Abstract: An hydraulic ram is situated between the tillage tool and the frame and is normally fully extended and acts as a rigid link. The ram has a predetermined and adjustable pressure so that if an obstruction is encountered by the tool, it only retracts when the preset pressure is exceeded and then returns to the fully extended position as soon as the obstruction is passed. It can be used on machines such as discers, hoe drills, press drills or any ground working implement which includes tillage tools which are pivoted to the frame and which do not engage the ground by raising and lowering the frame. An adjustable pressure reducing valve is situated in the hydraulic line extending to the ram and senses the pressure downstream of the valve rather than the pressure upstream as is usual.

Abstract: A cultivating implement such as a discer is provided with a coulter disc engageable with the ground and secured to the tail beam with the depth being preset by the hydraulic setting of the main disc gang. A fluid operator is included at a preset pressure and normally is fully extended until an obstruction is reached at which time the preset pressure is exceeded and the fluid operator or ram unloads and allows the coulter to raise up and clear the obstruction. Once cleared, the pressure in the ram returns the coulter to the preset depth. This coulter assists in maintaining the angle of travel of the discer, particularly on side hills, together with the pivoted rudder wheel assembly. In this invention the rudder wheel assembly is normally held against a stop at the desired angle, by a further ram or fluid operator instead of a spring and which only unloads during turning to allow rudder wheel assembly to break away.

Abstract: A depth control device is attached to agricultural implements such as cultivators, seed drills, discers and the like, in order to control, within pre-determined limits, the depth of penetration of the earth working components. It comprises firstly a ground or surface engaging sensing member extending forwardly of the framework and secondly, a sensor that is connected to the earth working components. Both of these sensors are connected to mechanism to raise and lower the earth working components which controls the depth of penetration thereof so that, for example, if uneven ground is encountered, the depth penetration is corrected and if the density changes of the ground being worked, thus affecting the suction, then once again depth penetration is corrected. Structure is provided to average out the effect of conditions changing the depth of penetration so that the desired average depth of penetration is maintained particularly in relatively wide machines.