Patent GB-230824-A (GB)
IPC: H01H67/16
Filed: 1925-03-09
Abstract: 230,824. Aldendorff, F. March 11, 1924, [Convention date]. Automatic exchange systems; selectors.-Relates to a selector in which the wipers are lifted by a stepping magnet, then whirled round by a spring and then given a rotary stepping movement. Circuit arrangements are described for controlling the selector as a group selector. These include means for preventing the operation of the selector if it is seized and then released without having received any dialling impulses, and means for keeping the busy mark on the selector until its wipers reach normal. Construction of selector. All the parts are secured in position on rods 1, 2. Fig. 1, by means of screws easily accessible from the front. The terminal bank is in four sections. each clamped between arcuate members 13, 14 of iron with holes at their ends whereby they are threaded on the rods 1, 2. The members 13 are secured to the rods by clamps 17, 18 consisting of two hooks and a connecting yoke, the latter having a threaded hole for a screw 19. Top and bottom plates 20, 30 supporting a shaft 29 capable of rotation but not of longitudinal motion are similarly secured to the rods 1, 2. The plate, 20 is additionally secured by means of slots 21, 22, Fig. 4, and screws 23, 24, Fig. 2, by which its position can be adjusted after the clamps 25. 26 have been screwed up. The wiper carriage, Figs. 5 and 6. is made of sheet metal and has an eye 54 arranged to slide along the shaft 29. It is rotated with the shaft 29 by means of eyes 57 - - 60 through which passes a rod 61 screwed at its lower end into a disc 62 secured to the shaft 29 and at its upper end connected to the shaft 29 by an arm 64. The wipers 126 - - 129 are held between a flat plate 130 and an angle piece 131. the latter being screwed to the wiper carriage at 55, 56 &c. The holes in the plate 131 are large enough to allow the position of the wipers to be adjusted. The lifting magnet consists chiefly of an iron framework, Fig. 7, and the rotary magnet of a similar framework, Fig. 8. These frameworks carry the detents, springs, stops &c. and are secured to the rod 2 by hooks 34, 35 and 96, 97 and screws such as 39. Fig. 2. The wiper carriage is first stepped vertically by the magnet 33 which on being energized extends a spring 45 and causes the lifting pawl 43 to engage a tooth on the bar 41. The stroke is limited bv an adjustable stop 42 and by a piece of hard rubber secured at 50, 51. When the wanted level is reached, the clutch magnet 72, Fig. 3, is energized via slip rings 76, 77 and withdraws a member 80 pivoted to the plate 62 from a slot in a ratchet disc 84. The disc is rotatable about the shaft 29 and is connected to one end of a spring 89 the other end of which is connected to a sleeve 85 fast with the shaft 29. The disc is prevented from rotating by a detent 90, and the shaft 29 therefore whirls the wipers until the clutch magnet is released. The wiper carriage is maintained in its raised position after the ratchet 41 leaves the detent 40, by the notched portion 141 which engages a member 28, Fig. 4, secured to the top plate 20. The relapse of the clutch magnet allows the member 80 to enter another slot in the disc 84 and the wipers stop. The rotary magnet 92 now receives impulses to operate the driving pawl 91 and move the disc 84. and therefore the wipers, step by step. Movement takes place at each relapse of the stepping magnet. In its forward position, pawl 91 locks the disc against further forward motion. The tension of the pawl-operating spring is adjustable. Release is initiated by the steady energization of the clutch magnet. The wipers fly round until a member 142 on the disc 62 reaches a stop 143. In this position the bar 141 is clear of the part 28, and the wipers fall to their lowest position. The rotary magnet now receives impulses until the driving spring is fully re-wound, whereupon a cam 124 on the disc 84 engages a cam 123 ou the rotary detent 90 and causes it to be latched by a member 115, Fig. 9, out of engagement with the disc 84. The clutch magnet is now released and the rotary magnet held steadily energized. The spring 95 restores the shaft 29 and therefore the wipers to normal, and a pin 125 on the disc 84 unlatches the detent 90. Circuit arrangements, Fig 10. The selector is tested over wiper 202 and off-normal contact 204, and when the talking wires are switched through impulse relay 206 energizes release relay 212 which shunts the contact 204. The number dials are arranged to send one more impulse than the number dialled. The first relapse of relay 206 energizes change-over relay 222, and if it does not pull up again, relay 212 falls back and the switch is not operated. If dialling proceeds however, reenergization of relay 206 energizes relay 221 and the remaining impulses are repeated to vertical magnet 33. The relapse of the change-over relay 222 energizes the clutch magnet 72 over off-normal contact 231. If the first group of trunks contains an idle one, the clutch magnet is released immediately but otherwise is held over contact 232 and a chain 233 - - 235. Thereafter the circuit of the clutch magnet goes over wiper 220 and arcuate contacts such as 239, and when the arc of a group containing an idle trunk is reached, magnet 72 is released and the wipers come to rest on the first terminals of the group. Relay 246 pulls up in series with the clutch magnet (which does not pull up in the circuit), locks itself and energizes relay 227 which locks up and connects interrupter 249 to the rotary magnet 92. When an idle trunk is reached, switching relay 253 opens this circuit and completes a circuit to hold up the impulse relay after it is cut off from the line. Release is effected bv the relapse of relays 253, 206, 212. Clutch magnet 72 pulls up over 215, 260, 261 and the wipers fly round and drop back. Magnet 92 re-winds the spring in a circuit 249, 250, 251. When the spring is rewound the rotary detent 90 is latched out of engagement with the rotary ratchet, the rotary magnet 92 is energized steadily over 262, the clutch magnet 72 and relay 227 are released at 261 and the returning spring restores the wipers to normal. The detent 90 then re-engages the ratchet and its spring and the off-normal springs are restored to normal.