Abstract:
A release ski binding having a sole plate which in its center area can be pivoted about an approximately vertical axis and can be tilted up about a transverse axis arranged in front of the vertical axis, which in the skiing position is held on the ski by a holding mechanism biased by a release spring, which holding mechanism is responsive to a swivelling movement of the sole plate relative to the ski and upon reaching a predetermined angle of traverse effects both an upwardly and also a side opening of a locking mechanism.

Description:
FIELD OF THE INVENTION 
     This invention relates to a ski binding which engages the middle part of a ski boot and, more particularly, to a ski binding incorporating therein a sole plate movable elastically of the ski until a release condition is exceeded. 
     BACKGROUND OF THE INVENTION 
     Such release ski bindings are described in German Pat. No. 2 533 337. In these conventional ski bindings, the spring of the holding mechanism acts through a piston onto an approximately mushroom-shaped follower member, which is supported swingably to all sides in the housing of the holding mechanism. The stem portion of the mushroom-shaped follower member is received in a recess of a ski-fixed fitting. In these known ski bindings, the ski shoe is held at its tip or toe by means of a rigid bar on the sole plate. In the case of a fall of the skier to the rear, the ski shoe is therefore released only with great difficulty. 
     This disadvantage is avoided in the ski binding according to German Pat. No. 2 324 078, however, this binding is very complicated in its design. That is, the release mechanism is housed in the space between the base plate and the sole plate. This, however, requires special seal structure to prevent the penetration of snow and dirt therein. Furthermore, the mounting is complicated and expensive. 
     The goal of the invention is to overcome the disadvantages of the conventional designs and to provide a release ski binding of the above-mentioned type, which is simple in its design and permits a very exact adjustment of the desired release moment during a frontal fall and during a twisting fall. 
     This goal is inventively attained primarily by providing a locking mechanism having two clamping jaw pairs which laterally engage the ski shoe and which are constructed as two-arm levers, are supported on the sole plate and can be moved into the clamping position by a slide-member plate which is guided on the sole plate and is provided with wedge-shaped shoulders, whereby the slide-member plate is coupled by means of a control lever having a stepping bar which is supported on the sole plate. 
     The concept of supporting one-arm clamping jaws, which laterally engage the ski shoe, on a sole plate and to move same through a slide-member plate with the help of wedge-shaped shoulders into the clamping position is actually already known through the teachings in German OS Nos. 2 943 209 and 3 026 918. However, in these constructions, the locking spring acts directly onto the clamping jaws, the load of which is utilized for the involuntary or automatic release of the ski binding, and brings about certain inexactnesses compared with the ski bindings of the above-mentioned type in which the angle of traverse of the sole plate is decisive for effecting the opening of the locking mechanism. 
     Furthermore, it is no longer new to use stepping bars in ski bindings (compare U.S. Pat. No. 4,312,517). However, in the known ski binding the stepping bar is only used to swing during a stepping in procedure wherein the ski shoe effects a movement of the two braking mandrels from their braking position upwardly over the plane of the upper surface of the ski and at the same time to align the ski shoe both in the longitudinal direction and also in the transverse direction of the ski. An operation of the holding elements for the ski shoe by action of the stepping bar does not take place in this construction. 
     Furthermore, the invention provides that the axle for the stepping bar is arranged in the end region of the sole plate, closest the tip of the ski. This causes the stepping of the ski shoe into the ski binding to be simplified inasmuch as the relative movement between the tip of the ski shoe and the ski, compared with the reversed arrangement (arrangement of the stepping bar axle on the end of the sole plate remote from the tip of the ski), is substantially reduced. 
     Furthermore, the control lever is inventively constructed as a two-arm lever supported on the sole plate and the upper end of which is guided by means of a roller in guideways provided on the underside of the stepping bar. This enables a large amount of leverage to be achieved and with it the force, which is necessary for the adjustment of the slide-member plate, can be substantially reduced. 
     According to another characteristic of the invention, the lever arm of the control lever, which lever arm lies opposite the roller, is constructed fork-shaped and is provided with two inner prongs and two outer prongs. Through this construction the function which is to be carried out by the control lever is divided into two pairs of elements, whereby the one pair is to cause only the movement of the slide-member plate toward the tip end of the ski, the other pair, however, causing first an adjustment of the slide-member plate toward the tip of the ski and thereafter a sudden movement of the slide-member plate rearwardly into the clamping position. 
