Patent GB-752785-A (GB)
Title: Accounting machines and similar calculating machines
IPC: G06C21/04
Filed: 1954-12-14
Abstract: 752,785. Calculating-apparatus. NATIONAL CASH REGISTER CO. Dec. 14, 1954 [April 21, 1954], No. 36100/54. Class 106 (1). The tabulating paper carriage of an accounting- or like calculating-machine is power driven, through a reversing clutch, in both directions and a single manipulative control member having dual modes of operation is adapted directly to control the clutch and release the carriage so that the carriage is immediately driven forwardly or in reverse according to the mode of operation of the control member. The invention is applied to the machine described in Specification 680,992. The reversing clutch comprises wheels 45 and 47 adapted to be driven in opposite directions and through a fluid clutch (not shown) by a continuously running motor, the driven member of the reversing clutch being a coupling finger 43 on a shaft 39 which is axially shiftable to engage the finger alternatively with studs 44 or 46 secured to the wheels 45, 47. The shaft 39 carries a gear 38 in continuous mesh with a broad pinion 37 on the carriage driving shaft 34, having a pinion 33 in engagement with the carriage driving rack 32. Axial positioning of the shaft 39 is controlled by means of a rock shaft 59, an arm 58 on this shaft being connected through a lever 55 and link 54 with a shifting lever 53 for the shaft 39. A second arm 89 on the control shaft 59 has a pin 90 engaged in a slot in the reversing lever 91 of the normal carriage reverse tabulating mechanism as described in Specification 680,992, a third arm 60 on the shaft bearing a pin 61 engaged in an opening 62 in a lever 63 adapted to release the escapement pawls 71, 72 and antirebound pawls 74, 75 from the carriage escapement bar 27. According to the invention, an extension 78 of the lever 63 is connected through a link 79 with a manually-operated tabulating key 81, and a pawl 96 pivoted at 97 to the lever 63 engages over the pin 61 on the arm 60. Upon partial depression of the key 81, the lever 63 is rocked clockwise to disengage the carriage escapement pawls, whilst the pawl 96 rocks idly counterclockwise relatively to the lever and without actuating the arm 60. The reversing clutch consequently remains in its normal position shown, and the released carriage is driven in the forward direction. Upon full depression of the tabulating key, the further clockwise movement of the lever 63 brings the tail 98 of the pawl 96 to bear against a stop 65; this results in clockwise movement of the pawl to rock the arm 60 and shaft 59 whereby the clutch shaft 39 is shifted downwardly to engage the finger 43 with the stud 46 of the lower wheel 47 so that the carriage is driven in the reverse direction. The pin 90 is held in the slot of the reversing lever 91 by means of an arm 93 pivoted to the lever and actuated by a spring 94. A noticeable increase in pressure is required to operate the tabulating key 81 through its second stage for reverse tabulation, since this is accompanied by movement of the pin 90 out of the slot in the reversing lever 91 and against the action of the spring 94.