| 摘要 |
A reversing gear drive system is provided in an irrigation sprinkler for reversibly shifting the direction of rotation of a sprinkler spray head for back and forth part-circle rotation between adjustably set end limits, to sweep an outwardly projected stream of irrigation water through a predetermined arcuate pattern to irrigate a surrounding terrain area and associated vegetation. The reversing gear drive system includes a gear carrier having first and second output gears driven rotatably in opposite directions. A shift mechanism is provided for shifting the gear carrier between forward-drive and reverse-drive positions with the first and second output gears alternately engaged with a ring gear for rotatably driving the spray head in opposite directions. The shift mechanism includes a shift lever and a reverse trip spring for engaging arcuately spaced limit stops mounted for rotation with the spray head. As one of the limit stops rotates into engagement with the shift mechanism, the limit stop initially engages and loads the trip spring to apply a reversing shift force to the shift lever, and then engages and retracts a latch to release the shift lever for spring-loaded shifting of the gear carrier to reverse the direction of spray head rotation. Upon such reversal, the latch re-engages the shift lever to positionally retain the gear carrier until the opposite limit stop rotates into engagement with the shift mechanism.
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