Patent GB-214000-A (GB)
Title: Improvements in or relating to inter-connecting arrangements between groups of switches in automatic or semi-automatic telephone systems
IPC: H04Q1/16
Filed: 1923-01-15
Abstract: 214,000. Automatic Telephone Manufacturing Co., Ltd., (Automatic Electric Co.). Jan. 15, 1923. Automatic exchange systems; selectors.-Relates to systems for multipling the bank cables of selectors and connecting them to trunks leading to subsequent switches, and to a distributing frame for enabling this to be carried out easily and in a readily alterable manner. As shown, Fig. 1, twelve shelves of selectors A - - L are mounted in a frame comprising three uprights of which two 46, 47 are shown, the third being behind the upright 45. A " shelf is a row of ten selectors, the banks of which are multipled. A similar collection of switches is arranged parallel to and behind that shown but facing the other way, and the distributing frame, Fig. 2, is arranged between uprights 48, 49 across the space between the two sets of switches. The frame comprises a horizontal row of terminal blocks for each shelf of selectors associated with it. Each row contains ten blocks, one for each level, and each block has ten sets of three terminals arranged as shown in Fig. 3, corresponding to the terminals in that level of the selectors. The terminal blocks are preferably moulded round the terminals and are secured between bolts 65 by means of the grooves shown in Fig. 6 so as to be readily removable. Fig. 7 shows one of the terminals. The two grooves shown are for connecting jumper wire to an outgoing trunk and for making the connection from the terminal banks of the selectors. The other end of the terminal is flattened and divided into three portions, the central portion being bent away from the others, and is for multipling different shelves by means of straight bare jumper wire as shown in Fig. 3. In the upper part of the frame are arranged a number of terminal blocks, the terminals of which are connected to outgoing trunks or to the cables going to corresponding terminals in other distributing frames. Fig. 11 shows an arrangement for cases in which the selectors are of larger capacity than 100 lines, the distributing frame being arranged in three sections forming three sides of a rectangle instead of on a single flat panel. The Specification describes the connections of the frame in a grouping arrangement in which ten outgoing trunks are associated with different numbers of shelves of switches in different levels according to the traffic requirements. The tie cables enable a number of shelves associated with one frame to be grouped with shelves associated with another not necessarily adjacent frame. In another system the connections of which for one level are described the shelves are grouped in sets of four, each group having five trunks individual to it associated with the first five terminals of the selectors, and five trunks in common with eleven other shelves, connected to the remaining terminals. To level up the traffic in the individual trunks alternate shelves have their first five terminals on the frame reversed, i.e. the fifth terminal is multipled to the first trunk, the fourth to the second, and so on.