Patent GB-428316-A (GB)
Title: Improvements in or relating to devices for controlling the operations of a machine
Filed: 1934-01-24
Abstract: 428,316. Gearing for stopping machinery. BALDWIN, R. E., 123, Fairlands Avenue, Thornton Heath, Surrey. Jan. 24, 1934, No. 2629. [Class 80 (ii)] [See also Group XIX] Mechanism for controlling the operations of a machine comprises a plurality of toothed segments, racks, or the like, a pawl operative to actuate the segments in turn, and means whereby the pawl, after having stepped all the segments to the limit of their travel, is effective to operate mechanism to cause a particular machine operation such as stopping. The invention is particularly applicable to a recordcard-controlled statistical machine as described in Specification 271,935, [Class 106 (i)]. The main shaft of the machine carries a cam 9, Figs. 1 and 2, which co-operates with a roller 10 on a lever 7 pivoted in a structure attached to the frame of the machine. The lever 7 at its other end contacts with a lever 11 which carries a pawl 13 adapted to actuate successively three toothed segments 14, 15 and 16 mounted on a shaft 17. Pawls 19 are provided to hold the segments in their adjusted positions, and, when freed, the segments are restored to initial position by their springs 18 ; these springs are relatively heavy but exert comparatively little pull in order to reduce rebound on release. The pawl 13 has a three-stepped face designed to step round the segments in succession. When the third segment has been moved to the limit of its travel the pawl 13 falls inwardly and a finger 20 thereon is brought below a shoulder 21 on a lever 22 pivoted to an arm 24 on a shaft 25 that is rocked at each operation of the machine. In this position the upstroke of the pawl 13 raises the end of the lever 22 above a pin 26 on an arm 27 on a pivot pin 30, and as the arm 24 is swung the end of the lever by engagement with a fixed screw 29 depresses the arm 27 and therewith the arm 31<a> of an inverted U-shaped frame 31. The rocking of the frame 31 by coacting with lugs 19<a> of the retaining pawls 19 disengages the pawls and a screw 32 on the lower limb of the frame 31 rocks the actuation pawl 13 out of the path of movement of the segments thereby permitting them to return to their initial position. The stopping of the machine is effected by a stirrup-shaped claw member 33 pivoted on the arm 24 and connected by a spring to the lever 22 ; the lever when displaced moves the claw member 33 into the path of the end 37 of a bell-crank and on the subsequent operation rocks the bell-crank and through its connection with the forked end of a lever 40 rocks the lever 40 that is associated with known stop mechanism. Means are also provided to pre-set each segment to a predetermined position to vary the number of operations. For this purpose stops 57a, 57<b>, 57<c>, Fig. 4, are provided against which the segments normally abut; these stops are arranged at the end of setting levers 58<a>, 58<b>, 58<c>, which levers may co-operate with notched retaining segments. In the arrangement shown, the levers 58<a> and 58<b> are connected by a forked member 63 to move integrally, the lever 58a having a hand grip 62 for adjusting the lever in any one of the notches of a retaining segment 60, Fig. 2. The lever 58<c> terminates in a setting knob 61 and co-operates with a retaining segment 59. A settable cam 68 in the position shown allows normal operation of the pawl 13 ; when turned at right angles to this position a forked lever 69 is moved thereby to bring the end 72 into engagement with a pin 23 on the arm 24, so that on each movement of the arm 24 the lever 69 is swung to bring the end 71<b> of the fork over a projection 74 on the actuating pawl 13 which on rising is rocked clear of the segments and rendered inoperative. The end 71<b> is stepped in accordance with the steps on the pawl. Another manually-set cam 75 is adapted to lift the actuating pawl lever 11 clear of the operating lever 7 to render the device inoperative.