| 摘要 |
1,271,115. Ratchet gearing. R.C.A. CORPORATION. 10 Sept., 1969 [23 Sept., 1968], No. 44606/69. Heading F2Q. A reversible stepped ratchet gear rotatably driving in steps an indicator disc 31, for remotely indicating the direction that an antenna rotator (not shown) is pointing, comprises a rotatable star wheel 25, geared at 47, 37 to the indicator disc 31, and a solenoid controlled fork-shaped pivoted pawl 15 having two diagonally opposing pairs of pawl teeth 65, 68 and 66, 67 as shown, or alternatively (not shown), three teeth of which two are in different planes relative to a single third opposed tooth to again form the two opposing pairs of teeth, one or other pairs of which is adapted to engage the star wheel 25 for forward or reverse drive thereof by selectively axially positioning the wheel 25 via a lever (51) (Fig. 5, not shown) and opposing spring 43, the pawl 15 being rocked about a pivot A by the solenoid 13 and a return spring 19 when the solenoid receives intermittent signals from a power source (not shown) via a switch (not shown) which opens and closes a given number of timers for one revolution of the antenna support shaft (not shown), the oscillating movement of the pawl 15 driving the star wheel 25 in steps i.e. one tooth at a time in a forward or reverse direction. The indicator disc 31 may be restricted to one revolution in either direction by a stop pin 45 on the disc 31 cooperating with a stop plate 39 which is slotted at 41 on the star wheel shaft 26 to compensate for the thickness of the pin 45 &c. |
