GB379124A - Improvements in and relating to electro-hydraulic apparatus - Google Patents

Abstract

379,124. Hydraulic transmission of power. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. -(Assignees of Woods, W. J. ; 602, Union Street, Schenectady, New York, U.S.A.) Oct. 2, 1931, No. 27452. Convention date, Oct. 2, 1930. [Class 69 (ii).] Electro-hydraulic mechanism, which may open and close elevator doors, comprises a fluid casing, a plurality of pumps for producing different pressure differences in the fluid, piston means movable in different directions in response to said pressures, and electric driving means selectively operating said pumps to cause a corresponding movement of the piston means. A central oil reservoir 10 has fixed to its sides cylinders 11, 12, in which pistons 29, 30, connected by lateral rods 35, 36, are slidable on tubes 31, 32, which give communication between the reservoir 10 and the outer ends of the cylinders. In the reservoir is a pump housing 15 open above and below to the reservoir and containing two impellers 17, 18 loose on a shaft 21 driven by a reversible electric motor 22 cooled by a fan 23 ; one or other impeller is driven, according to the direction of motion of the shaft 21, by splined sleeves 27<1>, 27<1>, pressed by a spring 27 and provided with teeth engaging ratchet indentations in the impellers, whereby oil is forced through one or other of the passages 19, 20 to move the pistons. Blocks 37, 38 on the pistonrods 35, 36 are connected by a lost motion connection to cranks 39, 40, whereby, through stub shafts 41 above the oil level, a workengaging member 42 is operated.