| 摘要 |
1,125,697. Intermittent gearing. SIEMENS A.G. 28 March, 1967 [28 March, 1966], No. 14004/67. Heading F2Q. [Also in Division B6] In an intermittent drive for a teleprinter, the tooth 6 of a worm on a shaft 4 extends for one complete turn less a gap of width equal to the tooth width of a worm-wheel 1, so that when the gap is aligned with the worm-wheel, the latter is free to rotate unless held by a detent (not shown). A continuously rotating shaft 2 drives the shaft 4 through a friction coupling 3, a pin 3a thereon being engageable by a stop 5 to arrest the shaft 4 with the worm tooth gap aligned with the worm-wheel. The worm tooth entry and exit are purely circumferential, so that on release of the stop 5 the worm-wheel is accelerated smoothly from rest, advanced one tooth pitch, and decelerated to rest. The wormwheel teeth la may comprise pins of involute contour, or be helical. The worm tooth 6 has a trapezoidal cross-section and is tapered at its start 6a. |
