Patent GB-1384637-A (GB)
Title: Alternating mechanism for hydraulic markers of agricultural implement
IPC: A01B69/02
Filed: 1972-02-22
Abstract: 1384637 Alternating mechanism for markers of agricultural implements INTERNATIONAL HARVESTER CO 22 Feb 1972 [26 Feb 1971] 8110/72 Headings A1B and A1D A multi row planter 10, or other agricultural implement, comprises a frame 11 with markers 12, 13 pivotally connected to its ends and operated by hydraulic cylinders 14, 15, pivoted to frame 11 and with their piston rod 16, 17 connected to the respective marker, and automatically controlled by hydraulic circuit 32 so that the right and left, alternately, hand marker is lowered (the other being maintained in, a raised position) as the implement is swung vertically about wheels 20 lowering it from its raised transport position to its lowered operative position at the end of the field as the implement is turned round. The implement is swung vertically about wheels 20, each of which is carried at one end of an arm 21, the other end of which is connected to transverse shaft 22 rockably mounted on frame 11, by a double acting hydraulic cylinder 23, the piston rod 27 of which is pivoted about pin 30 to an arm 31 fixed to shaft 22. Fluid under pressure from pressure source 24 on the tractor is fed to the cylinder 23 via pipe-lines 25, 26 to raise and lower, respectively, the implement. Marker cylinders 14, 15 are connected via conduits 39, 40 and alternator valve 36 to hose 34 which leads to the raise side of cylinder 23. Alternator valve 36 comprises ports 35, 37, 38 to which pipes 34, 39, 40 respectively are connected, and a plunger 42 slidable in the valve and with a reduced neck portion 43 by means of which port 35 is put into communication with either of ports 37, 38 depending on the position of plunger 42, which is shifted by an actuating mechanism including an extension 44 fixed to arm 31 and having mounted on it a swivel 45 with a recess in it to slidably receive a rod 46 connected at 47 to one end of a slide member 48 with a slot 49 in which is received a pair of guide pins 50 carried by a bracket 51 on frame 11. The other end of slide 48 has a reduced neck portion 55 terminating in laterally projecting ears 56, 57. A T- shaped member 59 has a broad cross member 60 straddling neck portion 55 of slide 48 with flanges 61, 62 at its ends projecting from its plane, and a pin 63 which is received in a slot 64 in bracket 51. Leg 65 of member 59 is pivotally connected to valve plunger 42 by pin 66, which is received in slot 67 in the leg 65, and is situated at one end of the plunger. Operation. Assume the implement to be in the transport position as in Fig. 1. The right hand marker 13 is to be lowered. Slide 48 is at the bottom of its stroke as in Fig. 2, and plunger 42 is to the right as in Fig. 10, connecting ports 35 and 38. Rod 27 is retracted in cylinder 23 as fluid from the raise side of cylinder 23 returns to reservoir 28 together with fluid from the right hand marker cylinder 15 expelled by the weight of marker 13 through conduit 40 and ports 38 and 35 to the raise side of cylinder 23. As the implement is lowered, the movement of arm 31 moves slide 48 upwardly until the lower pin 50 engages the lower end of slot 49. One edge of neck portion 55 of the slide engages flange 62 rocking T-shaped member 59 about the axis of pivot pin 66 so that pin 63 is moved to the mid-region of slot 64 without shifting plunger 42. When the implement reaches the end of the field, piston rod 27 is extended in cylinder 23 to raise the implement about shaft 22. Fluid under pressure from source 24 entering the raise side of cylinder 23 also flows through hose 34 and alternator valve 36 to right hand marker cylinder 15, extending rod 17 and beginning to lift marker 13. Slide 48 is moved downwardly by the motion of rod 31 and ear 56 of slide 48 engages flange 61 of member 59. The member 59 is left disposed by the upward motion of slide 48 whenever the implement is lowered so that whichever of flanges 61 and 62 had previously not been engaged by an ear 56 or 57 is on a level higher than the flange which had been engaged. Thus whenever the slide is moved downwardly a different one of flanges 61, 62 is engaged causing member 59 to rock about the fulcrum provided by pin 63, when moved to one end of slot 64, and to shift plunger 42. And so in this instance flange 61 is engaged by ear 56 and valve port 38 remains connected to port 35 until the counter clockwise rocking of member 59 shifts plunger 42 to the left, as in Fig. 11, closing port 38 and opening port 37 to port 35, as pin 63 is seated in the right end of slot 64 providing a fulcrum for member 59 to turn about. Fluid can still flow to right hand marker cylinder 15, lifting the right hand marker 13, by by-passing alternator valve. 36 by way of check valve 68 in conduit 69. The implement can be turned round and upon lowering it again the left hand marker 12 is lowered, slide 48 leaving member 59 positioned so that flange 62 is higher than flange 61, and on raising the implement fully the valve plunger 42 will be shifted, so that when the implement is subsequently lowered, the right hand marker 13 will be lowered. The movement of arm 31 is greater than that required to cause plunger 42 to be shifted and so the implement may be partly raised to cross obstacles, without reversing the valve 36 and alternating markers as the extra motion is absorbed by springs 52, 54 on shaft 46 at either end of swivel 45, and by the lost motion before pin 63 is seated in either end of slot 64.