GB615845A - Lifting gear of agricultural machines - Google Patents

Abstract

615,845. Agricultural machines. HALLEWELL, G., and BLACKSTONE & CO., Ltd. Aug. 14, 1946, No. 24202. [Classes 6 (i) and 6 (iii)] An agricultural machine with self-lift gear includes a driven member, lifting mechanism comprising a linkage operatively connecting the said member with the working tool and means to adjust the position of a pivotal connection at which a member of the lifting mechanism operates upon another, the adjustment being effected by movement along a line so chosen that the movement does not substantially affect the fully lifted position while varying the mechanical ratio exerted between movement of the lifting gear and movement of the tool from its fully lifted towards its working position. The lifting gear 1 is mounted on the axle 2 and includes a clutch and eccentric operating an eccentric strap 12. An actuating lever 13 on said strap is pivotally attached to a transmission lever 14 which is rigidly attached to a lifting shaft 4 which through a system of levers raises the tine bar fliers 7, 8. A slot is formed in the lever 14 in which a pin on the lever 13 engages, said pin carrying a block 16 through which a screw 19 operates. A trip lever co-operates with the eccentric and allows it a half revolution turn, the eccentric being stopped at either its highest or lowest position. In the latter case the tools are in the raised position. The working height is varied by movement of the screw 19 in the slot changing the effective length of the lever 14 and so the extent to which the shaft 4 is turned. The raised position remains constant as the slot is formed on an arc having its centre coincident with that of the eccentric in its lowest position. Specification 441,857 is referred to.