Telephone switching system having call pickup service

Claim 2

In a switching system, a switching network having a line side and trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, a plurality of call pickup circuits each of which is unique to a different one of said groups, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for transmitting a pickup request signal to the pickup circuit for said requesting line circuit, means further responsive to the dialing of said pickup code for initiating a scanning of said trunk circuits, a system controller, means responsive to the scanning of a trunk circuit currently in a ringing condition for transmitting an identification signal to the pickup circuit associated with the called line circuit currently connected to said last named trunk circuit, and means including said last named pickup circuit responsive to the receipt of said identification signal for indicating to said system controller whether said called line circuit and said requesting line circuit are in the same group.

Claim 3

In a switching system, a switching network having a line side and a trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, a plurality of call pickup circuits each of which is unique to a different one of said groups, memory means in each of said pickup circuits, each of said memory means having a normal and a set state, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for switching to a set state the memory means of the pickup circuit for the group of said requesting line circuit, means further responsive to the dialing of said pickup code for initiating a scanning of said trunk circuits, a system controller, means responsive to the scanning of a trunk circuit currently in a ringing condition for transmitting an identification signal to the pickup circuit associated with the called line circuit currently connected by said network to said scanned trunk circuit, and means including the memory means of said last named pickup circuit responsive to the receipt of said identification signal for indicating to said system controller whether said called line circuit and said requesting line circuit are in the same group.

Claim 4

In a switching system, a switching network having a line side and a trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, a plurality of call pickup circuits each of which is unique to a different one of said groups, memory means in each of said pickup circuits, each of said memory means having a normal and a set state, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for switching to a set state the memory means of the pickup circuit for the group of said requesting line circuit, means further responsive to the dialing of said pickup code for initiating a scanning of said trunk circuits, a system controller, means responsive to the scanning of a trunk circuit currently in a ringing condition for transmitting an identification signal to the pickup circuit associated with the called line circuit currently connected by said network to said scanned trunk circuit, and means including the memory means of said last named pickup circuit responsive to the receipt of said identification signal for indicating to said system controller whether said called line circuit and said requesting line circuit are in the same group.

Claim 5

The system of claim 2 in combination with means responsive to an indication that the called line circuit and said requesting line circuit are not in the same group for scanning additional ones of said trunk circuits until a trunk circuit is scanned that is in a ringing condition and is currently connected to a called line circuit in the same group as that of said requesting line circuit.

Claim 6

The system of claim 3 in combination with means responsive to an indication that said called line circuit and said requesting line circuit are in the same pickup group for releasing the network connection between the currently scanned trunk circuit and said called line circuit and for establishing a connection from said scanned trunk circuit to said requesting line circuit.

Claim 7

The system of claim 2 wherein said means responsive to the dialing of a pickup code for switching said memory means to a set state comprises, a register connected to said trunk side, means for detecting the dialing of said pickup code, means responsive to said detection for applying a register call-back signal from said register and through said network to said requesting line circuit, a line scanner responsive to said detection and to the application of said call-back signal for scanning said line circuits to identify said requesting line circuit, and means responsive to said identification for transmitting a pickup request signal from said requesting line circuit to its associated pickup circuit to switch the memory means therein to a set state.

Claim 8

The system of claim 5 wherein said means for initiating the scanning of said trunk circuits comprises, a ringing trunk circuit scanner in said system controller, and means responsive to the reception of said pickup request signal by the pickup circuit of said requesting line circuit for transmitting a signal to said system controller to initiate the operation of said ringing trunk circuit scanner.

Claim 9

The system of claim 6 wherein said means for transmitting an identification signal comprises, means responsive to the scanning of a trunk circuit currently in a ringing condition for suspending the operation of said trunk circuit scanner for a predetermined time duration, means responsive to the scanning of said trunk circuit for applying a trunk call-back signal from said scanned trunk circuit to said called line circuit, means responsive to said suspension of operation and to said trunk call-back signal for causing said line scanner to scan said line circuits to identify said called line circuit, means responsive to the identification of said called line circuit for transmitting said identification signal to the call pickup circuit associated with said called line circuit, and means responsive to the receipt of said identification signal when the memory element of said last named pickup circuit is in a set state for indicating to said system controller that said called line circuit and said requesting line circuit are in the same group.

Claim 10

The system of claim 7 in combination with means responsive to the receipt of said indication that said called line circuit and said requesting line circuit are in the same group for terminating the operation of said trunk scanner, and means effective if said called line circuit and said requesting line circuit are not in the same group for reinitiating the operation of said trunk circuit scanner.

Claim 11

In a switching system, a switching network having a line side and a trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, call pickup circuitry, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for trAnsmitting a pickup request signal to said call pickup circuitry, means in said circuitry for registering an indication of the group number of said requesting line circuit, means further responsive to the dialing of said pickup code for initiating the scanning of said trunk circuits, a system controller, means responsive to the scanning of a trunk circuit currently in a ringing condition and connected to a called one of said line circuits for transmitting and identification signal to said pickup circuitry, and means in said circuitry responsive to the receipt of said identification signal for indicating to said system controller whether said called line circuit and said requesting line circuit are in the same group.

