TOE-PIECE FOR SKI BINDINGS

The present invention relates to a toe-piece for ski bindings provided with safety release means for the toe of the ski boot . It is known in the technical sector relating to ski touring that there exists the need to provide safety bindings comprising a front part or toe-piece able to lock the toe of the ski boot, allowing it to be rotated about a substantially horizontal axis, and a rear part or heel-piece able to cooperate with the heel of the ski boot so as to allow three different modes of use, respectively: heel released (normal walking) ; heel resting with greater or lesser degree of inclination of the ski boot (walking uphill) and heel locked (downhill skiing) .

EP 0,199,098 describes, for example, known bindings of the type mentioned above which have, however, the drawback consisting in the fact that the toe-piece does not have independent means for releasing the boot in the transverse direction, as required in the event of a fall or a twisting movement during downhill skiing, said safety condition being achieved by means of corresponding means for operating the rear heel-piece, which is therefore very complex and heavy and results in an assembly which has poor rigidity and is awkward during fitting.

The technical problem which is posed, therefore, is to provide a ski binding toe-piece able to achieve locking of the boot toe with the rigidity normally required for such applications and with the possibility of rotating the same toe about a horizontal axis, but at the same time able to allow the toe to come out of the toe-piece in the event of it being acted on by transverse forces, independently of the action of the heel-piece. In connection with this problem it is also required

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that this toe-piece should have small dimensions and a reduced weight, be easy and inexpensive to produce and assemble and be able to be fitted easily to skis using normal standardised connection means. These results are achieved according to the present invention by a toe-piece for ski bindings comprising a fixed support base having two jaws, with a respective end pin, able to rotate about an axis substantially perpendicular to the support base so as to pass from an open position into a closed position for locking the toe of a ski boot, said jaws having a resistance arm co-operating with actuating means able to rotate about an axis perpendicular to the support base against the opposing action of resilient means integral with the said toe-piece, said actuating means being constrained to a sliding piece able to be displaced in both senses in the longitudinal direction upon actuation of associated operating means, so as to cause closing/opening of the two jaws. Further details may be obtained from the following description of a non-limiting example of embodiment of the subject of the present invention provided with reference to the accompanying drawings, in which:

Figure 1 is an exploded view of the toe-piece according to the present invention;

Figure 2 is a top plan view of the toe-piece according to Fig. 1;

- Figure 3 is a cross-section along a plane indicated by III-III in Fig. 2; - Figure 4a, 4b is a perspective view and a top plan view of the toe-piece according to Fig. 1 during normal opening for positioning of the toe of the ski boot;

- Figure 5a, 5b is a perspective view and a top plan view of the toe-piece according to Fig. 1 during closing onto the toe of the ski boot;

Figure 6 is a top plan view of the toe-piece according to Fig. 1 during release of the ski boot when acted on by transverse forces;

- Figure 7a, 7b is a perspective view and a top plan view of the toe-piece according to Fig. 1 during resetting;

- Figure 8 is a perspective view of a second embodiment of the toe-piece according to the present invention;

Figure 9 is a view, from above, of a further embodiment of the toe-piece according to the present invention;

- Figure 10 is an exploded view of a further embodiment of the toe-piece according to the present invention;

- Figure 11 is a view of the toe-piece according to Fig. 10, partially open;

- Figure 12 is a perspective view of the toe-piece according to Fig. 10 during opening for positioning of the toe of the ski boot ;

- Figure 13 is a perspective view of the toe-piece according to Fig. 10 during closing onto the toe of the ski boot for use during downhill skiing;

- Figure 14 is a perspective view of the toe-piece according to Fig. 10 during closing onto the toe of the ski boot for use when walking uphill; - Figure 15 is a view of the toe-piece according to Fig. 10 during release of the ski boot when acted on by transverse forces; and

- Figure 16 is a perspective view of the toe-piece according to Fig. 10 during resetting. As shown in Fig. 1 and with reference to the directions shown by way of example in the figures, so that the toe-piece part furthest from the seat for the toe Ia of the ski boot is assumed to be the "front", and a set of three axes, i.e. a longitudinal axis X-X, transverse axis Y-Y and vertical axis Z-Z, conventionally assumed

for the sake of convenience of the description, the toe-piece according to the invention comprises essentially:

