Patent GB-191402530-A (GB)
Title: Improvements in Telephone Exchange Systems in which the Connections are Established through Electromechanically Controlled Switches.
Inventor: ALDENDORFF FRITZ
Filed: 1914-01-30
Abstract: 2530. Aldendorff, F. Jan. 30. Semi-automatic exchange systems.-In an operator's keyboard controller, the sets of selectiug-impulses are determined by two counting-brushes which operate alternately. The operation of a counting-brush commences immediately the keyboard has been set, and the remaining sets of impulses are determined by the second and first counting-brushes acting alternately under the influence of brush-starting relays dependent fur their action upon a testing or change-over function of the selectors. A brush-starting relay is introduced into the controlling-circuit at the end of each set of impulses, and is operated by an opening of the controlling-circuit by a relay at the selector which is momentarily energized on a testing or change-over function of the selectors. The invention is described as applied to a system in which a calling subscriber is connected through a quick-acting call-finder to an operator's keyboard equipment which has been previously connected to an idle selector trunk, and while the operator is making the required connexion, a slow-acting call-finder associated with the selector trunk makes connexion with the calling line. As soon as the selection of the wanted subscriber is completed, the quick-acting finder is released and, together with its associated keyboard equipment, is connected to a further idle selector trunk for use in setting up the next call. Figs. 1 to 5, which are to be read side by side, show subscribers S2, S14, Fig. 1, connected to terminals of quick-acting callfinders F1 and slow-acting call-finders LV1, LV2. The quick-acting call-finders connect to an operator's position, Figs. 2 and 3, and through a trunk finder, Fig. 4, which is resting on an idle trunk, to a first selector, Fig. 5, and a slow-acting finder LV1, Fig. 1. Connexion through quick-acting call-finder, Figs. 1 and 2. When the subscriber S2 calls, his line relay LTR2 sends a momentary impulse on the starting-wire sl by means of the contacts 4, 5, 6. This impulse passes to the motor magnet Mr of the next idle quick-acting call-finder F1 and starts the finder moving. The movement of the off-normal switch OS connects the magnet Mr over the contact 13 to the interrupter 16, and the brushes a<1>, b<1>, c<1>, d<1>; a<2>, b<2>, c<2>, d<2>, &c. are moved over their contacts pa, pb, pc, pd, &c. Each call-finder is provided with, say, ten sets of brushes each moving over ten sets of terminals, and each set of brushes is provided with a separate test relay p<1>, p<2>, &c. When the test brush c<1> reaches the terminal pc, a circuit for the test relay p<1> is made from the contact 17, contacts 18, 19', &c. of the test relays p<1> p<2>, &c., lead 20, contact 21 of test relay p<1>, winding p<1>, brush c<1>, terminal pc, lead C<2>, relay TR<2>, to earth at contact 3. The relay TR<2> closes a hold-on circuit for itself over the contact 9 and cuts off the line-relay LR<2> at the contacts 1, 2. The energization of the test relay p<1> connects the relay directly to the contact 17 over the contact 22. and shortcircuits part of its winding over the contact 23 so as to make the calling-line test busy. The contact 26 brings the lamp AL into circuit, and the contacts 19, 24 connect the calling-line to the operator's position. While the operator's speaking key 27, Fig. 3, is depressed, a contact 240 energizes a relay 241, Fig. 2, which disconnects the starting-wire sl from the callfinders F1 &c. belonging to the operator's position, and extends it over a lead sll to callfinders at an idle operator's position. Control of group and final selectors by operator. The operator depresses the speaking-key 27, Fig. 3, and enquires, and then sets up the desired number on her keyboard; in the case chosen, the number 4567 has been set up by closing contacts T4, T5, T6, T7. The operation of a thousands, hundreds, &c. key operates common locking-bars to close a circuit for a relay 33 through the resistance 34. The relay 33 completes a hold-on circuit for itself over the contact 37, disconnects the calling-line from the trunk A3, B3 at the contacts 35, 36, and completes the circuit of the motor magnet 39 at the contact 38. The motor magnet 39 steps round the impulse-counting brush 40 over the contacts t1, t2, &c., and also actuartes the interrupter contact which is included in a circuit bridged across the leads A3, B3 by the contacts 44, 43, 51, 50, 49. The leads A3, B3 are also connected through the brushes B1, B2, Fig. 4, and leads A4, A5, Fig. 5, to the selector controlling-relay LO. The relay 63 having also been energized over the leads 60, 64, the relay RR has been brought into circuit and has prepared a circuit for the vertical magnet HM. The interruptions of the circuit of the relay LO at the contact 43 thus cause the magnet HM to raise the wipers ga, gb, gc to the desired level. When the