Patent GB-1251798-A (GB)
IPC: H04M1/274
Filed: 1967-11-14
Abstract: 1,251,798. Repertory diallers. JOSEPH LUCAS (INDUSTRIES) Ltd., and AUTOMATIC PHONE HOLDING CO. S.A. 1 Nov., 1968 [14 Nov., 1967], No. 51726/67. Heading H4K. In a repertory dialler of the type having a plurality of rotatable memory units each comprising a plurality of notched discs separated by notched disc like separators, and a plurality of sensing fingers one engageable with each memory unit, when a push-button associated with a memory unit is operated the associated sensing finger is displaced axially relative to that memory unit against spring action so as to pass over the notched discs of that unit and is then displaced radially towards the memory unit and further resiliently biased in that direction while being released for axial movement. The arrangement shown has twenty memory units 13, ten on each of two shafts 12. The corresponding sensing fingers 16 are mounted five on each of four shafts 14 which are linked for simultaneous rotation. The sensing fingers are keyed for rotation with the shafts and are free for axial displacement therealong. The twenty push buttons 18 are arranged in four rows of five. When a button is depressed an abutment 25 on the key engages one end of a spring 27 which pivots on a horizontal shaft 26 and functions as a bell crank lever. The other end of the spring engages a recess 31 in the mounting of the corresponding sensing finger and displaces that sensing finger along its shaft 14 past the notched discs of its memory unit. During further downward movement of the push button a projection 21 carried on a lower part of the button engages a groove 23 in a bail 20 pivoted on the shaft 14 and causes the bail to rotate on the shaft. The bail is linked to similar bails 20 on each of the other shafts 14 so that all bails rotate together blocking the depression of further push buttons. The shafts 14 are spring biased to rotate with the bails 22 and thus the sensing fingers 16 all move into engagement with their associated memory but only the finger associated with the depressed push button has been displaced relative to its memory unit. As the button nears full depression a solenoid not shown locks the bails 20 in their displaced positions, a motor is started driving via a differential both a dial of a telephone mechanism and the drive of the shafts 12 and the end 28 of the spring 27 rides over the abutment 25 and releases the sensing finger which commences to move axially towards its original position under the action of a spring 17. This motion is stopped as the finger engages each separator disc and the shafts 12 rotate until the sensing finger drops into a notch in the first notched disc the position of this notch characterizing the first digit. At this point the shafts 12 lock and the motor drives through the differential the dial of the telephone. At the end of one revolution the motor circuit is broken and the sensing finger is lifted out of the notch by cams on a shaft driven by the motor. The return of the dial under the normal action of its return spring drives through the intermediary of the differential the shafts 12 through the remainder of a revolution during which time the sensing finger aligns with and passes through a notch in the separator disc so that the next digit can be sent in similar manner.