Fracturable-key activated control system

摘要

PCT No. PCT/AU86/00337 Sec. 371 Date Aug. 7, 1987 Sec. 102(e) Date Aug. 7, 1987 PCT Filed Nov. 5, 1986 PCT Pub. No. WO87/02810 PCT Pub. Date May 7, 1987.A key activated control unit to be activated by a key having a shank portion and a blade portion, the unit is operated by inserting the key and having the blade portion trigger a switch at a predetermined location. The blade portion is not returnable from that predetermined position, and a key destruction blade is provided to destroy the blade portion once at that predetermined position.