- a fixed base 100 formed by a first substantially flat base-piece 110 with raised longitudinal sides 111 having a respective eyelet 112 elongated in the longitudinal direction and a respective hole 113; the base-piece 110 is elongated in the longitudinal direction towards the front in the form of a strip 114 in which a hole 114a is present. The base 110 also has formed therein an inset area 110a able to contain the thickness of a counter base-piece 120 made of steel and having raised flanges 121 in the form of a C, the arms of which parallel to the plane of the base 110 are provided with respective coaxial holes 121a able to receive a pin 122 forming an axis of rotation perpendicular to the plane of the base 110; this being intended for two jaws 123 arranged opposite each other and symmetrical with respect to the longitudinal axis X-X and in turn formed with a power arm 123a, substantially perpendicular to the base 110 and having a respective conical pin 124 extending parallel to the said base and able to engage with a respective seat Ib in the toe Ia of the ski boot, and a resistance arm 123 substantially parallel to the base 110; the fixed base 110 also has, integral therewith, resilient means 200 arranged so as to project towards the inside of the said base and acting in a direction parallel to the transverse axis Y-Y; said resilient means essentially consist of a pair of springs 210 supported by the respective transverse guiding and retaining elements 220 able to be displaced longitudinally inside the said eyelets 112 in the raised sides 111 so as to vary the position of the

springs in the longitudinal direction;

- the free end of the two springs 210 arranged opposite each other acts on the sides of the means 300 for rotationally actuating the jaws 123 retaining the toe of the ski boot; said actuating means comprise a lever 310 formed by a central body 311a extending in the longitudinal direction so as to be able to be arranged between the two said springs 210, a head 311 shaped so as to have two curved seats 312 symmetrical with respect to the longitudinal axis X-X and open towards the outside, as well as a through-hole 315 able to allow the insertion of means 320 perpendicular to the base 100 and forming an axis of rotation for the lever 310, as well as the element for locking displacement thereof in the two - longitudinal and transverse directions; said axis of rotation 320 comprises essentially a threaded pin 321, the head 321a of which makes contact against the bottom surface of the base 110 and the shank 321b of which passes through an eyelet 115 in the said base, an eyelet 125 in the counter base-piece 120 and enters into the said hole 315 of the lever 310 so as to engage with a counter-pin 322 having a female thread; in a preferred embodiment it is envisaged that said lever 310 is fastened by means of the pin 320 to a sliding piece 350 having a respective hole 355 for insertion of the said pin. The sliding piece 350 also has, formed thereon, a flange 356 in the form of an overturned L, the free arm of which is able to support a longitudinally acting safety spring 357, the function of which will become clear below in connection with operation of the toe-piece. In its front part, the sliding piece has an eyelet 354 suitable for engagement with retaining means 354a able to prevent raising in the vertical direction Z-Z, but allow displacement of

the sliding piece 350 in both senses of the longitudinal direction X-X. At the front end the sliding piece 350 has a transverse seat 355 which houses inside it : - the transverse arm 411 of a resilient U-shaped element 410, the longitudinal arms 412 of which have ends 412a folded towards the outside for insertion in corresponding seats 421 of a lever 420 for operating the entire toe-piece, able to be rotationally operated by the user.

According to preferred embodiments, it is envisaged that said operating lever 420 is provided with an eyelet 422 elongated in the longitudinal direction and receiving, inserted inside it, a button 430 with a gripping head 431 and fork-shaped body 432 able to be arranged over a longitudinal extension 313 of the lever 310 so as to lock/release rotation thereof. In addition to this, it is envisaged in a preferred embodiment that the sliding piece 350 is situated, in the vertical direction, between two strips 340 of material with a low coefficient of friction for facilitating displacement thereof with respect to the base and rotation of the lever (311) . With the configuration described, the operating principle of the toe-piece is as follows:

