GB1352465A - Hydokentic fluid torque transmission - Google Patents

Abstract

1352465 Change-speed control; friction clutches BROCKHOUSE ENG Ltd 6 May 1971 [9 May 1970] 25819/72 Addition to F2 Headings F2C and F2D A lock-up friction disc clutch 20, in parallel with an hydrodynamic torque-converter on a motor-vehicle, is disengaged by a bias fluid pressure permanently supplied to one side of a clutch piston 22 to overcome a diaphragm spring 23, and is engaged by controllably supplying an equal balancing fluid pressure to its other side A, permitting the spring 23 to engage the clutch. The supply to the side A is controlled by an automatic centrifugal valve 32, which, in its radially innermost position, exhausts the side A through a port 45 and shaft passages 46, 51, causing clutch disengagement, whilst, in its outermost position, the valve 32 supplies pressure to the right side A from the constantly pressurized left side B through ports 42, 41a, 40, for spring engagement of the clutch. The outward centrifugal movement of the lock-up valve 32, for clutch engagement, is resisted by a bi-stable rapid movement means, comprising a spring-loaded plunger 35, Fig. 3, loading the valve 32 through a triangular lever plate 37, pivoted at 39 to a part 31 of the torqueconverter turbine 13, either parallel or tangential to the shaft axis, and engaging the valve 32 and load plunger 35 through rollers 38, which, during outward valve movement, cause the moment arm of the plunger 35 to decrease, whilst that of the valve 32 increases, the reverse occurring on inward movement, so that movement in either direction, once initiated, proceeds rapidly. Inward movement may occur at the same or a lower speed than outward. An override valve 50 in a passage 47 can be actuated manually or by a gear-shift lever, to connect the passage 46 to a pressure inlet passage 41 instead of to exhaust 51, to cause clutch engagement in a desired gear setting.