Claim 12

In a switching system, a switching network having a line side and a trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, call pickup circuitry, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for trAnsmitting a pickup request signal to said call pickup circuitry, means in said circuitry for registering an indication of the group number of said requesting line circuit, means further responsive to the dialing of said pickup code for initiating the scanning of said trunk circuits, a system controller, means responsive to the scanning of a trunk circuit currently in a ringing condition and connected to a called one of said line circuits for transmitting and identification signal to said pickup circuitry, and means in said circuitry responsive to the receipt of said identification signal for indicating to said system controller whether said called line circuit and said requesting line circuit are in the same group.

Claim 13

The system of claim 9 in combination with means responsive to the receipt of an indication that said called line circuit and said requesting line circuit are not in the same group for scanning additional ones of said trunk circuits until a trunk circuit is scanned that is in a ringing condition and is currently connected to a line circuit in the same group as that of said requesting line circuit.

Claim 14

The system of claim 10 in combination with means responsive to an indication that said called line circuit and said requesting line circuit are in the same pickup group for releasing the network connection between the currently scanned trunk circuit and said called line circuit and for establishing a connection from said scanned trunk circuit to said requesting line circuit.

Claim 15

The system of claim 9 wherein said means responsive to the dialing of a pickup code for transmitting a pickup request signal comprises, a register connected to said trunk side, means for detecting the dialing of said pickup code, means responsive to said detecting for applying a register call-back signal from said register and through said network to said requesting line circuit, a line scanner responsive to said detecting and to the application of said call-back signal for scanning said line circuits to identify said requesting line circuit, and means responsive to said identification for transmitting said pickup request signal from said requesting line circuit to said pickup circuitry.

Claim 16

The system of claim 12 wherein said means for initiating the scanning of said trunk circuits comprises, a ringing trunk circuit scanner in said system controller, and means responsive to the reception of said pickup request signal by said pickup circuitry for transmitting a signal to said system controller to initiate the operation of said ringing trunk circuit scanner.

Claim 17

The system of claim 13 wherein said means for transmitting an identification signal comprises, means responsive to the scanning of a trunk circuit currently in a ringing condition for suspending the operation of said trunk circuit scanner for a predetermined time duration, means responsive to the scanning of said trunk circuit for applying a trunk call-back signal from said scanned trunk circuit to said called line circuit, means responsive to said suspension of operation and to said trunk call-back signal for causing said line scanner to scan said line circuits to identify said called line circuit, and means further responsive to the identification of said called line circuit for transmitting said identification signal to said call pickup circuitry, said pickup circuits being responsive to the receipt of said identification signal for determining whether the group number of said called line circuit is the same as the group number of said requesting line circuit.

Claim 18

The system of claim 14 in combination with means for terminating the operation of said trunk scanner in response to the receipt of an indication that said called line circuit and said requesting line circuit are in the same group, and means for reinitiating the operation of said trunk circuit scanner in response to an indication that said called line circuit and said requesting line circuit are not in the same group.

Claim 19

In a switching system, a swItching network having a line side and trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for scanning said trunk circuits, means responsive to the scanning of one of said trunk circuits currently in a ringing condition for transmitting a call-back signal from said one trunk circuit and through said switching network to a called line circuit to which said one trunk circuit is currently connected, means responsive to the receipt of said signal by said called line circuit for indicating whether said called line circuit is in the same group as said requesting line circuit, and means responsive to an indication that said called line circuit and said requesting line circuit are in the same group for releasing the network connection between said one trunk circuit and said called line circuit and for establishing a network connection from said one ringing trunk circuit to said requesting line circuit.

Claim 20

In a switching system, a swItching network having a line side and trunk side, a plurality of line circuits arranged into a plurality of groups and connected to said line side, a plurality of trunk circuits connected to said trunk side, a plurality of stations each of which is connected to a different one of said line circuits, means responsive to the dialing of a pickup code at a station connected to a requesting one of said line circuits for scanning said trunk circuits, means responsive to the scanning of one of said trunk circuits currently in a ringing condition for transmitting a call-back signal from said one trunk circuit and through said switching network to a called line circuit to which said one trunk circuit is currently connected, means responsive to the receipt of said signal by said called line circuit for indicating whether said called line circuit is in the same group as said requesting line circuit, and means responsive to an indication that said called line circuit and said requesting line circuit are in the same group for releasing the network connection between said one trunk circuit and said called line circuit and for establishing a network connection from said one ringing trunk circuit to said requesting line circuit.

Claim 21

The system of claim 16 wherein said means responsive to the dialing of a pickup code comprises, a register connected to said trunk side, means in said register for storing dialed digits received from any calling one of said stations, and means in said register for detecting the dialing of a pickup code by any one of said stations.