US3129951A

US3129951A - Safety ski bindings

Info

Publication number: US3129951A
Application number: US223394A
Authority: US
Inventors: Lusser Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-10-21
Filing date: 1962-09-13
Publication date: 1964-04-21
Anticipated expiration: 1981-04-21
Also published as: DE1578810A1

Description

April 21, 1964 R. LUSSER SAFETY SKI BINDINGS 5 Sheets-Sheet 1 Filed Sept. 15, 1962 April 21, 1964 R. LUSSER SAFETY SKI BINDINGS 5 Sheets-Sheet 2 Filed Sept. 13, 1962 April 21, 1964 R. LUSSER 3,129,951

SAFETY SKI BINDINGS Filed Sept. 15, 1962 5 Sheets-Sheet 3 Aprzl 21, 1964 R. LUSSER 3,129,951

SAFETY SKI BINDINGS Filed Sept. 13, 1962 5 Sheets-Sheet 4 A ril 21, 1964 R. LUSSER 3,129,951

SAFETY SKI BINDINGS Filed Sept. 1:5, 1962 5 Sheets-Sheet 5 United States Patent 3,129,951 SAFETY SK! BINDINGS Robert Lusser, Steinhauserstr. 27, Munich, Germany Filed Sept. 13, 1962, Ser. No. 223,394 Claims priority, application Germany Sept. 18, 1961 12 Claims. (Cl. ass-41.35

The present invention relates to safety bindings for ski boots and more particularly to safety bindings which, when the skier falls, will automatically open if a predetermined tension at the heel, or leg which was selected for preventing injury to the skier is exceeded.

There is known a safety binding in which the toe of the ski boot sole is supported against a fixed clamp mounted on the ski, and a pressure member which extends in a generally oblique direction from the rear downward toward the front of the ski presses rearwardly upon the heel portion of the sole. This pressure member is hinged to one end of a two-armed lever so as to swing in a vertical longitudinal plane, with the two-armed lever being mounted on the ski in such a fashion that such lever can also swing in a vertical longitudinal plane. At the other end of the two-armed lever, tension spring means engages in such a direction that it tends to press the free end of the pressure member into a fitting mounted on the heel portion. Thus the heel of the ski boot is pressed upon the ski by the pressure member which is acted upon by the spring means.

When the pull on the heel and the leg becomes greater than the vertical component of the force exerted obliquely by the pressure member on the heel portion, the heel portion begins to separate from the ski. With the raising of the heel portion, the vertical component of the force exerted by the pressure member initially increases due to the increasing spring tension, but since with the raising of the heel portion the inclination of the pressure member becomes increasingly flatter, a point is reached after which the magnitude of the vertical component which endeavors to return the heel portion onto the ski decreases in spite of the increased spring tension. If the pull of the heel portion becomes so great that the heel portion reaches such instable point, the heel portion will continue to move further, thereby freeing itself from the ski.

The advantage of such a binding resides in releasing the boot completely when the safe load of the heel portion is exceeded, and that such releasing point can be predetermined with safety. The length of the path in which the heel portion can move away from the ski prior to disengagement of the binding, the force by which the heel portion is held to the ski, and the force at the moment of release, depend on the inclination or angularity of the pressure member, the length of the pressure member, the pivot point of the lever, and the tension of the spring.

In the known ski safety binding, adjustments can be made, in the tension of the spring and in the horizontal distance between the pivot point of the level and the heel portion of the boot and thus in the inclination of the pressure member. By changing the spring tension, the force can be selected at which the heel portion will begin to lift from the ski, but the path which the heel portion must travel to reach the point of disengagement is not changed materially. Since the kinematics remain the same with a change in the spring pretensioning, the char acteristic of the force increase with the raising of the boot heel portion from the ski also remains the same. It begins only at a greater or smaller force. If the horizontal distance between the pivot point of the lever and the heel portion is increased, and thus the inclination of the pressure member is decreased, then, at the same pretension of the spring means, the vertical pressure component of the force endeavoring to hold the heel portion on the ski and acting from the pressure member on the heel portion will become less, and, due to the change in kinematics, the characteristic of the increase of force with the raising of the heel portion from the ski will become flatter. At the same time the path traversed by the heel portion in raising from the ski until it moves past the unstable point becomes shorter. However, a fiat rise of force with a small initial force is desired only for cross-country runs and for climbing, but, at the same time, it is desirable that the heel portion can be raised quite far from the ski without the binding opening.

in the known safety binding, the two above noted adjustment possibilities are provided only for the purpose of being able to adapt the force by which the heel portion is held upon the ski and the releasing force to the physical constitution of the skier. It is much more important, however, that each skier can readily adapt his binding by a simple manipulation to the various, completely different requirements in skiing down-hill on the one hand, and in skiing cross-country or climbing on the other hand. In a down-hill run, the heel portion should be held firmly on the ski and should raise from the ski only at a greater pull of the heel portion. For example, when falling forward, if the pull of the heel portion exceeds a predetermined safety value or factor, then the boot should disengage quickly from the ski. To alford the skier the feeling to note that the pull of the heel portion approaches the pre-determined releasing forge, only a short path is desired for the heel portion to the point of release, but with a steep rise in force. It is not desirable in a downhill run that the heel must initially travel a long path with increasing restoring force before the heel portion can disengage from the ski. On the other hand, in climbing or in cross-country skiing, the pre-tension by which the heel portion is held to the ski should be small, but the path great which the heel portion can traverse in raising from the ski until the point of release is reached.

