Patent GB-197983-A (GB)
Abstract: 197,983. Gledhill, A. H. Dec. 13, 1921. Cash registers; zeroizing-mechanism. - In a differentially-set and independently operated machine of the kind having a detachable zeroizing key, the setting slides which also carry the type are set, on zeroizing, so as to print the complement of the total. The invention is shown applied to a machine such as that described in Specification 19318/09. The zeroizing key is placed on the shaft b having a worm b<1> gearing with a wheel b<2> on the zeroizing shaft a which carries the adder wheels A. A complete rotation is imparted to this shaft a during which it picks up the adder wheels and returns them to zero, the adder wheels carrying with them slides C, the upper surfaces of which bear cash columns and the lower surfaces the type numerals. A comb D, Fig. 7, which arrests the adder wheels at zero, is normally held out of the path of pins a<1> on the adder wheels by a pin d engaging a lever d', Figs. 7 and 14, pivoted on a plate E which is pivoted to the adder frame at e. The zeroizing key depresses the plate E so that the lever d' is raised and a spring pulls the comb D into contact with portions a<2> of the adder wheels so that it engages the pins a<1> when they arrive at zero position. After zeroizing, the key is withdrawn, a release lever F is pulled forward and the cycle of operations completed as in the prior Specification. As the adder is lowered it causes a pin d<3> which holds the plate E in its depressed position by resting on the end of lever d', to move to one side of this lever, whereupon a spring d<4> returns the plate E to its upper or normal position, Fig. 7, a pin e' on the plate E coming to rest against a bracket b<3>, Fig. 13, and the pin d being depressed by the lever d' to withdraw the comb D. During ordinary operations the zeroizing shaft a is locked by a tooth h on a member H, Fig. 12, engaging a notch h<1> in a collar h<2> fast on this shaft. When the plate E is depressed by the zeroizing key, a trigger lever h<3>, Figs. 7 and 12, on the plate E lifts a pin h<4> on the member H so that the tooth h is lifted from the notch h<1>. During this movement the lever h<3> is moved past the pin h<4> and to the right and a spring pulls the member H down so that the pin h<4> locks the lever h<3> and holds the plate E in its depressed position. A spring-controlled tumbler lever J, Fig. 12, prevents the tooth h re-engaging the notch h<1> before the shaft a has turned a complete revolution. The plate E is prevented from being actuated should the zeroizing key be inserted a second time before the machine has been operated, the amount printed and the printing slides returned to zero, by the lever d' which is kept raised by the pin d<3> which is mounted on a frame 51 pivoted at 46, Fig. 4, and operated by the cams 44, 44a as described in Specification 19318/09. To prevent the releasing lever F being pulled forward before the zeroizing key has been withdrawn, this lever passes through a slot in a keyhole plate K, through which the zeroizing key projects to engage the shaft b. When the lever F is pulled forward a latch f, Fig. 2, falls into engagement with a tooth f<1> which prevents the return of this lever until it has been pulled to the end of its stroke to disengage the catch plate 32 from a pin on the cam 30, in which position) the latch f engages a tooth f<2>. The main operating handle of the machine can now be turned and during its movement a cam lifts the latch f so that the plate K and lever F are returned to normal position. A ratchet wheel on the zero. izing shaft prevents the zeroizing key being turned in the wrong direction and a hook M on the member H, Figs. 7 and 12, engages a pin m on an arm m<1> rigid with the lever F so that the latter is locked as long as the member H is kept raised by the tooth j resting on the collar h<2>. In this manner the machine is locked against a second operation until the first operation is fully completed.