GB602144A - Improvements in or relating to power-take-offs for use with tractors - Google Patents

Abstract

602,144. Driving auxiliary apparatus. FERGUSON, Inc.. H. Dec. 10, 1945, No. 33275. Convention date, Jan. 25. [Class 79 (ii)] A power take-off unit for tractors of the type having a transmission case with a rear opening through which rearwardly projects a propeller shaft fast with the crankshaft, i.e. independently of the tractor transmission shaft and clutch, comprises a unitary housing boltable to said rear opening, and supported in the housing a power take-off shaft, one end of which carries a clutch supported and driven by the rear end of said propeller shaft, and means for applying and releasing pressure to the clutch members such means being located wholly in or upon the housing. The clutch may be of the selfenergizing type and its operating means may be a rod which passes longitudinally through the power take-off shaft. As shown in Fig. 1. the engine crankshaft 1 drives the normal flywheel 2, clutch 4, tubular shaft 5, change speed gears 6-9, shaft 10, pinion 13 and differential crown wheel 14. Attached directly to the crankshaft 1 is a propeller shaft 20 which drives through a self-energizing clutch 24, Fig. 3, the shaft 31, bevel-gears 37, 38 and hence the transverse power take-off shaft 57 carrying belt pulley 40. The shaft 31 also drives through spur gears 41, 43 a second power take-off shaft 44, whose splined outer end is protected by the pivoted guard 66. The clutch 24, which controls both take-off shafts, comprises an annular ring 25 fast with the housing 24 and propeller shaft 20, the ring having clutch facings 26. On one side of the driving disc 25 is the driven member 28 and on the other side is the driven member 27 fastened by cap screws 32 to the member 30. Interposed between the members 30 and 28 are light springs 29 which serve merely to maintain the driven members 27, 28 in light contact with the driving disc 25. When the drive is taken up by the clutch the members 28, 30 undergo slight relative rotation which causes the balls 34, held in conical seatings, to force the driven members 27, 28 into tighter contact with the driving disc 25 and so to transmit full load. The clutch can be released by rearward movement of the lever 53, Fig. 4, which rotates shaft 52 and causes cam 55 (see also Fig. 3) to act on the thrust race 56 to withdraw the rod 57 and so compress the clutch springs 29 to declutch. Such a layout of the clutch and its actuating lever permits the whole device to be made as a self-contained unit for bolting on to an existing tractor.