Abstract:
An improvement in an attachment for release ski bindings enabling the skier to selectively decide the mode of skiing, namely downhill skiing or cross-country skiing. The attachment includes a sole plate which holds the ski boot onto the ski. The sole plate has a connecting piece fixedly connected thereto and is pivotally secured to a ski binding element about an axis extending transverse of the longitudinal axis of the ski. The connection between the sole plate and the ski binding element is a releasable connection to facilitate the skier&#39;s selection of the mode of skiing.

Description:
FIELD OF THE INVENTION 
     The invention relates to an attachment for release ski bindings for cross-country skiing comprising a sole plate which holds the ski boot on the ski and on which sole plate the ski boot is releasably secured by releasable holding elements and is held lockably between the sole plate and a ski binding part by means of a connecting piece. 
     BACKGROUND OF THE INVENTION 
     An attachment of the abovementioned type is for example described in Swiss Pat. No. 504 216. In this known construction, the connecting piece consists of two hinge parts which can engage one another, of which hinge parts the one part can be released from its active position of being in engagement with the other part and can be moved into an inactive position in which the boot plate cooperates with the locking mechanism. The one hinge part is thereby fixedly arranged on the boot plate and the other hinge part is releasably arranged on the ski. The hinge part which can be connected to the ski is designed substantially as a tongue or tab which extends in longitudinal direction of the ski and carries on the end adjacent to the tip of the boot two upstanding fins to which a pivot pin is secured and engage open holding eyelets which are provided on the other hinge part. For downhill skiing, the hinge part which is only releasably connected to the ski is removed and the boot plate is received in the usual manner by the ski binding parts which are secured on the ski and which can effect a safety release. 
     A disadvantage of this known construction consists in the pivot axis which is needed for cross-country skiing lying in front of the tip of the boot and approximately in the upper area of the sole of the boot. This &#34;front connection&#34; leads to early fatigue because the entire weight must be absorbed by the screw which holds the hinge part connected to the boot plate. Finally the hinge part which is releasably connected to the ski must be stored separately during downhill skiing. The hinge part which during downhill skiing extends forwardly and is secured on the sole plate means, in the case of a fall, an additional risk for injury and can itself also be easily damaged. 
     Also a device is known (Swiss Pat. No. 513 659) in which a sole plate is suited for both cross-country skiing and also downhill skiing. The pivot axis of this known device lies also in front of the tip of the boot and in the upper area of the front holding mechanism so that the earlier mentioned fatigue appearances also occur. 
     In a different known attachment for the downhill skiing and cross-country skiing according to German OS No. 2 231 058, the ski boot lies, by the interpositioning of a sole plate, between parts of a release ski binding. The boot is held by means of a transverse axle which is defined by a through bolt and extends through a transverse opening in the sole of the boot adjacent the toe thereof. At the rear part of the plate there is provided a swingable snap mechanism which for downhill skiing presses the heel on the plate and releases same for cross-country skiing. 
     A disadvantage of this device consists in the sole of the boot having an opening therein which serves as a pivot axis and has to be equipped with a separate holding mechanism. Thus common ski boots which are available on the market are not suited for the use of this sole plate. A further disadvantage consists in the holding bolts are required to be guided in or out during every stepping in and out and still an additional lock is required for use thereof. A separate storage of the lock is needed during periods of nonuse. A still further disadvantage consists in a certain play or clearance provided between the opening and the transverse axis for cross-country skiing and this play is disadvantageous for downhill skiing. Since the snap part which holds down the heel does not press the boot on the holding axis, the play or clearance which exists between holding bolt and bore has a disadvantageous effect for the guiding of the ski. 
     Also devices are known in which the pivot axis is loaded by a spring. U.S. Pat. No. 2,450,526 describes a construction having a pressure spring; U.S. Pat. No. 3,388,918 describes a device for cross-country skiing in which the tension is produced by a resilient safety tensioning means. 
