MULTI -POSITION HEEL PIECE FOR SKI MOUNTAINEERING BINDINGS

Description

The present invention relates to a multi -position heel piece for ski mountaineering bindings .

It is known in the technical sector of ski touring that there exists a need to provide safety bindings comprising a front part or toe piece, able to lock the toe of the boot, while allowing rotating thereof about a substantially horizontal axis, and a rear part or heel piece, able to co-operate with the heel of the boot so as to allow three different modes of use, i.e. : heel released (walking) , heel resting with greater/lesser inclination of the boot (uphill) , and heel locked (downhill) .

It is also known, for example from EP 0,199,096, that there exist bindings of the type described above, these, however, having the drawback due to 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 descent, said safety condition being achieved by means of corresponding means for actuating the rear heel piece, which are therefore very complex and heavy, and result in both poor rigidity and boot fitting problems .

The technical problem which is posed, therefore, is to provide a ski binding heel piece able to perform:

- locking of the heel of the boot with the rigidity normally required for these applications;

- improved locking of the heel with a reduction in the lateral play;

- the possibility of changing over between the three operating configurations in a simple and rapid manner suitable for the conditions in which said heel pieces are used.

In connection with this problem it is also required that such a toe piece should have small dimensions and a low weight, be easy and inexpensive to produce and assemble and be able to fitted easily also to skis using standard connection means.

These results are achieved according to the present invention by a heel piece for ski bindings according to the characteristic features of Claim 1.

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 shows an exploded view of the heel piece according to the present invention;

Figure 2 shows a side view of the heel piece during closing onto the heel of the boot (downhill) ;

Figure 3 shows a schematic cross-section along a longitudinal vertical plane indicated by the line III- III in Fig. 2 ;

Figure 4 shows a side view of the heel piece during insertion of the boot;

Figure 5 shows a side view of the heel piece in a first raised position of the heel (released for walking) ;

Figure 6 shows a side view of the heel piece in a second raised position of the heel; and

Figure 7 shows a side view of the heel piece in a third raised position of the heel .

As shown in Fig. 1 and with reference to a set of three axes, i.e. longitudinal axis X-X, transverse axis Y-Y and vertical axis Z-Z, and the orientational layouts shown by way of example in the figures, conventionally assumed solely for the sake of convenience of the description, such that "front/inner" is assumed to mean the part of the heel piece directed towards the boot and "rear/outer" as the opposite part, the heel piece according to the present invention comprises:

- a fixed base piece 10 elongated in the longitudinal direction and formed by a perimetral frame 11 which defines two internal seats, i.e. a front seat 12 and rear seat 13, which are open in the vertical direction Z-Z; the longitudinal arms 11a of the frame 11 are provided with holes 14 having a vertical axis for fixing the base piece to the ski (not shown) by means of screws 14a;

said openings 12,13 in the base piece form a corresponding number of guides for:

- a slide 20 movable in both senses of the longitudinal direction by means of conventional screw means 25 which, passing through the rear transverse side of the base piece 11, co-operate with a nut 25a which is fixed to the said slide so that rotation of the screw causes displacement of the slide.

The front part of the slide has, formed .thereon, a step 22 covered by a reinforcing cover piece 23 fixed by- means of a vertical screw 23a for resting- the heel Ia 5 of the boot; it is also possible to insert shims 22a between the step and the cover piece in order to adjust 'precisely the height of the heel.

The slide 20 also has at the rear a body 24 having, 10 formed therein, a hollow cylindrical seat 26 which is designed to form the seat for resilient means 30 • comprising a spring 31 which is fixed under compression inside the seat 26 between a top closing cap 33 with a thread 33a which can be screwed into a female thread 15 26a of the seat 26 and a bottom shaped foot 32.

The shaped foot 32 has undercuts 32a in the longitudinal and transverse directions, able to allow seating of a longitudinal lever 34 mounted on a cross-

20 pin 34a which passes through the body 24 via eyelets

24b.

Using said pin 34a of the lever 34 it is also envisaged fixing to the body 24 a substantially U-shaped bracket 25 130 which extends in the longitudinal direction and the longitudinal arms 130a of which have .first holes 131 for receiving the said pin 34a.

The bracket 130 forms the first component of a

30. kinematic chain for transmitting the manoeuvring forces of the heel piece; said chain comprises:

- a rear lever 120 which can be operated by the user and rotates on the bracket 130; 35

a front rotating engaging member 110 which is designed to engage with the heel Ia of a boot 1 and in turn rotates on the bracket 130;

- two longitudinal connecting bars 140 which are arranged between and pivotably mounted on the front engaging member 110 and on the rear lever 120.