The requirements above mentioned are fulfilled if the known ski safety binding is developed further in accordance with present invention, so that the spring engages a selector lever mounted on the lever, or on the pressure member and is swingable between two stops, with the pivot point of the selector lever being so positioned that the spring loads the selector lever for pressure and that, in the position of the latter away from the lever pivot point, for a down-hill run, the selector lever pivot point moves across the connecting line of the two spring suspension points if the raising of the boot heel portion from the ski exceeds a predetermined distance of travel, so that when this travel distance is exceeded, the selector lever moves automatically into the position near the lever pivot point, for climbing or cross-country skiing, and in which position the pressure member presses upon the heel portion with less force.

When the skier has placed the selector lever into the position near the lever pivot point, the spring engages at a smaller lever arm than in the other position away from the lever pivot point. Thus, in the position near the lever pivot point, the heel portion is held on the ski with less force, and with the raising of the heel portion from the ski such force rises more flatly than in the position away from the lever pivot point. The first-noted position is provided for climbing or cross-country skiing, and in such skiing, the skier should be able to raise his boot heel from the ski quite a distance without much force. The disengagement of the heel portion takes place in the same manner as described above in reference to the known ski safety binding.

When the skier desires to start downhill, he merely needs to swing, on both of his skis, the selector lever into the position away from the lever pivot point, and in which position the spring engages a large lever arm. In that position, the force of the spring acts upon the boot heel portion several times more strongly, and the heel portion is held on the ski with great force. When the pull of the heel portion becomes greater than that force, the heel portion raises from the ski, but the skier will feel a steep rise in force which indicates to him when the binding approaches the disengagement point. When the heel portion has been raised from the ski a certain distance determined by the position of the selector lever pivot point, the selector lever pivot point moves past the connecting line of the two spring suspension points, i.e.,

past its dead center. Therefore, immediately after exceeding this raising distance of the heel portion the selector lever will automatically snap from the position away from the lever pivot point into the position near the lever pivot point. From this point on, the force tending to return the heel portion onto the ski equals the very much smaller force for climbing and cross-country skiing.

If with the position of the selector levers of the two bindings set for a downhill run, the skier falls forward and hence the safe pulling force for his heel and his leg is exceeded, the selector lever snaps automatically into the climbing or cross-country position. Since therewith the force tending to return the heel portion upon the ski is suddenly reduced very strongly, the heel portion will continue to move further until it is completely freed from the binding and thus from the ski. Consequently, the skier can, without unbuckling the ski and without any cumbersome adjustment, adjust his binding very simply by merely shifting a lever into the position for a downhill run or into the position for climbing or cross-country skiing. In each position, the magnitude and the characteristic of the force tending to hold the heel portion on the ski corresponds to the physical constitution of the skier, and in both positions any excess strain on the heel, 'or the leg of the skier in a fall is positively avoided.

The invention and further objects and advantages thereof will become apparent from the ensuing description and annexed drawings illustrating several embodiments of the invention by way of example.

FIG. 1 is a side elevational view of a ski safety binding according to the basic principle of the invention.

FIG. 1a is a diagrammatic View of the path of force in raising the heel portion away from the ski.

FIG. 2 is a view along the lines of FIG. 1 showing the first further development of the ski safety binding according to the invention.

FIG. 2a is a diagrammatic view of the path of force with the binding of FIG. 2.

FIG. 3 is a view along the lines of FIG. 1 showing the second further development of the safety binding according to the invention.

FIG. 3a is a diagrammatic view of the path of force with the binding of FIG. 3.

FIG. 4 is a side elevational View of yet another embodiment of a ski safety binding according to the invention.

FIG. 5 is an elevational view, partly broken away of a ski safety binding constructed according to the invention.

FIG. 6 is a cross section taken along line A-B of FIG. 5, the view looking in the direction of the arrows.

FIG. 7 is an elevational view showing the safety binding of FIG. 5 immediately before disengagement.

FIG. 8 is a rear elevational view of the heel fitting used with the binding.

FIG. 9 is a diagrammatic view of the force acting vertically upon the heel, superimposed over the lifting path of the heel from the ski.

FIG. 10 is a side elevational view partly in cross section, of a preferred embodiment of the invention.

FIG. 11 is a cross section taken along line CD of FIG. 10, the view looking in the direction of the arrows.

FIG. 12 is an elevational view of the ski safety binding of FIG. 10 immediately prior to the attachment to the heel fitting.

FIG. 13 is an elevational view of the safety binding according to FIG. 10 in the position for a downhill run.

FIG. 14 is an elevational view showing the binding set for the downhill run immediately prior to the switchover into the climbing position, and

FIG. 15 is an elevational view of the same binding immediately prior to the release of the ski boot.

In FIG. 1, a ski is denoted 1 and sole 2 of a ski boot 3 coacts at toe portion 4 with a known torsion toe clamp 5 attached to the ski and which releases the boot at the toe of the sole when the torsional force acting in the leg exceeds a predetermined safe factor or value.

