Patent GB-1488066-A (GB)
Title: Powdered link device for alternate operation of two movable members
IPC: A01B69/02
Filed: 1975-10-24
Abstract: 1488066 Linkwork DEERE & CO 24 Oct 1975 [24 Oct 1974] 43876/75 Heading F2K [Also in Division A1] Alternate operation of a pair of row markers 82, 84 of an agricultural implement such as a planter is effected by a single acting hydraulic link 32 controlled by a pair of double armed pivoted respective detent and actuating levers 50, 56 and an overcentre spring toggle link 62. The row markers 82, 84 are connected via rods 78, 80 respectively to L.H. and R.H. end blocks 36, 34 of the hydraulic link 32, which ends 36, 34 carry guide blocks 44, 42 which slide in guide slots 26 in a wall 14 of a surrounding housing 10, the wall 14 having a fixed pivot pin 28 on which the levers 50, 56 are mounted via a hole 54 and an elongate slot 66 respectively. The detent lever 50 has notched ends 94, 98 which act as detents to lock one or other of the hydraulic link blocks 36, 34 (36 as shown in Fig. 6) at the end of the guide slots 26. The actuating lever 56 has raised hook ends 58, 59 and is slidably mounted via its slot 66 on the pivot pin 28. The overcentre spring toggle link 62 is effective to pivotally bias the levers 50 and 56 in relatively opposite directions such that when the actuating lever 56 is turned clockwise the detent lever 50 is turned anticlockwise, and vice versa, as the toggle link 62 moves across the dead-centre position through the pivot 28. In operation, and starting with the mechanisms in the position shown in Figs. 1, 4 and 6, i.e. with the L.H. row marker 84 in its lowered operative position and the R.H. row marker 82 in its raised inoperative position, the detent lever 50 is in its full clockwise position in which it locks the L.H. block 36 of the hydraulic link 32 to maintain the R.H. row marker 82 raised (Fig. 1), the actuating lever 56 being at its fully moved L.H. position, i.e. with the R.H. end of its slot 66 engaging the pivot pin 28, in its fully anticlockwise position. Operations of the hydraulic link 32 moves its free, i.e. unlocked, end 34 rightwards along slot 26 (Fig. 7) to raise the L.H. row marker 82 via the rods 80 and during this movement engages the upraised end hook 59 of the actuating lever 56 to additionally also slide this lever 56 to the other end of its slot 66 on the pin 28. As the spring detent link moves across the pivot pin 28 (Figs. 7 and 8) the actuating lever 56 is turned clockwise to disengage its R.H. hooked end 59 from the R.H. block 34 and, also via the spring toggle link 66, simultaneously turn the detent lever 50 anticlockwise to release the L.H. block 36 and engage and lock the R.H. block 34. The L.H. block 36, now being free, allows the R.H. row marker 82 to descend by gravity, the L.H. block 36 freely sliding in its slot 26 (Fig. 7), until the R.H. row marker 82 contacts the ground whereafter the L.H. block 36 can float in its slot 26 to allow the R.H. row marker 82 to move up and/or down to follow varying ground contours. Further alternate operation of one or other row marker is effected by simply repeatedly operating the hydraulic link 32 to move one or other end 34 or 36 respectively of the link 32 as set out above.