In greater detail :

- the rear operating lever 120 is formed in the manner of a fork with parallel arms 121 which have respective holes 121a through which the said pin 34a passes, said pin also supporting the lever 34 and being used to pivotably hinge the lever 34 on the bracket 130;

- the lever 120 has a seat 120a formed at the free end and designed to form a part for gripping by the user;

- the front engaging member 110 is pivotably mounted on the front end of the arms 130a of the bracket 130 by means of respective holes 132 passed through by a pin 114 which also passes through the front engaging member 110 via respective holes Ilia in its arms 111;

a substantially L- shaped transverse body 112 is arranged between the said arms 111, the longitudinal arm 112a thereof being designed to co-operate with the said lever 34 which has the function of keeping the engaging member 110 in the correct position when the latter tends to rotate owing to the deformations resulting from the dynamic stresses of the ski; the vertical arm 112b of the L is instead designed to cooperate with an inclined surface 27a ^' of a nose 27 which extends from the body 24 towards the front;

- the arms 111 of the engaging member 110 are also provided with two further holes 113 inside which the first front end 140a of each connecting bar 140 is pivotably mounted, while the other rear end 140b is designed to be inserted inside suitable openings 122 in the arms 121 of the lever 120, thus closing the kinematic chain which will transmit the movement from the operating lever 120 to the front engaging member 110, as will emerge more clearly below with reference to operation of the heel piece.

According to a preferred embodiment of the heel piece it is envisaged that the bottom end of the lever 120 is formed in the manner of a cam 123 consisting of a first surface 123a which is substantially parallel to the longitudinal direction X-X, a second surface 123b, forming an obtuse angle with said first surface 123a, and a third surface 123c, forming an obtuse angle with said second surface 123b.

Similarly the bottom end of the arms 111 of the engaging member 110 has a respective cam 115 formed by a first surface 115a substantially parallel to the longitudinal direction X-X and a second surface 115b forming an acute angle with said first surface 115a.

With this configuration the operating principle of the heel piece is as follows:

- firstly the binding is fixed to the ski and the desired height of the boot is adjusted by means of the rest piece 23 and the shims 22a;

- then the heel piece is arranged in the open •

configuration (Fig. 4), rotating the lever 120 downwards so that the engaging member 110 is totally rotated towards the rear, pulled by the connecting bars 140;

- the heel Ia of the boot 1 is inserted inside the heel piece (Fig. 2) and the heel piece is closed by raising the lever 120 via the seat 121 so that the upwards rotation produces a thrust which forces the engaging member 110 to rotate towards the heel of the boot until the respective surfaces 123a, 115a of the cams 123,115 of the lever 120 of the engaging member 110 assume the longitudinal position, resting on the base piece 10; in this position the heel piece is ready for downhill use;

in the case of different use of the binding for walking (Fig. 5) it is possible to:

• open the binding by pressing the lever 120 downwards so as to cause retraction/rotation of the front engaging member 110 until the heel is released;

• extract the heel Ia/ and rotate again the lever 120 towards the front until the second surface 123b of the cam 123 is positioned parallel to the longitudinal direction X-X resting on the base piece 10;

such operation of the lever 120 causes, by means of the connecting bars 140, simultaneous rotation of the engaging member 110 which pivots down towards the front so as to bring the second surface 115a of the cam 115 parallel to the longitudinal direction X-X resting against the base piece 10; in this way the convex rear surface 110a of the engaging member is made available for resting thereon the boot which is retained solely

by the toe piece (not shown) , while the heel Ia is free to move upwards/downwards in accordance with the walking movement of the user;

- in the case of use for walking uphill on steeper slopes (Fig. 6) , the lever 120 is rotated towards the rear so as to bring the cam 123 and therefore the front engaging member 110 back into the initial condition; in this position the heel Ia of the boot rests on the upper surface 110b of the engaging member 110;

if the heel piece must be used for even steeper slopes it is possible to rotate the lever 120 (Fig. 7) towards the front until the third surface 123c of the cam 123 is positioned parallel to the longitudinal direction and rests on the base piece 10, and therefore the front engaging member 110 is pivoted down towards the front; in this position the lever 120 rests stably against the engaging member 110 and the heel Ia of the boot rests on the free end of the lever 120, causing greater inclination of the boot, which is particularly favourable for steeper slopes .

Safety release of the heel piece during downhill use occurs with the following sequence:

the pulling force exerted by the boot 1 on the engaging member 110 causes raising of the engaging member by means of rotation of the bracket 130; the engaging member therefore disengages from the lever 34 and brings the top end of the vertical arm 112b of the transverse body 112 into contact with the inclined surface 27a of the nose 27 which, with continuation of the pulling action of the boot, causes the engaging member 110 to rotate towards the rear, disengaging from

the heel Ia and freeing the boot which in this way is able to come out of the heel piece freely.

It is therefore clear how the heel piece according to the present invention, while ensuring a high rigidity and absence of play in the transverse direction compared to the known bindings of the art, forms a particularly light assembly which is simple to use, allowing fast change-over of the configuration by means of the rear lever which can be operated also using a ski stick without the user having to bend down, this solution being particularly useful in the working conditions which are typical of ski mountaineering.

In addition, the heel piece according to the invention incorporates the system for vertical release which is caused by the retracting/rotational action of the heel piece, said action in turn causing compression of the reaction spring. This vertical release system constitutes an obvious improvement in the sector of ski mountaineering also in view of the simple design and lightness of the assembly.

Although not shown, it is also envisaged being able to associate the heel piece according to the invention with a plate made of rigid material and designed to be fastened to the heel of the boot so as to able to ensure more precise interference between the boot and the engaging member of the heel piece, resulting in greater engaging/disengaging precision.

Said plate may also be fitted to the boot or form an integral part thereof .