Patent GB-936292-A (GB)
Title: Improvements in or relating to change-speed gear mechanisms
IPC: F16H37/04
Filed: 1958-12-22
Abstract: 936,292. Change-speed gear and control. HUMBER Ltd., and A. M. WEST. March 1, 1960 [Dec. 22, 1958], No. 41379/58. Class 80 (2). In a motor vehicle, an epicyclic change-speed gear providing 1/1 and an increasing or reducing ratio is serially arranged behind, or before, a sliding-gear or a constant-mesh type two-speed and sliding idler reverse gear having its driven shaft 46 parallel to, and vertically offset below, its driving shaft 40 and providing an increasing or reducing ratio in either forward gear. The output shaft of the change-speed gearing may be connected to a rear-axle driving member, through a universally-jointed propeller shaft, or directly where the engine and change-speed gearing, or the gearing alone, is directly coupled to said rear axle driving member. Control may be manual and/or automatic and effected by electromagnetic, compressed air, suction, or, as shown, by hydraulic pressure means. As shown, the epicyclic gear comprises a driving-ring 13 fixed to a shaft 12 connected through a spring drive 11 and a main friction clutch 54 to an engine flywheel 10, a driven planet carrier 20 splined on a forward extension 15 of the shaft 40, and a sun 16. A friction clutch/brake member 23 is splined on the sun and is axially moved leftwardly to clutch at 24 the sun to the carrier for locked-up 1/1 ratio or rightwards to engage at 27 the sun with a fixed member 28 for reducing ratio through the epicyclic gear. The clutch/brake member 23 is actuated by pressure hydraulic fluid selectively admitted to servo chambers 31, 32 on opposite sides of a piston part 30 of the member 23. The constant-mesh gears comprise wheels 41, 42 integral with the shaft 40 and meshing wheels 44, 45 loose on, and selectively clutched to, the driven shaft 46 by a double, synchronized, positive dog clutch 48. The shafts 40, 46 also carry reverse wheels 43, 52, respectively. The main friction clutch 54 is actuated by pressure fluid admitted to a chamber 55 through line 56, and is cooled by fluid through line 59. In Fig. 1 (not shown), the shaft 12 is connected to the flywheel through spring drive 11 only, the epicyclic clutch/brake being employed as the main clutch. Fig. 3 shows a control for the change-speed gearing of Fig. 2 and comprises an engine-driven supply gear-pump 65 and two valves 66, 67 operated manually and/or automatically by output pump pressure. The valve 66 controls, through lines 69, 70, a servomotor the piston 78 of which is spring connected to a fork 50 actuating the clutch 48. The valve 67 controls, through lines 33, 35, the epicyclic servomotor 31, 32. A valve 82 has pistons 80, 88, respectively movable with the fork 50 and a reverse ratio selector and is arranged to exhaust pressure from the main clutch 54 through a line 84, and, through a line 85, exhaust the epicyclic servomotor 31, 32 and connect the pump 65 to the main clutch cooling line 59 during gear changing and neutral positions of the pistons 80, 88. The valve 67 incorporates a spring- loaded valve 92. The valve 66 exhausts to the main clutch cooling line 59 through a non- return valve 76. The main clutch feed 56 includes spring-loaded non-return and relief valves 96, 97.