Patent GB-935170-A (GB)
Title: Improvements in or relating to ten key calculating machine
IPC: G06C7/08
Filed: 1962-06-29
Abstract: 935,170. Mechanical calculators. BURROUGHS CORPORATION. June 29, 1962 [July 27, 1961], No. 25139/62. Class 106 (1). An indicator slide 60 (Fig. 3) which also acts as a stop for a differential actuator 68 is power driven to a registering position determined by the selection of a slide 29 by the depressed number key 20 of a ten-key machine. The indicator slides 60 are mounted in a carriage 61, sliding on a bar 64 and engaging a frame member 75A by means of a roller 61A, which is moved to the left after each digit is entered. Operation of number keys.-The one to nine keys are mounted on identical shanks 21 (Fig. 5) which each cam rearwardly, by means of lug 26, a slide 27 which has a projection 27A which bears on a similar projection on the associated slide 29 and moves the slide 29 into the path of a stop 60A on an indicator 60. The slide 29<SP>1</SP> selected by the nine key does not engage the indicator which moves until the lug 60B engages frame 61. The zero key permits a small movement of the indicator slide to cause denominational shift of the indicator carriage (see below). The selected slide 29 (Fig. 7) cams a frame 31 to the left by means of cam edge 29A. The leftward movement of frame 31 besides initiating power operation of a slide 60 brings a frame member into engagement with the shoulders 29B on the non-selected slides preventing operation of another number key. The calculator is part of an electric typewriter and by moving a guiding frame 28 (Fig. 3) so that the projections 27A are moved from register with the projections on the slides 29 the number keys can perform only a recording function. Power operation of slides 60.-A cam 40 (Fig. 7) is brought into engagement with a continually rotating roll for one half rotation of the cam. The leftward movement of frame 31 moves a slide 36 to the left which releases an abutment 40A from engagement with a projection 36A on the slide allowing the cam 40 to engage the roll. The cam is of such shape that its subsequent clockwise rotation causes shaft 41 carrying the cam to move levers 33 and 39 first clockwise and then anticlockwise of shaft 34. A lever 80 is mounted on shaft 34 and is connected to a vertical slide 81 having a lug 80A, and also by spring 82 to lever 39. When lever 39 moves clockwise it carries lever 80 with it, raising slide 81. The lug 80A engages under projection 60B on slide 60 (Fig. 3) and raises the slide 60 until projection 60A engages the selected slide 29. Pawl 70 holds the slide 60 in its registering position. Spring 82 then yields so that lever 39 can continue its movement. After cam 40 has turned through nearly a semicircle a stud 40B forces the slide 36 to its original position so that projections 36A underlies a projection 40A and disengages the cam from the roll. Lever 80 is returned by spring 93. Indicator carriage escapement.-A slide 90 has a lug 90A which engages the leftmost slide in the home position. As soon as an indicator slide is moved upwardly (including a small movement when registering zero) lug 90A is cleared and the indicator carriage 61 tends to move to the left under the influence of a spring (not shown). The movement of the carriage is partially prevented until the lever 80 is in home position, by a movement to the right of slide 90 due to spring 96. A bell-crank 94 rocks to latch slide 90 in this position until stud 33A on lever 33, which is in home position at the same time as lever 80, unlatches the slide and allows full escapement of the carriage. Resetting indicator carriage.-All activated indicator slides are moved upwards to their full extent (the " nine " position). A vertical slide 121 has an arm (122, Fig. 2, not shown) which sweeps the indicators to the nine position when slide 121 is operated, ultimately, by slide 128 driven by slide 130 and cam K2 (Fig. 6). The connection between slides 128 and 130 is dependent on the setting of a cam 132, which may be manually controlled, which operates a connecting pawl 129. Cam K1 rotates lever 110 clockwise to return the indicator carriage 61 when pawl 108 operatively connects bell-crank 104 and lever 110, which it does in the normal position of cam 132. For a repeat operation cam 132 is moved so that pawl 129 is clear of stud 130A on slide 130 and pawl 108 is held clear of lug 106 by stud 132A, thus preventing both resetting operations. For total or sub-total operations the indicator carriage is cammed a half-step to the right to disalign add bars and indicator slides, by raising the slide 151 (Fig. 7) by means not shown and thus camming the slide 90 to the right. This is done at an appropriate time in the machine cycle by a motor-driven cam (Fig. 2, not shown).