GB718423A - A step-by-step electric motor and improved sheet counting apparatus embodying such a motor - Google Patents

Abstract

718,423. Counting-apparatus. UNITED STATES STEEL CORPORATION. March 21, 1951, No. 6748/51.. Class 106 (1). '[Also in Groups XXXV and XL (b)] A device for counting sheets passing along a conveyor comprises two shafts moving with respect to indicating dials for indicatimg the number of sheets and packages of sheets counted, a clutch which drives the device and which is disconnected after a preset count has been carried out, and a reset motor which is energized to return the dials to zero after each count. The device is driven by a step-by-step motor 30 (see Group XXXV) fed with impulses from a thyratron circuit (see Group XL(b)) every time a sheet passes a photoelectric cell, thus producing a rotation of 1/112 of a revolution for each sheet. This motion is transmitted through a clutch 210, 214, which is controlled by an electromagnet 220, to drive a high-speed shaft 232 carrying the sheet number indicating pointer 272 moving, over a scale 362 divided into 112 graduations. A low-speed shaft 270 carrying a low-speed package indicating pointer 334 moving over a scale 364 divided into 16 graduations, is driven from the high speed shaft by means of reduction gearing 266, 274, 276,. 278 having a reduction ratio of 116. The highspeed shaft 232 carries a cam. 250 which operates a microswitch 246 when the sheet counter pointer 272 passes the zero position, and a cam 252 which carries a slot 253 into which a cam lever 252 drops also when the hand indicates zero. This has the effect of opening microswitch 254 and stopping the reset motor 354 during the return motion when it has returned the sheet count pointer to zero. The low-speed shaft 270 carries a cam 282 having a similar slot receiving a cam lever 286 opening a microswitch 284 during the reset operation only when the hand 272 is at zero. The low-speed shaft also carries a cam 290 which closes a microswitch 292 a few sheets before a bundle of packages is completed to operate a warning 376 to the operator, and a cam 294 which closes a microswitch 296 when the package count hand 334 indicates a preset number (12 in this case) of packages to make up a bundle, and the sheet count hand indicates zero. Since microswitch 246 is already closed and switches 254 and 284 are closed except when both hands indicates zero, closure of switch 296 completes a circuit through all four switches to operate a relay causing the following actions to take place:-The clutch magnet 220 is actuated thus disengaging the clutch 210; 214, and engaging 228, 229. This. couples the high-speed shaft 232 to a friction disc 230 engaged by friction discs 358 driven by the reset motor 354. The reset motor 354 is started in operation thus rotating shafts 232 and 270 in reverse by means, respectively, of the discs 230 and a disc 262 carrying the reduction gears 278, 276 and driven by friction discs 360. The shafts rotate in reverse until both the sheet count pointer 272 and the package count pointer 334 register zero, at which point, microswitches 254 and 284 are operated. The closure of the relay also operates a flap gate stopping the flow of sheets to the counter during the reverse motion. Opening of the switches 254 and 284 resets the device for a new count after a suitable delay produced by a delay circuit which is dependent on the conveyor speed so that a predetermined number of sheets passes before the counter is returned to its original position. In order to compensate for the addition or subtraction of sheets, a knob 338 is turned until a sheet indicating scale 322 indicates this number of sheets. This knob 338 is connected by gears 342', 344, 240 to the carrier 242 of the sheet counting switch 246 which is rotated about the cam 250 to advance or delay its operation by the required number of sheets. Simultaneously, the package count switch 296. and the warning switch 292 are correspondingly turned on their carrier 298 through gearing 340; 326, 318. 316, 314, 310, 312 and 300. The knob 338 is also used to preset the number of packages in a bundle by turning it until the indicator mark 368 is opposite " 12 " (on the present setting) on the package indicating disc 306 and turns the carriers of the counting microswitches in the same way.