Into a recess or socket 6, preferably reinforced by a fitting (not shown), at the heel portion 7 of the sole 2 is engaged one end of a pressure member 8 which extends from the recess 6 in an oblique rearward and upward direction and which is pivoted at its other end to a lever 10 by pivot pin 9. The lever 10 in turn is swingably mounted by a pivot pin 11 to a bracket 13 fastened to a base plate 12 which is secured to the ski by screws or the like (not shown). The lever 10 is provided with an extension 14 which projects downwardly and a selector lever 16 is mounted thereon by means of a link pin 15. The selector lever 16 is defined by two legs, one leg being disposed on each side of the lever 10, with the legs being connected at their outer ends by a bolt 17. The ends of the bolt project beyond the legs of the lever 16. At each of the lateral projections of the bolt 17 there is suspended a tension spring 18 and the lower end of the spring is connected to an eye 19 on the base plate 12.

The rearward end position of the selector lever 16 is determined by the bolt 17 resting upon the upper edge of the lever 10, and the forward end position by the selector lever abutting against the upper end of the pressure member 8.

In the position of the selector lever shown in FIG. 1

in full lines, the spring 18 acts on the long lever arm L upon the lever 10, while in the rearward position adjacent the pivot pin 11, shown in dotted lines, the spring 18 acts only upon a small lever arm L. Depending on the vari able length of the lever arm by which the spring 18 acts upon the lever 10, the force in also variable at which the gressure member 8 presses upon the heel portion 7 of the cot 3.

In FIG. la there is shown diagrammatically the vertical component of that force which tends solely to return the heel portion 7 upon the ski 1. Legend I designates the vertical force component with which the heel portion is held to the ski 1 in the downhill position of the binding, and legend II the vertical force component with which the heel is held to the ski 1 in the climbing or cross-country position of the binding.

For illustrative purposes it is assumed that the selector lever 16 is in the position adjacent the lever pivot pin 11 (as shown in dotted lines in FIG. 1), and in which position the spring 18 acts upon the small lever arm L. In this position, the boot heel portion 7 is held on the ski 1 only with the relatively small force II. In climbing or cross-country skiing, the skier needs to employ merely the small force II in order to raise the heel portion 7 from the ski 1. After raising the heel, the force tending to hold the heel portion 7 upon the ski 1 increases fiatly along the curve a. In that position, the ski safety binding functions like the above-mentioned known safety binding. Although the force of the spring 13 increases with the raising of the heel portion 7, the vertical force component tending solely to return the heel portion 7 upon the ski 1, will because of the increasingly stronger inclination of the pressure member 8 attain a maximum as indicated at legend III. When the heel portion is raised so far that the vertical force component has attained the maximum value III, the heel portion 7 will be in an unstable position. H the skier exerts a somewhat greater pull with his leg, the heel portion will move beyond the point III. Since from this point onward the force tending to return the heel portion to the ski decreases again, the heel portion will continue to move further under the force effective in the leg until it is completely freed from the pressure member 8.

If the skier desires to make a downhill run, the selector lever 16 is placed in the position away from the pivot pin 11 (as shown in full lines in FIG. 1). In that position, the heel portion 7 is held on the ski 1 with the greater force I. If the pulling force exerted by the Achilles tendon of the leg upon the heel exceeds the force I, such as, for example, when the skier leans forward, then the heel portion 7 will rise from the ski I. The farther the heel 7 moves away from the ski, the more the vertical component of the force exerted by the pressure member 8 upon the heel portion 7 will increase. This rise in force is designated in FIG. la at b. With the raising of the heel portion 7 from the ski 1, the bolt 17 and the pin 15 of the selector lever 16 will move along a circular path around the pivot pin 11 of the lever It). Thus, a position of the lever 14) is attained in which the center of the bolt 17, the geometrical axis of the pin 15 and the eye 19 are all in one line, whereby the selector lever 16 assumes a dead-center position. The vertical force component acting in that position on the heel portion is designated in FIG. 1a by legend IV. When the pull of the heel portion exceeds the force IV, the connecting line between the two suspension points of the spring 18 travels across the geometrical axis of the pin 15, with the result that the spring 18 swings the selector lever 16 into the rearward position adjacent the lever pivot pin 11. Thus, the vertical force component acting on the heel portion drops immediately to the legend V on the curve a which describes the course of the vertical force compo nent tending to return the heel portion 7 to the ski in the climbing or cross-country position of the binding. Since at that moment, the force exerted by the pressure member 8 upon the heel portion 7 is suddenly strongly reduced, the pulling force exerted by the body on the skiers leg outweighs at that particular moment. The result is that the heel portion moves farther away from the ski and is released, as described above from the bind ing at the point III.

The point III in the force pattern is reached before the pressure member 8 and the rearward part of the sole 2 have reached a stretched position relative to each other. If the path which the heel portion traverses to attain this point is too short for climbing or cross-country skiing, and if a longer lift path is desired then a limiting device can be included.

The limiting device serves to hold the member 8 fixedly at a predetermined angle relative to the lever 19 whereby the pressure member 8 can no longer swing freely upwardly as in FIG. 1. The end angle position can be delimited rigidly by a fixed stop (not shown) or, as illus trated in FIGS. and 12 at 326 by means of a flexible but non-stretchable tension member.

As shown in FIG. 2, a spring 21 can be anchored in an eye 22 on the base plate 12 and is connected at its free end to a hole 23 of the pressure member 8. Otherwise,

6 the ski safety binding of FIG. 2 is similar to that shown in FIG. 1.

