GB1461773A - Clay forming press - Google Patents

Abstract

1461773 Piston extruder O M BULLEY 27 June 1974 [6 April 1973] 16678/73 Heading B5A A piston extruder for clay, comprises a die member removably mounted to the barrel, and apiston reciprocated by a pair of manually operated levers 50, each of which is pivotally attached at 52 to the barrel, and slidable through a pivot 56 connected to the piston. The die member may comprise a plate for extruding a solid section, or an adaptor for the extrusion of a tube. The die member is releasably supported inturned flanges, Fig. 2 (not shown), formed around three walls 14, 16 and 14, of the extruder barrel, and a further such flange formed in a door 18 comprising a further wall of the extruder barrel and which is closed by pivotable latches 28 engaging pins 30 at each side, and which is openable about a pivot for removal and replacement of the die, or adaptor, and for cleaning of the barrel and removal of surplus clay. The piston comprises a plate (42) Fig. 2 (not shown) which fits closely within the barrel, and from which depends a smaller plate (44) secured thereto with lost motion, by a pin (46), which permits air to flow around the pin (46) when the plate (42) is raised, to relieve any vacuum between the plate (42) and the clay. For its reciprocation, the piston plate is attached to the base of a U-shaped member, the arms 38 of which slide within the barrel walls 14 and are attached to frame members 36 which slide externally of the walls 14 between guide strips 48. The reciprocation is effected by the pair of levers 50, joined by an operating bar 54. A hopper 72 is provided, for loading the extruder with clay between the raised piston plate and the door 18. The clay is downwardly extruded through a guide frame having adjustably spaced apart upper and lower members 58, 62, the outer surfaces of which serve as guides for a wire, or knife, by which a required length of the extrudate may be severed. For extruding a tube, the adaptor, Fig. 3, comprises a member 64 having outturned flanges 66 locating onto the inturned flanges of the barrel wall and door 18, and defining a flow passage of increasing section towards a tube extrusion die plate 68 retained by a frame 70. The tubular orifice of the plate 68 is defined between outer and inner parts 69, 71, of the plate, which are replaceably attached together so that the orifice size may be varied.