GB1205475A - Improvements in or relating to agricultural implements - Google Patents

Abstract

1,205,475. Agricultural implements. INTERNATIONAL HARVESTER CO. 6 Feb., 1968 [6 Feb., 1967], No. 5801/68. Heading A1B. An agricultural implement comprises front and rear tool carrying units 13 and 14 in tandem which are so connected that, on encountering a low draught resistance, both units rise together, and, on encountering a high draught resistance, the front unit may rise independently of the rear unit. The rear unit 14 may always rise independently of the front unit. The rear unit is attached to the front unit via vertically spaced parallel links 40 and 41 which are pivotally connected to standards 37 on the front unit and triangular flanges 47 on the rear unit. This arrangement allows relative vertical movement of the units. The auxilliary frame 89 comprises angle bars 88, pivotably mounted on shaft 22 of the front unit, and a U-shaped member 97. This frame may be maintained, by a toggle linkage 90, in a substantially horizontal position, so that if the front unit rises due to a low draft resistance, the rear unit will rise, supported on the member 97. If the front unit rises due to a high draught resistance the toggle linkage 90 shown in the over centre locked position in Fig. 6 is released and the frame 89 pivots on shaft 22 to allow the rear unit complete freedom of vertical movement. Draught is transmitted to the implement through draught member 74 consisting of forward rod 78 and rear rod 75 carrying pin 81. A spring 79 surrounds the draft member 74, and at one end abuts plate 60 attached to the front unit and at the other end abuts a collar 80 attached to the rod 78. Under normal conditions, spring 79 absorbs the draft load. In high draft conditions the spring 79 becomes compressed, moving member 74 relative to the main frame and causing pin 81 to move against and release the toggle. Wheels 82 are pivoted on arms 83 attached to shaft 22. Said shaft may be rocked to raise or lower the wheels by a system comprising a hydraulic cylinder 84, the cylinder being anchored at one end to the auxiliary frame, and at the other to the shaft 22. Each of the front and rear units has two laterally spaced subunits 28, 29, 42, 43, each pair being connected together by flexible springs 30 and 53 respectively. These flexible connections allow the subunits to conform to the irregularities in the ground.