Since the center line of the spring 21 in the initial position of the binding embraces only a small angle with respect to the ski, it is barely efiective at the initial raising of the heel portion from the ski so that the force pattern b in the downhill run and the beginning of the force pattern a in the climbing or cross-country skiing of FIG. 2a are similar to the corresponding force patterns of FIG. 1. However, the closer the pressure member 8 and the rear portion of the sole 2 approach the stretched position, the greater the effect of the spring 21 becomes. The curve a no longer attains a maximum and then again drops off, but rather the vertical force component tending to bring the heel portion upon the ski increases steadily, and increasingly steeper, until the stretched position of pressure member 8 and the rear portion of the sole 2 is exceeded and, with attainment of force III, the free end of the member 8 moves from the recess 6 of the heel 7 since with a further lifting of the heel, the end of the member 8 moves approximately along path 2 2- and the recess 6 in the heel portion along path 25.

The binding shown in FIG. 3 differs from that of FIG. 2 only in that a loose cable 26 is inserted between tension spring 21a and the pressure member 8. The binding so made acts initially exactly like the binding of FIG. 1. The cable member 26 interposed between the end of spring 21 and a hole 23 in the pressure memher 8 is of such a length that it will become taut at about, or shortly after, that position of the binding at which the force tending to return heel portion 7 to the ski attains the unstable point III of FIG. 1a. From that point on, the force pattern of this binding changes as compared to that of FIG. 1. Depending on the selection of the spring 21a, the force will rise more or less steeply from that point up to the point III" at which the recess 6 in the heel portion 7 will separate from the free end of the pressure member 8 as described in connection with FIG. 2.

The binding in FIG. 3, possesses the advantage that in the climbing and cross-country position of the selector lever 16, the force tending to pull the heel portion onto the ski increases only slightly within the normal range of the movement of the heel portion and therefore it is unnecessary for the skier to expend appreciable effort in climbing or in cross-country skiing. But, when the heel portion approaches the releasing position III", the force rises steeply so that the skier senses that he is now approaching the releasing position of the binding. For practical purposes, the magnitude of the force III" can be selected just about as great as the force IV, but will as a rule probably be selected somewhat smaller.

If, with the binding in FIG. 3, and the position of selector lever 16 in the down-hill position (in the position away from the pivot point of the lever), the skier should fall forward, the force will rise initially from I to IV along the curve b. There, as has been described in connection with FIG. 1, the selector lever will shift automatically into the climbing or cross-country position, so that the force now drops from IV to V. The result of the foregoing is that the force now along the line a is no longer suihcient to return the heel portion to the ski, and the skier will continue to fall further forward. Hence the force rises again steeply at the end, but due to the kinetic energy possessed by the skier the pressure member 8 will, despite the force acting thereon in the opposite direction be jerked upward by the heel portion 7 until point III is reached and the heel portion is released from the binding.

Referring to FIG. 4 there is shown a binding which in principle is similar to that of FIG. 2. In the binding in FIG. 2, in every position of the binding, there is transmitted from the sprin 18 to the pressure member 8 a force acting in the direction of the connecting line hetween the pivot pin 9 and thesupporting point of the end of the pressure member 8 in the recess 6, which force can be combined with the force of spring 21 into a resultant force which engages at connection 23. Proceeding fromthis concept there is provided in FIG. 4 only a single spring 28 which acts by way of a selector lever 16a upon pressure member 3a. Here also, the pressure member 8a is connected by a pivot pin 59 to the end of a lever 10a which can swing relative to bracket 13a fastened to the ski 1. The pressure member 8a is U-shaped in cross section and is open downwardly. The selector lever 16a is provided at the free end with a pin 17a which projects through a slot 29 in the wall of the pressure member 8a. Between the two side walls of the pressure member 3a the upper end of pressure spring 28 is connected to the bolt 17a. By the co-action of the bolt 17a with the ends of the slot 29 are determined the two positions of the selector lever 16a which include a handle member 16!) so as to be able to move the same easily from one position to the other, position. Also with such binding the force tending to hold the heel portion on the ski is greater at the position of the lever 16a adjacent the heel portion than at the position remote from the heel portion. Here again the selector lever snaps automatically, after the raising of the heel portion from the position adjacent the heel portion into the position remote from such portion. The force pattern is generally similar to that illustrated in FIG. 2a.

With reference to FIGS. and 6, there is shown a binding according to the basic principle of FIG. 1 as regards its details. There is mounted on the ski rearwardly of the heel portion base plate 112 carrying the ski b nding. A bracket 113 extends upwardly from plate 112 and is provided at its upper end with a slot 131 for forming a fork. The lever 11% is pivotally connected to the upper end of the bracket 113 by bolt means 111. A pressure member 108 is connected to the free end of the lever 110 by a transversely extending bolt 109 and free end 1055a which is generally cylindrical engages recess 166 of a fitting 106a attached to the rear end of the heel portion 7 of the ski boot. The axis of the end 168a extends transversely to that of the ski 1; the end of 1128a, if desired, may be in the configuration of a sphere. Selector lever 116 is of approximately U-shape with the legs thereof being positioned on the opposite sides of the lever 110. At the lower ends of the legs of the lever 116 are provided pivot pins 115 which project inwardly and engage a bore in the lever 11%), with the same being held in the bore by virtue of the rigidity of the lever 116. A handle 116a is provided for the lever 116 and is in the form of a disk having lens-shaped recesses on the respective sides thereof. A substantially fork-shaped cross-piece 1116b of the lever 116 is extended on each side of the lever and the terminal ends are bent in a downward direction.