     In order to make the opening of the ski binding easier, two bearing blocks are inventively secured to the upper surface of the slide-member plate, in which bearing blocks a bolt is movably guided in the longitudinal direction of the ski, which bolt is under the influence of a spring urging it toward the tail end of the ski. A further characteristic of the invention is to provide the control lever with a nose at its end which carries the roller, which nose serves as a load bearing place against which the bolt rests in the skiing position of the ski binding. 
     Of course it would be possible to provide the slide-member plate with shoulders for the engagement of the two prong pairs. However, it is preferable that the slide-member plate be provided with a hole located between the bearing blocks, which hole is preferably approximately T-shaped in the top view, into which hole, in the stepping-in position of the ski binding, is received the four prongs of the control lever. 
     Furthermore, it is provided inventively, that the slide-member plate is releasably connected to the resilient holding mechanism through at least one one-arm locking lever, which holding mechanism, is housed in a housing on the sole plate. According to this characteristic, a retaining spring is utilized for loading the slide-member plate. The spring thus has to fulfill two functions simultaneously. This brings about a certain simplification of the construction. It is thereby preferable for the slide-member plate to be constructed fork-shaped at its end which is adjacent to the holding mechanism and supports a roller thereon on each forked prong. The roller, in the skiing position of the ski binding, rests on a shoulder of the associated locking lever, which shoulder extends transversely with respect to the longitudinal axis of the ski. The two rollers substantially increase the exactness with which the ski binding opens during the adjusted release moment, since the friction between the slide-member plate and the two locking levers is substantially reduced by the rollers. 
     In a ski binding wherein the holding mechanism includes a mushroom-shaped follower member, the enlarged head of the follower member is supported swingably to all sides in a hole in a wall of the sole plate. The follower member is held in the normal position under the influence of a piston which is loaded on one side thereof by the release spring and with its stem received in a ski-fixed fitting. A bolt or pin extends through the piston, the ends of which bolt are guided in slotted holes in the wall of the sole plate. The legs of an approximately U-shaped intermediate lever, is supported in the housing on the sole plate and engage under the influence of a torsion spring the ends of the bolt. The ends of the bolt project laterally beyond the slotted holes in the wall and operatively engage each leg of the intermediate lever. A reliable coupling of piston and locking lever is brought about in this manner. This effect is also desired by a further characteristic of the invention, namely, that for coupling of the intermediate lever with each locking lever, the first supports an axle thereon, which axle is guided in a slotted hole which extends in the longitudinal direction of the locking lever. 
     In order to facilitate a manual release of the ski binding in a simple manner, the invention includes the provision that at least one link member has one end arranged on the axle and the other end hingedly connected to a two-arm release lever which is supported on the housing of the sole plate. 
     Also a direct loading of the piston associated with the follower member by the spring of the holding mechanism would principally be conceivable. However, in order to permit a very sensitive adjustment of the initial spring tension, a one-arm lever is inventively supported on the axis for the intermediate lever, which one-arm lever rests with a cam on the piston in the hole of the sole plate and on the oppositely lying side is loaded by the spring of the holding mechanism. It is thereby preferable, if the release spring is housed in a spring housing which is pivotal about the axis of the axle for the locking lever so that the axle is movable approximately in the longitudinal direction of the ski in at least one slotted hole in the housing. Furthermore, it is provided that in the center area of the spring housing, bearing pins are connected thereon, on which bearing pins are supported two laterally spaced two-arm levers, the lower ends of which are connected through a rotatably supported bolt and the upper ends of which are supported on a support wall in the housing, which support wall extends at least approximately parallel with respect to the upper surface of the ski. The bolt has a threaded hole therein which extends transversely with respect to the bolt axis, into which threaded hole is threadedly engaged an adjusting screw, the end of which is supported for example by means of a flange on the inner side of the spring housing. This development makes it possible to maintain constant the relationship of the initial tension of the locking spring at the start of the elastic range and at the release point even when the initial tension of the locking spring which is active at the start of the elastic range is changed by means of the adjusting screw. 