     German Pat. No. 2 307 427 describes a device for securing a ski boot on the ski in two different positions, namely one position for downhill skiing and one position for cross-country skiing or racing. For this purpose, a support part is utilized between ski boot and ski adjacent the rear area of which the heel holding means can be secured in two different positions. For downhill skiing, the ski boot is held between a front ski binding part which is secured on the ski and the heel holding means and, in this case the heel holding means is fixed on a locking mechanism which is secured to the ski. For cross-country skiing or for racing, the ski boot is moved backwardly on the surface of the support part and is fixed to the support part by a front holding element which, in the downhill skiing position, is swung out of active position and wherein the heel holding means rests in a mounting which is provided on the support parts. To adjust the heel holding means, the support part has at the two sides elongated recesses. Moreover, the support part has a U cross section which permits, on the one hand, an adjustment of the holding part of the heel holding means and, on the other hand, the reception of the locking for said holding part. The support part is supported at its front area on a pivot axis which is held on a ski-fixed fastening part. 
     This known device permits a support of the ski boot for cross-country skiing and for racing in the toe area, however, it has the following disadvantages. For downhill skiing the ski boot is held in an elevated position by the support part, which position is disadvantageous for guiding the ski. The use of the support part for downhill skiing is not related to the advantages of common sole plates because the ski boot is held between ski-fixed parts--namely the front ski binding part and the heel holding means which is suspended in the ski-fixed locking mechanism. In addition, a ski boot having a soft sole cannot be used because the front area of the ski boot lies free. For downhill skiing there exists a disadvantage in that the heel holding means, which in this case must necessarily be a safety release binding, is hauled along during each step and produces a torque which must be considered and is caused by the arm between the heel holding means and the axis of rotation. This torque stresses the limbs of the skier and can result in premature fatigue. Finally it must also be considered that the heel holding means can also be a type of upright piston bindings so that this device cannot be used in connection with other safety ski bindings. 
     In conclusion it can therefore be stated that in all efforts which are directed to producing a device which is suited simultaneously for downhill skiing and for cross-country skiing, limitations as to comfort and additional manipulations must be accepted. 
     The purpose of the invention is to aid and to design an attachment for cross-country skiing of the abovementioned type so that same meets all requirements of cross-country skiing without requiring separate ski binding holding parts for downhill skiing. An as large as possible selection of known ski binding parts is to be used. 
     The set purpose is inventively attained by the connecting piece being permanently connected to the sole plate, as actually known, by an axle which extends transversely with respect to the longitudinal axis of the ski and is capable of being swung upwardly against the force of a spring, wherein the pivot axis, as is acutally also known, is arranged substantially below the toe area and, in addition, the sole plate which is provided with the connecting piece is capable of being removed for downhill skiing and replaceable, if desired, with a common sole plate. 
     Through the inventive construction of the attachment, a device is provided for cross-country skiing which combines the advantages of all known devices, permits the use of existing ski boots namely both those with a stiff sole and a soft sole, both in the case of ski binding parts which hold sole plates on the skis and those which permit a direct mounting of ski boots on the skis and can be mounted easily on the skis. For downhill skiing, the attachment is also detached in a simple manner and is replaced if necessary with a common sole plate. If ski binding parts are used which receive the ski boot without using a sole plate, then the release ski binding is ready for downhill skiing after removal of the attachment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages and details of the invention result from the following description which will be discussed more in detail with reference to the drawings, which show some exemplary embodiments. 
     In the drawings: 
     FIG. 1 is a side view of a first exemplary embodiment of the inventive attachment with a ski boot mounted thereon; 
     FIG. 2 illustrates in an enlarged scale the front part of FIG. 1; 
     FIGS. 3 and 4 are each a cross-sectional view of FIG. 2 taken along the lines III--III and IV--IV, wherein FIG. 3 is the position of attachment or detachment and FIG. 4 is the position during cross-country skiing without a holding piston; 
     FIG. 5 illustrates a front view of the attachment with the remaining parts omitted therefrom; 
     FIG. 6 illustrates the front part similar to FIG. 2, however, for a second exemplary embodiment; 
     FIGS. 7 and 8 are each a cross-sectional view taken along the lines VII--VII and VIII--VIII, wherein FIG. 7 illustrates the locking position and FIG. 8 the attachment or detachment; 
     FIG. 9 is a cross-sectional view taken along the line IX--IX of FIG. 7; and 
     FIG. 10 is a side view of a third exemplary embodiment. 
