GB499165A - Change speed gear device with hydraulically operated clutches and free wheels - Google Patents

Abstract

499,165. Clutches ; variable speed gearing. KEGRESSE, A. March 16, 1938, No. 8184. Convention date, April 20, 1937. [Class 80 (ii)] In a three-speed gear, in which nested shafts are adapted to be connected to the engine by fluid-operated clutches 24, 25 and 26, Fig. 3, a conduit 33, supplied under the control of a pressure-varying device 32 by a pump 31, leads to the first-speed clutch 24, from which a conduit 37 leads to the secondspeed clutch 25, from which a conduit 38 leads to the direct-drive clutch 26. The conduits 33, 37, and 38 contain valves which are loaded by springs of increasing strengths, so that the clutches engage in succession as the pressure in conduit 33 is increased. A gear 42 on the shaft associated with clutch 24 meshes with a gear 28 connected to a countershaft through a free-wheel clutch 27 in parallel with a friction clutch 27<1>, a gear 43 on the shaft associated with clutch 25 meshes with a gear 44 rigid with the countershaft, and a further gear 45 rigid with the countershaft meshes with a gear 30 connected to the output shaft 46 through a free-wheel clutch 29 in parallel with a friction clutch 29<1>. The clutches 27<1> and 29<1> are engaged by springs and adapted to be disengaged by pressure fluid acting on diaphragms. A conduit 34 branching from the conduit 33 feeds fluid to the clutch 27<1> under the control of a valve 35, and a conduit 39 branching from the conduit 38 feeds fluid to the clutch 29<1>. When in first speed, valve 35 is closed, and both the free-wheel clutches are locked by their friction clutches. When in second speed, valve 35 opens and the friction clutch 27<1> is disengaged, while, when in top speed, the friction clutch 29<1> is also disengaged. Each combined free-wheel and friction clutch may be constructed as shown in Fig. 1, comprising rollers 6 arranged between an outer driving ring 2 and an inner cam member 5 secured to a driven shaft 3, while a female cone 10 splined on the shaft is normally pressed into engagement with a coned part of the ring 2 by a spring 14. The cone 10 is disengageable by pressure fluid fed through a passage 17 and acting on a diaphragm 16 secured to a plate 15 fast on the shaft. Fluid is supplied to the passage 17 from a duct 19 in the shaft 3 under the control of a spring- loaded valve 20, which also controls an outlet passage 22. A friction clutch may be arranged on each side of the free-wheel clutch, as shown, and the diaphragms may be replaced by pistons. Alternatively, the friction clutch may be of the disc, segment, or band type. Specifications 481 ,007 and 432,632 are referred to. According to the Specification as open to inspection under Sect. 91, the locking friction clutches may be controlled by electromagnets. This subject-matter does not appear in the Specification as accepted.