GB693528A - Data-indicating apparatus - Google Patents

Abstract

693,528. Electric selective signalling system. NATIONAL CASH REGISTER CO. April 16, 1951 [April 22, 1950], No. 8775/51. Class 40 (i) [Also in Groups XVIII and XIX] . An indicator capable of successively displaying a plurality of items is operated by a revolving clutch to move one item position for each revolution of the clutch, a controlling signal causing the clutch to continue operating the indicator until the required indicator item is displayed. The indicator unit comprises, as shown, a drum 25 (Figs. 1, 2) supported between two fixed plates 15, 16, on a shaft 26, one end of which is attached to gears 28, 29. Gear 29 operates an external type wheel 35 through gearing 37, if required. Gear 28 operates through gearing 30, 31, 33, the latter being attached to a shaft 42 driving a cam 43, which co-operates with a roller 44 on a spring urged lever 45. A control lever 48 (Figs. 2, 3) can be engaged by a trip lever 49 in the rest position of the clutch to hold a pawl 46 from engagement with a ratchet 47, which is attached to a gear 50 meshing with a gear 51 driven by a motor (not shown), during the operation of the indicating mechanism. The clutch control magnet 59, when energized, attracts the armature 58 forcing trip lever 49 downwards to release the clutch for operation, the gearing being such that one cycle of cam 43 steps the drum 25 forward by one indicator item. When operated, the armature 58 also presses against a spring blade contact 66 to restore the trip lever 49 when the magnet 59 is deenergized, and to' supply an external indication that the indicator is being set. The shaft 26 carrying the drum 25 passes through a central hole in a commutator 71 fixed to the wall 15, comprising a ring 72 and segments 73, there being one segment for each indicator position. The required indication is obtained by applying to the appropriate segment 73 a more negative potential than to the remainder. A wiper 75 carried by the drum 25 connects the ring 72 to each segment successively, so that a valve 76 (Fig. 6) is normally conducting to energize magnet 59 in its anode circuit until the wiper contacts the negative potential segment, when the magnet 59 is de-energized and trip lever 49 engages control lever 48 to stop the clutch. A further commutator 80 with wiper 81, of similar construction, is also attached to the shaft 26 to provide a read-out means by extending a potential on the ring to a particular segment, for control purposes. The Specification also states that the control signal may be other than a negative potential. Specification 675,946, [Group XIX], is referred to.