| 摘要 |
1,147,845. Intermittent gearing. NATIONAL CASH REGISTER CO. 30 Oct., 1967 [27 Feb., 1967], No. 49177/67. Heading F2Q. An intermittent drive mechanism comprises, in a casing 12, a disc 18 secured on an input shaft 14 and having a driving dog 24, and a rotatable output disc 28 carrying equi-angularly spaced plungers 36 axially movable into and out of the path of the dog 24 under the control of a fixed plate 60 located between the discs 18, 28 and having a cut-out 70 defining an arc of driving engagement. As the shaft 14 is uniformly rotated manually or by a motor, the dog 24 travels round a circular groove 72 in the plate 60 until on entering the cut-out 70 at 70a it engages one of the plungers 36 and carries it to the edge 70b where a ramp 76 acts on the inclined head 74 of the plunger to cam it out of the path of the dog 24. By this time another plunger 36 has entered the cut-out 70 ready to be engaged on the next revolution of the dog 24. The advance of the output disc 28 thus depends on the arcuate extent of the cut-out 70 and the number of plungers 36. The plate 60 and disc 28 are replaceable to alter the step angle. The plungers 36, which may be of trapezoidal or circular cross-section, are urged axially by springs 40 which react on a plate 46 bolted to the disc 28, flanges 38 limiting the plunger travel. The output disc 28 may carry a cam 82 to operate a switch (86) (Fig. 3, not shown) or may be connected to a tubular output shaft. To stop the shaft 14 after one revolution, a stop 78 is slidden into the path of a dog 26 on the disc 18. Two or more mechanisms having different step angles may be driven by a single input shaft 14. Reverse rotation of the shaft 14 is prevented by the abutment of a plunger 36 against the edge 70a of the cut-out 70. |
