Patent GB-191109142-A (GB)
Title: Improvements in and relating to Telephone Exchange Systems.
Inventor: JENSEN PETER
Filed: 1911-04-12
Granted: 1912-04-12
Abstract: 9142. Jensen, P., [Clement International Engineering Corporation]. April 12. Automatic and semi-automatic exchange systems.- The semi-automatic system described is, apart from the means for making reverting party-line calls and for trunking between automatic and manual exchanges, identical with that described in Specification 7611/11. The claims relate to the operator's circuits and impulse-sending devices ; to the control of the trunk-finding switches which associate the operator's key set &c. with a first-selector trunk appropriated by a calling subscriber; and to the means by which the operator is enabled to effect reverting calls on party-lines and trunk connexions to a manual office. The side - switches usually associated with the selectors and connectors are dispensed with, the operations in the selector trunk circuits being controlled by master-relays which are energized and cut off in succession in the order of operation of the successive switches. The calling lines are divided into groups of 100, each group having a distributing-switch S, Fig. 2, which starts and controls the movement of an idle two-coordinate call-finder S<4>, Fig. 3, to connect a calling line to a first selector S<5>. There are ten firstselector trunks, such as shown in Fig. 3, allotted to each group of calling lines. A second distributing- switch S<2>, Fig. 2, simultaneously starts and partially controls the movement of a two-co-ordinate trunkfinding switch S<8>, Fig. 5, which connects an idle operator's key-set, Fig. 6, to the appropriated firstselector trunk, Fig. 3. A " kick-off " switch S', Fig. 2, prevents the calling line from being tied up by the failure of a defective finder - switch or trunk. The operator sends impulses to control the selector S<5> which finds an idle second selector, if the exchange is a very large one, or it may fasten directly on the terminals of an idle connector S<6>, Fig. 4, serving the group of subscribers to which the wanted subscriber belongs. Further impulses are then forwarded to the connector trunk to select, by means of a switch S<7>, a ringing generator corresponding to the position of the wanted subscriber on his party-line, Fig. 7, and then to set the connector itself on the terminals of that line. The successive operations of the operator's key-set are controlled by a distributing-switch S<3>, Fig. 5. A fuller description of the operations is given in the following paragraphs. Seizure of idle first-selector trunk and operation of its finding-switch S<4>, Fig. 3. When subscriber A, Fig. 2, takes down his receiver, relays R', R<3> are energized in series and ground the test terminals c<25>, c<26> multipled in the banks of the callfinding switches. The relay R<3> and terminals c<26> belong to a group of ten lines, and control the first or rotary motion of the call-finder to bring its wipers opposite the vertical row of bank-terminals corresponding to these ten lines. The relay R' and terminals c<25> are individual to the calling line and control the second or vertical motion of the call-finder. Relay R<3> energizes an indicating-lamp L and a starting relay R', which connects an interrupter I to the stepping-magnet M of a distributing-switch S until the switch-arm ws finds batterypotential on the test-circuit 38 of an idle firstselector trunk, Fig. 3. A circuit is now closed through relay A<5> (which locks up and cuts out the magnet M) and a master relay R<13>, Fig. 3, which locks up and connects an interrupter I to the relay R<18> controlling the rotary magnet M<5>. The callfinder switch S<4> is rotated until wiper w<26> comes into the grounded row-test contact c<26>, energizing relay R<12>, which locks up and puts the interrupter I on to the relay R<19> controlling the vertical magnet M<6>. The switch S' is now stepped vertically until wiper w<25> comes on to the grounded individual test contact c<25>, when relay R<15> is energized and cuts out relays R<12>, R<18>, R<19>. The de-energization of relay R<12> completes a holding-circuit through relay R<15>, wiper w<4>, trunk 4, and relay R<2>. Relay R<2> connects the trunks 3, 4 to the calling line 1, 2, which is now supplied with current over the relays R<15>, R<14>, which remain alive until the release of the connexions. The battery - potential thus established on the multiple terminals c<4>, Fig. 2, guards the line from interference. Seizure of idle operator's trunk and connexion thereof to the appropriated first-selector trunk by trunk-finding switch S<8>, Fig. 5. These operations proceed concurrently with the seizure of an idle first-selector. When relay R<5> is energized as above it energizes relay R", which connects an interrupter I to the stepping-magnet M<2> of a three-armed distributing-switch S<2>. When the switch arm ws<200> comes on to the test-circuit 79 of an idle operator's set, Figs. 5 and 6, it receives battery potential