Each terminal end is provided with a bore 133 in which is lodged an upper hook 134 of tension spring 113. At its lower end, the spring is connected by means of a hook 135 to a pin 136 which is inserted into two eyes 119 extending upwardly from the base plate 112. The rearward position II of the selector lever 116 shown in FIG. 5 by full lines is determined by its abutment against the bracket 113. The position I of the lever 116 provided for the down-hill run is determined by its striking cheek 168k of the pressure member 108.

In departure from the binding of FIG. 1, there is attached in FIGS. 5 and 6 at each side of the lever 110 by rivets a generally angle-shaped spring shoe 137, free leg 138 of which is positioned behind the spring 118 when the spring is in the climbing position. The leg 138 of each shoe, as can be seen in FIGS. 5 and 6, has a curved shape.

Upper edge 139 of the'lever 110 in the range of the pivotal movement of the selector lever 116 is provided with a contour corresponding to a circular are around the center. of the pin 115, so that during the swinging of the lever 116 the distance between the component 11617 of the selector lever and the upper edge 1315 of the lever remains constant and that a jamming of the glove is prevented during adjustment of the selector lever. The lever 110 which, because of this construction, has a relatively large surface, includes a large aperture 14% which, in addition to a material saving in weight, serves at the same time as a handheld for moving the lever 110 when, in attaching the binding, the skier desires to bring the pressure member 198 into the recess of the heel fitting 106a.

The heel fitting 166a is provided with an angular lug or the like 143 which engages the top heel portion of the sole and has two fastening holes for the reception of screws 144 which pass transversely through the material of the heel. The angular lug 143 transmits the vertical pressure component exerted on the recess 196 directly to the heel portion. The screws 144 serve, therefore, merely as fastening means and do not have to transmit any force so that there exists no danger of the fitting 106:: being torn from the heel portion of the boot sole.

For attaching the binding, the selector lever 116 is initially swung into the position 11 adjacent the pivot pin III. Then, the lever 11% can be moved by placing a finger in the opening 146, and in this regard, at the same time, the finger can press on the cheek 10% of the pressure member thereby forcing the pressure member 163 in the direction of the heel, so that with the raising of the lever 11th, the end 1138a of the member 1113 engages the recess 106 of the heel fitting, whereby the binding is fully attached.

As shown in FIG. 9, the binding presses vertically upon the heel portion with a force of about 3 kg., and if'the skier in climbing or cross-country skiing lifts the heel up from the ski, then the lever 116 will swing upward and the two springs 11% become tensioned. .As apparent from FIG. 5, in such regard the force k of the two springs 118 acts upon small lever arm l If the spring shoes 137, 138 were not provided, the vertical force component acting on the heel portion would have a path such as is shown at a in FIG. la and in FIG. 9. As already described, in connection with FIG. 1a, the force rises only relatively flatly along the curve a up to the unstable point III. It is assumed in connection with FIGS. 5 and 6 that the skier desires clear indication he is approaching the unstable point 111 and hence the releasing point of the binding and this is obtained by the spring shoes 137, 138. The effect of the spring shoe can be seen in FIG. 7. As soon as the heel portion 7 is raised about 2 centimeters from the ski the leg 138 of the spring shoe 137 abuts against the spring 118 and presses the spring with a further swinging of the lever 110 in an intermediate zone between its two suspension points increasingly out of its stretched position so that the spring force now increases more rapidly and moreover engages a lever arm which becomes increasingly larger. The result is that the vertical pressure component exerted by the member 108 upon the heel portion 7 takes the course [1 In that course, the force increases flatly at first and then, when it approaches the releasing point, increases more steeply until, at about 6 cm. of the lift path of the heel, it reaches releasing point III" with 50 kg. Thus, if the skier, for example while falling forward, pulls the heel upwardly with a tension force of more than 50 kg, the heel, after exceeding a path of 6 cm., will automatically be released from the binding.

If the skier desires to make a downhill run, he places the selector lever 116 into the position I. In such position, the spring force k acts on the lever arm l and as seen in FIG. 9, the heel portion is held on the ski with a force of 30 kg. Now, if the skier falls forward, for example if he hits an obstacle or gets into deep snow, the heel portion will be jerked upward. As explained in connection with FIG. la, in such a case the vertical pressure k component increases at first toward the line b, until after a very short lift path of only about 2 cm., the lever 110 with the selector lever 116 has reached a position in which the upper suspension point 133 of the spring 118 lies in the extension of a line between the suspension point 119 of the spring and the pivot point 115 of the selector lever. When such unstable point is passed, the spring 118 pulls the selector lever 116 into the position 11. Thus, after the vertical pressure component has, with a lift path of 2 cm., attained about 100 kg. at point IV, which is assumed in the selected example as the maximum admissible stressing of the Achilles tendon, the pressure component tending to press the heel upon the ski will drop oif suddenly to about 5 kg. at point V and, if the fall forward continues further, will rise again to about 50 kg. at point 111" at a lift path of about 6 cm. before the heel portion will be released from the binding. It is apparent from the above that in a fall forward a tension force of 100 kg, respectively 30 kg, on the Achilles tendon can never be exceeded. The assumed maidmum force of 100 kg. is set with respect to an experienced skier, and for skiers of normal constitution and for children, the springs 118 are exchanged for weaker springs.