    
    
     DETAILED DESCRIPTION 
     In the following description, the same parts have the same reference numerals; parts which have the same purpose but are different are identified with the addition of a prime (&#39;) suffix. 
     In the embodiment according to FIG. 1, an attachment is identified as a whole by reference numeral 1 and consists of a sole plate 2 and a connecting piece 3 which are connected by means of an axle 4 and are held on a ski binding part 5. A further ski binding part 6 is provided at the other end of the sole plate 2 such that between the ski binding parts 5 and 6 a common sole plate (not separately illustrated) can be inserted. In the exemplary embodiment according to FIG. 1, a ski boot 7 is positioned on the surface of the sole plate 2 and is releasably held on same by holding elements 8,9. The ski binding parts 5,6 are secured to a ski 10. 
     Details of the embodiment of the connecting piece 3 according to FIG. 1 are illustrated in FIGS. 2 to 5. As can be recognized from these figures, the connecting piece 3 has two lateral holding arms 11 which extend parallel to the longitudinal axis of the ski and have recesses 12 thereon. In addition, the connecting piece has an upwardly projecting flange 13 which functions as a support and engages a pistonlike holding part 5a of the ski binding part 5. The flange 13 is for this purpose, as can be recognized from FIG. 5, provided with an opening 14. The diameter of the opening 14 corresponds with the outer diameter of the pistonlike part 5a of the ski binding part 5. 
     To secure the connecting piece 3 on the ski binding part 5 or to permit attachment and detachment of the same, a locking mechanism 15 is housed in the ski binding part 5. The locking mechanism 15 consists in the present exemplary embodiment of two detents 16, each of which have a locking hook 17, a pushing part 18 and a projection 19. The projections 19 engage adjacent areas of the two detents 16 and serve to guide and hold a pressure spring 20 in place. The pressure spring 20 constantly presses the detents 16 apart so that they desire to assume the position shown in FIG. 4. If the two detents 16 are pressed together by a force applied to the pushing parts 18, as shown in FIG. 3, then the holding arms 11 of the connecting piece 3 can be moved inwardly unhindered or can be pulled unhindered outwardly in the opposite direction. The pressing together of the detents 16 is not absolutely necessary for the connecting piece to move inwardly because the locking hooks 17 have sloped abutting surfaces 21 thereon. As a result, the connecting piece 3 can be moved inwardly and as soon as the locking hooks 17 are in alignment with the recesses 12 on the holding arms 11, engagement occurs automatically. 
     The axle 4, which serves as the pivot axis for the sole plate 2, has a conventional torsion spring 22 encircling same. The objects and purposes of said spring should be known to the man skilled in the art. Also further parts of the exemplary embodiment according to FIG. 1, as for example structure and operation of the ski binding part 5 are also known. 
     It will be recognized from FIG. 1 that if the ski boot 7 is held by the holding elements 8,9 on the surface of the sole plate 2 and the sole plate 2 is held with the connecting piece 3 on the ski binding part 5, then the possibility for cross-country skiing is assured by the axle 4. The sole plate 2 can thereby be designed as a common sole plate, as this is illustrated with the support on the rear ski binding part 6 in FIG. 1. The provided sloped position of the sole plate 2 is even advantageous, because accumulations of snow, ice or the like on the surface of the ski 10 have no influence on the operation. 
     In the exemplary embodiment according to FIGS. 6 to 9, the sole plate 2 is connected similarly to the first exemplary embodiment through an axle 4 to a connecting piece 3&#39;. The connecting piece 3&#39; is secured to a ski binding part 5&#39;; the design of the securement will be discussed hereinbelow. 