     In order to also permit in the region of the spring housing a transfer of the spring force without large friction losses, a piston, which is loaded by the release spring, is guided in the spring housing, which piston has a roller on the side thereof remote from the release spring. The roller is adapted to rest on the lever. 
     Finally, it has been proven to be particularly preferable for the manufacture of the ski binding, if the slide-member plate consists of at least two plate-shaped parts, which receive the wedge-shaped shoulders therebetween them and are connected to one another by plural rivets or the like. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One exemplary embodiment of an inventive ski binding is illustrated in the drawings, in which: 
     FIG. 1 is a cross-sectional view taken along the line I--I of FIG. 2; 
     FIG. 2 is a top view of the ski binding with the stepping bar stepped down upon; 
     FIG. 3 is a cross-sectional view of the holding mechanism taken along the line III--III of FIG. 5; 
     FIG. 4 is a cross-sectional view of the holding mechanism taken along the line IV--IV of FIG. 5; 
     FIG. 5 is a top view of the holding mechanism with the housing lid removed; 
     FIG. 6 is a cross-sectional view taken along the line VI--VI of FIG. 2; 
     FIG. 7 is an enlarged longitudinal cross-sectional view of a detail of the ski binding; and 
     FIG. 8 is a cross-sectional view taken along the line VIII--VIII of FIG. 7. 
    
    
     DETAILED DESCRIPTION 
     Three holding elements are secured to the upper surface of a ski 1, namely a down-holding means 1a, a center bearing pin 1b and a bearing block 1c for a follower member 2. A sole plate 3 is provided above the ski 1 and has at its front end a transversely extending upper support bar 3a, a lower support part 3b spaced rearwardly therefrom and which extends parallel to the upper support bar, a downwardly opening receiving hole 3c adapted to receive therein the bearing pin 1b, and a housing 3d in which is housed a holding mechanism 4. Two pairs of clamping jaws 5 are pivotally supported on the side surfaces of the sole plate 3 and about longitudinally extending axes 5a (see FIG. 6). Each clamping jaw 5 is constructed as a two-arm lever. 
     A stepping bar 6 is pivotally supported for movement about a horizontally extending axle 6a in the sole plate 3. The stepping bar 6 is responsive to an erecting spring 6b which, in this embodiment, is constructed as a torsion spring. In addition, the stepping bar 6 has on its underside a longitudinally extending guideway 6c and in which is guided a roller 7a which is supported at the end of a control lever 7. The end of the control lever 7 has a nose 7e thereon. The control lever 7 is constructed as a two-arm lever and can be pivoted about an axle 7b which is supported on the sole plate 3. The end of the lever arm remote from the roller 7a has plural prongs thereon, namely, it has two longer inner prongs 7c and two shorter outer prongs 7d (see FIG. 8), the purpose of which will be discussed hereinbelow. 
     A slide-member plate 8 is movably guided on the sole plate 3. The slide-member plate 8 has, viewed from the top, wedge-shaped shoulders 8a, which act onto the lower arms of the clamping jaws 5 when in the clamping position of the ski binding. According to FIG. 6, the slide-member plate 8 consists of two parts, one on top of the other and between which is provided the shoulders 8a. The two parts are connected by rivets schematically shown as at 8h in FIG. 6. Two bearing blocks 8b and 8c are secured to the slide-member plate 8, in which bearing blocks is movably guided in the longitudinal direction of the ski, an elongate rod 9. The rod 9 has a flange or collar 9a thereon against which engages one end of a pressure spring 9b, the other end of which engages the bearing block 8b (see FIG. 7). The spring 9b urges the rod 9 toward the tail end of the ski. A hole 8d, which is approximately T-shaped, when viewed from the top (see FIG. 8), is provided in the slide-member plate 8, into which hole, in the stepping-in position of the ski binding, extend the inner prongs 7c and the outer prongs 7d. If the stepping bar 6 is stepped down upon by the foot of the user, then the outer prongs 7d become supported on the two shoulders of the approximately T-shaped hole, which shoulders are provided laterally adjacent the stem portion of the T-shaped hole 8d, whereas the inner prongs 7c can swing unhindered into the cross portion of the hole 8d. The prongs 7c are designated only for engaging the right boundary or edge of the hole 8d illustrated in FIG. 8. 
