Patent GB-536405-A (GB)
Abstract: 536,405. Calculating-apparatus. MERCEDES BUROMASCHINEN-WERKE AKT.-GES. June 13, 1939, Nos. 17244 and 17245. Convention dates, July 12, 1938 and Oct. 24, 1939. [Class 106 (i)] In a typewriter calculating machine having means for automatically taking a total from a totalizer denomination by denomination, the unlocking of the totalizer wheels for this purpose, the coupling and uncoupling of the main camshaft with the actuating shaft and the aligning bf the totalizer actuating gears are effected under the control of a control unit arranged to be operated by the driving shaft. The control unit and associated devices form an auxiliary means to aid the mechanisms hitherto used for these purposes. The machine, as shown in Fig. 9, has a typewriter carriage 2 on which are mounted column totalizers 4, two cross totalizers 8, the machine also having numeral and type letter keyboards, a total key 11 for the column totalizers and total keys (not shown) for the cross totalizers, and a main driving shaft 16 operated continuously by a motor (not shown). Totalizer unlocking mechanism. When a total key is depressed it releases a pawl 12, Fig. 2, and couples a pair of cam plates 14, 15 to the driving shaft 16. The plate 14 co-operates with a release slide 17, Fig. 3, controlled by springs 19 to rock a locking shaft 22 in known manner. As shown the locking shaft 22 carries an unlocking arm 32 for the totalizers 4 and is operatively connected to unlocking arms 30 for the totalizers 8. To assist in the unlocking operation in accordance with the present invention the cam plates have associated therewith a control unit comprising an assembly of cams 38, 39, 42 and 197 on a sleeve 36 which engages notches in the sleeve 34 of the cam plates. To assist the springs 19 of the release slide 17 the cam 38 co-operates with a bell crank 47 to operate through a yielding connection, a vertical slide 53 which is pivoted at its upper end to a dog 57 which acts on the lug of an arm 64 to rock the locking shaft 22. Coupling and uncoupling the zero-setting slide. Normally a pin 68, Fig. 7, on the arm 23, that co-acts with the release slide 17, engages an arm 69 on the coupling shaft 70, Figs. 2, 3 and 4, which is rocked and through arms 71, 72 aligns the pinion 75 on the actuating shaft 76 with the rack teeth on the zero-setting slide 80. To assist this coupling movement the slide 53 has adjustably connected thereto a tooth 85 which overlies the upper edge of one arm of a bell crank 87, the other arm of which bears against the arm 72 so as to rock the coupling shaft when the slide 53 is lowered. After each figure of the total has been typed a slide 99, Fig. 7, is raised to rock a lever 98 which frees an arm 94 on the coupling shaft 70 and a second lever 99a engages the arm 94 to rock the shaft 70. To assist this normal operation an auxiliary slide 103, Fig 2, is provided. The slide 103 is formed with a notch and an abutment 107 that cooperates with one arm of a three-armed catch 111 the other arms forming a hook 114 and pusher 115 for the arm 94. The slide 103 carries a roller at its lower end engaging the cam 42 of the control unit which raises the slide to effect the uncoupling movement. Zero-setting slide operating means ; overthrow preventing means. The zero-setting slide 80 carries a rack 134, Fig. 7, that meshes with a pinion on a shaft 154 operatively connected through a second pinion and interconnected rack members 129,128, Fig. 9, with the main rear camshaft 171. By this means the zeroizing movement of the totalizer wheel is effected. Due to the slack in the gearing operated by the slide 80 the detent pawl 151 Fig. 7, may not engage properly with the gear wheel 149 for the column totalizers 4. To eliminate this trouble the cam 39 of the control unit co-operates with a slide 156, Fig. 2, on which is mounted an adjustable bracket 163 carrying a pawl 166. After the zeroizing operation the slide 156 is restored to raised position and the pawl 166 actuates a ratchet wheel 167 on the shaft 154 and rotates the gearing to ensure the proper setting of the wheel 149. For the cross totalizers 8 the proper aligning movement is effected through the gear 151b and the detent 151a. The release of the slide 80 for the zeroizing operation is effected on the descent of the release slide 17 by a dog 184, thereon cooperating with a bell crank 185 and a holding pawl 188. In the known machines the power means to produce the movement of the slide 80 is a spring 130, Fig. 9, connected to the rack member 128. In the present invention the spring is replaced by a tension-equalizing device operated by the control unit. This device comprises a pivoted lever 199 with a roller engaging the cam 197, and aT-lever 201 pivoted on the same axis with a roller bearing on the lever 199. The levers are connected by a spring 205 and the slotted end of one of the arms of the T-lever engages a pin 211 on the rack member 129. By this means a steady operation of the zero-setting mechanism is effected.