Patent GB-371843-A (GB)
Title: Improvements in interconnecting arrangements for use in telephone exchanges
IPC: H04Q1/10
Filed: 1931-01-27
Abstract: 371,843. Automatic and manual exchange equipment. ASSOCIATED TELEPHONE & TELEGRAPH CO., 1033, West Van Buren Street, Chicago, U.S.A. Jan. 27, 1931, No. 2664. Convention date, Feb. 17, 1930. [Class 40 (iv).] The main and intermediate distributing frames are combined in a single distributing frame by providing protector blocks for subscribers' lines on one side of the frame and terminal blocks for trunks to line switches and cables from connector banks on the other side of the frame. Jumpers are run between the line-switch and connector blocks on one side of the frame and between either the lineswitch or connector blocks to the protector blocks on the other side of the frame. A similar arrangement may be provided when call-finders are used. When two offices are housed in the same room one distributing frame may be used for both. When separate frames are used for two offices in the same building, arrangements are made so that when a subscriber changes his office area, he retains his original number. For this purpose, the two frames are slightly extended at one or both - ends to carry tie-cable blocks connected by a cable, jumpers being run between subscriber's protector block and a tie-cable terminal on one frame, and between the corresponding tiecable terminal on the other frame and a connector or line-switch block. Alternatively, a common additional frame is provided where the lines enter the building, the desired connections between a subscriber's line in one office area and the equipment in the other office being made by jumpers on the common frame. The frame may be used in a manual office for making connections between subscribers' lines and conductors leading to the multiple jacks and line jacks. Provision is made for unequal sized groups of line switches with one master switch controlling switches on different shelves and for adjusting the switch frames of selectors on the racks. General arrangement of exchange equipment, Fig. 1. Outside lines come in to protector blocks such as 171 on one side of the main frame MDF on the other side of which are situated bays of line-switches and connectors alternately arranged. On the other side of these bays are arranged bays of first and second group selectors. The frame MDF forms a unitary structure with the switch racks, and the line switch trunks and connector bank cables are brought out to terminal blocks 369, 370 and 333, 334 situated between the switch racks and the MDF frame proper. The bank cables from the line-switches are taken to terminal blocks 115, 122 at the ends of the bays of the first selectors, the bank cables of which terminate on blocks such as the vertical rows 116, 117, 120, 121 between the bays, the terminals of these blocks being grouped by jumpers, and other jumpers being used to connect the groups to blocks in vertical rows such as 118, 119 from which cables 103, 104 run to blocks 131, 138 at the ends of the second selector bays. The bank cables of the second selectors are taken over vertical rows of blocks such as 124 .. 129 to blocks such as 215, 218 at the left-hand end of each connector bay. The switches are mounted back to back in each bay and spare shelves in group selector bays may accommodate test distributers reverting call switches, toll switches, &c. Main distributing frame. The frame proper comprises a floor bar 161, Fig. 3, and uprights 165 connected together at intervals by horizontal bars. The horizontal protector blocks 176 to which the outside lines are connected, are carried on horizontal bars 182 which are secured to bars such as 194, Fig. 3, and 261, 262, 263 and 361, 362, 363, Fig. 1, projecting from the main framework and forming supports for jumpers passing from the connector or lineswitch terminal blocks to the protectors, jumper rings being provided on the main framework. Fanning strips 179, 180 are secured to the bars. The bars such as 262, 362 which come opposite the switch bays are longer than the others and are used to connect the distributing frame to the switch block frames to form a single structure with the switch frames. The frames for the connector and line-switch terminal blocks comprise vertical and horizontal bars, the vertical bars being connected directly to the bars 194, 262, 362 of the MDF and by horizontal bars such as 313, 314 to the switch frames. Jumpers between the connector and line-switch blocks pass over short horizontal bars such as 195 on the main frame, round vertical bars being provided to keep the jumpers clear of the jumper rings. Connector terminals corresponding to subscribers on a party line are taken to a bunching block such as 191 on the MDF the terminals of which are connected together in a group and connected by a jumper to a line-switch terminal and to a protector. Line-switch frames and arrangements. The frame for four bays comprises four pairs of vertical channel bars 306 .. 309, Fig. 3, the bars of a pair being connected by short flat bars and the upper ends of the vertical bars being connected by angle bars. Each shelf comprises two sets of 25 line-switches with room for a master switch in the centre and th two sets in one shelf or two in one shelf and one in the next may be controlled by a master switch. Where a master switch controls sets of switches on different shelves the control shafts of the two sets are linked together. The switches of a shelf are directly carried on a frame comprising bars 331, 332 connected to end bars 333, 334 which are pivoted at their lower ends and detachably connected at their upper ends to the frame so that the shelves may be turned down for inspection. The plates 335 .. 338 serve as bearings for the shaft controlling the plungers of line switches. Removable hinged covers are provided for the shelves, and enclosure of the switches is completed by metal sheets at the sides, top, and bottom of the bay frame. Each shelf is provided with a terminal block 319 and fuse block 320. Connector and group selector frames and arrangements. The bay frame of connectors comprises angle floor irons 201, vertical channels 202 .. 205, a top channel 206 carrying cable guides 222. The switches of a shelf are mounted on pairs of horizontal bars 207, 208 which are adjustably carried on vertical rods 209 secured to brackets 210, 211 on the bay-frame. The shelves may thus be raised or lowered to facilitate inspection of the wiring. Each shelf of 10 connectors and a test connector has a fuse panel 213 and terminal block 215. The group selectors may be similarly mounted. Modified arrangements. The frame MDF may be set away from the switch bays to leave an aisle. In this case, terminal blocks are mounted on the switch side of the frame from which cables are taken in suitable runways to the terminal blocks 333, 334, 369, 370 on the switch bays. The protector blocks may be mounted on a frame near to the point of entry of the cables into the building, cables being run from the protector blocks to ordinary terminal blocks on the front of MDF.