Abstract:
A ski brake comprising at least one braking member which, when no load is applied by a foot, protrudes from the plane of the ski running surface, and upon application of a load by a foot lies substantially within the ski body.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a ski braking means for preventing a ski from continuing downhill when it becomes detached from the boot. 
     2. Description of the Prior Art. 
     The numerous known ski braking means of this type are disadvantageous in several respects such that so far their use in place of tethers has not gained acceptance. 
     First of all, all parts of the known ski braking means are provided above and laterally of the ski body, respectively, especially the braking member is arranged along one side edge of the ski. This is the cause for the disadvantages listed below: 
     (a) The running resistance of the ski in trackless snow is considerably increased, because the track produced by the upturned ski tip must be continually widened by the braking members. 
     (b) On sloping courses during canting of the ski edges or on turns the lateral braking member will frequently scrape into the snow and so decrease the speed. Particularly, sudden decreases in speed of the more steeply canted ski edges may result in dangerous falls. 
     (c) With most of such ski braking means, after relief of a tension spring by release of the ski boot the braking members are swung out laterally downwardly, thus inhibiting further running on the ski running surface. In most cases, the suddenly braked skis will be hurled through the air, and the extended braking members may injure other skiers. 
     (d) A risk of injury caused by the protruding braking members also during insertion of the foot into the ski binding and during tensioning of the braking means, respectively, as well as during ski transport. 
     (e) Assembling problems, since assembly of the braking means is effected later by drilling and threading fasteners into the ski body, which is not only cumbersome but also weakens the ski body. 
     (f) Complicated operation and high price, which is why they are unsuitable particularly for children&#39;s skis. 
     (g) Danger of icing and thus of failure to release, as snow will be collected on the protruding braking members. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the invention to provide a ski braking means of the type specified, which is of simple construction, easily operated and yet effective, and which neither obstructs running nor incurs a risk of injury. 
     With the subject-matter of the invention, during skiing basically no part will protrude from the ski body, or at most within the dimensions of the safety binding. The skier will not be handicapped by the braking member, as the bottom surface of the latter is substantially in alignment or flush with the running surface or the tracking groove of the ski, respectively. Even when the braking member is slightly offset to the rear, there will be no impediment during skiing. 
     One embodiment of the invention, which utilizes a thrust bolt, ensures not only a very simple operation of the ski braking means but in this embodiment the thrust bolt for operating the braking member may protrude in the braking position to a relatively great extent from the ski upper surface, for when the safety binding is locked the abutting surface thereof will press the bolt downwards so that the bolt will not represent an annoyance; this entails an increased overall height of the bolt and consequently facilitates the structural design of the braking means. 
     Further, locking of the braking member in the non-braking position is also possible with very simple means, so that also during transport of the ski there will neither be any damage of the braking member nor will the braking member represent a cause of danger for persons or objects. 
     The ski braking means according to the invention may be used with particular advantage in conjunction with skies manufactured by common techniques from plastic material. The required recess may be provided in the ski during manufacture thereof without any significant extra labour. Weakening of the ski by the recess need not be feared. Even if the recess is provided at a later time, the use of the ski for skiing will not be impeded as the deflection of the loaded ski in the region of boot and binding is minimized so as not to endanger an easy and reliable binding release by a shortening of the spacing between front and rear jaws of the safety binding. If the recess is provided at the time of manufacture of the ski, this area may, if desired, be reinforced with little expense. 
     A set screw permits the height adjustment of the braking member with respect to the ski boot and the boot sliding strip, respectively. As the braking member of the pivotable embodiment in its protruding portion is preferably given such a height that there will be no free space between the ski running surface and the braking member, no snow will get beneath the braking member even when the ski slides with the braking member swung out. 
     A particular braking effect is achieved by the provision of two parallel levers at the braking member or by the use of a plate at the protruding end of the long arm of an L-shaped lever as a braking member. When two such braking members are mounted on a ski behind one another and with opposite swing, braking of the ski in either direction is achieved in a simple manner. 
