Dial and multifrequency telephone system employing ringing and lamp flash signalling

Claim 2

A telephone system comprising: a. means for connection to a plurality of rotary dial or tone stations or both, b. a selector switch having a plurality of contact levels, each contact level having A wiper and a plurality of contacts engageable by said wiper, said contacts of each contact level representing the respective digits represented by dial signals received from a calling station, c. said selector switch including a selector control circuit coupled to said means (a) and responsive to receipt of dial pulses received over said means (a) to advance said wipers of each contact level to the contact of each such contact level representing the digit dialled, d. a tone adapter circuit coupled to said means (a) and adapted to receive tone signals, said tone adapter circuit including decoding means having a plurality of outputs representing dialled digits and responsive to receipt of a tone signal by said tone adapter to energize one of said outputs, e. means connecting the outputs of said decoding means to the contacts of a first said contact level of said selector control circuit, f. means connecting said selector control circuit to said decoding means, said selector control circuit operative in response to receipt of a tone signal representing a particular digit by said tone adapter circuit to operate said selector control circuit to advance said selector switch to a position in which said wipers of each contact level engage the contact of each such contact level representing said particular digit, g. means for connection to a source of ringing voltage, h. means for connection to a source of lamp flash voltage, i. means for connecting said means (g) to said wiper of a second said contact level, j. means for connecting said means (h) to said wiper of a third said contact level, k. at least some of said contacts of said second and third contact levels being coupled to respective said subscriber stations.

Claim 3

A telephone system comprising: a. means for connection to a plurality of stations rotary dial or tone stations, or both, b. a selector switch having at least three contact levels, each level having a wiper and a plurality of contacts contactable by said wiper, said selector switch having a home position and being operable to advance said wipers from said home position past said contacts back to said home position, said contacts of each level being associated with respective digits represented by dial signals received from a calling station, c. a selector control circuit coupled between said means (a) and said selector switch for controlling said selector switch dependent upon dial pulses received over said means (a), thus to step said wipers of said selector switch to respective contacts corresponding to the digit dialled, said selector control circuit further including first input means responsive to a predetermined start signal to start stepping of said selector switch and second input means responsive to a predetermined stop signal to stop stepping of said selector switch, d. a tone adapter circuit coupled to said means (a) and adapted to receive tone signals, said tone adapter circuit including an input and a plurality of outputs, and decoding means adapted to connect said input to a selected output dependent upon the digit represented by the tone signal received over said means (a), e. said tone adapter circuit including start means connected to said first input means of said selector control circuit and responsive to receipt of a tone signal by said tone adapter circuit for applying a said start signal to said first input means of said selector control circuit, f. means for connecting a source of said predetermined stop signal to said input of said tone adapter circuit, g. means connecting the respective outputs of said tone adapter circuit to respective corresponding outputs of one level of said selector switch, and means connecting said wiper of said one level to said second input means of said selector control circuit, h. means for connection to a source of ringing voltage, i. means for connection to a source of lamp flash voltage, j. means for connecting said mEans (h) to said wiper of a second level of said selector, k. means for connecting said means (i) to the wiper of the third level of said selector, l. at least some of said contacts of said second and third levels of said selector switch being coupled to respective said subscriber stations so that when a dial pulse representing a digit is received over said means (a), said selector control circuit responds to step said selector switch to a position corresponding to the digit dialled, and when a tone signal representing a digit is received over said means (a), said tone adapter circuit causes said selector control circuit to cause said selector switch to step to a position corresponding to the digit represented by the tone signal received, and in both cases, said ringing and lamp flash voltages are applied to the called station through said contacts of said second and third levels of said selector switch.

