Patent GB-514998-A (GB)
Title: Improved rotary hoe
IPC: A01B33/02
Filed: 1938-05-16
Abstract: 514,998. Machines for working land; clutches. GRAY, W. H. May 16, 1938, No. 14518. [Class 6 (i) [Also in Group XXIV] In a rotary hoe, adapted to be drawn by a tractor, the rotor 8 carrying the tines 105 is driven from the tractor through means which permit movement in all directions of the hoe relative to the tractor, and means are provided for (1) varying the speed of the rotor while the machine is in motion (2) raising the frame of the machine by power from the tractor, and (3) for adjusting and maintaining the depth of working of the tines when the machine is passing over rough ground. The frame of the machine is connected by a universal joint, Fig. 3 (not shown), with the draw bar of the tractor and the tractor driving shaft 18 is connected through a universal joint 21 to a splined socket 20 in which slides shaft 17b connected by a second universal joint 19 to the main longitudinal shaft 17, 17a. The means for raising and lowering the frame while the machine is in motion for adjusting the depth of working comprises land wheels 34 carried by cranks 35 on a shaft 36 driven by worm gearing from a vertical shaft carrying a bevel wheel 40 which can be rotated in either direction by a pinion 41 or 41a on shaft 17. The pinions are controlled by a dog clutch 42 sliding on shaft 17. To determine the extent to which shaft 36 is rotated, and hence the depth of working, pins 49a, 50. Fig. 5, are inserted in holes in collars 48 on shaft 36, and these pins, by engaging lever 51, throw the dog clutch into neutral position when the frame has reached the desired height. The means for limiting the depth of working on uneven ground comprises a depth control wheel 92, Figs. 2 and 8. on each side of the machine, the centres of the wheels being in vertical alignment with the rotor shaft 8. The wheels 92 are carried by arms 94 pivoted to the frame 1 and adjustable by inserting a pin through one of the holes 99 in the arcuate member 96. The rotor shaft 8 may be driven by chain gearing 12, 13 from either end of the composite shaft 11. 11a, 11b, 11c. The connection between shafts 11, 11a includes variable speed spur gearing 64 (see also Fig. 4, not shown), controlled by rods 72, 76 from a single hand lever working in a gap formed by recesses in two adjacent sliding plates connected to rods 72, 76 (Fig. 4a not shown). The connection between shafts 11b, 11c includes dismountable gears 88, 87, 89, 90 which can be selected to give any desired speed ratio. The rotor 8 may carry U - shaped tines or cutters, Figs, 28 - 31 (not shown), or "pick" tines, Figs. 23 - 27, and 32 - 35 (not shown). To destroy the surface grasses, the tines may be replaced by cutting knives helically disposed and extending from each side of the rotor towards the middle, thereby reducing the tendency of side-sway (Figs. 21, 22 not shown). The friction clutch 24, Fig. 2, coupling the parts 17, 17a of the longitudinal shaft comprises a recessed member 22, Fig. 10, on the driven shaft 17 receiving a plate 24 on the driving shaft 17a, the plate 24 having cylindrical dogs 25 engaging inclined arcuate recesses 27 in the member 22. The dogs are pressed into the recesses by a spring-pressed plate 28. A combined sprocket-wheel and clutch by which the shaft 11 drives the rotor 8, may be. similarly constructed.