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Title: Captured key electrical safety lockout system

Patent ·
OSTI ID:870139

A safety lockout apparatus for an electrical circuit includes an electrical switch, a key, a lock and a blocking mechanism. The electrical switch is movable between an ON position at which the electrical circuit is energized and an OFF position at which the electrical circuit is deactivated. The lock is adapted to receive the key and is rotatable among a plurality of positions by the key. The key is only insertable and removable when the lock is at a preselected position. The lock is maintained in the preselected position when the key is removed from the lock. The blocking mechanism physically maintains the switch in its OFF position when the key is removed from the lock. The blocking mechanism preferably includes a member driven by the lock between a first position at which the electrical switch is movable between its ON and OFF positions and a second position at which the member physically maintains the electrical switch in its OFF position. Advantageously, the driven member's second position corresponds to the preselected position at which the key can be removed from and inserted into the lock.

Research Organization:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
DOE Contract Number:
AC02-76CH03000
Assignee:
Universities Research Association, Inc. (Washington, DC)
Patent Number(s):
US 5463196
OSTI ID:
870139
Country of Publication:
United States
Language:
English