Patent GB-1004384-A (GB)
Title: Decimal system for calculating machines comprising an overcapacity control
IPC: G06C7/10
Filed: 1963-08-27
Abstract: 1,004,384. Mechanical calculating apparatus. MONROE CALCULATING MACHINE CO. Aug. 27, 1963 [Sept. 7, 1962], No. 33841/63. Heading G4B. A mechanical calculating machine includes an over-capacity control comprising separate devices which disable the machine drive upon entry of more than a given number of decimal digits or a given number of whole number digits respectively. The parts shown form part of the four rules, ten key-machine described in Specification 1,004,383. A pair of stepped barrels 97, 98 are rotated by hand-set gearing and cable connections, through angles proportional to the numbers of decimal digits required in say the multiplicand and multiplier if a multiplication is to be performed. A stop member 103 is mounted on a transversely movable carriage (119, Fig. 1, not shown). A selector carriage (2, Fig. 1, not shown) is stepped transversely as successive digits are entered, most significant digit first, into its storage gears. When the decimal key 3 is pressed in correct ordinal position, a bail 148f is rocked anti-clockwise on a shaft 149 causing corresponding rotation of a link 151 through abutments 148f, 151a, then producing a rearward movement (towards the right in the Figure) of a link 152, and anti-clockwise rotation of an arm 153 and a pawl 145. This connects the carriage bearing the stop 103 for lateral shift with the selector carriage; thus for each decimal digit entered stop 103 is moved one step nearer the barrels 97, 98. When the decimal digits have been entered into the selector carriage, a multiplicand entry key 15 is depressed rocking a bail 168 anticlockwise, which motion is transmitted through a link 169 to a pivoted lever 170 and then through a link 173 to cause clockwise rotation of pawl 103 to bring it into the path of barrel 97. The key 15 also depresses a bail 175 having an extension 175a which pushes a link 178 rearwardly against the action of a spring 181. A link 179 having a pin- and-slot connection with the link 178 is biased rearwardly so as to rock a locking pawl 177 over an abutment 15a on the key 15 and then rotate a pawl 180 to release the pawl 135p of a one revolution clutch 135 to drive actuator bars which transfer the number from the selector carriage to the multiplicand register after the selector carriage has been correctly positioned laterally by stop 103, engaging the correct step of barrel 97. If too many decimal digits have been entered stop 103 is already beyond the correct step of barrel 97 and thus cannot be rotated. Pin 164 on link 173 moves along a slot 165s to rotate a lever 280 against spring action so that an abutment surface 280s prevents rotation of the pawl 180, thus preventing engagement of the clutch. As the selector carriage is stepped towards the barrel 97, a stop member 266 is moved towards a second set of abutment steps on the barrel, and if too many digits are entered stop member 266 engages the barrel 97, and is rotated clockwise causing through links 268, 269, 272 corresponding rotation of a lever 276 about a pin 153p on arm 153. This is prior to the anticlockwise rotation of the arm 153 at which time lever 276 would move rearwardly, thus a hook 276b will on rotation of lever 27 6 engage a cranked bail 278a, 278b and rock it clockwise, thus locking bail 168 from rotation and key 15 from depression.