     As will better be recognized from FIGS. 7 and 8, the connecting piece 3&#39; has lateral holding arms 11&#39; pivotal about the axis of the axle 4. In the forwardly extending area, the connecting piece 3&#39; has a tongue or tab 23 which has a notch 24 therein. The tab has at its front end zone a sloped guide surface 25 which serves to guide the tab 23 into a receiving section 26 of the ski binding part 5&#39;. To lock the tab 23, a laterally movable slide member 27 is provided, which substantially consists of a Z-shaped profile (see FIG. 9) and is biassed by a spring 29. An upwardly projecting part of the slide member 27 is designed as an operating lever 28. The spring 29 has the purpose of holding the slide member 27, which serves as a locking mechanism, at all times in locking position. If a force is applied to the operating lever 28 to move same against the force of the spring 29 transversely with respect to the longitudinal axis of the ski, then the profile part which has the locking projection 30 thereon becomes disengaged from the recess 24 of the tab 23 and the connecting piece 3&#39; can be removed together with the sole plate 2. 
     As will be recognized from FIGS. 7 and 8, the base plate 31 of the ski binding part 5&#39; has in the area adjacent the connecting piece 3&#39; rounded-off support surfaces 32A. The tongue 23 and arms 11&#39; are connected by a connecting bar 33 which has in the areas of the support surfaces 32A rounded-off surface portions 32B corresponding to said surfaces 32A. In this manner, a secure hold against lateral forces is assured for the connecting piece 3&#39; in or on the ski binding part 5&#39;. A reinforcement 34 which exists in the center area of the connecting bar 33 is designed as a rib which is formed from the material and serves also to reinforce the connecting piece 3&#39;. 
     If the attachment 1&#39; is released by opening the locking mechanism and is removed from the ski binding part 5, then a common sole plate 2 similar to the first exemplary embodiment can be inserted and can be used for downhill skiing. The only difference between this and the preceding embodiment consists in the ski binding part 5&#39; having here the laterally upwardly standing operating lever 28. If an attachment according to the invention is not used, then the ski binding parts 5&#39;,6 with a common sole plate can only be used for downhill skiing. 
     In the third exemplary embodiment according to FIG. 10, an attachment according to the invention can be used also in connection with other release ski binding parts. The ski binding parts identified with reference numerals 5&#34; and 6&#34; may be of any desired construction; the attachment is designed either according to the first or according to the second exemplary embodiment. Therefore, the reference numeral is 1,1&#39; is utilized for identification. For this reason, the anchoring type in the ski binding part 5&#34; is not separately indicated. It is preferable if the rear ski binding part 6&#34; is of a conventional rental ski construction. In this case it can be moved backwardly during the time of cross-country skiing, as is shown in FIG. 10 or it can be pulled off from the holding rail. The locking and the releasing of the attachment 1,1&#39; takes place in a similar manner as already described above. Further details correspond to the embodiment according to FIG. 1. 
     If the attachment 1,1&#39; is removed, then for downhill skiing the ski boot can be placed in the usual manner between the ski binding parts 5&#34;,6&#34;, wherein the rear ski binding part 6&#34;--like in a rental ski construction--must be adjusted to the length of the inserted ski boot. Also in this construction the sole plate stands slightly inclined which in turn is of an advantage for independence from the effects of snow, ice accumulations or the like. 
     If the attachment is not used, because the ski is being used for downhill skiing, then the attachment can be stored in a knapsack or the like. Since skiers which use the skis for cross-country skiing or for racing are sportsmen which take trips lasting many hours, such as half day or day long trips, the carrying along of knapsacks or the like is a normal procedure. Such skiers easily accept thereby the taking along of the attachment if by this good control for both for cross-country skiing or for racing and also for downhill skiing is assured. 
     The invention is not limited to the listed exemplary embodiments. Further variations can be made without departing from the scope of the invention. For example, it is possible in the exemplary embodiment according to FIGS. 1 to 5 to make the locking mechanism also of a separate structural part attached from the front onto the ski binding part and thus engages the recesses in the holding arms. Since the vertical forces are absorbed by the flange, this part is stressed only in the horizontal direction. 
     It is, in addition, conceivable to design the locking mechanism symmetrically for the second exemplary embodiment, namely to provide the tab with two notches into each of which is received one slide member engaging both sides of the tab. To guide the slide member, it will be preferable to let these slide into one another, wherein the width dimensions of the slide members and thus also of the notches can be slightly different. 
     As already mentioned in the third exemplary embodiment, the ski binding parts which are used may be of any type. 
     Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.