Patent GB-1007425-A (GB)
Title: Calculating machine
IPC: G06C15/06
Filed: 1962-09-10
Abstract: 1,007,425. Mechanical calculators. ADDMASTER CORPORATION. Sept. 10, 1962 [Sept. 25, 1961], No. 34518/62. Heading G4B. [Also in Division B6] The ten-key adding-listing machine disclosed is essentially that described in Specification 971,662 which is referred to, but additional details of paper feed, printing function symbols, suppressing zeros, ink ribbon and repeat operation control are given. Depression of a number key 11 (Fig. 1) sets through a flexible cable 30 a pin 14 in an arcuate pin carriage 15 and rocks bail 63 to depress an escapement pin 54 whereupon the carriage presents the next order pins to the cables 30. The differential actuators are wheels 16 each carrying a rack 242 for engagement with the digitizing wheel 240 of the like order of a crawl carry totalizer 21, and printing types ] 7. Movement of an actuator 16 is limited by the abutment of a stop 53 with a set pin 14 or a pin 135 or 129 with the teeth of a comb 134. The pin carriage (Fig. 3) frame has an edge 73 which acts as a zero stop for actuators 16 in orders higher than the most significant order of the entered number. The actuators are driven by a universal bar 122 rocked about axis 33 on each machine cycle and engaging each actuator by location in a recess in a flexible tail 133. When an actuator is arrested the tail yields to permit the bar 122 to finish the stroke. There are two function control keys. An add key initiates a subtotal operation if the pin carriage is in home position, i.e. no number has been entered, and a subtract key initiates a total operation under the same circumstances (see Specification 971,662). Starting motor (Fig. 13).-Depression of a function key 12 or 13 cams slide 105 forwardly. This pulls slide 101 forward and releases pawl 94, sprung by its tail 98, into engagement with motor driven ratchet 97. Slide 101 also closes contacts 119 in the motor circuit. An interlock slide 114 (Fig. 19) prevents simultaneous depression of both function keys. Depression of the key 12 holds the slide in the position shown whereas depression of key 13 requires that the slide cam forwards. Repeat operations.-Depression of a repeat key, which is self latching breaks a pin-and-slot connection between a motor-cam operated lever and a bell crank which linkage normally returns the pin carriage to home position at the end of each machine cycle. Printing; paper feed.-Print hammers 18 (Fig. 1) are spring urged towards the actuators 16 by a leaf spring 151, but are held in the position shown by a hinged bail 152 acting on the leaf spring which urges the bail against a cam 154 which rotates once in a machine cycle. When the cam presents its cut-away portion to the bail the leaf spring is released. The paper is guided from roll 137 between rollers 138, 139 in a guide 140 and up between frame member 140 and a transparent tear-off strip 143 through which the last line printed is visible. The strip 143 is pivoted at 167 for movement to position 143a to enable threading the paper through the guides. The underside of strip 143 comprises teeth 165 which serve to space the edges of the print wheels 16. Paper is fed by rotating the roller 138. A lever 125 is rocked to and fro once each machine cycle and is connected to a lever 1661 (Fig. 20) to which is pivoted a pawl 1701 engaging ratchet 164 on shaft 163. This mechanism causes the shaft 163 to be rotated, and with it roller 138, sufficient to present the next line to the print hammers. The print wheels are aligned by a bail 281. During the printing stage of a machine cycle and when the motor is not operating. Just before printing the bail 281 is moved by a linkage (Fig. 10, not shown) so that all print wheels are rotated a few degrees anticlockwise giving a positive aligning action. Ink ribbon.-A short ribbon is wound in spool 171 (Fig. 16) about an ink pad 183 and is pulled out of the spool, freshly inked, and returned each machine cycle. The spool consists of four pins 182 about which is wound the ribbon mounted on a base 181 which fits on a central stud 174 in a magazine 172 removably mounted on a bracket 176 of the machine frame. The spool is rotatable relative to the magazine but is biased by a tension spring 184 (Fig. 17 against a stud 189 in the magazine. The ribbon (Fig. 15) passes over rollers 190 and 191, the latter on a slide 192, and is secured to the machine frame at 193. A cable (not shown) is secured to the slide and is connected to a pulley on a shaft rotated each machine cycle by the lever 125 (the connection is illustrated in Figs. 9 and 11, not shown). The slide is moved by this means to the position shown in Fig. 15, when the ribbon is fully withdrawn from the spool. A spring 194 returns the slide 192 to home position. Symbol printing.-Symbols for total, subtotal and negative are mounted on a print wheel 220 having a stop 226 (Fig. 22) and mounted on shaft 33 opposite the left end row of pins of the pin carriage when this is in the home position. Total and subtotal operations take place with the carriage in home position. In a total operation slide 230 (Fig. 3) is in the position shown and stop 226 on the print wheel engages projection 228. Depression of the add key cams slide 230 to the right so that if the pin carriage is home projection 236 will engage stop 226. If the pin carriage is not in home position the print wheel is stopped by the edge 237 (Fig. 22) of the carriage whereupon a negative symbol is presented to the hammer 224. If the operation is an add operation, selection of the appropriate function cam also operates a lever (Fig. 6, not shown) which prevents actuation of the print hammer. Eliminating non-significant zeros.-A slide 210 (Fig. 15) is spring connected to the ribbon slide 192 and moves with it. The extent of movement is determined by the number of high order print wheels 16 registering zero for a lower limb 214 of the slide can pass through a slot in a print wheel only when the wheel registers zero. A flange 217 prevents operation of corresponding hammers 141.