Patent GB-341435-A (GB)
Title: Improvements in calculating machines
IPC: G06C7/06
Filed: 1929-09-09
Abstract: 341,435. Calculating- apparatus. DEHN, F. B., 103, Kingsway, London.-(Felt & Tarrant Manufacturing Co. ; 1717, North Paulina Street, Chicago, U.S.A.) Sept. 9, 1929, No. 27389. [Class 106 (i).] Adding-apparatus with operating- means.-In a key-responsive, poweroperated machine mechanism is provided to ensure complete depression of a key and to prevent re-depression before the previous operation has been completed. As shown applied to the machine described in Specification 181,043, [Class 106 (i), Calculating &c.], the keys serve to depress a bar 32 pivotally carried by levers 35, 36 pivoted at 37, and cause a hook 43 to engage a motor-driven ratchet-wheel 48 to stretch a spring 28 and through a link 44 and clutch 47 move the actuating sector 29 down to the required extent as controlled bv the differential bar 45. In the downward movement of the bar 32 a link 38 shifts to the right. Pivoted on this link is a three-armed spring-controlled lever 51, Fig. 2, the forward end of which terminates in a shoulder 59 co-operating with a dog 63 carried by a lever 61 pivoted at 62. As the link 38 advances, the shoulder passes under a lug 67 of the dog and on the return journey, if the key has not been sufficiently depressed, the shoulder meets the lug and therefore rocks the lever 61 and shifts a link 83 to the left. This through a lever 85 rocks a shaft 89 counterclockwise and, by means of a cut-away portion of the shaft allows displacement of an arm 98 and shaft 97 and so a latch lever 101 in each bank to bring lugs 108 below the bars 32 of all banks (other than the one concerned) which are thereby locked. If, on the other hand, the key is sufficiently depressed to connect the hook 43 with the wheel 48, the link 44 in its leftward travel engages by a lug 81 the depending arm 53 of the lever 51 which is consequently rocked clockwise and then held by a latch 74 (subsequently released by meeting shaft 181) so that on the return stroke of the link 38 no operation of the lever 61 and link 83 occurs. By the above arrangements when a key is not adequately operated the keys of all other banks are locked against movement but the bank concerned is free to enable the mis-operation to be rectified. When this is effected the bar 32 of this bank also becomes locked by its lever 101 and in order to release the mechanism a key 112, Fig. 6, must be operated so as through a lever 114 and roll 147 to rock arm 98 and permit shaft 89 and the parts controlled by it to return to normal position. To prevent a key from being depressed before completion of the previous operation lever 51 is ratchet-toothed at 121 to co-operate with a lug on a second dog 64 carried by the lever 61. If an attempt is made to depress a key before the latch 74 is freed by striking the shaft 181, the ratchet-teeth prevent the link 38 from again advancing. Zeroizing mechanism. The totalizer is zeroized by the motor through connections shown in Fig. 6. When the zeroizing-key 137 is depressed, it lowers a lever 139 and this in turn engages a pawl 129 with a roll 132 on a lever 133 reciprocated by a cam 136 on the power shaft 27. When the latter rotates therefore, the pawl and link 127 on which it is mounted are urged to the right and through the lever 125, link 124 and lever 123 rock the zeroizing- shaft 122. The lever 128 supporting the link 127 also engages a lever 143 and through a link 146 rocks the arms 98 to free the shaft 89 and restore the locking-devices to normal. A roll 154 on the link 127 also rocks a shaft 152 to raise the dogs 63 from the levers 51.