71624208
Jan 28, 1952
Mar 17, 1953
ELECTRICAL SUPERVISORY ALARM SIGNALLING APPARATUS WHICH CONSISTS OF AN ENCLOSURE CONTAINING SEVERAL RELAYS, SIGNAL LIGHTS, AND ASSOCIATED WIRING FOR AUTOMATICALLY SUPERVISING INDUSTRIAL-CHEMICAL PROCESSES CAUSING AN AUDIBLE AND VISIBLE ALARM TO BE REGISTERED WHENEVER THE SUPERVISED CONDITION DEPARTS FROM THE NORMAL
Housewares and Glass