GB1142043A - Control arrangement for the hydraulic power lift of an agricultural tractor - Google Patents

Abstract

1,142,043. Tractor power lift mechanism. KLÍCKNER-HUMBOLDT-DEUTZ A.G. 4 May, 1966 [7 May, 1965], No. 19764/66. Heading A1P. A single control lever 62 has a cam 60 which can be moved to engage rollers associated with three separate linkages 20, 50 and 45 (Fig. 3, not shown) to provide position control, a combination of position and draft control, or draft control alone. Position control feedback from a cam 10 on the rockshaft 9 rotates a two-armed lever 15 about a shaft 17 to move the link 20, which, if the cam 60 engages the roller 22 associated with this link, operates the auxiliary control valve 32 to return it to neutral as the lift links reach the position selected by rotation of the cam 60. For draft control. the lever 62 is moved longitudinally of its pivotal axis to engage cam 60 with the linkage 45. Movements of the upper link 34 are transmitted via links 35 and 38 to a lever 41 (Fig. 3, not shown), which is fixed to the shaft 17 to move independently of the two-armed lever 15 to operate linkage 45 and hence the auxiliary control valve 32. For control under the combination of position and draft, the cam 60 is engaged with the linkages 50, movement of which is derived from a two-armed lever 52 (Fig. 3, not shown) which is pivoted to both the draft control lever 41 and to the arm 18 of the position control lever 15.