     Certain other embodiments of the invention are still more advantageous, as a braking effect in either direction will be obtained from the very beginning. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the ski braking means according to the invention will be described below with reference to the drawing, in which 
     FIG. 1 is a longitudinal sectional view of a first embodiment of the ski braking means of the invention, in which the braking member has been swung inwards by the ski boot; 
     FIG. 2 is a longitudinal sectional view similar to FIG. 1, in which, however, the braking member is shown in the swung-out position released by the ski boot; 
     FIG. 3 is a cross-sectional view of the ski braking means of FIGS. 1 and 2 at the level of the pivot axis of the braking member; 
     FIG. 4 is a plan view of the upper surface of the ski including a built-in ski braking means according to the FIGS. 1 to 3, the front part of the binding having been removed; 
     FIG. 5 is a plan view similar to FIG. 4, but showing a braking member having two parallel arms; 
     FIG. 6 is a longitudinal sectional view of a second embodiment of the ski braking means of the invention, in which the braking member at its front comprises a plate; 
     FIG. 7 is a plan view of the ski braking means of FIG. 6, the front part of the binding having been lifted off; 
     FIG. 8 is a cross-sectional view along the line A -- A of the ski braking means of FIGS. 6 and 7 at the level of a spring; 
     FIG. 9 is a longitudinal sectional view of a third embodiment of the ski braking means of the invention having two braking members provided one behind the other; 
     FIG. 10 is a plan view of the ski braking means of FIG. 9, the parts of the binding having been removed; 
     FIG. 11 is a longitudinal sectional view of a fourth embodiment of the ski braking means of the invention having two coupled braking members, which are adapted to be swung out in different directions; 
     FIGS. 12 and 13 are a plan view of a cross-sectional view, respectively, of the ski braking means of FIG. 11; 
     FIG. 14 is a perspective view of a fifth embodiment of the ski braking means of the invention at a larger scale than the FIGS. 1 to 13 (the ski body being omitted) in non-braking position; 
     FIG. 15 is a longitudinal sectional view of the ski braking means of FIG. 14; 
     FIG. 16 is a cross-sectional view of the ski braking means of FIG. 15 at the level of the thrust bolt; 
     FIG. 17 and FIG. 18 are a longitudinal sectional view and a plan view, respectively, of the embodiment of FIGS. 1 to 4 comprising a sliding bar for locking the ski braking means during transport, FIG. 18 being drawn to a smaller scale than FIG. 17. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In a first, basic embodiment of the ski braking means of the invention at least one braking member is used, which is pivotable about a transverse axis of the ski body. FIGS. 1 to 13 show various embodiments of this type. 
     In FIGS. 1 to 4, which show a first embodiment of the ski braking means of the invention, there is provided a recess 3 in a ski body 1 beneath a forward binding part or front jaw 2a of a safety binding, said recess 3 being open at the running surface 2 of the ski over the entire extent thereof but being covered in its front portion at the ski upper surface by a section 3a of the ski body 1. 
     The recess 3 includes a central transverse space. In an already finished ski, the recess 3 may be cut into the body 1 of the ski so that the ski braking means may be mounted later. The recess 3 may, however, be provided already during manufacture of the ski, e.g. when the ski is made from plastic material, most of the manufacturing methods for plastic materials (e.g. injection molding, thermoplastic foam casting, or polyurethane) permitting the forming of the recess 3 without extra costs. 
     In the embodiment of the ski braking means according to the FIGS. 1 to 4, which comprises only a single braking member, the recess 3 ends at the ski running surface 2 within the area of the tracking groove. 
     According to the FIGS. 1 to 4 the braking member consists of an L-shaped lever 4 having a long arm 4a and a short arm 4b. Approximately centrally, the L-shaped lever 4 has a pivot axis 7, which is provided on the long arm 4a and may, especially in the case of manufacture from plastic material, be formed integrally therewith. 
     The braking member is inserted in the recess 3 from the ski upper surface. The long arm 4a at the rear end of the braking member as viewed in running direction extends almost to the ski upper surface or, respectively, to a bottom plate 2a&#39; of the front jaw 2a of the safety binding, it being advantageous that the bottom plate 2a&#39; also covers the recess 3. 
