GB695710A - Improvements in or relating to agricultural implements - Google Patents

Abstract

695,710. Agricultural machines. SALMON, N. and OVERSEAS FOOD CORPORATION. April 5, 1951 [Feb. 21, 1950]. No. 4430/50. Class 6(i) Relates to agricultural machines of the type in which a tool-carrying frame is pivctally mounted upon a wheeled carriage in such manner that it can be raised and lowered, and in which releasable locking means are provided to lock the carriage to the frame when the frame is lowered and the tools are in the soil. According to the invention, the locking means is operatively connected to the means which swing the frame relatively to the carriage so as to be unlocked automatically whenever force is applied for raising the tools. The machine shown comprises a frame 11 carrying the root-cutting tools 17 and supported by a carriage or mounting in the form of a swinging boom 12 carrying land wheels 13. The boom comprises a pair of bell crank levers 18, 19, mounted one on each side of the frame 11 and mounted to swing about pivots 14 between stops 26, 28 to raise and lower the frame. As shown in Fig. 2, each stop 28 is adapted to be engaged by a lever 27 which rocks with the boom. The stop is mounted on a plate 30 which can rotate about the axis of the pivot 14 and can be secured in any one of four positions of adjustment by a bolt 31 which can pass through either one of two holes 33 in the plate and any of four holes in a fixed plate 29. The plate 30 carries a housing for a spring-controlled locking bolt 40, which by means of bevelled edges is first depressed and then released by arm 27 when it moves towards the stop 28, the release being effected when the bolt is spring- urged into locking engagement with a hole 39 in the arm. The wheel structure is lowered by a pull on a cable 23 connected to a winch on the towing vehicle and passing around pulleys 24 on the frame and boom. The end of the cable is connected to bell crank levers which are connected by further cables to the bolt. By this means the initial pull on the cable serves to withdraw the locking bolts. When the cable 23 is released to allow the frame to descend by gravity the cables leading to the bolts are slack and the bolts are therefore free to move into the locking positions under the action of their springs. Specifications 695,707 and 695,711 are referred to.