- under normal conditions (Figs. 4a, 4b) the toe-piece has the operating lever 420 partially raised in the clockwise direction, lever 311 kept in alignment by the two opposite springs 210, jaws 123 with resistance arm 123b inserted in the seat 312 of the said lever 311 and rotated outwards so as to allow entry of the toe of the ski boot in the axial direction; once the toe Ia of the ski boot is correctly positioned (Figs. 5a, 5b) the operating lever 420 is rotated in the anti-clockwise direction, causing by

means of the U-shaped means 420, recalling, towards the front, of the sliding piece 350 which, via the pin 320, causes displacement of the lever 311 which in turn, acting on the resistance arms 123b of the jaws 123 causes rotation thereof towards the inside with closing of the toe-piece and penetration of the conical end pins 124 inside the respective seats Ib of the toe Ia of the ski boot; in this condition the ski boot may only rotate about the said pins 124 if the heel-piece part (not shown) of the binding is free; if (Fig. 6) the ski boot is acted on by transverse/twisting forces - schematically indicated by the arrow F - with a high enough modulus, the power arm 123a of the jaws 123 is acted on by a corresponding thrust which causes rotation of the resistance arm 123b which in turn rotates the lever 310 about the pin 322; At this point two different conditions may occur: i) if the force F is not high enough to overcome the total resistance of the transverse spring 320, the latter, reacting, will bring the jaw 123 and therefore the entire toe-piece back into the normal position, resulting in an automatic self-centring effect; ii) if the force F is such as to overcome the total resistance of the spring 320, the rotation of the lever 310 causes the rotation towards the outside/inside of the two jaws 123 so that the one which rotates outwards in the same direction as that of the force F is released from the seat 312 and, disengaging, allows the toe Ia of the ski boot to come out; - ) at this point the toe-piece is totally open and it is necessary to bring it back into the initial condition, resetting the mechanism;

- for this purpose, the lever 420 is operated (Fig. 7a, 7b), applying a force such as to overcome the resistance of the longitudinal safety spring 357 which

hitherto had not intervened and forcing the rotation in a clockwise direction of the said lever which pushes the sliding piece 350 and therefore the lever 310 in the axial direction, causing the arm 123b of the other jaw to come out also from the respective seat and total opening thereof ;

- upon reaching the end-of-travel position - formed by the transverse side of the eyelet 354 which comes into contact with the pin 354a - the lever 420 is rotated in the opposite direction so as to obtain the return movement of the sliding piece 350 towards the front of the toe-piece, said return movement causing reinsertion of the resistance arms 123b into the respective seats 312 of the lever 310 and therefore resetting of the toe-piece which is again ready for use.

Fig. 8 shows a first variation of embodiment of the toe-piece according to the present invention, in this configuration the operating lever 1420 being connected to the resilient U-shaped element 1410 so as to rotate in the opposite direction to that described above, namely with rotation in the anti-clockwise direction for closing of the toe-piece and rotation in the anticlockwise direction for opening thereof. In both cases the lever 420 and the lever 1420 have respective seats 420a, 1420a for engaging with the end of the ski pole so that the force for closing/opening the toe-piece can be applied.

Fig. 9 shows a further variation of embodiment of the toe-piece according to the present invention which, in this configuration, has opposition springs 1210 arranged parallel to the longitudinal direction X-X; as shown the springs 1210 are supported by associated means 1220 which are fixed to the base piece 110 and conventional per se and therefore not described in detail, the springs acting in this case against the

head part 312 of the lever 311 and the operating principle of the toe-piece remaining the same as that already described.

As shown in Fig. 10, a further embodiment of the toe- piece according to the present invention comprises essentially:

- a fixed base 2100 formed by a first substantially flat base-piece 2110 with raised longitudinal sides 2111 provided with two respective holes 2113,2114 coaxial with each other and arranged at different heights from the plane in the direction Z-Z. The base 2110 also has, incorporated therein, a counter base- piece 2120 provided with raised flanges 121 in the form of a C, the arms of which parallel to the plane of the base 2110 are provided with respective coaxial holes 121a able to receive a pin 122 forming an axis of rotation perpendicular to the plane of the base 2110;

- this being intended for two jaws 123 opposite each other and symmetrical with respect to the longitudinal axis X-X, in turn formed with a power arm 123a substantially perpendicular to the base 2110 and provided with a respective conical pin 124 extending parallel to the said base and able to engage with a respective seat Ib in the toe Ia of the ski boot, and a resistance arm 123b substantially parallel to the base 2110; said jaws being able to rotate towards the outside through an angle greater than 90°;

- means 2300 for reacting to rotation of the jaws 123 for retaining the toe of the ski boot; said reaction means comprise a cam 2311 shaped so as to have two curved seats 2312 symmetrical with respect to the longitudinal axis X-X and open towards the outside, for allowing entry/exit of the resistance arms 123b of the jaws 123; as well as a through-hole 2315 able to allow the insertion of means 2320 perpendicular to the base

2100 and forming an axis of rotation of the cam 2311; said axis of rotation 2320 comprises essentially a pin 2321 fixed by means of pressure to the sliding piece 2350 and able to be inserted inside corresponding holes 2355 of a sliding piece 2350 inside which said cam 2311 is inserted.

