| 摘要 |
<p>949,541. Time switches. CONTROLS CO. OF AMERICA. Jan. 21, 1960 [March 16, 1959], No. 2180/60. Headings H2A and H2B. [Also in Division D1] A switch unit for an electrical sequence timer is operated normally at one speed but is advanced to a selected point at the end of its cycle at a higher speed during which time the control circuits are de-energized. The unit comprises a bank of cam-operated switches 46 driven by an arbor 32 rotated normally by a motor 10 driving a cam 12 imparting oscillatory motion to a pawl 24, 28 driving a ratchet wheel 26. The arbor is driven at high speed by a shaded pole motor 48 having an axially movable shaft carrying a peg on a spring 58 engageable with cut-out portion on a pinion 60 which alternatively drives the arbor through gearing and another ratchet wheel 84. The stopping position of the ratchet 84 is determined by a switch 55 co-operating with a cam 68 and a selector switch mounted underneath the ratchet wheel 84, the stopping position being selected manually by switches, Fig. 11 (not shown). On deenergization of the motor 48 the peg disengages with the pinion, thus halting the drive immediately, the rotor kinetic energy dissipating itself in friction. A switch 52, 54, 56 completes a self-holding circuit to the motor, which switch also disconnects another motor providing a slower speed drive. Specifications 949,547 and 949,550 are referred to.</p> |