     The slide-member plate 8 is constructed fork-shaped at the end thereof remote from the clamping jaws 5, namely, adjacent the holding mechanism 4. That is, the plate 8 has a pair of rearwardly extending bifurcated prongs 8e and 8f. Each bifurcated prong 8e and 8f has a roller 8g thereon, which in the skiing position of the ski binding engages a shoulder 10a on a one-arm locking lever 10. Each locking lever 10 extends substantially in a longitudinal direction of the ski and is pivotal about a transversely extending bolt 10b (FIG. 4) secured to an extension 11a on a spring housing 11 and which is movably guided in slotted holes 3e in two platelike projections 3f, 3g (FIGS. 2, 3 and 4) of the housing portion 3d of the sole plate 3. A compression release spring 12 is housed in the spring housing 11. One end of the spring engages a piston 13, on the side thereof which is remote from the release spring 12 is supported a roller 14. The roller 14 is urged by the release spring 12 against a one-arm lever 15 which is pivotally supported in the housing 3d of the sole plate 3 on an axle. The lever has a cam or protuberance 15a on the side thereof remote from the roller 14. The cam rests on one side of a piston 16 movably guided in an opening 3k  of the housing 3d. The side of the piston 16 opposite the cam engages the enlarged head of a mushroom-shaped follower member 2. In addition, a bolt or pin 16a, which extends in transverse direction, extends through the piston 16. The ends of the pin are guided in slotted holes 3m in the sidewalls of the housing 3d and project laterally beyond the sidewalls as shown in FIG. 5. 
     Approximately in the central region along the length of the spring housing 11, there transversely extends lateral bearing pins 11b which are connected to the spring housing, on which bearing pins are supported two two-arm levers 17. The lowermost ends of each lever 17 are connected to a bolt 17a rotatably supported thereon, which bolt has a threaded hole therein which extends transversely with respect to the axis of the bolt. An adjusting screw 18 is threadedly received into the threaded hole, which adjusting screw engages with its flange 18a the inner surface of the spring housing 11. A support wall 3n provided in the housing 3d of the sole plate 3 is engaged by the end of the other arm of each of the two-arm levers 17. The support wall 3n extends at least approximately parallel with respect to the upper surface of the ski. 
     Furthermore, an intermediate lever 19 which, viewed in the longitudinal direction of the ski, is approximately U-shaped, is pivotally supported for movement about the axle 15b, which lever 19 is urged clockwise (FIG. 4) under the influence of a torsion spring 19a. The intermediate lever 19 rests with one arm 19c on the bolt 16a of the piston 16. A further arm 19d of the intermediate lever 19 has an axle 19b thereon, which on the one hand extends through a slotted hole extending approximately in the longitudinal direction in the locking lever 10, and on the other hand serves as a bearing pin for a link member 20. The other end of the link member 20 is hingedly connected to one end of a release lever 21, which is constructed as a two-arm lever which is pivotally supported for movement about the axis of an axle 21a arranged on the housing 3d of the sole plate 3 or in the platelike projections 3f, 3g thereof. 
     The mushroom-shaped follower member 2, which is supported under the pressure of the piston 16 with its head on a pulled-in edge of the hole 3k in the housing 3d of the sole plate, has on its stem portion two axially spaced, approximately spherically enlarged regions 2a and 2b, of which the one spherical enlargement 2a is received in a horizontal guideway and the other spherical enlargement 2b is received in a vertical guideway, both guideways being provided on the bearing block 1c. The relationship between the release moment, which is necessary for effecting a release during a frontal fall and for effecting a release during a twisting fall is determined by this measure in adjustment with the corresponding moment arms of the sole plate. 
