Patent GB-736026-A (GB)
Title: Improvements in or relating to computing machines
IPC: G06C7/08
Filed: 1952-11-25
Abstract: 736,026. Calculating-apparatus. NILSSON AKTIEBOLAG, R. Nov. 25, 1952 [Nov. 28, 1951], No. 29861/52. Class 106 (1). Key-set stops of a ten-key machine are carried in abutting contact in transverse guides along which they are moved from denomination to denomination by driving means engaging them over a part of each guide. In the machine shown, the guides are channels 7 bordering a transversely elongated aperture 6 in a block comprised of a series of plates 4, and the stops 8 have studs 18 for driving engagement with sprocket wheels 32 on a common shaft 30. Associated with each guide, in the setting position, is a setting lever 65 by which the stops are projected inwardly of the aperture 6 to control the differential racks 140, each such lever 65 having a cam slot 63 engaged by a pin 62 on a respective transverse crank rod 59 rocked by depression of the corresponding numeral key 47. The rods 59 overlie a longitudinal crank rod 60 which consequently is lowered at each key depression and operates ratchet mechanism (not shown) to rotate the shaft 30 and advance all the stops along their guides one step. Set amounts are entered by depressing a hand lever 120 (Fig. 1) the two arms of which are formed as cams which actuate respective arms, as 106, linked to an operating slide 38 and to a rack 35 which thus move forwardly, and back under control of the two cams. The rack 35 drives a transverse shaft 136 clockwise and return through one revolution, pinions 134, connected to the shaft through springs, advancing the differential racks 140 until arrested by engagement of their upturned ends 142 with set stops 8. The racks 140 are of strip steel crimped to form teeth for engagement with the setting pinions 134 and totalizer wheels 132. The operating slide 38 effects the totalizer engagement, actuates the zero stops and restores the set stops 8 at the end of each cycle : a wedge 216, on the slide cams a bar 178 upwardly as the slide approaches its normal rearward position, the bar 178 lifts a frame 146 supporting the differential slider and the frame 146 engages and restores the set stops. The frame 146 is also operable by a key for cancelling erroneous settings. A rail 20, 24 and 26 extends over the greater part of each guide channel 7, and engages in either of two grooves formed in the stops 8 in order to retain them set or unset. The section of rail 26 in the operative part of the guide channel is spring mounted to yield and allow resetting by the frame 146. Zero stops. Pivoted zero stops 152 are released to engage and lock the differential racks 140 when cams 168 on the operating slide 38 release a disabling slide 166 at the commencement of the forward stroke of the operating slide 38. In orders where a " 1 "-" 9 " digit key has been depressed, a longitudinal bail 93 (Fig. 3) is lowered by one of the key-operated rods 59 and projects an additional stop 8b to hold the zero stop inactive and permit advance of the differential rack 140. Totalizer engagement. The totalizer wheels 132 are engaged with the racks 140 by leftward (Fig. 17) movement of a bar 282, the bar having studs 290 engaging cam slots in the totalizer frame. The bar 282 is moved by the engagement of any one of three pins 298, 299, 300 in a respective cam track 310, 320, 330 formed in a rear extension of the operating slide 38. The pins are mounted in vertical bores in the bar 282, and when the pin 298 is lowered it travels counterclockwise round its cam track 310 to engage the totalizer in add timing; the cam track 320 traverses its pin 299 clockwise to engage the totalizer in subtract or total-taking timing, whilst the track 330 causes engagement in subtotal timing. The pins are engaged by arms 260 spring-connected to a shaft 248 which is rocked by a cam on the operating slide 38 so as to tend to engage all the pins with their cam tracks at the commencement of each operating cycle. A transverse slotted bar 243, positioned by the control keys of the machine, underlies projections 280 on the hubs of the arms 260 and selectively controls the engagement movement of the arms 260 and pins. Normally a slot in the bar 243 registers with the projection 280 associated with the pin 298, so that the pin 298 is lowered by its arm 260 to cause engagement of the totalizer in add timing. When the subtotal key is operated, the bar 243 is given a full movement to the right permitting engagement of the pin 300 with its cam track 330. The total and subtract keys actuate the bar 243 with lost motion, and the bar consequently assumes an intermediate position permitting the pin 299 to engage its cam track 320. Printing mechanism. Rear extensions 362 of the flexible differential actuator strips 140 carry type characters. As the operating slide 38 completes its forward stroke, its inturned end 382 strikes toggle-links 372, 376 supporting a carrier for the strips 140, so raising the strips to impress the type against a platen 356. The platen 356 is rotated counterclockwise to bring the record strip into printing position at the commencement of each cycle by means of a cam 384 on the operating slide 38, and is returned to render the print visible when the slide completes its rearward movement.