Improvements in or relating to oscillation mechanisms for irrigation lines

907,291. Crop sprayers; liquid-pressure engines. HUGGAN & CO. Ltd., JOHN. July 20, 1959 [July 21, 1958], No.23268/58. Classes 69 (2) and 69 (3). An irrigation pipe-line is angularly oscillated about its axis by an hydraulic motor comprising a piston within a cylinder 15, control valve 17 and valve operating mechanism 18. The motor is pivoted to a base 10 at 21 and to a crank 14 attached to a tubular member 13, Fig. 3, rotatably carried in a fixed bearing 12 supported by a post 11. Pipe-lines 39, 40 with spray nozzles therealong have their one ends received by clamping rings 64, 65 surrounding the member 13. Water from the pipe-lines is fed from an opening 62 and outlet 61, Fig. 3, to a hose 41 leading to the motor control valve, and waste water from the motor is fed from a valve-controlled outlet 25 of the valve via a hose 42 to a discharge nozzle 43. The control valve connects, through tubes 27, 28 to the upper and lower ends of the cylinder, and the arrangement is such that water is alternatively fed to the opposite ends of the cylinder to drive the motor, and exhaust water is fed to the nozzle 43. The valve is automatically operated by a lever 29 operated by a mechanism 18 comprising a rod 30 passing through the lever and pivoted to the reciprocating member 19. Collars 33, 34 are bolted to the rod, and springs 35, 36 are interposed between the collars and the lever 29 and act thereon at the extreme positions of the piston to move the valve lever from one position to another. The lever is held in those positions by a spring-loaded plunger which engages notches in the lever. The amplitude of the oscillation can be adjusted by adjustment of the collars, and the frequency by the valve 26 in the outlet 25. In a modification water is fed to the pipe-line via a main connection on the bearing member, and the latter carries a filter from which a hose leads . to the control valve.