brush 40 reaches the contact t4, corresponding to the depressed thousands key, a circuit is made over the relay 75, brush 40, contact T4, magnet Mt, arm 76, and magnet Mc. The relay 75 opens the circuit of the motor magnet 39 at the contact 41, the magnet Mt releases the thousands locking-bar, and the magnet Mc moves the arm 76 on to the contact 117 of the hundreds row. The relay 75 also places the relay 80 in circuit at the contact 47, and the controlling-circuit being now closed for a prolonged period, the change-over relay OR, Fig. 5, is short-circuited over the contact 73 of the controlling-relay LC, thus bringing the sideswitch magnet S into circuit over the contact 82. The side-switch arms 45, 46, 84, 85, 87, 88, 89, 207 are now moved into their second positions, and the rotary magnet DM is brought into circuit with the interrupter 90. As soon as an idle trunk is reached, a circuit is made over the test relay PR, brush gc, contact 93, and resistance 92 at an idle second selector. The test relay opens the circuit of the rotary magnet and short-circuits part of its winding to make the trunk C6 test busy. An impulse is also sent by the contacts 95, 96, 97 over the lead 98 to the side-switch magnet S, and over contacts 95<1>, 96<4>, 97<1> to the relay 47a. The side-switch arms thus move to their third positions, connecting the trunk A3, B3 to the second selector and cutting out the controlling- relay LC. The impulse in the magnet 47a causes a break in the controlling-circuit over the trunk A3, B3, thus de-energizing the relay 80, Fig. 3. The release of the armature 100 of this relay momentarily closes the contact 101, thus energizing the restoring-magnet 103 for the brush 40 and also energizing the relay 102. This relay locks itself up over the contacts 106, short-circuits the contacts 43, 51 over the contact 103, and completes a circuit for the magnet 110 over the contact 109. The magnet 110 drives the brush 140 and operates the interrupter 50, to send the hundreds impulses in the controlling-circuit, and these impulses operate the second selector in the same way that the thousands impulses operated the first selector. When the brush 140 reaches the contact h5 corresponding to the depressed hundreds key, the relay 114 is energized and opens the circuit of the magnet 110 and closes that of the restoring-magnet 122. The contact 126 brings into the controlling-circuit a relay 125 corresponding to the relay 80, and when the second selector has completed its rotary movement, and a relay corresponding to relay 47a, Fig. 5, momentarily breaks the controlling-circuit, the armature 127 momentarily closes the contacts 128, 129. The effect of this is to de-energize the relays 114, 75, 102 and so to prepare the circuits for the sending of a fresh set of impulses by the movement of the brush 40. The tens and units impulses are sent to the final selector by the brushes 40, 140 respectively in the same way that the thousands and hundreds units were sent to the first and second selectors. When all the impulses have been sent, and the locking-bars have been released, the contact 32, Fig. 2, is closed, and the de-energization of the relay 125 in this case also de-energizes the relay 33 and cuts out the number-controller from the circuit. Release of quick-acting call-finder. When the relay 33 de-energizes, the contact 180 is momentarily closed, thus energizing a relay 181 over the lead 183. The relay 181 closes a circuit for the motor magnet Mr over the contact 186, and disconnects the contact 17 to prevent the call-finder from stopping on another calling line during the return movement. In case the subscriber calls and only talks to the operator, the release impulse is sent on the line 183 by the de-energization of the relay 230. Connexion through slow-acting call-finder. The starting-impulse in the lead sl, besides actuating the magnet Mv, passes along the leads 60, 62 to the motor magnet My of the corresponding slow-acting call-finder LV1. The magnet Mv moves the arms va, vb, vc, vd, ve over their terminals, and when the calling-line is reached, a circuit is completed from the lead 65, Fig. 3, over the contact 25 of relay p1, brush d1, brush vd, lead hd1, and stopping- relay H. The opening of the contact 61 by the relay H stops the movement of the call-finder LVI. The brush ve and lead hd2 are used when a second quick-acting call-finder is taken into use. When the connexion has been set up, and the relay 33, Fig. 3, is de-energized, the closing of the contact 180 completes a circuit for the relay RD, Fig. 2, over the leads 184, 185. The relay RD connects the subscriber's lines through the slow-acting finder and the contacts 194, 195 to the first selector, and the contact 188, 189 of the relay RD connects the subscriber's test relay TR2 to negative potential over the lead 191 and contact 86 of the first selector. The slow-acting call-finder may have more than one set of brushes, but preferably has fewer sets than the quick-acting finder. Connexion of quick-acting call-finder to idle trunk. When the re