| 摘要 |
<p>The irrigation system has a jet head rotated at a given speed to ensure adequate coverage, but not too fast to reduce the efficiency of the jet. The rate of flow of the jet is varied regularly for each amount of rotary movement of the jet. This effect is obtained by using a Geneva mechanism to control the jet, which may be rotated by the force of the water. This is forced through holes (36) in a partition (34) causing turbulence, driving the blades of a turbine (38) on a spindle (40) forming an input of a speed reduction device (42) with the Geneva drive (44, 46) at its output. This operates another speed reducer (80) which rotates the projection head (10) incorporating the jet nozzle (12). Water is discharged at the same rate which the head is rotating or nearly stationary.</p> |
