Patent GB-314789-A (GB)
IPC: G06C23/02
Abstract: 314,789. Burroughs Adding Machine Co., Assignees of Pasinski, W. J.). July 2, 1928. [Convention date]. Adding apparatus; operating by motors.-In a multiple bank machine depression of a key effects closure of a motor circuit and the coupling of the motor drive to the differential stop-bar to move the latter until stopped by the key. The coupling is thereupon disabled, and the circuit broken, and the stop-bar returns to the home position. Each key-bank is provided with a stop-bar 20, Fig. 2, connected at 2 to an actuating- sector 22, and with a detent-bar 60, having an extension 62, adapted to rock a bail 58, controlling a switch 53 Fig. 10, in the supply to an electric motor 40. The speed of this motor is automatically governed by the spindle 75 of a disc 76 that rests against balls in a cupped plate 77 fixed to the motor shaft. With excessive speed therefore the spindle 75 rocks a lever 71 so as, in turn, to rock the switch lever 53 into open position. The differential stop-bar 20 is supported at its rear-end by a pin and slot, the slot being in an arm 30 pivoted at 33 and adapted to be rocked clockwise by the motor through a pawl and ratchet coupling. When a key is depressed, the detent bar 60 is forced to the rear until a. latch 80 carried by it engages behind a fixed rail 86. The latch is spring-pulled upwards but is normally forced downwards by a stud 88, carried by a spring-controlled yoke 90, pivoted at 91 on the arm 30. Rigid with this yoke is a pawl 92 tending to engage a ratchet wheel 47 geared with the motor shaft but normally held up by a lug 100 forming part of a pivoted yoke 102. When the bar 60 moves rearwardly a shoulder 85 on one arm of the latch 80, engaging a lug 107 on this yoke, rocks the lug 100 from beneath the pawl 92 to allow it to engage the rachet wheel. The arm 30 is thereby coupled with the motor and moves counterclockwise to advance the stop-bar 20. In the first part of this advance an extension 110 of the arm engages a shoulder 112 of the stop-bar to effect a positive drive of the latter, but, later on, the extension moves away from the shoulder and the drive is taken over by a lever 113, pivoted on the arm at 114, and pulled counterclockwise bv a spring 94 attached to the lever and to the yoke 90. When the stop-bar finally reaches the end of its forward travel as determined by the key depressed, the continuance of the movement of the arm 30 produces a relative clockwise displacement of the lever 113 sufficient to rock the yoke 90 and disengage the pawl 92 from the ratchet wheel. At the same time the spring 94 is carried to the other side of the pivot 91 so as to tend to maintain the pawl out of engagement. The rocking of the yoke also raises stud 88 to enable the latch 80 to rise to permit restoration of the detent bar 60 by its spring 65. By this restoration of the bar the shoulder 85 takes up its position again in front of the lug 107, and when the stop-bar 20 returns, the lever 13 resumes its normal position and the pawl 92 is again held by the lug 100. Specifications 24996/11. 6/15, 4131/15, and 131,109 are referred to. The Specification as open to inspection under Sect. 91 (3) (a), also contained the subject matter now described and claimed in Specification 332,598.