     If the ski binding is to be adjusted to the skiing ability and the physical characteristics of the skier, then first the adjusting screw 18 is turned, for example deeper into the threaded hole in the bolt 17a. This causes the lever 17 to be pivoted counterclock. wise and the spring housing 11 to be pivoted clockwise about the axis 10b relative to the sole plate due to the urging of the release spring 12 which, in this instance, becomes slightly relaxed. However, the roller 14, which is urged by the release spring 12 through the piston 13, moves at the same time along the side surface of the lever 15 in direction of the axle 15b. This causes, however, the effective lever arm of the lever 15 to be reduced in size and additionally the pressure which is applied on the piston 13 is reduced because of the slightly relaxed release spring 12. 
     During stepping in, the ski shoe 22 (same is only schematically indicated in FIG. 6) is positioned so that the cross surface of the heel is placed on the stepping bar 6 and is thereafter stepped or urged downwardly toward the sole plate 3 against the urging of the torsion spring 6b. The clamping jaws 5 are thereby opened due to the slide-member plate 8 being moved by the control lever 7, which is coupled with the stepping bar 6 through the roller 7a, first against the force of the release spring 12 generally to the left in FIG. 1. This is done by the outer prongs 7d of the control lever 7 engaging the two shoulders of the approximately T-shaped hole 8d and which cause the slide-member plate 8 to be moved toward the tip of the ski. The bolt 10b moves at the same time in the slotted holes 3e in the platelike projections 3f and 3g of the sole plate 3, which bolt, as explained above, forms the swivel axis for the locking lever 10. If, however, the outer prongs 7d of the control lever 7 have passed the upper boundary surface of the shoulder on the slide-member plate 8, then same moves quickly to the right under the influence of the release spring 12, whereby the wedge-shaped shoulders 8a of the slide-member plate 8 will rest on the corresponding sloped surfaces on the lower arms of the clamping jaws 5. In this manner, the ski shoe 22 becomes clamped in the ski binding. In this position the bolt 9 is supported on the nose 7e of the control lever 7. 
     If a fall occurs during skiing, then, independent from whether the fall is a frontal, a twisting or a combined fall, the follower member 2 is swung relative to the housing 3d on the sole plate 3 to cause the piston 16 to be moved back in the hole 3k against the force of the release spring 12 housed in the spring housing 11. The movement of the piston 16 and the bolt 16a thereon thereby effects a clockwise pivoting of the intermediate lever 19 and a lifting of the left end (FIG. 4) of the locking lever 10 due to the connection provided by the axle 19b and in this manner moves said locking lever 10 upwardly away from the rollers 8g which are supported on the slide-member plate 8. The slide-member plate 8 is now moved to the left in FIG. 1 due to the urging of the pressure spring 9b, which spring 9b was initially under tension on the flange 9a of the bolt 9 or through same on the nose, 7e of the control lever 7. The wedge-shaped shoulders 8a of the slide-member plate 8 are, however, through this removed from the corresponding surfaces on the lower arms of the clamping jaws 5, and the ski shoe 22 can leave the ski binding. 
     If the ski binding is to be voluntarily opened, a force is then applied to the release lever 21 with, for example, the tip of the ski pole, which force effects a clockwise swinging of the lever 21. However, this causes the locking levers 10 to be lifted due to their connection to the link members 20, which thence cause the rollers 8g to roll off from the shoulders 10a on the locking lever 10. The remaining operation corresponds to an automatic release of the ski binding. 
     Before the ski shoe 22 had left the ski binding, the slide-member plate was moved to the left by the pressure springs 9b, as was already discussed. This would permit the two outer prongs 7d of the control lever 7 to be able to again enter the hole 8d of the slide-member plate 8. The stepping bar 6, which is under the influence of the erecting spring 6b and is coupled with the control lever 7 through the roller 7a, thus reaches the position illustrated in FIG. 1. The slide-member plate 8 is thereby moved to the right by the inner prongs 7c of the control lever 7, which come to rest on the right boundary or edge of the hole 8d, until the rollers 8g will engage the shoulders 10a of the locking lever 10 as shown in FIG. 4. The stepping-in position of the ski binding is again created in this manner. 
     Of course, the invention is by no means to be limited to the exemplary embodiment which is illustrated in the drawings and which is described above. Rather, various modifications of the same are possible, without leaving the scope of the invention. For example, it would also be possible to equip the ski binding with a differently constructed follower member or with two follower members, which are arranged parallel to one another--one for frontal falls, the other for twisting falls.