Patent GB-169794-A (GB)
Abstract: 169,794. White, A. E., (Burroughs Adding Machine Co.). July 2, 1920. Adding - apparatus;; splitting - machine; zeroizing - mechanism; overthrow-preventing mechanism. - Relates to key set and operated machines of the comptometer class, as described in Specifications 24996/11, 14777/12, and 6/15, and comprises means whereby the numeral-wheels of the totalizer may be zeroized individually for the correction of an error in key depression, as well as collectively for clearing, and means for splitting the totalizer. The mechanism described in Specification 131,109 for collectively disabling the driving-pawls 13, Fig. 1, back-stop pawls 16, and overthrow-preventing mechanism 31, 32, and for setting hooks 2a, 4a to engage stops e, A<3> respectively on the intermediate gear-wheels C and numeral-wheels A, so as to allow the numeral-wheels to turn backwards to zero either positively or under the action of the transfer springs, is modified to permit of the individual or collective action. When a numeral-wheel is to be zeroized individually a corresponding special key 8, 8<a> at the front of the machine is depressed. Further, by pushing the key backwards the numeral wheel is prevented from backward rotation, and the transfer action is dissipated by an idle movement of the gearing, the totalizer then being split. The rook-shaft S connected to the zeroizing-handle in the usual way is provided with a set of fast arms 5 and a set of loose arms 6, the latter set having pins 6a engaged by springs 7, and pins 6<b>, Fig. 1, separately engaging the slots in the hooks 2a, 4<a>. The special keys, except that of the units wheel, are pivoted to levers 8<c>, Figs. 5 and 6, which are pivoted on a frame-rod 9 and have lugs 8<d> to engage the pins 6<a> on the loose arms 6 and depress them without moving the fast arms 5, thereby positioning the hooks 2<a>, 4<a>. Each lever 8<c> also carries a pin 8<k> engaging a slot in a lever 21 carrying a plate 22, which is raised when the special key is depressed and engages a forward extension 16<b> of the back stop pawl 16, to disable both this pawl and the driving-pawl 13. The compounded mutilated pinion 31 and pinion 82 forming part of the overthrow-preventing mechanism of each transmission gearing is slidably mounted on a shaft 34, Fig. 4, the shaft being also movable laterally by cam arms 18a, 18<c>, as in Specification 131,109, for the collective zeroizing. The hub 32<a> of each pinion 32 is grooved and embraced by an arm 40<a> of a bail member 40 mounted on a rod 41 movable laterally with the shaft 34. Normally, the bail member 40 and the pinion 32 are held to the right by a spring 42, but on the depression of a special key for zeroizing an individual wheel a cam arm 22<b> on the plate 22 engages a projection 40b on the bail member 40 and moves the mutilated pinion 31 out of the plane of the notched disc 30. The pins or studs 6<b> engage the ends H<3> of the transfer levers H to ensure a positive movement of the mechanism, independently of the transfer springs. For splitting the totalizer, each special key 8<a> is provided with a hook 8 adapted to engage the end 50b of a pivoted member bearing a friction stop 50a for engagement with the periphery of the numeral wheel. A pin 8f on the key engages a slot 8<g> in the lever 8<c> to depress it sufficiently to elevate the plate 22. The backstop pawl, driving-pawl, and overthrow-preventing means being thus disabled, and the backward movement of the numeral wheel being prevented, the gear wheel A<1> of the transfer mechanism is free to rotate backwards and take up the transfer movement of the planetary gearing. The stop 50<a> returns partly by gravity and partly by the engagement of a lug 8<i> on the key with the end 50<b> of the stop member. The key may be latched at 54 in the " split " position. Specifications 4131/15 and 100,293 also are referred to.