Patent GB-229642-A (GB)
Abstract: 229,642. Friden, C. M. F. Feb. 18, 1924. [Convention date]. Multiplying and dividing apparatus.-Relates to a power-driven machine for the four rules having means for setting both factors and consists in the provision of means for initiating the operation by the depression of a starting control key or of a key representing a digit of the second factor, and for automatically disconnecting the source of power on the completion of a calculation. Means are also provided in division operations for stopping the machine when the divisor has been subtracted an excess number of times, whereupon the divisor is added once and the totalizing-counter carriage shifted one place to the left. The revolutions counting mechanism and the means for effecting a lateral shift of the totalizing-counter carriage are similar to those described in Specifications 212,206 and 212,207, respectively. Differential mechanism. - The setting and actuating mechanism is similar to that described in Specification 207,858. Operating by motors.-The totalizer-actuating elements 55 are mounted on a shaft 53 which is driven by an electric motor 135 on the shaft of which is arranged a flexible coupling 137 and a pinion 138, Figs. 2 and 8, that gears with a pinion 139 on a hollow shaft 141 and connected through a friction clutch with a pinion 143 in gear with a pinion 146 secured to a shaft 145. The shaft 145 carries one member 188 of a clutch 147, Fig. 11, the other member 192 of which is pivoted in a housing 189 secured to a shaft 191 in alignment with the shaft 145. The clutch is normally held in the open position by the engagement of the tail 196 of the member 192 with a spring-controlled pivoted stop arm 203, Fig. 12, and a second stop arm 206 that engages a recess in the housing 189 in the normal position. Slidably mounted on the shaft 191 is a collar 148 integral with a pinion 149, Fig. 16, adapted to be set in one or other of two positions to drive a pinion 157 directly or through a reversing pinion 155, the pinion 157 being mounted on a shaft 156 that carries a pinion 158 gearing with a pinion on the shaft 53. The collar 148 is engaged by an arm 151 secured to a rod 152 that passes through the hollow shaft 141 and is slotted at the outer end to engage the bent arm 153 of a lever 154 to which is attached a link 224 operated by the starting control keys. Shifting of the pinion 149 is prevented except when the clutch is in the normal position by a headed pin 213 on the arm 151 being adapted to engage a disc 209 on the housing 189, a notch in the disc allowing the pin to pass when in the said position. Keyboards.-The key banks 25 and the bank of special keys, viz. the clear key 171, the non-repeat key 172, and repeat key 173 are similar to those described in Specification 207,858 referred to above. In addition a pair of starting control keys 216, 217 for the operations of addition and subtraction respectively and a bank of keys 236, 237 for the second factor are provided. Depression of either key 216, 217, serves to rock a pivoted T-shaped lever 221 so as to move the link 224 that controls the position of the reversing gear pinion 149. At the same time the clutch 47 is rendered operative by the engagement of the depressed key stem with the surface 228 or with the inclined face 231 of a pivoted plate 226 which is rocked rearwardly to cause a clutch control lever 232 pivoted to the said plate to engage a pin 235 on the stop arm 203 to move the said arm and the associated arm 206 to the disengaged position, whereupon the pawl 192 engages the ratchet wheel 188. The clutch will remain in engagement as long as either key is held depressed; on release of the key the parts return to their normal position under the action of a spring 227 secured to the control lever 232 and the casing. To relieve the operator of the task of counting the number of rotations of the actuating mechanism the keys 236 are provided, depression of any one of which effects the stopping of the machine after the number of rotations corresponding to the value of the key depressed. Projections 241 on the key stem when lowered effect the movement of a slide bar 242 to the forward end of which is attached a bracket 243 that is connected by a link 244 to the plate 226, thus effecting the closing of the clutch. The key is held in depressed position bv a pivoted latch plate 246. A projection 253 at the lower end of the latch plate supports the forward end of the control lever 232. The key stems are disposed above a duplex lever similar to that described in the Specification last referred to, and comprising a main lever 255 and an auxiliary lever 258 pivoted at their front and rear ends respectively and connected by a pin-and-slot arrangement. The rear end of the lever 255 has a slot in which works a pin 265 on a lever 262 that is pivoted on a frame 261. The lever 262 is thus rocked by the depression of a key and the position of a pin 278 at its forward end depends on the value of the key depressed, the movement being conveyed to a slotted arm 276 that is pivoted to a rack-bar 267, Fig. 7. The rack 267, which is supported on a roller 271 and has the pivot pin 268 guided in a slot 269 in the frame 261, gears with a pinion 272 that is adapted to be rotated step by step by means of a pin 273 extending from the clutch housing 189. The arm 276 has a depending arm 281 provided with a pin 282 adapted to co-operate with a stepped plate 283 mounted on pins and slidable to a limited extent on the frame 261. When the pin 282 is moved by the rack to engage the step to which it is presented, the next succeeding movement is effective to stop the machine by means of a lever 291 which is pivoted to the stepped plate and engages a fixed abutment on the frame. 261 so as to be rocked thereby to release the latch 274 of the rack bar and at the same time, through the engagement of the cam face 297 of the lever 291 with a pin 296 on the control lever 232, to raise the rear end of control lever 232 to free the pin 235 of the stop arm which is moved to disengage the clutch. At the same time the lowering of the front end of the control lever 232 releases the latch plate to permit the depressed key to rise to normal position. To ensure one operation only of the machine even if the key 216 or 217 is held depressed, the non-repeat key 172 is depressed to rock the lever 185, Fig. 5, whereupon a pin 312 thereon co-operates with the auxiliary lever 258 to set the pin 282 to the position corresponding to that for the first key 236 so as to throw out the clutch after one revolution. Dividing apparatus.-In division operations the divisor is taken from the dividend, set up in the totalizer, until the wheels to the left expose a series of " 9's, " whereupon the transfer arm 113, Fig. 4, associated with the highest numeral wheel rocks an arm 299 to sound an alarm by ringing a bell 302 and by the movement of a link 306 rocks a bell-crank lever 305 to cause it to lift the rear end of the control lever 232 to throw out the clutch. The key 216 is then depressed to cause a single rotation in the additive direction, and the totalizer carriage is then shifted one step to the left and this sequence of operations repeated.