The present invention relates to a locking device particularly for snowboards. Background Art

Snowboards are constituted by a single board on which shoe bindings must be associated; these bindings usually must allow the skier to achieve a position which is slightly rotated with respect to the longitudinal axis of the board.

The technology used so far to provide ski bindings is not applied directly to the case of snowboards: in this regard, patent DT 23 56 052 discloses a safety ski binding with a plate which can be accommodated on the ski; the shoe is engaged with the tip by means of supporting elements which are fixed on the plate and with the rear part by lateral supporting elements which are fixed to the plate.

This conventional solution entails drawbacks, since it cannot be transferred directly to an application on snowboards, since the user must arrange the shoes at an angle with respect to the longitudinal axis of the board and so as to be able to preset slight rotations of the shoes in order to improve control of the board. In snowboarding it is also necessary to have perfect adhesion of the shoe or of most of it to the board, since steering is achieved by shifting the weight of the body from one side to the other of the board; in ski bindings of the illustrated kind, instead, layers of snow or ice can form between the skis and the sole of the shoe, consequently worsening the control of the board.

In relation to the specific use of snowboards, French

patent no. 2,669,237 discloses an adjustable safety binding for skiing boards, also known as snowboards, which comprises a base which is meant to be fitted to the board and a top part which is connected to detachable shoe locking means; the base comprises a spherical pivot which is complementary to a spherical pivot of the top part, so as to provide a ball-and-socket joint which allows mutual angular adjustment of the base and the top part with three degrees of angular freedom and furthermore provides a means for locking the base and the top part.

In this solution, therefore, an angular adjustment of the position of the shoe with respect to the board is substantially achieved, but the connection and disconnection of the shoe with respect to the binding is not easy, since it is in any case locked by the interaction of means which act on the tip and on the heel unit of the shoe; all this entails difficult transmission of forces from the foot to the board, since these forces must be located in the small area of interaction between the base and the top part, dissipating for example the forces applied during body weight shifting and possibly deforming the components which are mutually rotatably associated.

The use of any flexible elements does not solve the problem, since it leads to an unwanted dissipation of forces and therefore the skier is unable to have good sensitivity on the board, since he cannot directly transmit the forces applied to the shoe.

US patent no. 5,299,823 relates to a snowboard binding which comprises a fixed jaw for coupling one side of a shoe and a movable jaw which is fitted so as to engage the

opposite side of the shoe.

A lever places the seat for the movable jaw in a locked condition, in which the fitted movable jaw is fixed so as to be in a locked condition with the shoe; in an intermediate condition, in which the seat for the movable jaw can be shifted laterally towards a free condition; and in a released condition, in which the seat for the movable jaw can be either moved safely towards the free condition or can be promptly moved towards the free condition in contrast with a spring.

This solution is structurally complicated and is subject to possible jamming of its components, which are affected by several relative movements in order to lock and/or release the shoe. All these solutions furthermore have the drawback that they require to place the board on a level surface in order to achieve easier fixing of the shoe, but this is a seldom available condition. Disclosure of the Invention

The aim of the present invention is to solve the described problems, eliminating the drawbacks of the cited prior art and thus providing a locking device which is specific for snowboards, is compact and allows to achieve optimum transmission of forces from the shoe to the board, in order to achieve optimum control of said board. within the scope of this aim, an important object is to provide a device which allows to minimize the presence of any snow at the sole of the shoe when it is activated and therefore when said shoe is locked.

Another important object of the invention is to provide

a device which, despite the possible presence of thin layers of snow or ice between the shoe and the snowboard, allows to achieve the above characteristics even if the snow or ice melts during sports activity. Another important object of the invention is to provide a device which allows optimum, quick and simple engagement and disengagement of the shoe even if those operations are performed on slopes.

Another important object of the invention is to provide a device which allows to achieve optimum insertion and centering of the shoe therein.

Another object is to provide a device which associates with the preceding characteristics that of being structurally simple as well as reliable and safe in use and of being producible with conventional machines and equipment.

This aim, these objects and others which will become apparent hereinafter are achieved by a locking device particularly for snowboards which comprises a circular plate which is rigidly coupled to a board of a snowboard, characterized in that it is constituted by a rotating body which is rotatably associated with said plate and is provided with means for engaging and temporarily compressing complementarily shaped grip means which are associated with the sole of a shoe, means being provided for temporarily locking the rotation of said rotating body. Brief Description of the Drawings