and completes a circuit in series through a relay R<10> (which energizes relay R<9>, which locks up and cuts out the magnet M<2>) and through the master relay R<32>, Fig. 5, of the operator's circuits. Relay R<32> locks up and connects an interrupter I to the relay R<39> controlling the rotary magnet M<13> of the operator's trunk-finder S<8>, which is rotated until the wipers are opposite the vertical row of contacts belonging to the ten first-selectors which serve the group of 100 lines in which the call originated. Wiper w<82> is now on contact s<82>, connected to battery by the arm ws<20> of the distributing-switch S<2>, Fig. 2, and a circuit is closed through relay R<31>, which locks up and transfers the interrupter I to the relay R<40> controlling the vertical magnet M<14>. The switch S<8> therefore steps up vertically until wiper w<84> comes on to contact s<84>, which has been connected to battery by the energization of the master relay R<13> of the switch S<4>, Fig. 3, whereupon a circuit is closed through relay R<30>, which unlocks relay R<32> and cuts out relay R<40>. The operator's circuits are now connected by switch S<8> with the appropriated firstselector trunk, Fig. 3, and thereby with the calling line. As long as the switch S<8> remains in use, the foot-switch F<8> lights the off-normal lamp L<7> and cuts off battery from the test circuit 79, so that the operator tests busy to the distributing- switch S<2>. Release of the distributing-switches S, S<2>, Fig. 2. The engagement of wiper w<83>, Fig. 5, with contact s<83> energizes in series the relays R<34>, Fig. 5, and R<42>, Fig. 3. This leads to the de-energization of relays R<5>, R<8>, R<9>, R<10>, and R<11>, Fig. 2, and of the master-relay R<13>, Fig. 3, and leaves the distributing- switches S, S<2> free to deal with other calls in the group of lines with which they are associated. The energization of relay R<42> also has the effect of cutting-off the calling-line from the subsequent selecting-impulses. Automatic disengagement from defective operator's or selector trunks. A " kicking-off switch S', Fig. 2, slowly advanced by a stepping-magnet M<1>, bas every fourth contact in its two contact-arcs multipled respectively to relays R<6>, R<7>, the remaining contacts being dead. The live contacts in one arc are one in advance of those in the other arc. After the relays R<8>, R<9> have been energized, the arm ws<10> coming on to a live contact energizes relay R<7>, which locks up and closes a preparatory contact in the circuit of relay R<6>. The switch S' must then take at least three steps before the arm ws<11> comes on to a live contact. This interval is sufficient for the complete operation of the first selector's and operator's finding-switches S<4>, S<8>, and for the subsequent release of relays R<9> &c. as above ; but if, owing to defective action of these switches &c., the relay R<9> is still energized when the arm ws<11> comes on to a live contact, a circuit is closed through relay R‹, which energizes the release magnets of the switches S', S<8> and steps forward the switch S to find another first-selector trunk. Operator's signalling-arrangements and key set. Relay R<34> energized as above, supplies current to the night alarm bell N and service meter E, Fig. 5, and to the guard lamp L<2> and line lamp L<3>, Fig. 6. The operator, perceiving the signal, presses her listening key LK, Fig. 6, energizing the listening- relay R13, Fig. 5, which locks up, open-circuiting relays R<34> (which extinguishes lamp L<3>) and R<42>, and connecting her telephone OR over the lines 130, 135 with the trunk 9, 10, Fig. 3. The lamp L<4>, Fig. 6, is energized in parallel with relay R<23>. If the calling subscriber should have hung up his receiver, relay R<14>, Fig. 3, will have been deenergized, and the actuation of relay R<33>completes a circuit from battery, Fig. 3, over contacts of relays R<15>, R", resistance r, trunks 7, 9, line 130, Figs. 3 and 5, wiper w<80>, trunk 131, contact of relay R<33>, through relay R<38> to earth. Relay R<38> connects the tone - test T<t> to the telephone OR notifying the operator, who restores the circuits and switches in a manner described later. Otherwise, the operator ascertains the number wanted and sets it upon her key set, Fig. 6, depressing those keys in the rows K<1>, K<2>, K<3>, which correspond to the figures of the first, second, and third digits, and that key in the row K<4> which corresponds to the position of the subscriber wanted on his partyline. For sending the appropriate numbers of impulses, the keys are multipled as shown in Fig. 6 to contacts d<1>, d<2>, d<3>, &c. of a sending-machine, these contacts being closed periodically by rotary cams D', D<2>, D<3>, &c. during one, two, three, &c. contact closures of an interrupter I By means of a distributing-switch S<3>, Fig. 5, the sets of impulses representing the different digits are successively forwarded to the selective switches over wires 130, 135. First selector S<5>, Fig. 3. Having set up her number-keys, t