     A set screw 6, provided on the short arm 4b, permits an accurate setting of the effective height so that the ski boot 2b, which is clamped in the front jaw 2a and the sole of which is pressed onto a boot sliding strip 2c, will firmly press onto the set screw 6 and thus onto the braking member formed by the L-shaped lever 4. Thus, the ski braking means is adjusted by the set screw 6 in such a manner that in the tensioned condition, i.e., when loaded by the ski boot 2b, the set screw 6 will be at the same levels as the boot sliding strip 2c and at the same time the L-shaped lever 4 will be swung into the ski body 1. In the case of a ski made from plastic material the boot sliding strip 2c may be integrally formed in the ski body 1. 
     As is clearly apparent from the FIGS. 1 and 2, the long arm 4a of the L-shaped lever 4 may be formed as a uniformly rising wedge extending from the pivot axis 7 in ski running direction. This wedge portion has a longitudinally extending slot 4c permitting in the forward part thereof the anchoring of one end of a spring 8, the other end of said spring being anchored in a blind bore 10a in a boss 10 formed on the ski upper surface. 
     In simple embodiments it will, however, suffice that the long arm 4a is of uniform, e.g. square, cross-section. 
     When no ski boot 2b presses onto the L-shaped lever 4 by way of the set screw 6, the front end (viewed in ski running direction) of the long arm 4a is pressed downwardly by the spring 8 and out of the ski running surface 2, so that said end will protrude into the snow and the ski cannot glide inadvertently in the direction of the ski tip. So that no snow will be pressed into the recess 3 and the long arm 4a will not be damaged by the braking, respectively, the wedge provided at the front end of the long arm 4a is of such a height that even in the fully swung-out position of the L-shaped lever 4 no gap will remain between the lever and the recess 3, the enlarged front face of the wedge increasing the braking effect. 
     As soon as the ski boot 2b applies pressure to the set screw 6, the boot being secured in upward direction by the front jaw 2a of the safety binding, the L-shaped lever 4 will be fully swung into the ski body 1 so that it cannot form an impediment to skiing. The bottom surface of the lever may be flush with the running surface 2 of the ski or it may be somewhat offset in rearward direction (cf. in this respect FIG. 3). 
     So as to prevent any kind of damage to the ski during transport, a sliding bar 31 or a similar locking element may be provided on the ski upper surface (cf. the FIGS. 17 and 18), which sliding bar maintains the L-shaped lever 4 in its withdrawn position also when no load is applied by a ski boot; the sliding bar may include an upwardly protruding portion which, when the ski boot is placed onto the ski, facilitates pushing-back of the sliding bar and thus a release of the braking member 4, i.e., the ski braking means is automatically brought into a state ready for release. In particular, the sliding bar 31 includes a lateral slot in which a transverse pin 31a is provided permitting sliding motion of the sliding bar 31 in longitudinal direction of the ski. The recess 3 is covered by a cover plate 29. The dashed lines in FIG. 17 indicate the pushed-back position of the sliding bar 31, in which the L-shaped lever 4 has been swung out. 
     As shown in FIG. 5, the L-shaped lever may also include two long arms 4a extending parallel to each other, which at their front ends terminate separately but are joined at their rear ends through a common short arm 4b. In this double-arm embodiment the braking member lies in the ski running surface on either side of the tracking groove. 
     As shown in FIGS. 6 to 8, a transversely extending plate 9 may be provided at the end or ends of the long arms 4a adapted to be swung out, so that the braking effect is enhanced. 
     With the embodiments of the ski braking means according to the invention described so far, an effective braking is ensured only in one direction, i.e., in the ski running direction. These embodiments will be especially useful when the ski running surface is scaled (cf. e.g. Published German Patent Application No. 1,578,922), i.e., when the running surface itself already effects a braking against backward sliding. 
     However, in the case of skis having a smooth running surface an additional safeguard against unintentional backward sliding is desirable. 
