Patent GB-1514492-A (GB)
Title: Electrical ski boot release
IPC: A63C9/088
Filed: 1975-05-07
Abstract: 1514492 Ski-bindings N F D'ANTONIO and R L BATES 7 May 1975 [7 May 1974] 19145/75 Heading A6D [Also in Divisions E1 E2 and G1] Electrical means function automatically to release a ski binding when dangerously high and/or prolonged forces exist between the ski and the skiers boot. The forces may be downward forces exerted by the toe and/or heel regions of the boot on the ski, the torque imposed by either the boot or the ski on the other, or the forward force exerted by the boot on the ski. The forces are sensed by either strain gauges, magnetoresistive devices, combinations of light emitting diodes and photodetectors secured respectively to relatively movable parts of the ski/binding, devices which conduct electricity when subject to mechanical force, or piezo electric devices. The electrical outputs from the force sensing devices are fed to circuits, Figs. 13-18 (not shown), abridgment Division G1, where they are amplified and summed. If the sum exceeds a relatively high value for a relatively short time or exceeds a relatively lower value for a relatively longer time measured by the integral of the sum with respect to time, the circuit produces an output signal to operate a device for releasing the binding. The release device may be a solenoid, a combination of electro- and permanent magnets, or an explosive cartridge. Means for adjusting the critical force/time values which trigger the release device may be provided. First embodiment, Figs. 1-3. Pivotal movement of an arm 88 from a vertical position to the horizontal position shown causes rearward movement of bar 78, formations 80, 82 of which then engage notches 70 formed in clamps 62, the latter then pivoting inwardly about axes 72 so that clamp jaws 68 engage opposite sides of the boot. Arm 88 is held by plunger 114 of solenoid 110. The boot rests on force sensors 124, 126, mounted on a plate 100, itself mounted on ski 50 so as to permit small transverse movements of the front end 106 of the plate relative to the ski. The front end 106 is formed with a rearwardly-extending finger 162, Fig. 3, located with small clearance between projections 158 of plate 140, which is secured to the ski. A sensor 164 mounted on finger 162 detects torque between ski and boot. Second embodiment, Fig. 6. The boot (not shown) carries toe and heel plates 202, 204. The toe plate is engaged with a stud 238 carried by bracket 242, which also mounts a sensor 237 for detecting forward force applied to the ski. Pivoting arm 284 to the latched position shown cams a rod 264 into engagement with the heel plate. The latch arm 302 includes a permanent magnet 314. Energisation of electromagnet 318 causes like poles to repel and thus release the latch. A plate 220 is bonded via elastomeric material 240 to the ski. A web 228 is secured to the ski, extends through a slot in plate 220 and mounts a sensor 236 for detecting torque. Third embodiment, Figs. 9-12. A toe plate 352 is located on stud 354, mounting torque sensor 380, whilst the heel is held by a band 370 held in tension by pivoted arm 386 latched at 398. When the latch is to be released, the output signal from the circuit is used to electrically fire a cartridge 416, the explosive force tripping the latch. A removable case 404 for containing several cartridges and a spent cartridge ejecting mechanism 420 are provided.