GB738881A - An improvement in or relating to hydraulic lift mechanism for agricultural tractor-implement combinations - Google Patents

Abstract

738,881. Agricultural implements. BROWN TRACTORS (ENGINEERING), Ltd., D. May 26, 1954 [May 26, 1953], No. 14552/53. Class 6 (1). A tractor-implement linkage comprising two laterally-spaced lower links b, f and a central upper link r is characterized in that each of the lower links is operable by a separate hydraulic piston and cylinder and the upper link r incorporates a further hydraulic cylinder n and piston q operable to lengthen or shorten the link r. As shown, hydraulic fluid is fed from a supply conduit d to the bottom of a cylinder a by means of a valve c. The upper end of cylinder a is connected to the lower end of a cylinder e by a conduit g which is fed by hydraulic fluid through a valve h. When the interconnected spaces above piston i and below piston are filled with liquid, the admission of fluid below piston i results in both the lower links being raised simultaneously. Admission of fluid through valve h will result in raising the piston j relative to the piston i, thus adjusting the transverse level of an implement. Both ends of the cylinder n are interconnected and joined to the conduit d through a valve p. The piston q has a difference in area between its two faces due to the attachment to one face of the piston rod. Thus admission of fluid through valve p will cause lengthening of the effective length of the upper link r. The cylinder n may be connected to the supply conduit d by means of two separate conduits and valves.