged at the foot instep and heel regions. 
     This locking is easy due to the presence of the mechanical reduction means constituted by the toothed wheels 6, 7, 9, the wheel 9 interacting directly with the wheels 11 and 12 actuating the first and the second winding spool. 
     The second knob 18 contributes to differentiate the tensioning among the cables 24a, 24b, and 14 and, for example once the selected degree of locking of the quarters is achieved, allows the further fine adjustment of the tensioning of the cable 14. 
     If the user wishes to unlock the pulleys 13 and 23 he may act in two separate manners. 
     The first consists of pressing the pushbutton 31 of the lever 30, obtaining the rapid uncoupling between the tooth 26 of the ratchet 27 and the ring 25. 
     Alternately said uncoupling can occur in a slower manner by rotating the knob in the direction opposite to the unwinding one: by doing this it will shift slightly at the ring 3 causing in turn the shifting of the lug 28 and then lifting the tooth 26 from the ring 25. 
     The presence of the flange 19 with the related pawl 21 slideable within the seat 20 prevents the cable 14 from being unwound beyond the point of maximum unwinding. 
     It has thus been observed that the invention achieves the intended aim and objects, a device having been obtained which, besides allowing the simultaneous locking, for example, of the quarters and/or of pressers arranged at the instep and at the heel of the foot, also allows to differentiate the degree of locking of said quarters and/or pressers. 
     The mechanical reduction means constituted by the toothed wheels 6, 7 and 9 furthermore provides a rapid and effortless locking on the part of the skier, yet attaining high tensionings. 
     The device furthermore provides the boot with optimum support upon rearward movements of the leg, the locking of the quarters and/or of the pressers remaining in an optimum condition, thus ensuring a perfect transmission of the forces from the foot to the boot and thus to the ski. 
     The possibility of obtaining the unlocking according to two different manners increases the functionality of the device and therefore its practical use. 
     The device is furthermore structurally very simple, having very small dimensions, thus increasing the possible arrangements on the boot. 
     Naturally the invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the same inventive concept. 
     As illustrated in FIGS. 6-8, a device 100, according to another aspect of the invention, comprises a body 102 associable to a ski boot and from which protrudes an externally threaded ring 103 associated to a knob 104, in a manner fully similar to what has been described above. 
     The device 100 also comprises a first pulley 113, coaxially associated to a first toothed wheel 111, and a second pulley 123 coaxially associated to a second toothed wheel 112, adapted to wind traction elements as described above. 
     A pinion 105 is coaxially associated to the knob 104 and has a toothed end wheel 106 engaging both a first wheel 111 and a second wheel 112; thus the rotation of the knob 104 controls the winding of the traction elements 124a, 124b and 114, the pinion 105 and the wheels 111 and 112 having a suitable reduction ratio. 
     The traction element 114 is advantageously a cable acting on a foot presser and is provided with means for the fine adjustment of its tensioning comprising a threaded rod 115, associated with the body 102, supporting a threaded pawl 116 carrying a small pulley 117 engaging the cable. By turning the rod 115 the pulley 117 is displaced varying the working length of the cable as described above. 
     The device is provided with a locking/unlocking means of the pulleys&#39; rotation comprising a flange 103a formed on the ring 103 and provided with a frontal set of teeth. The flange 103a engages a tooth 126 of a ratchet 127. The ratchet 127 is pivoted at a pivot 130 associated with the body 102 and has a pushbutton 131 which is located outside the body 102. 
     Elastic means (not illustrated in the drawings) bias the ratchet 127 to engage the flange 103a; the set of teeth of the flange 103a and the tooth 126 of the ratchet 127 are shaped so as to allow a rotation of the knob 104 in the direction of winding of the pulleys and to prevent a rotation in the direction of unwinding. 
     An end stop assembly is also provided to prevent the pulleys from rotating beyond the point of maximum unwinding and thus winding the cables in a direction opposite to the designed one. 
     The end stop assembly comprises a set of teeth 106 provided on the pinion 105 and having a partially filled interspace 106c between the teeth 106a and 106b. The set of teeth 106 of the pinion 105 engages the toothed wheels 111 and 112 respectively provided with set of teeth 111d and 112d. 
     The toothed wheels 111 and 112 are similar and only the toothed wheel 111 is illustrated in FIG. 8 and described. 
     The set of teeth 111d of the wheel 111 has trimmed teeth 111a, 111b, 111c adapted to couple with the interspace 106c of the pinion set of teeth 106 allowing a rotation of the pinion 105 and wheels 111 and 112. At a point of maximum unwinding of the cables, the partially filled interspace 106c engages a complete tooth of the wheels&#39; set of teeth preventing any further rotation. 
     The trimmed teeth 111a, 111b, 111c may be of any number and may have different location depending on the number of turns deemed for the pulleys 113 and 123 to be sufficient to wind a suitable length of cable. 
     The operation of the device 100 is substantially similar to what has been described before; in this case the locking/unlocking means requires a reduced effort to press the push button 131 to release the cables. 
     Furthermore the device 100 has an even more simple and lightweight structure which is nevertheless very sturdy and reliable. 
     The materials, as well as the dimensions constituting the individual components of the device, may also be the most pertinent according to the specific requirements.