Patent GB-794415-A (GB)
Title: Improvements in or relating to drive transmissions for material-handling machines
IPC: F16H3/091
Filed: 1954-05-03
Abstract: 794,415. Change-speed gearing. EIMCO CORPORATION. May 3, 1954 [Aug. 28, 1953], No. 24714/55. Divided out of 794,413, [Group XXI]. Class 80 (2). Change-speed and reverse gearing for a mobile materials handling machine, such as a shovel bucket as described in Specification 794,413 [Group XXXI], comprises parallel input, intermediate and output shafts, gear trains between the intermediate shaft and one of the other shafts selectively rendered operable to give different speeds by engaging clutch means, and further gear trains between the intermediate shaft and the remaining shaft similarly rendered operable by selectively engaging further clutch means to give forward and reverse drive for any of the available speeds. As shown, the change-speed and reverse gear is driven through a torque converter (not shown) and a universal joint 34, Fig. 2, to rotate an input shaft 242. Gears 254, 256 fast thereon mesh gears 272, 258 selectively clutched for low and high speeds to a shaft 248 by multidisc clutches 274, 260. Each clutch is disengaged by a spring 282 and engaged when lubricating oil under pressure is admitted through conduits 270, 284, partly in the shaft 248, to cylinders 278 fast on the shaft containing pistons 280 which act as presser plates. A gear 286, fast on the shaft 248, meshes through idle gears 320, 322, Fig. 5 with gears 318, 318<SP>1</SP> rotatable on and clutchable to two driven shafts 246, 252. A gear 288, also fast on the shaft 248, meshes directly with gears 302, 304 also clutchable to the two driven shafts. The trains between the shafts 248 and the driven shafts 246, 252 all have the same ratio and are used to reverse the directions of rotation of the driven shafts and of the two tracks &c. of the machine. The forward-reverse clutches on the driven shaft are of the multi-disc fluid-operated type generally similar to the clutches 260, 274. The gear 256, Fig. 2, on the input shaft 242, also meshes a gear 256<SP>1</SP> fast on a power take-off shaft 240. A gear 401, fast with the gear 254, drives through a gear train to a governor 286<SP>1</SP> which controls a valve in a chest 342 to set the two-speed gear for high or low speed. The chest 342, Fig. 7, contains three slide valves 344, 350, 352 of which the first selects and establishes the desired ratio, while the second and third select and establish the engagement of the forward and reverse drives to the driven shafts 246, 252. A pump 222 supplies fluid through a conduit 340 to a central chamber 346 in the valve chest. Displacement of the valve 344 left or right from the neutral position shown allows oil to be supplied through the conduit 270, or 284 to engage the selected clutch 260, 274. A line 354 returns the oil to the sump of the gear. The pump 222 also supplies oil through a reducing valve 366 to the torque converter 22. Excess oil passes through a filter 370 and by-pass valve 372 to a conduit 374 and lubricating line 378. Branch lines 380, 382, 384, partially in the shafts 248, 246, 252, Fig. 5, carry the oil to the bearings and clutches of the gearing and to the gears, whence it drains into the lowermost portion of the casing.