Patent GB-1178689-A (GB)
Title: Change-Speed Gearboxes
Inventor: PICKLES JOHN ROBERT
IPC: F16H3/08
Filed: 1966-08-16
Abstract: 1,178,689. Change-speed gear. ROVER CO. Ltd. 18 Aug., 1967 [16 Aug., 1966], No. 36559/66. Heading F2D. In a manually controlled motor vehicle change-speed gear, providing wide ratio range yet suitable for control by a single gear-shift lever, wherein one of the higher gear ratios is through two pairs of constant-mesh gears in series, a lower gear ratio is through two pairs of constant-mesh gears in series with said firstmentioned two pairs. In the six Forward speed and Reverse gear-box shown, front and rear compartments, to the left and right of a transverse wall on the line Z-Z, respectively contain a generally conventional constant-mesh four Forward speed gear providing 3rd-6th ratios, and gearing providing 1st, 2nd and Reverse ratios. In the front compartment a first layshaft L has fast thereon a gear A 2  constantly meshing a gear A 1  fast on an input shaft I and three gears respectively constantly meshing gears B, C, D loose on an output shaft K, the input shaft I and the gears B, C, D being selectively clutchable to the output shaft K by double sliding dog clutches N 1 , N 2 . The gear D is also connected to a gear E in the rear compartment by a sleeve H which is journalled in the transverse wall and also forms an intermediate bearing for the output shaft K. The gear E constantly meshes the step P 1  of a cluster P 1 /P 2  free on a second layshaft T having fast thereon a gear Q constantly meshing a gear G fast on the output shaft K. A gear F free on the output shaft K constantly meshes the step P 2  of the cluster P 1 /P 2  and also the step V 2  of a reversing idler cluster V 1 /V 2 . A clutch member/ gear S slidably keyed on the second layshaft T has dog clutch teeth engageable with the cluster P 1 /P 2  and gear teeth engageable with the step V 1  of the cluster V 1 /V 2 . In operation, 1st is by clutching, via a dog clutch N 3 , the gear F to the output shaft K for drive through the gears D/E, P 1 /P 2 , F; 2nd is by clutching, via the clutch member/gear S (leftwardly shifted), the cluster P 1 /P 2  to the second layshaft T for drive through the gears D/E, P 1 /P 2 , Q, G; and Reverse is by engagement of the clutch member/gear S (rightwardly shifted) with the step V 1  for drive through the gears D/E, P 1 /P 2 , F, V 1 /V 2 , S, Q, G. For four wheel drive, one or both outputs can be taken from the second layshaft T or, preferably, from the main output shaft K and an auxiliary output shaft Y drive from the shaft T through gears Q, W. For front wheel disengagement, a dog clutch M may be incorporated in the shaft Y, a rear wheel disengaging dog clutch R being provided at the rear end of the output shaft K. A P.T.O. may be provided at the rear of the shaft Y, via a dog clutch N, or at either end of the second layshaft T. In a suitable gate arrangement, Reverse is opposite 2nd on the left, 3rd opposite 4th and 5th opposite 6th (top). 1st is on its own on the extreme right and is engageable only by lifting a detent, conveniently that used in respect of Reverse. In the modification of Fig. 2 (not shown), the cluster P 1 /P 2  and the gear Q are respectively fast and loose on the second layshaft T, and the clutch member/gear S is slidably keyed to the gear Q.