     This is achieved with the third embodiment shown in FIGS. 9 and 10, which is practically a duplication of the ski braking means shown in FIGS. 1 to 4 but with a second, rear brake having an opposite swinging direction, and in which the second L-shaped braking member 4&#39; is installed beneath the rear jaw 2a&#34; of a safety binding in the ski boot 1. 
     A fourth embodiment of the ski braking means of the invention shown in the FIGS. 11 to 13 represents, as it were, a simplification of the embodiment shown in FIGS. 9 and 10 in that a single thrust bolt 27 resting on a spring 28 and having a bolt head 27a for operating two braking arms 24a is employed, said braking arms forming two braking members and being pivotally connected to the thrust bolt 27. Each of the two braking arms 24a is also pivotable about a transverse pin 26 mounted in lost motion slots in the ski body (indicated in dotted lines), as is clearly apparent from FIG. 11. For the rest, each braking arm 24a is provided within a punched out portion 30, and the top of the recess 3 in the ski body 1 is covered by a cover plate 29 and a boot sliding strip 2c. 
     With the embodiment of the ski braking means shown in FIGS. 11 to 13 there is, however, a tendency for snow to penetrate into the punched out portions 30, and possibly that cover plates 29 may not be arranged in sufficiently close relationship. 
     In this respect, therefore, the other basic embodiment of the ski braking means of the invention shown in the FIGS. 14 to 16 is more advantageous. 
     This ski braking means comprises a braking member 34 having two rod-like braking bolts 34a of approximately square cross-section, which are guided in a recess 3 of the ski body 1 vertically with respect to the ski running surface 2. At their upper ends the braking bolts 34a are pivotally connected with connecting arms 35 which in turn are downwardly inclined and pivotally connected to transverse pins 36 and the lower ends of which are pivotally connected to a thrust bolt 37. The pins 36 may be mounted in lost motion slots, as in the embodiment shown in FIGS. 11-13. The thrust bolt 37 is vertically guided in the recess 3 and loaded at its lower end by a spring 38 while the upper end carries a bolt head 37a which may also be formed as a set screw. The bolt length may be adjusted in such a manner that during application of load by a ski boot the bolt will be fully pressed into the cover plate of the recess 3 in the ski body 1 or that particularly in case of boot sliding strips 2c being used the bolt will be at the same level as said strip so that the braking member 34 is retracted (cf. FIGS. 14 to 16). 
     The braking member 34 is installed in such a manner in the recess 3 that in the case of no-load condition of the ski the lower ends of the braking bolts 34a will protrude outwardly from guide recesses 40 formed in the ski running surface and also the head 37a of the thrust bolt 37 will protrude from the cover plate 39 and beyond the boot sliding strip 2c, respectively. As this ski braking means also is installed in the ski body 1 in the area of a binding section, the ski boot 2b clamped into the binding will apply pressure to the head 37a of the thrust bolt 37 and will thus retract the lower ends of the braking bolts 34a into the ski body 1. The lower ends of the braking bolts 34a may be either flush with the running surface 2 or slightly withdrawn therefrom. When the ski boot is lifted off the ski and the thrust bolt 37 is released, the lower ends of the braking bolts 34a will immediately emerge from the ski body 1 and cause braking. 
     The ski braking means according to the invention is preferably mounted in such a manner that the braking bolts 34a are positioned centrally with respect to the longitudinal axis of the ski. In case of the ski having a tracking groove the braking bolts 34a will emerge in the area of said groove. 
     The parts of the braking member 34 may be made of corrosion resistant metal or also of plastic material. Also, the cover plate 39 and the boot sliding strip 2c may form a unit. 
     The running properties of the ski are in no way impaired by the ski braking means shown in FIGS. 14 to 16. The ski braking means is effective in either direction. It is therefore insignificant whether a free ski runs unintentionally with its tip or its trailing portion leading. 
     With this embodiment, too, a safeguard similar to that shown in FIGS. 17 and 18 may be provided by means of which the thrust bolt 37 may be locked in the depressed position so as to prevent, e.g. during transport, a damaging of the braking bolts 34a and the ski running surface 2.