Hydraulic coupling between tractor and implement - has two spring loaded pressure relief valves in series to discharge pressure in line

摘要

The hydraulic coupling between e.g. a tractor and an agricultural implement such as a plough incorporates a socket which fits a conventional sleeve. This socket (1) has a tapered plug (2) at its outer end which is held in contact with its sloping inside face (2a) by a spring (10) forming an outer valve. This is mounted on a spindle (6) with a tapered part forming an inner connection for a bore (14) down the centre, when pushed inwards. This bore is in a spindle (8) behind the plug and which carries the spring. The spindle also carries an inner plug (3) which rests against a collar (3a) forming a second valve. This spindle is pushed back against a second spring (13) housed partly inside it and partly inside a partition (12) at the rear.