In order that, with the lifting of the heel portion from the ski and a fall forward, the unstable position corresponding to point 1V shall be exceeded safely and quickly, the pressure member 1% is provided with a nose portion 1030 which coacts with the front edge 1160, for pressing the selector lever positively beyond the unstable position.

In FIGS. 10 and 11 there is illustrated the details of a ski safety binding constructed according to the principle explained in regard to FIG. 3. In this embodiment, base plate 212 is slidable longitudinally of the ski in a guide plate 252 mounted on the ski 1 by screws 251. A threaded socket 293 is welded to the base plate for the reception of a locking screw 2114. The screw 204 is provided with a pointed end which can engage one of the conical recesses 295 in the guide plate 252 for fixing the base plate 212 in a definite position relative to the guide plate 252. By virtue of this arrangement, the ski safety binding can be adjusted at a variable distance from the customary toe clamp mounted in front of the boot and can thereby be adapted to boots of different sizes. Bracket 213 mounted on the base plate 212 is provided adjacent the top with a slot 231 which forms a fork adapted to engage the lever 211 which is pivoted to the bracket 213 by a pivot bolt or pin 211. The strongly designed lever 21% is provided at its end with a bore in which is mounted pivot pin 209 of a pressure member 208, and the pin 2 .39 is in the form of a hollow cylinder. The pressure member 208 is provided with a slot 255 so that the upper end is shaped in the nature of a fork. At the lower end of the member 2113 is formed a cylinder 2418:: having a transversely extending axis which cylinder is adapted to engage correspondingly formed recess 2% of the heel fitting 2116a.

The lever 21! is of arcuate configuration, with the convex edge being downward. A fork-shaped selector lever 216 is swingably mounted to the lowest point of the lever 210 by a pivot pin 215. The lever 216 is formed at its outer end with a transversely extending U-shaped recess 216a, in which is positioned the central part of a U-shaped bolt 217. Each of the two legs of the bolt 217 is provided with a thread 217a and is threaded into a threaded socket 256. The socket 255 is formed with an exterior thread conforming to the convolutions of the helical spring 213 and defining the upper mounting component for the suspended spring 213. The uppermost convolutions of the spring are threaded about the socket with a radial pretensioning. Each spring 218 is provided at its lower end with a hook 235 which engages an eye 219 secured to the base plate 212.

t a point located between the ends of the spring 218, a stiff cable 226 is passed between two adjacent convolutions, with the end of the cable extending into the sprin The end of the cable is provided with a bulge or protuberance 226a which may be soldered or pressed onto the cable end. The bulge prevents the end of the cable from being withdrawn between the convolutions of the spring 1b 218. The cable 225 extends from one spring 213 through an aperture 223 in the pressure member 2133 to the spring 218 on the other side of the binding. The cable 226 tends to straighten and thus swing the pressure member 208 in a direction toward the heel portion 7. Instead of a relatively stiff wire-strand cable, it is possible, for example, to employ a chain composed of two links. In such situation, the movement of the pressure member in the direction of the heel portion can be eifected by means of a torsion spring which tends to force the pressure member away from the lever forward toward the heel portion.

A flange 258 extends upward from the forward end of the base plate 212 and includes a slot 259 which widens out somewhat toward the top. The flange 258 can be curved so as to adapt itself to the contour of the heel portion of the boot. The fitting 206a which is secured to the heel portion 7 fits into the slot 259. The function of the slot 259 is for maintaining the heel portion 7 firmly centered on the ski during tilting of the ski and during the so called Wig-wagging, against the strong lateral force active during those conditions. In addition, the slot 259 assures that the heel, after it has been raised, will always return into the central position on the ski, and any lateral play still existing is automatically eliminated thereby.

In lieu of the heel fitting 2%a, or in addition thereto, another part of the binding, such as the pressure member 2% or the lever 21%, can be guided laterally, by providing two guide rails projecting vertically upward from the base plate with each guide rail coacting with a side face of the respective part. More particularly, as shown in FIG. 4, the flange of eye 19 extends upwardly as shown at 19a with the upwardly extending component having a slot in which the pressure member $51 is guided laterahy. Hence, the slot of the component 1% constitutes vertically extending rails for guiding the pressure member.

\Vhen the binding is to be attached, the selector lever 216 is initially swung into the position shown in FIG. 10. After the ski boot has been positioned with the toe of its sole under the torsion toe clamp mounted forward on the ski, the heel portion 7 is lowered, as indicated by arrow 257. During this action the pressure member 263 is pressed rearward against the spring action of the cable 226. The fitting 2426a engages the slot 259 in the flange 253 and is thus placed automatically into a central position on the ski. 'When the heel portion rests on the ski, the pressure member 208 occupies the position directly behind the heel fitting 2 35a, as shown in full lines in FIG. 12. To hook the binding, i.e., to place the cylinder Zilba into the recess 2th; of the fitting Ellen, it is merely necessary for the skier to pull on the latch strap 26% whose lower loop passes through hollow pivot pin 2139 serving as a hinge pin for the pressure member With the pulling upward of the lever 21% by means of the latch strap 26%, the pressure member 2% is pressed forward through the spring action of the cable 226 as soon as the cylinder 283a has been raised above the recess 2%. The skier merely has to release the latch strap 26%, whereupon the cylinder 292 a, engages the recess 29% whereby the attachment of the bindin is completed. The latch strap 2-56 is attached to the boot in the customary manner by means of a strap 261, as is shown in FIGS. 13-15.

in order to be able to make the hold-down force acting on the heel somewhat stronger or weaker, as desired, for climbing, the tension of the spring 213 can be changed by the adjustment of the threaded socket 256 along the thread 217a. For this purpose, the U-shaped bolt 217 is first lifted from the recess 216a and then the hooks 235 are released from the eyes 219. After the adjustment, the remounting is accomplished by the reversal of the above steps.

