Abstract: On a work appliance, an extension arm is held rotatably, and a scoop is held rotatably on the extension arm. Actuation of the extension arm and of the scoop is by means of hydraulic cylinders. Each cylinder is assigned a valve which controls the flow of pressure medium from a pump to the cylinder and from the latter to the tank. A rotational movement of the extension arm is accomplished with the top edge of the scoop maintaining its angular position when the extension arm is being raised or lowered. Valves which control the flow of pressure medium to the cylinders are activated with the ratio of the pressure medium quantities supplied to the cylinders being kept at a constant value independently of the size of the control signal controlling the flow of pressure medium to a cylinder for the actuation of the extension arm.

Abstract: On a work appliance, an extension arm is held rotatably, and a scoop is held rotatably on the extension arm. The actuation of the extension arm and of the scoop takes place in each case by means of a hydraulic cylinder. Each cylinder is assigned a valve which controls the flow of pressure medium from a pump to the cylinder and from the latter to the tank. A rotational movement of the extension arm entails a change in the angular position of the top edge of the scoop, this change having an adverse effect during the raising of the extension arm, particularly when the scoop is full.