Abstract: A keypad enlarger kit (10) including a front cover plate (22), a plurality of large pushbuttons (24), a cushion pad (26), and a backing plate (28). Keypad enlarger kit (10) is adapted to be mounted to a front panel (15) of a conventional pay telephone (12) in a manner so that large pushbuttons (24) overly telephone keypad (14) and provide larger pushbuttons for selection by a user.

Abstract: A sensor that senses the absence of a high-magnetic permeable coin box (10) that, in its quiescent state, is mounted within a compartment (12) of a coin operated device, such as a pay telephone (14). The compartment has at least one interior surface (16). The sensor includes an electromagnetic switch (20) having two states (open circuit, closed circuit) that affect a signal to an output device (22) when the switch (20) is activated from one state to another. In preferred form, the switch (20) is a reed switch. A magnet (18) normally provides magnetic flux flow to the switch. When the magnetic flux flow is disrupted, the switch (20) changes from one state to another. The switch (20) and the magnet (18) are fixably-connected to at least one surface (16) of the compartment (12).

Abstract: A communications system includes at least two communications units, each communication unit including a transmitter capable of transmitting to the other unit on one or more frequencies, under the control of a mode control unit and wherein acquisition or a locking of frequencies of the two communications units and timing signal recovery is achieved by transmitting signals on a group of predetermined frequencies, the transmission on each frequency being for a predetermined time frame in a sequence which is repeated after n+1 time frames, wherein n is the number of different frequencies to be transmitted by the originating communications unit, and the receiving unit including a receiver operating on one of the predetermined frequencies for n+1 time frames until the receiving unit receives a signal from the originating unit and transmits an acknowledgment signal to the originating unit thus locking the two units on one of the predetermined frequencies such that information, transmission and reception can proceed