Further characteristics and advantages of the present invention will become apparent from the following detailed description of a particular but not exclusive embodiment

thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a perspective exploded view of some components of the device; figure 2 is a sectional view of the device in the assembled condition, prior to the insertion of the shoe; figure 3 is a partially sectional top view of the device in the condition of figure 2; figure 4 is a view, similar to figure 2, of the device with the grip means, which are glued to the sole of the shoe, associated therewith; figure 5 is a view, similar to figure 3, of the condition of figure 4; figure 6 is a sectional view of the grip means which is associable with the sole of the shoe; figure 7 is a bottom view of the sole of the shoe; figure 8 is a perspective view of a second embodiment of the device; figure 9 is a partially sectional view of the device of figure 8; figure 10 is a perspective exploded view of the components of the device of figure 8; figure 11 is a view, similar to figure 2, of the device in the condition in which the shoe is not associated with said device; figures 12 and 13 are respectively a top view and a side view of the device in the condition of figure 11; figure 14 is a view, similar to figure 11, of the device in the condition in which the shoe is associated with the device;

figures 15 and 16 are respectively a top view and a side view of the device in the condition of figure 14; figure 17 is a sectional view of the grip means associated with the sole of the shoe; figures 18 and 19 are respectively a plan view and a side view of the shoe with the device applied thereto. Ways of carrying out the Invention

With reference to the above figures, the reference numeral 1 designates a device which can be used particularly for locking shoes, designated by the reference numeral 2, at snowboards, designated by the reference numeral 3.

A plate 4 is rigidly coupled to a board of a snowboard by suitable means such as screws and has a circular plan shape.

The device 1 is constituted by a first rotating body, designated by the reference numeral 5, which is in turn constituted by a ring gear 6 which is rotatably associated at the plate 4 and perimetrica1 ly meshes with two complementarily toothed planetary gears 7a and 7b.

Said planetary gears, together with the ring gear 6, are accommodated inside an annular disk 8 which is rotatably associated with the underlying plate 4 by means of a suitable locking flange 9 which is rigidly coupled to said plate 4.

The annular disk 8 has, at the planetary gears 7a and 7b, suitable first holes 10a, 10b which accommodate the ste s 11a, lib of two second rotating bodies 12a, 12b which are mushroom-shaped so as to form a head 13a, 13b which has a circular plan shape and at which there is provided a first cutout portion, designated by the reference numerals 14a,

14b, which is formed along a chord.

The stems 11a, lib of the second rotating bodies are rigidly coupled at the underlying planetary gears 7a, 7b; engagement and temporary compression means, constituted by two jaws 15a, 15b which are substantially frustum-shaped and have a circular plan shape, are furthermore associated coaxially with said stems.

A helical tooth, designated by the reference numerals

16a, 16b, is provided on the lateral surface of the jaws; second cutout portions, designated by the reference numerals

17a and 17b, are formed on the lateral surface on a plane which passes through a chord.

The jaws 15a and 15b are furthermore axially perforated for the passage of the stems 11a, lib and of suitable flexible elements 18a, 18b, which are preferably constituted by two cylindrical helical torsion springs and are thus interposed between the heads 13a, 13b and the annular disk 8 or the planetary gears 7a, 7b.

Annular raised portions 19a, 19b protrude from the head 13a, 13b on the opposite side with respect to the ste s 11a, lib and can be inserted at complementarily shaped second holes 20a, 20b which are formed at two shoulders 21a, 21b which are mutually opposite and on which there are provided suitable first seats 22a, 22b for partially containing the rotating bodies 12a, 12b and the jaws 15a, 15b.

Two pins or screws 23a, 23b can furthermore be arranged at the second holes 20a, 20b; their function is to keep the shoulders 21a, 21b, the jaws 15a, 15b, the rotating bodies

12a, 12b and the planetary gears 7a, 7b packed together. A lever 24 is transversely and freely pivoted at at

least one of said first seats 22a, 22b and has a first arm 25 which can be accessed from outside the shoulder by the user and a second arm 26 which lies inside the seat and thus inside the shoulder and interacts or not at one of the first cutout portions which are adjacent thereto and are provided in the first rotating bodies 12a, 12b.

The device is furthermore constituted by grip means which are associated with the sole 27 of the shoe 2; the grip means are constituted by separate components which can be associated with the sole or are obtained directly by shaping the sole in a particular manner.

As shown in figure 6, said means are constituted by a plate 28 which is preferably associable at the region of the plantar arch of the sole 27 and has, at the inner side 29 and outer side 30 of the foot, a substantially C-shaped configuration in which a third wing 31, directed towards the device 1, is preferably inclined.

Advantageously, the lever 24 is forced to rotate counterclockwise by a spring 32 which is coaxial to the pivot for pivoting to the shoulder.

Use of the device is thus as follows: in order to engage the shoe it is sufficient for the user to rest the sole 27 and thus the plate 28 at the interspace between the shoulders 21a, 21b; in this condition, shown in figure 2, the lever 24 is not activated and therefore the jaws 15a, 15b are fully contained within the seats 22a, 22b.