The sliding piece 2350 is made in the form of a box open laterally so as to allow seating of the cam 2311 and a constraining element 2600. Said element 2600 has a hole 2605 extending in the transverse direction Y-Y and suitable for engagement with a pin 2430a passing through corresponding holes 2113 in the sides 2111 of the fixed base 2100; in this way the element 2600 forms the means for constraining the sliding piece 2350 to the fixed base 2100 with respect to which the said sliding piece is able to be displaced in both directions and the support surface for the cam 2311. In the preferred embodiment shown, the constraining element is in the form of a ^λλ U" with arms 2601 which have two transverse coaxial holes, one of which 2602a is a through-hole and the other one 2602b threaded, suitable for engagement with a corresponding pin 2603 having a threaded end and therefore able to exert a compressive force on the arms 2601 of the "U" for the purposes which will be described below with reference to operation of the binding.

The transverse arm 2604 of the ^λλ U" has, projecting axially therefrom, a pin 2605 able to form the support of resilient opposition means acting in the longitudinal direction X-X and consisting of a spring 2210 housed inside the sliding piece 2350 inside which it is inserted via a threaded hole 2351 which is closed by an adjusting screw 2351a, greater or lesser screwing of which causes greater/lesser compression of the

spring and therefore greater/lesser resistance to release of the jaws 123.

At its rear end the sliding piece 2350 has a surface 2350a which is suitably shaped so as to interact with a 5 corresponding surface 2311a of the said cam 2311 so as to cause correct centring thereof in the rest condition.

At the front end the sliding piece 2350 has transverse extensions 2352 shaped in the manner of a cam 2352a in

10 the vertical direction Z-Z and able to form a stop for the free end 2431a of arms 2431 of a lever 2430 for locking/releasing the sliding piece, able to be operated rotationally by the user about a pin 2430a inserted in the transverse direction y-y inside the

15 said holes 2113 of the flanges 2111 of the base piece 2110.

The toe-piece comprises, moreover, a front fork-shaped lever 2420 pivotably mounted on the base piece 2110 by means of an associated transverse pin 2420a inserted

20 inside the holes 2114 of the flanges 2111 of the base 2110 and the rear ends of which 2420b are able to act on the corresponding resistance arm 123b of the jaw 123 so as to bring it from the rest (closed position) into a more open position able to allow insertion of the toe

25 Ia of the ski boot.

The opposing rotation outwards of the two jaws 123 results in a displacement of the sliding piece 2350 and a compression of the longitudinal spring 2210 which, upon release of the lever 2420, will bring the sliding

30 piece, cam, lever and jaws back into the normal closed ) position.

With the configuration described, the operating principle of the toe-piece is as follows:

- in the rest condition (Fig. 11) the toe-piece is

35 normally closed and has the control lever 2420

partially raised in the clockwise direction, the locking/release lever 2430 raised in the clockwise direction and the jaws 123 closed;

- in order to allow entry of the toe Ia of the ski boot in the axial direction, the control lever 2420 is operated, causing it to rotate downwards (Fig. 12) and producing the action of the rear ends 2420b of the lever 2420 on the corresponding arm 123b of the jaw 123 so as to bring it from the rest position into a more open position able to allow insertion of the toe of the ski boot ; once the toe Ia of the ski boot is correctly positioned (Fig. 13) , the control lever 2420 is released and, rotating in the clockwise direction, disengages its ends 2420b from the resistance arm 123b of the jaw 123, causing the recall, towards the front, of the sliding piece 2350 which causes the displacement of the cam 2311 which, in turn, acting on the resistance arms 123b of the jaws 123 causes rotation thereof towards the inside with closing of the toe- piece and penetration of the conical pins 124 inside the respective seats Ib in the toe Ia of the ski boot; once the ski boot is positioned, release of the control lever 2420 causes the return of the toe-piece into the rest condition described above which allows the user to select two respective modes of use: for downhill skiing (Fig. 13) with the locking/release lever 2430 raised and sliding piece 2350 free, or • for uphill walking (Fig. 14) with the locking/release lever 2430 lowered so that the ends 2431a of its arms come into contact against the cam 2352a of the sliding piece 2350 locking it in position and preventing it from being displaced; in this condition the ski boot may only rotate about the said pins 124 if the heel-

piece part (not shown) of the binding is free;