The mode of operation of the binding of FIGS. 10-12 is the same as described with reference to FIG. 3. The diiference from the PEG. 3 embodiment consists only in that a special spring 21a is provided for pulling the presselector lever 21% swung into the downhill position.

ber.

7 l1 sure member 8 downward at the last part of its travel, while in FIGS. l()l2 a special spring is not present. The eifect of the spring 21a in FIG. 3 is obtained in FIGS. l12 by the lateral deflection of the spring 218.

In FIG. 13, the safety binding is illustrated wtih the In this position, the pressure member 2% is held onto the ski with a force corresponding to the point I in PEG. 3a.

The position of the heel portion 7 in FEG. l4 corresponds to the point IV in FIG. 3a, in which the connecting line between the suspension points of the spring 218 passes through the pivot point 215 of the selector lever.

The position of the heel portion 7 in FIG. 15 corresponds to a point directly below the releasing point 111, in FIG. 3a. The position of the heel portion 7, shown in FIG. 15 is the highest position at which the cylinder can still engage the recess 2%. In this position, the rim of the recess 2% extends into notch 23817 in the pressure member 2498 above the cylinder 2498a. Beyond this position, the recess 2% moves along path 225 and the cylinder 2984: along path 22 and the same separate, at which time the heel portion is released from the pressure mem- It can also be seen in FIG. 15 that in this position of the heel portion, 7, the cable 226 has bent the springs 213 forward, with the lateral deflection of the springs 218 corresponding to the tensioning of the spring 21a in FIG. 3.

The invention is not to be confined to any strict conformity to the showings in the drawings but changes or modifications may be made therein so long as such changes or modifications mark no material departure from the spirit and scope of the appended claims.

I claim:

1. A safety binding for holding a ski to a boot, including means for holding the toe of the boot to the ski, pressure means adjacent the rear of the boot and above the ski adapted to engage and press upon the heel of the boot, lever means pivotally mounted to the ski to lie above the ski and swingable in a vertical longitudinal plane, means pivotally mounting the pressure means'to the lever means for swinging movement in the same plme as the lever means, a selector lever pivotally mounted to one of said means and movable between a position nearer the pivotal mounting of the lever means to the ski and a position remoter from the pivotal mounting of lever means to the ski, spring means operably coupled at one end to the selector lever and at the other end to the ski, the pivotal mountings of the selector lever being so disposed that said spring means loads the selector lever when the selector lever is in the position remoter from the pivotal mounting of the lever means to the ski for a downhill run with said pivotal mounting of the selector lever passing across a line extending between the coupling points of the spring means to the selector lever and the ski when the heel of the boot being raised from the ski exceeds a predetermined distance whereby the selector lever upon exceeding such predetermined distance automatically moves to the position nearer the pivotal mounting of the lever means to the ski for climbing and cross-country travel with said pressure means pressing upon the heel with lesser pressure in such latter position.

2. A ski binding as claimed in claim 1 wherein said selector lever and pressure means are constructed and arranged so that said pressure means forcibly moves the selector lever from the position remoter from the pivotal mounting of the lever means to the ski to a point beyond the dead center position when the heel of the boot is raised a predetermined distance from the ski.

3. A ski binding as claimed in claim 1 further including means operably coupled with the pressure means for limiting the free swinging movement of the pressure means in upward direction.

4. A ski binding as claimed in claim 3 in which said limiting means includes an elastic component secured i2 to the pressure means at a point between the pivotal mounting of the pressure means to the lever means and the point of engagement of the pressure means with the heel of the boot, with said elastic component serving to urge the pressure means in a direction towards the ski.

5. A ski binding as claimed in claim 4 in which elastic component in its untensioned condition is of such length that said component begins to transmit a force upon the pressure means only when the boot heel has been raised from the ski a predetermined distance.

6. A ski binding as claimed in claim 5 including a movement transmitting member attached to the pressure means and having its free end connected laterally within the spring means at a point located between the ends of the spring means for deflecting the spring means laterally.

7. A ski binding as claimed in claim 6 including a relatively stiff member which tends to swing the pressure means in a direction towards the boot heel so long as the elastic component is untensioned.

8. A ski binding as claimed in claim 1 including a base plate on the ski rearwardly of the boot with said base plate adapted to support the lever means and the other end of the spring means, a vertical flange at the forward end of the base plate and provided with a curved surface adapted to conform to the contour of the boot heel, said flange serving as a rear support for the boot heel and having a slot which is of wider dimensions adjacent the top thereof, and a fitting on the heel of the boot for engagement by the pressure means with said slot receiving said fitting.