Thus, once the plate 28 has been rested at the annular disk 8, it is sufficient for the user to slightly rotate said shoe clockwise or counterclockwise: in this way, the entire first rotating body 5 is rotated and, by means of the

planetary gears 7a, 7b, the jaws 15a, 15b are rotated, making the helical teeth 16a, 16b interact at the third wing 31 of the plate 28.

In this manner, as shown in figure 4, the helical teeth 16a, 16b interact with the third wing 31, applying thereto a downward pressure and thus locking said plate 28 adjacent to the annular disk 8.

By virtue of the reduction between the planetary gears 7a, 7b and the ring gear 6, once the locking has been achieved, a rotation through approximately 180° of the rotating bodies 12a, 12b is also achieved so as to place the first cutout portions 14a, 14b so that they face the second arm 26 of the lever 24.

At this point, the spring 32 rotates the lever 24 counterclockwise and thus causes direct contact between the second arm 26 and one of the first cutout regions 14a, 14b, so as to lock any further rotation of the rotating body 5, thus in practice locking the position of the shoe with respect to the device. it has thus been observed that the invention thus conceived has achieved the intended aim and objects, a locking device specific for snowboards having been obtained which is compact, allows optimum transmission of forces from the shoe to the board in order to achieve optimum control of said board, allows to minimize the presence of any snow at the sole of the shoe when it is activated and thus when said shoe is locked, since the continuous pressure applied during the locking step forces the shoe onto the board even if the snow or ice, if present, melts during sports practice. T e device is furthermore compact and allows to rest

both the toe and the heel of the shoe at the board by virtue of the configuration of the plate 28 and of the pressure applied thereto towards said board.

The device furthermore allows to achieve optimum, quick and simple engagement and disengagement of the shoe, and this occurs even if these operations are performed on slopes, the shoe being centered in an optimum manner during the insertion step; finally, the pressure applied to the plate 28 allows to eliminate any snow or ice present under the sole; in case of thick layers of snow or ice, the presence of the springs 18a and 18b allows to compensate for these layers by torsion, thus ensuring the locking of the shoe even if the snow and ice melt over time, since in this situation they tend to elongate. The device is of course susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept.

Thus, for example, the remaining figures illustrate a second embodiment, in which the first rotating body 105 is constituted by a ring gear 106 which is rotatably associated inside an annular disk or base 108 which is in turn rotatably associated with the underlying plate 104 by means of a suitable locking flange 109 which is rigidly coupled inside said ring gear 106. The ring gear peri etrically meshes with two complementarily toothed planetary gears 107a, 107b which are in turn contained within the annular disk or base 108 and are pivoted thereto at suitable pins or screws 123a and

123b. Means for temporary engagement and compression, such as

two joints 133a and 133b shaped like truncated cones and two flexible elements such as two springs 118a and 118b arranged coaxially to the stem Ilia and 111b of two jaws 115a and 115b which have a helical protruding tooth 116a and 116b and are accommodated within shoulders or covers 121a and 121b, are furthermore pivoted to said pins and clamped in a pack¬ like con iguration.

A Y-shaped or fork-shaped element 134 is slidingly interposed between the two joints 133a and 133b and the annular disk or base 108, as shown in figure 9; two raised portions 136a and 136b, suitable to temporarily mesh with the teeth of the ring gear 106, are provided at the end of the fourth wings 135a, 135b of said element 134.

A tooth 139, suitable to temporarily engage in a second radial seat 140 formed below the facing joint 133a, protrudes at the connection between the fourth wings and the base 137 of the Y-shaped or fork-shaped element 134, which protrudes partially outside the annular disk or base 108 through a suitable opening 138 formed thereon. The second radial seat 140 is formed so that the tooth 139 affects the seat when the raised portions 136a and 136b mesh with the ring gear 106; in this condition, the ring gear is rotationally locked and thus the shoe is locked.

A protrusion or pin 141 protrudes from the base 137, on the same side as the tooth 139, and is associated with an L- shaped handle 142 inside which there is a third seat 143 for an additional cylindrical helical compression spring 144 which interacts with the outer lateral surface of the facing shoulder 121a; the spring forces the fork to mesh with the ring gear 106, and this operation can be reversed by the

user, who can manually shift the handle outward with respect to the device.

Advantageously, on the upper surface of the pair of joints 133a and 133b there are provided two concentric annular grooves, both designated by the reference numeral

145, for guiding complementarily shaped lower ends of the two jaws 115a and 115b.

The plate 128 associated below the shoe 102 or formed therewith interacts, by means of the third wing 131, with the helical teeth 116a, 116b, which lock the shoe as a consequence of the rotation applied thereto.

This solution, too, achieves the intended aim and objects.

The materials and the dimensions that constitute the individual components of the device may of course also be the most pertinent according to specific requirements.