Claim 4

A telephone system comprising: a. means for connection to a plurality of stations rotary dial or tone stations, or both, b. a selector switch having at least three contact levels, each level having a wiper and a plurality of contacts contactable by said wiper, said selector switch having a home position and being operable to advance said wipers from said home position past said contacts back to said home position, said contacts of each level being associated with respective digits represented by dial signals received from a calling station, c. a selector control circuit coupled between said means (a) and said selector switch for controlling said selector switch dependent upon dial pulses received over said means (a), thus to step said wipers of said selector switch to respective contacts corresponding to the digit dialled, said selector control circuit further including first input means responsive to a predetermined start signal to start stepping of said selector switch and second input means responsive to a predetermined stop signal to stop stepping of said selector switch, d. a tone adapter circuit coupled to said means (a) and adapted to receive tone signals, said tone adapter circuit including an input and a plurality of outputs, and decoding means adapted to connect said input to a selected output dependent upon the digit represented by the tone signal received over said means (a), e. said tone adapter circuit including start means connected to said first input means of said selector control circuit and responsive to receipt of a tone signal by said tone adapter circuit for applying a said start signal to said first input means of said selector control circuit, f. means for connecting a source of said predetermined stop signal to said input of said tone adapter circuit, g. means connecting the respective outputs of said tone adapter circuit to respective corresponding outputs of one level of said selector switch, and means connecting said wiper of said one level to said second input means of said selector control circuit, h. means for connection to a source of ringing voltage, i. means for connection to a source of lamp flash voltage, j. means for connecting said mEans (h) to said wiper of a second level of said selector, k. means for connecting said means (i) to the wiper of the third level of said selector, l. at least some of said contacts of said second and third levels of said selector switch being coupled to respective said subscriber stations so that when a dial pulse representing a digit is received over said means (a), said selector control circuit responds to step said selector switch to a position corresponding to the digit dialled, and when a tone signal representing a digit is received over said means (a), said tone adapter circuit causes said selector control circuit to cause said selector switch to step to a position corresponding to the digit represented by the tone signal received, and in both cases, said ringing and lamp flash voltages are applied to the called station through said contacts of said second and third levels of said selector switch.

Claim 5

A system according to claim 2 wherein said selector control circuit includes sensing means operative upon receipt by said selector control circuit of a signal indicating an off-hook condition at a said subscriber station; a source of said start signal, and means responsive to operation of said sensing means for coupling said source of said start signal to said start means of said tone adapter to enable said start means.

Claim 6

A system according to claim 3, wherein said selector switch includes a stepping magnet, a homing circuit connected to said magnet for energizing said magnet, said homing circuit containing in series a normally closed interrupter contact which is open when said magnet is energized and a normally open off-normal contact which is closed when said selector switch is is a position other than its home position, said selector control circuit including an operate lead also connected to said magnet to energize said magnet, said first input means of said selector control circuit being connected to said operate lead so that application of said start signal by said tone adapter circuit to said first input means energizes said operate lead thus to energize said magnet, said selector control circuit and tone adapter circuit including cooperating means responsive to receipt of said start signal by said selector control circuit to terminate application of said start signal by said tone adapter circuit to said selector control circuit, thus to release said magnet, whereby to step said selector switch from its home position, said selector control circuit further including means responsive to respect of said start signal to energize said homing lead to cause said selector switch to step past said contacts back toward its home position, said second input of said selector control circuit including means responsive to receipt of said stop signal to de-energize homing lead thus to stop said selector switch when said selector switch reaches a position corresponding to the represented by the tone signal received by said tone adapter circuit.

Claim 7

Apparatus according to claim 4 including means for stepping said selector switch to its home position when a called party answers, such means comprising detector means coupled to said means (a) to detect extra current flowing in said means (a) when said called party answers, and amplifier means coupled to said detector means and responsive to operation of said detector means to energize said homing circuit thus to cause return of said selector switch to its home position.

Claim 8

Apparatus according to claim 5 wherein said means (a) comprises a pair of tip and ring leads coupled to each of said subscriber stations; said detector means comprising a transistor having an output and means coupling said transistor to one of said tip and ring leads for operating said transistor for a first predetermined interval following said increase in current, said amplifier means comprising a second transistor connected to said output of said first transistor, and having an output, and a third transistor connected to the output of said second trAnsistor, capacitor means coupled to said second transistor to maintain said second transistor operated for a second predetermined interval following termination of operation of said first transistor, the sum of said first and second predetermined intervals being longer than the time required for said selector switch to step to its home position, said third transistor including an output adapted to be connected to said homing lead.

Claim 9

A system according to claim 2 wherein said selector switch includes fourth and fifth levels, each containing a plurality of contacts and a wiper; a transfer circuit; means connecting a selected contact of said second level of said selector to said transfer circuit; said transfer circuit including means responsive to receipt of a ringing signal from said selected contact of said second selector level for transferring said means (h) and (i) to the wipers of said fourth and fifth levels respectively of said selector, and for energizing said homing lead to return said selector switch to its home position preparatory to receipt of another dial signal.