Personal alarm apparatus including wrist supported transmitter and receiver/telephone interface circuit

Claim 1

A personal alarm apparatus comprising an alarm signalling device having a casing and strap adapted for ready transport on the wrist of the person, a manually operable switch mounted on the casing and a transmitter responsive to operation of the switch for transmitting a radio frequency alarm signal, and a relay station mounted within a single housing and comprising means responsive to the alarm signal, interface means for connection to a telephone line, means for opening said line and dialling telephone numbers on said line, a memory, means for storing in said memory a plurality of telephone numbers with an order of priority whereby said dialling means can dial each of said numbers in turn, means for transmitting a repeated message on said line and means responsive to a signal on the line for ceasing said message, said interface means comprising; means responsive to a dial tone on said line and arranged such that on detection of said dial tone said numbers are dialled and on failure to detect said dial tone said line is hung up and on three failures to so detect said dial tone said numbers are dialled, means to detect an extension phone on said line off hook and arranged to actuate said transmitting means in response thereto, means responsive to a ring tone on said line and arranged on receipt of a ring tone at any time subsequent to an alarm signal to actuate said transmitting means, and means for counting ring tone up to a predetermined number before actuating said transmitting means, and means for repeatedly checking for a line fault and for indicating a fault when detected.