9. A ski binding as claimed in claim 1 in which said spring means includes a helical spring positioned on each side of the selector lever, a cap threaded into the uppermost convolutions of each helical spring, a U-shaped member extending transversely of the ski at the upper end of the selector lever and each leg of the U-shaped member threadedly engaging each cap, a pair of eyelets on the ski, and a hook adjacent the lower end of each helical spring for engaging each eyelet with said U-shaped member maintaining the helical springs under tension.

10. A ski binding as claimed in claim 1 including a shoe on the lever so arranged that when the selector lever is in the position adjacent the pivotal mounting of the lever means to the ski, the spring means is deflected laterally for increasing the lever when the boot heel is raised from the ski a predetermined distance.

11. A ski binding as claimed in claim 1 including vertically extending rails for guiding one of the means of the binding.

12. A safety binding for holding a ski to a boot, including clamp means on the ski for holding the toe of the boot, a base plate secured to the ski rearwardly of the boot, a vertical support on the base plate, a lever pivotally connected to the support adjacent the upper end thereof for swingmg movement in a vertical longitudinal plane, a vertical flange at the forward end of the base plate and provided with a curved surface adapted to conform to the contour of the heel of the boot, said flange serving as a rear support for the boot heel and provided with a slot therein, a fitting on the boot heel received by the slot, pressure means adapted to engage said fitting, means pivotally connecting the pressure means to the free end of said lever for swinging movement in the same plane as the lever, a selector lever pivotally connected adjacent its lower end to said lever intermediate the ends of said lever and movable between a position adjacent the pivotal connection of the lever to the verti cal support and a position adjacent the pivotal connection of the pressure means to said lever, a helical spring positioned on each side of said selector lever, a cap threaded into the uppermost convolutions or" each helical spring, a U-shaped member extending transversely of the ski at the upper end of the selector lever and each leg of the U-shaped member threadedly engaging each cap, a pair of eyelets on said base, and a hook on the lower 13 end of each helical spring for engaging each eyelet with said U-shaped member maintaining the helical springs under tension, the arrangement being such that the helical springs load the selector lever when the selector lever is in the position adjacent the pivotal connection of the pressure means to said lever with the pivotal connection of the selector lever to the said lever passing across a line extending between the center line of the crosspiece of the U-sl aped member and the connections of the springs to the eyelets when the heel of the boot being raised fiom the ski exceeds a predetermined distance whereby the selector upon exceeding such predetermined distance automatically moves to the position adjacent the pivotal mounting of the lever to the vertical support and with the pressure means pressing upon the heel fitting With lesser pressure in such latter position.

References Cited in the file of this patent UNITED STATES PATENTS 2,396,373 Henrichsen Mar. 12, 1946 2,610,861 Campbell Sept. 16, 1952 2,823,922 Berlenbach Feb. 18, 1958 2,851,278 Berlenbach Sept. 9, 1958 FOREIGN PATENTS 171,853 Austria July 10, 1952 1,206,878 France Aug. 31, 1959

Claims

1. A SAFETY BINDING FOR HOLDING A SKI TO A BOOT, INCLUDING MEANS FOR HOLDING THE TOE OF THE BOOT TO THE SKI, PRESSURE MEANS ADJACENT THE REAR OF THE BOOT AND ABOVE THE SKI ADAPTED TO ENGAGE AND PRESS UPON THE HEEL OF THE BOOT, LEVER MEANS PIVOTALLY MOUNTED TO THE SKI TO LIE ABOVE THE SKI AND SWINGABLE IN A VERTICAL LONGITUDINAL PLANE, MEANS PIVOTALLY MOUNTING THE PRESSURE MEANS TO THE LEVER MEANS FOR SWINGING MOVEMENT IN THE SAME PLANE AS THE LEVER MEANS, A SELECTOR LEVER PIVOTALLY MOUNTED TO ONE OF SAID MEANS AND MOVABLE BETWEEN A POSITION NEARER THE PIVOTAL MOUNTING OF THE LEVER MEANS TO THE SKI AND A POSITION REMOTER FROM THE PIVOTAL MOUNTING OF LEVER MEANS TO THE SKI, SPRING MEANS OPERABLY COUPLED AT ONE END TO THE SELECTOR LEVER AND AT THE OTHER END TO THE SKI, THE PIVOTAL MOUNTINGS OF THE SELECTOR LEVER BEING SO DISPOSED THAT SAID SPRING MEANS LOADS THE SELECTOR LEVER WHEN THE SELECTOR LEVER IS IN THE POSITION REMOTER FROM THE PIVOTAL MOUNTING OF THE LEVER MEANS TO THE SKI FOR A DOWNHILL RUN WITH SAID PIVOTAL MOUNTING OF THE SELECTOR LEVER PASSING ACROSS A LINE EXTENDING BETWEEN THE COUPLING POINTS OF THE SPRING MEANS TO THE SELECTOR LEVER AND THE SKI WHEN THE HEEL OF THE BOOT BEING RAISED FROM THE SKI EXCEEDS A PREDETERMINED DISTANCE WHEREBY THE SELECTOR LEVER UPON EXCEEDING SUCH PREDETERMINED DISTANCE AUTOMATICALLY MOVES TO THE POSITION NEARER THE PIVOTAL MOUNTING OF THE LEVER MEANS TO THE SKI FOR CLIMBING AND CROSS-COUNTRY TRAVEL WITH SAID PRESSURE MEANS PRESSING UPON THE HEEL WITH LESSER PRESSURE IN SUCH LATTER POSITION.