GB624223A - Improvements in and relating to starters for internal combustion engines - Google Patents

Abstract

624,223. Elastic-fluid turbines. BRITISH THOMSON-HOUSTON CO., Ltd., GRAHAM, D. H., FORSLING, B. E. G., and TABBERER, G. June 16, 1947, No. 15814. [Class 110(iii)] [Also in Group XXVII] In starters for internalcombustion engines as described in Specification 517,844, [Group XXVII], in which either gases under pressure, formed by burning a cartridge, or compressed air, are utilised in a starter motor of the turbine type which is connected to the engine shaft through gearing and an automatic engaging and disengaging device, means are provided to reduce or shut off the supply of gas to the starter rotor at a predetermined speed to prevent overspeeding of the rotor, the means being operated by the rotors or some other members rotating at the same or proportional speed thereto when the increase in diameter of the rotor or members which occurs with increase of speed reaches a value corresponding to the predetermined speed. A starter turbine rotor 3 stretches upon attaining an abnormal speed and contacts a shutter 7, normally held stationary in a casing 2 by a friction disc or shear pin, (not shown), and causes the shutter 7 to rotate until its further movement is prevented by stops, (not shown). Axial holes 6 are provided in the shutter 7 which upon rotation of the latter shut off the working gases which normally flow to the rotor 3 through one or more inlet nozzles 4. A relief valve or bursting disc, (not shown), permits escape of the working gases to atmosphere. In a modification, a disc member, driven from the rotor shaft either directly or indirectly through gearing, actuates the shutter before stretching of the rotor occurs. In a further modification, the disc member contacts rollers journalled on the shutter. In another modification, the shutter is replaced by a ring in the casing and stretching of the rotor rotates this ring a limited amount which latter member through a cam form on its periphery, actuates plungers and rocker arms to operate relief valves that by-pass the working gases from the starter turbine. The ring may be replaced by the shutter and actuated by a disc member, instead of the rotor, either directly or through rollers. The shutters may incorporate a cam form which actuates plungers and rocker arms that in turn operate a switch and prevent the firing of further cartridges. The plungers may also be used to indicate the position of the shutter.