- from the downhill skiing configuration shown in Fig. 13 and if (Fig. 15) the ski boot is acted on by transverse/twisting forces - schematically indicated by the arrow F - with a high enough modulus, the power arm 123a of the jaw 123 is acted on by a corresponding thrust which causes rotation of the resistance arm 123b which in turn rotates the cam 2311 on the corresponding curved seat of the constraining element 2600, at this point two different conditions may occur: i) if the force F is not high enough to overcome the total resistance of the longitudinal spring 2210, the latter, reacting, will bring the sliding piece 2350 back into the normal position, causing an interaction between the corresponding rear shaped surface 2350a of the said sliding piece and shaped surface 2311a of the cam 2311 which will tend to rotate in the reverse direction, assuming the rest condition again and resulting in an automatic self-centring effect; ii) if the force F is such as to overcome the total resistance of the spring 2210, the rotation of the cam 2311 is such as to disengage the two opposite centring surfaces 2311a and 2350a, causing the rotation towards the outside/inside of the two jaws 123 so that the one which rotates outwards in the same direction as that of the force F is released from the seat 2312 and, disengaging, allows the toe Ia of the ski boot to come out;

- ) at this point the toe-piece is totally open and it is necessary to bring it back into the initial condition, resetting the mechanism; for this purpose (Fig. 16) the lever 2420 is operated, raising it completely in the clockwise direction; during rotation two opposite teeth 2425 engage with the locking/release lever 2430 , causing it

to rotate upwards and disengaging the arms 2431 from the cams 2352a of the sliding piece 2350; continuing its travel movement the lever 2420 enters- into contact with two reliefs 2356 of the sliding piece 2350 which is pushed in the axial direction towards the rear, causing the arm 123b of the other jaw to come out also of the respective seat and total opening thereof; - upon reaching the end-of-travel position - determined by the total compression of the spring 2210 - the opposite centring surfaces 2311a of the cam and 2350a of the sliding piece engage again causing the return of the cam 2311 into the normal position; rotating at this point the lever 2420 in the opposite direction, return of the sliding piece 2350 towards the front of the toe- piece will be obtained, said return movement causing the reinsertion of the resistance arms 123b into the respective seats 2312 of the cam 2311, bringing the toe-piece back into the normal rest condition. In order to facilitate operation of the lever 1420, the latter has an engaging seat 1420a inside which it is possible to insert the tip of the ski pole so as to exert the thrust providing the force for opening the toe-piece.

In the event of wear of contact surfaces of the engaging pins 124 of the boot and/or the seats Ib of the latter, it will be possible to adjust the transverse screw 2603, tightening the longitudinal arms 2601 of the U which, adhering more firmly to the surface of the cam 2311, takes up the play, resulting in restoration of the initial operating conditions.

It can therefore be seen how, with the toe-piece according to the present invention, it is possible to obtain all the advantages resulting from the safety release mechanisms incorporated in the said toe-piece, it being also possible, however, to obtain a lower

overall weight of the said heel-piece as well as simplification and reduction in the weight of the heelpiece, resulting in greater rigidity of the binding and therefore improved manoeuvrability of the ski. In addition to this, it can also be seen how it is possible to adjust easily the resistance to opening of the toe-piece by displacing, in the longitudinal direction, the position of the springs 210 inside the eyelet 112 of the base 110, this allowing the production of a single toe-piece model able to operate correctly for a wider range (weight) of users. Moreover, the toe-piece according to the invention allows easy adjustment depending on the variation in transverse width of the seats engaging with the ski boot, said width diminishing with the wear of the said seats, as well as a practical fitting action obtained by means of the thrusting force applied on the lever 2420 by the tip of the ski pole, resulting in widening of the jaws, allowing insertion of the toe of the ski boot.