Calling aids
AssigneeNational Research Development Corporation
InventorKarl Grossfield
Life of this patent
Estimating the term…
Abstract
A pocket-size portable transmitter in an emergency call transmission system for geriatric persons has an actuator including a simple switch part such as a push button and a simple cover part movable between a normal closed position covering the switch to prevent accidental actuation and an open position exposing the switch for actuation. In a preferred system a plurality of transmitters are inductively coupled with respective receivers distributed to determine separate areas for use of the transmitters, the transmitters producing multi-element code sequence signals to avoid false alarms from outside interference, and the receivers having wired connections to a central alarm indicator assembly.
Claims6
An emergency-call transmission system, comprising:
- a. a plurality of similar indirectly-coupled transmission sub-systems which each include a portable transmitter to be carried by an individual person at risk, and a stationary sited receiver,
- each said transmitter having a housing and an actuator mechanism which includes a switch part and a cover part integrally associated with said housing, said cover part being movable between a first position in which it covers the switch part and renders the same non-actuable and another position in which it exposes the switch part for actuation,
- each said transmitter including a transmission signal generator of multi-element code sequence form,
- each said receiver including a detector for said code sequence of the respective sub-system transmitter, and
- each said receiver being separately located to define an individual zone of effectiveness for said respective transmitter;
- and
- b. a stationary sited monitor unit including a plurality of first call indicators respectively directly connected to said receivers and operable therewith in response to said respective transmitters.
Dependencies are inferred from the claim text.