Abstract: Roughness or jerkiness in a hydraulic swing circuit in an implement having a plurality of control circuits each having a work performing device (28), (30), (32) including a swing circuit having a hydraulic motor (32), which when under an aiding load may function as a pump, is avoided in a construction that includes a source (10) of hydraulic fluid under pressure and a plurality of control valves (22), (24), (26) for the circuits which are interconnected between the source (10) and the associated work performing device (28), (30), (32). The system includes a pair of hydraulic conduits (34), (36) extending from the control valve (26) for the swing circuit to the hydraulic motor (32). A pair of pilot operated, dual level pressure relief valves (56), (58) are connected oppositely across the conduits (34), (36) at a location between the control valve (26) for the swing circuit and the hydraulic motor (32).

Abstract: Roughness or jerkiness in a hydraulic swing circuit in an implement having a plurality of control circuits each having a work performing device (28), (30), (32) including a swing circuit having a hydraulic motor (32), which when under an aiding load may function as a pump, is avoided in a construction that includes a source (10) of hydraulic fluid under pressure and a plurality of control valves (22), (24), (26) for the circuits which are interconnected between the source (10) and the associated work performing device (28), (30), (32). The system includes a pair of hydraulic conduits (34), (36) extending from the control valve (26) for the swing circuit to the hydraulic motor (32). A pair of pilot operated, dual level pressure relief valves (56), (58) are connected oppositely across the conduits (34), (36) at a location between the control valve (26) for the swing circuit and the hydraulic motor (32).

Abstract: A telescoping boom has a contact assembly carried on one boom section and has a contact member engaging an adjacent boom section. The contact member is biased toward the adjacent boom section by a spring between the contact member and a piston which is reciprocated in a chamber and defines a sealed compartment. Hydraulic fluid is introduced into the compartment to compensate for wear on the contact member.

Abstract: A tree with a harvester head includes a frame having a cutting area defined thereon and an accumulator area adjacent the cutter area with accumulator arms on the frame for holding the trees in the accumulator area and grapple arms for gripping a growing tree between the accumulator arms and the grapple arms. The arms are arranged such that the growing tree can be gripped between the closed accumulator arms and grapple arms during the cutting operation and then the accumulator arms can be opened to allow the grapple arms to automatically move the severed tree into the accumulator area in which it is then retained by the accumulator arms.

Abstract: An accumulator arm for use with a harvesting apparatus having support means with grapple means and cutter means on the support means consists of first and second portions which are pivotally interconnected and are normally biased to an end-to-end relation. The biasing means consists of a flexible member entrained over a sleeve forming part of the pivotal connection with first and second spring means interposed between opposite ends of the flexible member and the respective portions of the arm.