The invention concerns an arrangement for the movement of a working unit of an agricultural working implement between a first position and a second position, with an actuator that is provided with a chamber to which a pressurized medium can be applied and that is coupled to the working unit in such a way that it brings the working unit into the second position when the medium is applied to the chamber and the working unit reaches the first position when the medium is not applied to the chamber. An accumulator control arrangement serves to connect the chamber of the actuator to the accumulator only when the working unit moves into the first position.

Lift wheel structure for an implement includes four bar linkage having a curved lower link connected to the frame closely adjacent a first tool-carrying rank. A caster wheel is supported at the forward end of the linkage for castering in an accommodation area defined by the curved lower link. Plates are bolted to the sides of the lower link and extend along sides of an upper link to a connection with a lift cylinder directly above the upper link. The link and the cylinder closely overlie the frame to limit interference with other components mounted above the frame and to facilitate compact folding of implement sections. Loads, including cylinder lift loads, are transmitted primarily through the lower link. A protected transducer assembly is connected between the lower link and the frame to maximize and linearize transducer response in the depth control range. The lift wheel structure can by mounted at different locations on the frame to accommodate different tool configurations and provide the desired automatic depth control and leveling functions. In one embodiment a tension link connects a forward four bar linkage wheel structure with a rear single pivot lift wheel structure such that level lift is provided.

The present invention is related to lawn maintenance and describes a system for mounting an accessory, such as a grass trimmer, to a riding lawnmower. The mounting system is simple, durable, and relatively inexpensive to manufacture and maintain, but provides a lawnmower operator the ability to operate an accessory while seated in the lawnmower. The mounting system is also advantageous in that the lawnmower operator need not specifically align the mower with any objects that present an obstacle for mowing, but may instead move the accessory to the object. The accessory mounting system comprises at least one link between a vertical pivot bar forming an axis for horizontal movement of the accessory and horizontal pivot point allowing vertical movement of the accessory.