The present invention relates to ski bindings, and more particularly, to a releasable riser plate assembly especially adapted for use with a Telemark ski binding.
In the ski industry, the term “Telemark” refers to a type of a ski turn wherein the heels of the ski boots are not attached to the skis while conducting the turn. The Telemark style of skiing essentially disappeared with the advent of alpine skiing equipment. Alpine skiing equipment utilizes ski bindings that lock both the heel and toe of the ski boot on the ski.
Cross-country or touring skis typically include the use of soft ski boots and bindings that allow the heel to freely rotate to and away from the ski, while the toe of the boot remains attached to the ski. This free-heel characteristic of cross-country ski equipment enables the skier to conduct a standard walking motion in order to propel the skier. The Telemark turn can be used by cross-country skiers who encounter a downhill slope to be traversed.
More recently, back-country skiing has become popular. Back-country skiers search for back-country ski opportunities including considerable sized downhill slopes. Although cross-country/touring skis are adequate for traversing some downhill areas, attributes of alpine skiing equipment are still preferred by many back-country skiers.
The Telemark ski binding can be considered either a hybrid alpine ski binding or hybrid cross-country binding. More specifically, the typical Telemark ski binding affords the skier greater rigidity with respect to the connection between the boot and the ski as compared to cross-country ski equipment, but the Telemark ski binding allows for some rotational movement of the boot heel. The Telemark binding is a versatile binding that allows the skier to experience freedom both at traditional alpine skiing resorts and in open back-country skiing.
There are a number of prior art inventions directed to ski bindings, some of which are directed to Telemark type skiing equipment. Some examples of ski bindings especially adapted for Telemark skiing include the U.S. Pat. Nos. 6,685,213; 6,623,027; 6,409,204; 6,322,095; 6,299,193; 6,105,994; and 6,092,830.
While the inventions disclosed in these references may be adequate for their intended purposes, there is still a need for a releasable Telemark binding for particular types of Telemark bindings that do not have a designed release feature.
Genuine Guide Gear (G3)™ is a popular commercial Telemark binding. One style of the G3 binding includes two riser or spacer plates mounted to the ski. The riser plates act as a shim or separator which facilitates turning of a ski more easily since the boot is maintained at an elevated position with respect to the ski.
In many circumstances, it is desirable to have a Telemark binding with a specially designed release feature that allows the boot to separate from the ski based upon predetermined forces placed on the binding. Particularly in back-country skiing where there is an avalanche danger, a skier caught in an avalanche without releasable bindings creates a hazard. The ski remaining attached to the boot after the skier is buried in the avalanche results in the ski acting as an anchor preventing the skier from moving, and potentially being freed from the snow. During an avalanche when the snow is in motion, assuming the skier is conscious, the skier freed from his/her skis can perform a “swimming” motion that helps the skier to remain near the surface of the snow. Survivability is enhanced if the skier can make efforts to remain near the surface of the snow.
Releasable bindings in alpine skiing equipment are well known. Although some Telemark skiing is conducted on relatively flat terrain, downhill skiing conducted with Telemark ski equipment favors the use of a releasable binding for safety purposes.
In accordance with the present invention, a ski binding is provided with a releasable riser plate assembly. The releasable riser plate assembly is especially adapted for use in Telemark ski bindings that utilize riser plates to offset the ski boot with respect to the plane of the ski.
In a preferred embodiment of the present invention, the riser plate assembly includes a base plate, a release plate, and a front and rear housing that each include a force transmitting member. The release plate is positioned over the base plate, and is held in place by the force transmitting members of the front and rear housings. A ski brake mechanism is integrated with the riser plate assembly. The toe adapter of the Telemark binding is mounted to the release plate.
The release plate separates from the base plate when a force applied from the boot is enough to overcome the retaining forces of the force transmitting members. With respect to an adequate force generated by the boot at the rear portion of the release plate and directed substantially perpendicular from the plane of the ski, the rear edge of the release plate disengages from the base plate and rear housing. With respect to adequate lateral forces generated by the boot at the front portion of the release plate, the front edge of the release plate disengages from the base plate and front housing. Separation of the release plate from the base plate separates the boot from the ski, and activates the ski brake. Lateral extensions of the ski brake that are normally co-planar with the ski are moved to a non-planar position below the lower surface of the ski causing the extensions to engage the snow, and thereby preventing the ski from sliding freely along the surface of the snow.
