Patent GB-622278-A (GB)
Title: Improvements in or relating to walk type tractors
IPC: B62D51/00
Filed: 1945-08-18
Abstract: 622,278. Agricultural implements. GIRLING, A. H. G. Aug. 18, 1945, No. 21136. [Class 6(i)] [Also in Group XXXI] A walk-type power driven tractor or agricultural implement is arranged so that the centre of gravity of the power unit and transmission is offset relatively to the plane of the driving wheel. The transmission mechanism is enclosed in a casing which forms part of the chassis frame, and comprises a change-speed and reverse mechanism, a clutch, power take-off shafts on the driving and driven members of the clutch and a final reduction gear, embodying a further clutch which may be used to disconnect the drive to. the wheel when the tractor is being used as a stationary source of power. The tractor may be used to tow a trailer, the driver walking in front. or it may have a second wheel and an agricultural implement attached, the latter being power driven, the driver walking behind. Figs. 1 and 2 show the tractor with a second wheel 51 attached and rotary hoe units A and B also attached. The tractor, Figs. 1 and 2, comprises a casing 8, Figs. 4 and 5, which constitutes the main frame and encloses the change-speed and transmission gearing, the casing 8 carrying the driving wheel 44 and over the driving wheel a bracket 8b on which is mounted the power unit 12 (omitted from Fig. 2). Attached to the casing and engine are rods 9a, 9b, 9c terminating in a cross rod 9 to which is adjustably clamped a U-shaped handle 11, 11a. The transmission, Figs. 4 and 5, comprises an engine-driven pinion 13 in constant mesh with two other pinions 14, 15. Each of the pinions 13-15 is slotted at 13a 14a, 15a, one or other of the slots being engageable by a complementary tongue 16a on a chain sprocket 16 according to the position of the sprocket 16, which can be swung about the .shaft 25 by the gear lever 18. The gear lever is positioned in the notched gate 21 by a compression spring 20, and entry of dust through the gate is prevented by a sliding dust cover 22 which moves with and is spring-pressed from the gear lever 18. Engagement of the sprocket 16 with gears 13 and 15 gives low and high gear ratios, and with gear 14 gives reverse. Chain sprocket 16 drives sprocket 24 which is integral with the internally splined power take-off shaft 25. Drive is taken through the cone clutch 26a, 26b, which is operated by twisting the handle 11a which actuates chain 46a, bell crank lever 47, rod 32 and rotates the segment 31 whereby balls 35 held in recesses between the segment 31 and the gear casing cause axial displacement of the segment and of the clutch member 26b. Drive from the clutch is taken to the internally splined power take-off shaft 27a and to the train of gears 36, 37, 41, 42 to the axle 43 and wheel 44. The drive to the wheel can be interrupted by axially displacing the pinion 41 by means of the handle 40a, whereby the tractor can be used as a stationary engine and both the power take-off shaft 25 in direct connection with the engine, and the takeoff shaft 27a under the control of the clutch 26 can be used. For use as a power driven hoe, Figs. 1 and 2, a second wheel 51 is mounted on a bar 49 clamped to the gear casing 8, the distance between the two wheels being adjustable. Also secured to the bar 49 by clamps 52a, 52b are casings 53a, 53b carrying hoe units A and B driven by roller chains within the casings from a rotating shaft 55 in splined connection with the power take-off shaft 25. The roller chain drives rotary hoe blades 54. The depth of working is varied by adjusting the height of the wheel 61 which is mounted at one end of a centrally pivoted lever, the other end of which is quadrant shaped and notched, the lever being locked in the desired position by a detent 58a on lever 58 which is operable by rod 62, bell crank lever 47 and chain 46b from the rotatable handle 11a. One of the notches is arranged so that the hoe blades can be kept clear of the ground. The hoe blades are provided with dirt covers 57. Specifications 622,358 and 622,359 are referred to.