Patent GB-926331-A (GB)
Title: Improvements in or relating to agricultural implements
IPC: A01D78/00
Filed: 1959-08-24
Abstract: 926,331. Haymaking machines. C. VAN DER LELY N.V. Aug. 24, 1959 [Sept. 1, 1958], No. 28864/59. Class 6(3). In an agricultural implement having tools 8 movable between alternative settings by means of an actuating mechanism 5, the mechanism includes a displaceable control-member 21, 13, which is held in either of two positions by a latch 15, against the action of a restoring means, the arrangement being that when the controlmember is moved to a certain extent by an operator against the action of the restoring means, the latch releases the control-member so that it can move under the restoring force towards the second position, it being necessary for the operator again to move the controlmember in the last part of its travel whereafter the latch will hold the member in the second position until a further change is required. The system is shown applied to the haymaking machine described in Specification 926,332 and which comprises four rake-wheels 8 mounted along a beam 1 so that the front two project forwardly and the rear two rearwardly, the frame being supported, in the middle, by two caster wheels 6, 7 each carried by a parallel-link assembly 4, 5 from a stub-beam 2, 3 projecting laterally from the main beam 1. The link assembly 5, Fig. 4, comprises a member 3B, integral with the stub-beam 3, and a member 5A carrying the vertical swivel-axle 7B of the wheel 7, these members being interconnected by pairs of parallel links 46, 47. One of the lower links 47 is bell-cranked and is connected by its other limb 51 to a corresponding link in the other assembly 4, through rods 52, 54 and intermediate levers 53, 55 on the beam 1. The whole frame can thus be raised and lowered parallelly by movement of the linkage 5, against the action of a spring 65 connected diagonally across it. An arm 44 is integral with the upper links 46 and is linked to an arm 42 on the end of a shaft 11 rotatable in a sleeve 10 carried by the frame. A lever 21 is rigidly secured to the upper end of the shaft and is pinned, by a spring- loaded pin 23, to a diamond-shaped controlmember 13 free on the shaft, the pin 23 being insertable into alternative holes 24, 25 in the plate 13. The plate carries a pivoted latch 15 which engages pins 30, 31 in a plate 28, or pins 33, 34 in a plate 32, the latter plate being fixed to the sleeve 10 and the plate 28 being adjustably anchored to it by a threaded rod 40 movable by a crank 39. When an operator pulls on the cable 68, the latch is caused to strike against the pin 31 which turns it and enables it to pass the pin 30, on release of the cable, with further turning due to lateral contact with the pin 30, the springs 64, 65 causing the beam 1 to rise on the link-assemblies 4, 5. The momentum of the system causes the lever 21 to swing, anti-clockwise, past the staticequilibrium position represented by the line 71. A further pull by the operator, towards the end of its travel, causes the lever to pass and then to lock itself against the pin 34, by means of the latch 15. This corresponds to the transport position for the tools, but a further pull on the cable 68 enables the sequence to be repeated in reverse. The adjustments 23-25, and 39, 40 enable the lever 21 to be positioned symmetrically about a line 73 joining the axis 12 to the point of application of force by the operator.