Teltone Corporation

Raymond Ma

Alexander D Vdolek

Arnold J Koster

Ardell T Dyste

Richard W Soshea

An electronic switch (29) for automatically connecting a subscriber telephone instrument (31a, 31b, 31c, or 31d) to either of two telephone signal paths (27 or 28) is disclosed. Outbound calls are selectively routed to one or the other of the two telephone signal paths, based on the nature of the initial digits generated by the subscriber. Local calls are sent to a local exchange carrier (23a) and toll calls are sent to an inter-exchange carrier (25) via a transmission medium that may also carry other signals, such as cable television or utility energy management signals. In the event the normal path is out of service, outbound signals are sent via the other path. Inbound signals from either path are automatically routed to the subscriber. Signal routing is completely transparent to the subscriber.

Subscriber telephone diverter switch

A switched access emergency (i.e., 9-1-1) telephone system that uses the trunks of a public telephone network (PTN) with the same reliability as a 9-1-1 telephone system that uses a dedicated line is disclosed. The switched access system includes a trunk dial unit (TDU) connected to the central office receiving 9-1-1 calls and a call access unit (CAU) connected to the 9-1-1 public service answering point (PSAP) that the caller desires to contact. 9-1-1 calls to the caller's central office are directed to the TDU, which calls the PSAP via the PTN and the CAU. The TDU captures the automatic number identification (ANI) information associated with the calling telephone and sends the ANI information to the PSAP when requested to do so. During idle periods, the TDU regularly communicates with the CAU via the PTN to determine the availability of the CAU and, thus, the PSAP. The TDU can be programmed to contact one or more secondary PSAPs if a primary PSAP is unavailable. In such embodiments of the invention, the TDU regularly communicates with the CAUs associated with the alternative PSAPs to determine the availability of the CAUs and, thus, their associated PSAPs, if the CAU associated with the primary PSAP has failed, the primary PSAP has failed or no primary PSAP number has been programmed. Alternatively, or in addition, the TDU can be programmed to contact different primary and secondary PSAPs at different times of the day. Regardless of the complexity of the overall switched access system, failure of the TDU to contact one or more of the CAUs creates an audible and/or visual alarm that alerts maintenance personnel to the loss of communication capability.

9-1-1 Switched access system

An offset adapter connector for use with a plug-in device, such as the line (L) relay of an originating register, that allows connections to be made to the terminals of the device and to the terminals of the socket into which the device is normally plugged is disclosed. The offset adapter connector includes an elongate housing having mounted therein, in axially offset positions, a plug and a socket. The connector plug fits into the socket into which the plug-in device is normally plugged and the plug-in device fits into the connector socket. Due to the side-by-side position of the connector plug andsocket, the plug-in device is offset from its normal position. While offset, the plug-in device retains its normal orientation, (e.g., vertical). As necessary, the connector plug and socket are wired together and to a cable suitable for making connections to related electronic circuitry.

Offset adapter connector

A solid state pulsing circuit and an adapter connector for pulsing the counting and register advance terminals of the L-(line) relay of an originating register in accordance with the digit nature of received DTMF signals is disclosed. The pulsing circuit includes a pair of solid state switches adapted to be alternatively actuated and the adapter connector connects the pulsing circuit to the counting and register advance terminals of the line relay without affecting the normal operation of the relay. Complementary MAKE and BREAK signals derived from the serial pulse output of a DTMF receiver operate the solid state pulsing circuit such that the pulsing circuit alternately pulses (opens and grounds) the counting and register advance terminals of the line relay in accordance with the production of pulses by the DTMF receiver. Other relay terminals (i.e., the terminals controlling the slow release supervisory relay adapted to detect the ON HOOK state of a subscriber's telephone) are not pulsed, whereby annoying line clicks are avoided.

Solid state pulsing apparatus for pulsing selected line relay terminals

A circuit for preventing the automatic operation of the time-out portion of a tone-to-pulse converter until after the first DTMF digit is dialed is disclosed. When a calling party goes OFF HOOK, the forward loop current flowing in the tip and ring in leads is sensed. The sensed current creates a binary zero signal that sets a latch circuit. The latch circuit inhibits the automatic operation of the time-out portion of the tone-to-pulse converter until the latch circuit is reset. The latch circuit is normally reset by the first output of the tone-to-pulse converter adapted to create a rotary dial-type pulse. Alternatively, going ON HOOK without creating a DTMF digit resets the latch circuit, as does the occurrence of a rotary dial pulse on the tip and ring in leads.

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Seattle, WA, United States of America

Raymond Ma