Patent GB-830716-A (GB)
Title: Electrical serial switching mechanism
IPC: H01H67/02
Filed: 1957-12-23
Abstract: 830,716. Actuation of switches; rotary distributers. NATIONAL CASH REGISTER CO. Dec. 23, 1957 [Jan. 15, 1957], No. 39820/57. Class 38 (5). A plurality of switches are successively actuated by a member which is progressively associated with the switches, means being provided whereby this association may be terminated at any desired point. As shown, contact spring pile-ups 94, 95, 96 are mounted on a block 39 with spring-pressed operating plungers 88 projecting into a channel 42 in the block 39. A motor-driven lead-screw 30 is arranged adjacent this channel which is normally divided into upper and lower parts by an exit gate 43 which is rectilinearly movable in a slot in the block. The plungers 88 are actuated by ball-bearings 38 which are fed into the threads of the lead-screw and are then moved along the channel 42 from left to right, Fig. 1, being discharged into a tube 67. This tube is connected to an inlet tube 66 by a resilient tube 76. The entry of the balls is controlled by an entry gate 80, Fig. 5, which comprises a rod having a portion with a concave section which intersects a bore 65 in the block 39. Normally, the rod 80 prevents balls from entering the screw 30, but it is connected by a forked member 83 to a pin 84 rotatable by a solenoid L1, so that the rod can be rotated momentarily to permit one ball to pass. A pin 98 also operable by the solenoid at the same time opens contacts L1b1 to de-energize the solenoid L1. The exit gate 43 is connected by a link 53 to a further solenoid L2, which is energized when it is desired to terminate actuation of the switches by a particular ball, thereby raising the gate and allowing the ball to pass into the lower part of the channel 42 where its subsequent movement by the screw 30 is in a path out of engagement with the plungers 88. The solenoid L2 also controls by a link 58 self-de-energizing contacts L2b1 The tube 67 contains a detent 71 which prevents balls falling back into the exit end of the screw 30. The latter carries an insulating disc 20 with a conducting surface 22 engaged by wipers 23, 24 in series with the solenoid L1 and shunted by an arc-suppressing resistor and capacitor 27, 29, so that the circuit to the solenoid can only be completed during a certain portion of each revolution of the leadscrew, thereby ensuring that a ball will be fed into the space between two parts of the thread without jamming the screw. The contact pileups may be replaced by the arrangement of Fig. 10, wherein each plunger 88 engages a member 112 which carries bridging contacts 122 and retaining springs 123 between transverse pins 114, these contacts co-operating with fixed contacts 110, 111. A modified form of entry gate, Figs. 11, 13, comprises a plunger 154 which is urged to the left against a stop 170 by a spring 151. The left-hand end of the plunger is connected to a lever 148 which is normally movable to-and-fro about its lower end in a slot 147 by balls 143 which are movable in a bore 144 by cams 139, 140. The latter are carried by a shaft 136 connected by 2-1 gearing 134, 135 to the lead-screw. The normal to-and-fro movements of the lever 148 are without effect, but puon energization of a solenoid L1A, a plunger 163 is projected into the slot 147 so as to lock the upper end of the lever 148, which thereupon pivots about its upper end when moved by the balls 143 so that the plunger 154 is moved to the right, Fig. 11, to force a ball 38 past a detent 157 into the lead-screw 30. The cam 140 has a projection 191 which opens contacts 194 corresponding to contacts L1b1 of the first embodiment. A modified form of the exit gate may also be used, Fig. 14, and this comprises a rod 173, similar to the entry gate 80, and having a reduced portion in the channel 178. This gate is also rotatable by a solenoid to permit a ball to pass from the upper to the lower part of the passage. The switch arrangement may be applied to a data-recording system for causing fixed and variable data to be recorded in a programmed sequence. Specification 779,005 is referred to.