Patent GB-497839-A (GB)
Title: Improvements in or relating to extrusion presses for the treatment of plastic masses
IPC: B28B3/22
Filed: 1937-05-25
Abstract: 497,839. Extrusion machines. LUDOWICI, W. May 25, 1937, No. 14553. Convention date, June 9, 1936. [Class 87 (ii)] An extrusion press for plas tic material such as clay com prises a worm and a mouth piece fixed relatively to on another without the inter position of webs or othe connecting members so as to provide an uninterrupted passage from the end of the worm to the outlet of the mouthpiece. In one construction, Fig. 4, the worm 12 and mouthpiece 13 are stationary and a casing 14 rotates. The mouthpiece 13 is disposed at right-angles to the axis of the worm. Alternatively, the casing may be stationary and the worm and mouthpiece rotate. In this construction an intermittently rotating disc is arranged below the mouthpiece so as to receive material extruded therefrom as it rotates. The diameter of the worm may diminish and the pitch increase in the direction of feed. In a further construction, the worm may be connected, as by welding, to the outer casing which carries the mouthpiece and an inner core is fitted inside the worm. The core may rotate and the other parts remain stationary or the core may be stationary as they rotate. In a further construction, Fig. 10, a stationary worm 25 carries a mouthpiece 31 and is arranged within a rotating casing 26. An outer casing 27 carries a mouthpiece 30 and has fixed within it a worm 28 between which and the casing 26 a core 29 rotates. The rotary and stationary parts may be interchanged, rotating discs then being provided below the mouthpieces. In a further construction one worm leading to one mouthpiece fixed thereto is disposed within a second worm fixed within a casing carrying a second mouthpiece, one worm and its connected parts being rotated relatively to the other worm and its connected parts. In further constructions, the worm is rigid and connected to the mouthpiece and extends between a cylindrical core and a casing. The upper end of the worm may be secured to a ring rotating about a reduced portion of the core. The upper end of the casing may be widened to form a funnel which may be provided with feed rollers disposed above the worm and comprising cylindrical or truncated conical sleeves or rolls. A conical feed roll may be mounted on the inlet edge of the worm thread. The lower end 74, Fig. 19, of the casing may fit within the upper part 66a of the mouthpiece which is enlarged to receive blades 79 carried by the casing. The blades may be triangular or rectangular and form part of a screw adapted to force back any material rising between the casing and the mouthpiece. The worm may be in the form of a hollow box-shaped member 85, Fig. 21, provided with a slot 86 and a pipe 88 for the withdrawal of air from the clay. A guide roller 87 may be provided adjacent the slot and rotate within a cylindrical recess 89. The Specification as open to inspection under Sect. 91 includes also constructions wherein a casing and mouthpiece rotate about a stationary worm and wherein a wheel engaging the worm is mounted in the casing funnel and is adapted to feed material to the worm. This subject-matter does not appear in the Specification as accepted.