Patent GB-540283-A (GB)
Title: Improvements in or relating to calculating machines
Inventor: BALL WILLIAM
Filed: 1939-04-29
Abstract: 540,283. Calculating-apparatus. BALL, W., KEEN, G. P., and BRITISH ADDING & CALCULATING MACHINES, Ltd. April 29, 1939, No. 10169. [Class 106 (i)] In a machine having a plurality of totalizers with the pinions arranged in denominational groups, a totalizer selecting mechanism is provided wherein the selective engagement and disengagement movement of the pinions with corresponding gear tracks, operated by the differential actuating mechanism, is effected by a movement in a direction along the axis of the pinions, the pinions being so disposed in relation to the gear tracks that the axial movement is alone sufficient to effect engagement and disengagement. The invention is shown applied to machines as described in Specifications 263,505, 288,672, [both in Class 106 (i)], 343,448, 343,473, 343,474, 343,475, 343,476 and 352,958. The machine is built up of a number of identical sections each comprising a row of keys, denominational elements of a plurality of totalizers, differential actuating elements and a transfer mechanism with or without printing elements. A section is also provided to control the selection of the totalizer element. Keyboard.-Each bank of keys 25, Fig. 1, is provided with a notched detent plate 128 to hold a digit key in depressed position. The zero key co-operates with a cam face on the detent plate and serves on depression to release the operated digit key. At the end of an operation the zero keys are depressed automatically ; for this purpose a lug 145, formed on each of the differential racks 13, as it reaches its home position, strikes a projection 144 on a slidable member 143 carried on an arm 141 on a shaft 140 which is rocked to depress a finger 139 and thereby the corresponding zero key. At the same time a latch finger 153, pivoted on an extension of the differential rack 13, presses against the shank of the zero key to hold the differential actuating parts until the pressure is released at the end of the operation. This mechanism forms the subject-matter of Specification 540,315. The keyboard is also provided with control keys for total and sub-total operations, repeat operations, non-add operations and errors correcting. For repeat operations a control rod 151 is rocked and a finger 147 thereon engages a lug on the slide 140 to raise it out of the path of the lug 145 to prevent depression of the zero keys and thereby release of the depressed digit keys. Triangular rods 157, 158 engage similar recesses in the detent plate 128 to prevent release of the keys during the active part of the cycle of operation. -The Differential mechanism.-The totalizers are actuated by racks 12, each rack is reciprocated by a differential rack mechanism 13, 14, similar to that described in Specifications 288,672, [Class 106 (i)], and 540,320. Each rack has an extension carrying a pinion 15 engaging the racks 13, 14, the rack 14 being normally fixed except for transfer operations. The rack 13 has pivoted thereto an abutment plate 22 with a pin 26 engaging an inclined slot in the extension of the rack 12. Reciprocating motion is imparted to each rack by a link 32, attached to the corresponding pinion 15, each link having a slotted connection with a spring-controlled bell-crank lever 35 operated by a corresponding cam 42 on the main shaft 43 The pins 26 ride up the slots as the racks 13 overtake the actuating racks 12, the movement of the parts being arrested by the appropriate abutment on the plates 22 engaging the stems of the depressed keys Totalizer selecting mechanism.-Ten totalizers are provided ; the pinions 11 of one denomination of each totalizer are shown in Fig. 2 arranged on spindles 54 extending different distances from a supporting plate 56 secured by pillars 58 to a partition plate 10. The movement of the rack 12 is transmitted through an axially movable pinion 49 when aligned with the rack to a wide pinion 50 in engagement with a gear wheel 51 keyed to a corresponding selector shaft 52. Each of the spigoted shafts 52 has fixed thereto another gear 57 that is displaceable with the shafts to select any one of the sets of pinions 11 for actuation. The longitudinal movement of the shaft is effected by a nut 61 and a quick pitch screw thread 66. The shaft 67 carrying the screw is adapted to be differentially rotated, as described in Specification 540,314 by a selection key bank and associated rack mechanism similar to that for the amount banks or a differentially set lever may be provided. A grand totals counter is provided comprising pinions 82 engaged, during every operation, with a gear track 65 on the underside of the racks 12. Transfer mechanism.-The carry over is effected by imparting a limited movement to the racks 14. Each totalizer pinion carries a transfer member 90 that co-operates with a pin 95, Fig. 4, on one of a pair of levers 93, 94, pivoted on the support plate 56. The action is such that an extension 99 of the lever 94 engages one of the pegs 92 of a ring 91 and rotates it through the pitch of the pegs whereby a bellcrank 106, 107 is rocked to withdraw a pin 105 thereon from the limb of an inverted T-slot in the rack 14 of the next higher denomination. This rack is held by a detent 109 until near the end of the return movement of the operating arm 35 when the rack is pulled to the right. The rack is restored to normal position by a depression on the corresponding cam 42 at the end of the operation. The transfer parts are reset at the beginning of the next operation by releasing a latch 108A for the bell-crank 106, 107, by a cam member 109A controlled by the means engaging the grand total counter. Aligning mechanism.-During the time the totalizer pinions are out of engagement with the driving gears 57 they are aligned by means of a ring plate 166, Fig. 4, with wedge-shaped projections 169 arranged to engage a facet of a polygonal disk 165 on the pinions when the plate is shifted by action of a lever 170. Printing mechanism.-Printing is effected in a manner similar to that described in Specifications 343,448 and 540,320. Each arm 35 carries a pin 114A that works in a cam slot 115 in a spring- controlled quadrant arm 116 to which is secured an arm 120 having pivoted thereon a link 121 supporting the type bar. Total and sub-total mechanism.-The intermediate pinions 49 are engaged during the forward stroke and to prevent the racks 12 being restored immediately after the pinions 49 disengage pawls 125 are rocked, by a triangular shaft 126, into engagement with ratchet teeth 124 on the racks until the operating cams 42 function with the arms 35 and the teeth ratchet over the pawls. A grand total is obtained under the control of a shaft 89 as described in Specification 540,312. In a modification shown in Fig. 5 the selection of one or another of two totalizers 215 is effected by the transverse movement of the actuating racks 12 which are mounted for movement, parallel to themselves, on the differential rack mechanism by means of an axially movable control rod 52. The transfer mechanism for this arrangement is similar to that described in Specification 540,318.