GB596122A - Improved axial flow pumps and extrusion apparatus - Google Patents

Abstract

596,122. Extrusion and injection-moulding apparatus. MUNRO, R. July 19, 1945, Nos. 18561 and 26637. [Class 87 (ii)] [Also in Group XXVI] An axial flow extrusion apparatus of the worm type Fig. 2, comprises a rotor 10 surrounded by a metering sleeve 21, the rotor being formed with at least one fluid-feeding thread 22, the pitch of which increases from a minimum at the fluid inlet end and to a maximum at the fluid outlet end, the flow of fluid from the pump inlet 1A to the pump outlet 6 taking place through the metering sleeve 21 in the groove or grooves between the turns of the rotor thread or threads 22. A thread with progressively increasing depth may replace or be incorporated with the thread of increasing pitch. Longitudinal vanes may be associated with the metering sleeve to prevent turbulence within the casing. The sleeve 21 is adjusted axially in the casing 1 by means of two screwed rods 26, 27 so that the sleeve may co-operate with different sections of the rotor thread or threads to vary the pump output without varying the speed of the rotor. In a modification, Fig. 8, the rotor 44 has an internal thread 45 and is fitted with an internal metering plug 46. Either the rotor or the metering means is adjustable relative to the casing either manually or automatically in accordance with the output pressure. In a further modification, Fig. 15, intermeshing rotors are used to prevent back flow and the metering means may consist of at least one fixed part and one or more moving parts. End thrust on the rotor may be balanced by discharge pressure acting on piston 94, Fig. 12, in space 93, via port 92, an axial hole in the rotor shaft, and ports 90, 91.