In the preferred embodiment, the force transmitting members of the front and rear housings each comprise an adjustable spring that provides a biasing force against a contact member such as a ball bearing. The ball bearing has a portion thereof which is exposed for engagement with the corresponding surface of the release plate. Specifically, the front edge of the release plate engages a front contact member, and the rear edge of the release plate engages a rear contact member. The housings each include an adjustment screw that allows the user to adjust the force generated by the spring which in turn regulates the retaining force for holding the release plate against the base plate. Adjustment of the amount of force desired for retaining the release plate against the housings and base plate can be chosen according to a desired standard to include the Deutsche Institut Fuer Normung (DIN), a known standard in the alpine ski industry for gauging release forces of ski bindings.
In one aspect of the present invention, it can be considered a ski binding including the releasable riser plate assembly. In another aspect of the present invention, it can be considered the releasable riser plate assembly as a subcombination. In another aspect, the invention comprises a method of providing a controlled release of a ski boot attached to a ski by means of a ski binding.
Other features and advantages of the present invention will become apparent from a review of the following detailed description, taken in conjunction with the drawings.
A Telemark binding of the type illustrated in
Referring to
The toe riser plate 24 of the prior art is replaced with the riser plate assembly 40 of the present invention. The remaining parts of the Telemark binding are still used. Accordingly, the base 16 of the toe adapter 12 is mounted over and attached to the release plate 42, as discussed in more detail below.
Referring to
The base plate 44 is substantially flat and extends between the front housing 46 and rear housing 48. The central portion of the base plate 44 has a depression 80 formed therein to receive the ski brake 50, as further discussed below. The front and rear housings each incorporate a force transmitting member. In the preferred embodiment, the force transmitting members are ball detent arrangements wherein a front force transmitting member 70 engages the front edge 88, and a rear force transmitting member 78 engages the rear edge 90. Holes 60 in the front and rear housings allow the housings and base plate to be secured to the upper surface of the ski 28.
Referring also to
The front edge 88 of the release plate includes a dimple or relief 86, and the front force transmitting member 70 is seated within the dimple 86 when the release plate is mounted over the base plate. The rear edge 90 of the release plate includes a channel or groove 84 formed on the rounded protrusion 92. The rear force transmitting member 78 is seated in the groove 84.
Referring to
When a lateral force is transmitted from the boot through the release plate, if the lateral force transmitted is greater than the retention force transmitted by the front force transmitting member, then the release plate is allowed to laterally displace either direction, and the boot separates from the ski.
In order that the release plate 42 may more freely rotate when the adequate lateral forces are supplied, the rear edge 90 includes the channel 84 which allows the rear edge 90 to rotate without undue friction with the rear force transmitting member 78. As mentioned above, the release plate may rotate out of engagement with the base plate in either lateral direction, assuming the lateral forces transmitted are great enough to overcome the retaining force of the front force transmitting member.
As shown in
Referring to
If the release plate has been disengaged thus separating the boot from the ski, the present invention provides a step-in attachment feature for reattachment of the release plate. The user simply reinserts the front edge of the release plate in the gap between the lip 49 and the upper surface of the base plate 44, and then presses the heel of the boot down so that the rear force transmitting member 78 is reseated within the groove 84.
There are a number of advantages of the present invention. Use of a releasable riser plate assembly which incorporates front and rear force transmitting members allows precise control in terms of the activation force required to separate the release plate from the base plate. The adjustment screws provide fine adjustment with respect to the amount of desired force transmitted to the front and rear edges of the release plate. In the event of release plate activation, assuming the binding still remains attached to the boot, the user puts on the ski by simply utilizing the step-in feature of the riser plate assembly. The ski brake is a simple yet reliable component that is easily incorporated within the construction of the base plate. The releasable riser plate assembly takes into consideration the two primary types of forces that should result in release of the boot with respect to the ski, namely, lateral forces, and upward or vertical forces directed from the heel of the boot. However, inadvertent activation of the release plate will not occur by upward or vertical forces directed from the toe of the boot. The force transmitting members can be generally described as ball detents which are simple yet reliable constructions.
This invention has been described in detail with reference to particular embodiments thereof, but it will be understood that various other modifications can be made within the spirit and scope of the invention as claimed.