GB681055A - Improvements in or relating to variable ratio power transmission apparatus for vehicles - Google Patents

Abstract

681,055. Change speed gear. INTERNATIONAL HARVESTER CO. Sept. 29, 1950, No. 23888/50. Class 80 (ii). [Also in Group XXXIj A variable ratio apparatus for a vehicle comprises a main gear unit having a driven shaft transmitting drive to final drive mechanism, an auxiliary gear unit, a primary drive shaft structure for driving both units, a selectively drivable shaft structure, selectively controllable means in the units for the drivable shaft structure at different ratios from the primary shaft structure and means in the main unit for transmitting drive from the drivable shaft structure to the driven shaft. As shown the transmission for a tractor includes a casing 19 enclosing a sliding tooth reversible change speed gear, a final drive casing 12 and an auxiliary reduction gear casing 22 detachably secured to the rear wall of the casing 12. The hollow primary drive shaft 25 carries a gear 29 and clutch teeth 38 and is internally splined to a shaft 32 carrying at its rear end a power takeoff extension 151. The gear 29 can be connected through the teeth 38 meshing with teeth 37 or indirectly through gears 51, 52 with a gear 36 axially slidable under the control of a lever 123 and splined on a tubular shaft 33 surrounding the shaft 32 and splinedly carrying gears 41, 42, 43 of the main gear. The gears 41, 42, 43 can be engaged with gears 44, 45, 46, 49 on a shaft 17 carrying a bevel pinion 16 meshing with a bevel gear 15 on oppositely extending final drive shafts 21. The rear end of the shaft 32 carries a pinion 67 of the auxiliary gear, the pinion 67 meshing with a gear 73 connected by a slip clutch 75 to a shaft 79 carrying an element 89 of a clutch under the control of a lever 112, by means of which the shaft 79 can be rigidly connected to a gear 74 meshing with a gear 71 on a tubular shaft 63 rigidly connected to the shaft 33 by a coupling sleeve 64. The levers 112, 123 are provided with an interlock so only one of the clutches in the main gear and the auxiliary gear can be operated, the arrangement being such that the drive can be transmitted through the auxiliary gear and the main gear or only the main gear. The interlock comprises recesses 137, 138 in the levers and an element 132 axially slidable in a fixed bracket 115, movement of one lever axially sliding the element 132 so that it positively engages the recess in the other lever, locking the lever locking in its neutral position.