Patent GB-1107223-A (GB)
Title: Change-speed gear transmission
IPC: F16H61/02
Filed: 1965-12-14
Abstract: 1,107,223. Change speed gear and control. EATON YALE & TOWNE Inc. 14 Dec., 1965 [8 June, 1965], No. 53081/65. Heading F2D. In an automotive vehicle, particularly " stopsynchronized ", change-speed gear, constantmesh gears are clutched to a shaft or shafts by sliding clutch members, such as 113, connected to fluid operated pistons 154 movable within cylinders 151 co-axially disposed in said shafts. The change speed gear may be a conventional single countershaft gear, a gear in which the clutchable gears are radially supported by their shaft, or, as shown, a gear in which the clutchable gears are radially supported by their engagement with corresponding gears of twin countershafts. The " stop-synchronized " arrangement shown comprises coaxial head (36), gear input 41, intermediate 67, gear output 56, and tail shafts (51). The head shaft (36), is gear driven and is connectible to the gear input shaft 41, by a fluid operated head main clutch (38). The tail shaft (51) is splined to the vehicle drive shaft (52) and is connectible to the gear output shaft 56 by a fluid operated tail main clutch (61). A fluid operated brake (43) is provided to station the gear input shaft 41. Front and rear constant mesh change speed gears are serially arranged respectively between the gear input shaft 41 and the intermediate shaft 67 and the latter and the gear output shaft 56. The front gear provides four forward ratios, viz. two reduced, one direct and one overdrive, and, as shown, the rear gear provides forward reduced, forward direct and two reverse ratios, the arrangement thereby providing eight overall ratios in both forward and reverse although the described embodiment is arranged to provideeight forward ratios and only one reverse. The rear gear may have ratios providing front gear ratio splitting or, as shown, range shift. The front and rear gears respectively comprise gears 101, 102, 103 constantly meshing and supported bY gears fixed to one pair of twin countershafts and gears 121 (through idlers), 122, 123 constantly meshing and supported by a further pair of twin countershafts on a plane angularly offset with respect to that of the front gear countershafts. Where ratio. splitting or range shift is not required, the gear 123 and its countershaft gears are eliminated. The gears 101, 102, 103 and the gears 121, 122, 123 axially abut. Clutch members 113, 114 respectively axially slidable on the shafts 41, 67 are respectively selectively engageable with internal clutch teeth of the gears 101, 102, and 102, 103; and clutch members 136, 137 respectively axially slidable on the shafts 67, 56 are respectively selectively engageable with internal clutch teeth of the gears 121, 122, and 122, 123. Each clutch member 113, 114, 136, 137 is internally grooved at 164 to accept ears 162 extending through shaft slots 152 from pistons 154, 154a, 154b, 154c movable in axial cylinders 151; in the shaft 41, 151a, 151b in shaft 67, and 151c in the shaft 56. The pistons are each urged to one end, i.e. the bottom, of its cylinder by a spring or, as shown, by fluid pressure acting on its small diameter face 161 and is opposingly moved to the other cylinder end by fluid pressure acting on its larger diameter face 159. The fluid pressure acting on the faces 161, is fed through a conduit 174 to the piston 154, a sealed, spring-loaded, abutting tube pair 181 to the piston 154a, a conduit 191 to the piston 154b, and a further abutting tube pair 208 to the piston 154c. The fluid pressure acting on the faces 159 of the pistons 154, 154a, 154b 154c is respectively, fed through passages 173, 196, 197, 214 in turn fed through rotary fluid joints. The head clutch and/or brake may be lubricated by the feed line of the conduit 174. A control valve box (227) supplied with pressure fluid from a vehicle engine or change speed gear oil pump comprises a clutch/brake handle (228) or pedal movable between " Engaged " and " Neutral " positions, and a shift handle (229) selecting 1-8 Forward and Reverse. In the " Engaged " position of the clutch/brake handle both head and tail clutches are engaged and the brake released, and in the "Neutral ,position the clutches are disengaged and the brake applied for " stopsynchronized" " gear shift. In operation, the clutch/brake handle is moved to " Neutral " and to " Engaged respectively before and after gear shift.