Abstract A radio frequency transmitter is adapted to be worn by a worker in a confined space. The transmitter includes a manual switch and a mercury switch which, when tilted by reason of the worker getting out of his normal work position, closes to cause the transmitter to emit a signal which is received by a receiver positioned outside of the confined space. The receiver closes a switch to put the coil of a relay across a power supply. The relay closes two switches, one being an alarm switch which causes energization of a strobe light and a siren; the other establishes a holding circuit by-passing the receiver actuated switch. The holding circuit includes an interrupt switch to turn off the alarm. There is a time delay in the relay circuit to avoid false alarms. Once the alarm is sounded, termination of the radio frequency signal alone will not stop the alarm; the switch in the holding circuit must also be opened.
Apparatus for monitoring the condition of a worker, comprising, radio frequency transmitter having a battery, a position responsive switch adapted to be worn by a worker and responsive to a position indicative of the worker being disabled to cause said transmitter to transmit a signal, a radio frequency receiver including a power supply, a relay, an alarm switch and a holding switch operated by said relay, a power switch operated by said received in response to said signal to connect said relay to said power supply to close said alarm switch and said holding switch, alarm means operated when said alarm switch is closed, a holding circuit including said holding switch, said relay and said power supply, a termination switch operative to break said holding circuit, said relay including a coil which is connected to said power supply through said power switch and through both said holding switch and said termination switch.
Claim 2
Dependent Claim
152 words
Apparatus for monitoring the condition of a worker, comprising, radio frequency transmitter having a battery, a position responsive switch adapted to be worn by a worker and responsive to a position indicative of the worker being disabled to cause said transmitter to transmit a signal, a radio frequency receiver including a power supply, a relay, an alarm switch and a holding switch operated by said relay, a power switch operated by said received in response to said signal to connect said relay to said power supply to close said alarm switch and said holding switch, alarm means operated when said alarm switch is closed, a holding circuit including said holding switch, said relay and said power supply, a termination switch operative to break said holding circuit, said relay including a coil which is connected to said power supply through said power switch and through both said holding switch and said termination switch.
Claim 3
Dependent Claim
18 words
Apparatus according to claim 1 in which said alarm means includes an audible alarm and a strobe light.