GB824186A - Improvements in or relating to change-speed gear units for tractors - Google Patents

Abstract

824,186. Change-speed gear; gearing for stopping and starting machinery. INTERNATIONAL HARVESTER CO. OF GREAT BRITAIN Ltd. (International Harvester Co.). April 25, 1957 [May 17, 1956], No. 15396/56. Class 80 (2). [Also in Group XXXI] A change-speed gear unit wherein drive is transmitted from a clutch sleeve 1 to a driven shaft 2 through selective gear ratio means and the clutch sleeve 1 is selectively driveable from a primary drive shaft 17 either directly or through reduction gearing, has a friction clutch 22 in the drive through the reduction gearing to the clutch sleeve and a power takeoff shaft 33 in constant driving connection with the primary shaft 17 through the reduction gearing, the clutch 22 being operable to disengage the drive to the clutch sleeve 1 while drive to the take-off shaft 33 is maintained. The latter is connected by an auxiliary shaft 32 and a pair of constant mesh gears 20, 21 to the primary shaft 17. A lay shaft 3 surrounds the auxiliary shaft 32 and carries gears 5 . . . 7 to cooperate with gears 9 . . . 11 slidably splined on the shaft 2 for operation by a gear lever 12 and selector mechanism to provide three gear ratios, a fourth ratio being provided by sliding a gear 4 to the left to couple the clutch sleeve 1 directly to dog clutch elements 2a on the shaft 2. The gear 11 also co-operates with reverse gears (not shown). For road use, the clutch sleeve 1 is connected to dog clutch elements 17a on the shaft 17 by movement to the right of an outer clutch sleeve 18 and drives the lay shaft 3 through the gear 4 and a gear 5, while for field use, the lay shaft 3 is driven at a lower speed through the friction clutch 22 and the gears 20, 21. The clutch is biased by springs 26 to the disengaged position and is moved to the engaged position by a thrust collar operated through a pair of levers 28 from a hand lever 34. Cams 36 on the lever 34 engage rollers 28b on the levers 28 and are arranged so that the clutch 22 is fully disengaged when the lever 34 is in mid position, a friction lining 30a co-operating with a taper 7a on the gear 7 to bring the shaft 3 to rest to facilitate gear changing. Further movement of the lever 34 causes a lug 37 mounted on the same shaft as the cams to engage a slot 38 in a selector rod 13 controlling the clutch 18 and causes cams 36b to move the collar 30 to a position in which the clutch 22 is disengaged but the friction lining 30a is clear of the taper 7a. The gears 5 . . . 7 and 9 . . . 11 may alternatively be of the constant mesh type.