73106782
Nov 16, 1976
Feb 20, 1979
INTERCOMMUNICATION TELEPHONE SYSTEM COMPRISING TELEPHONE SETS, HANDS FREE TELEPHONE SETS, WEATHERPROOF TELEPHONE SETS, DOOR INTERCOM UNITS, DOOR BELLS OR CHIMES, FIRE AND BURGLAR ALARM UNITS, ALARM SIGNALS AND SOUNDERS, CONTROL PANELS, TRANSFORMERS, POWER SUPPLIES, AND INTERCONNECTING CABLING AND WIRING
Electrical and Scientific Apparatus