GB661289A - Method of and apparatus for the manufacture of concrete pipes by moulding - Google Patents

Abstract

Apparatus for centrifugally moulding and lining concrete pipes, is of the type comprising a supporting framework having means for locating a vertical mould in axial alignment with a vertically reciprocating and rotating piston or packer having packing elements, and means for moving the piston up and down so that it traverses the mould from the bottom to the top, the piston and its associated parts being counterbalanced. In the apparatus of the invention, Fig. 2, the piston is mounted on the upper end of shaft 12 which is carried within an outer sleeve 12a, the shaft being rotated by the motor 13 through a belt drive 17. The supporting structure 16 has rollers 18 which run on vertical parts of the frame. The piston assembly is vertically lifted by a reversible electric motor 19 driving through automatic change speed and reverse gearing a cross-shaft 20 counterbalanced by weights 23, (see Group XXIV). With this arrangement overdrive is prevented. The mould support consists of a floor plate 43, and an upper supporting tray 45 with a mould retaining ring on its underside. The tray is guided at each side and may be raised or lowered by means of a lever 51, rods 50 and counter-balanced bars 59. The tray has a plate 47 arranged to receive a cylindrical pipe socket former which may be rotated by an electric motor 77. The table may be freed by movement of a lever 54 which causes the adjustable stops 53 to swing rearwardly, thereby enabling the table to rise and so allow the insertion or removal of the mould. The piston wall, Figs. 4, 5, is preferably built up from wear resisting metal strip 62, and packing elements 63 are mounted on the piston crown, each element consisting of a blade pivoted on a spindle 64. The blades are coupled together through a toggle mechanism 67, 68, to a vertical actuating rod 65 which passes through the centre of the piston and its driving shaft and is freely movable with respect thereto so that the rod may be lowered or raised by a lever 71, Fig. 1, (not shown), to open or retract the blades, the end of the lever being arranged to engage adjustable stops 73, 74, during the process. In operation the body of the pipe is first moulded and then the lining material which may consist of sand and cement with or without fillers such as powdered glass, carbon &c. is fed on to the piston crown. The motor 19 then raises the piston with the blades open or <PICT:0661289/III/1> <PICT:0661289/III/2> <PICT:0661289/III/3> projecting so that the material is wiped into the soft surface of the pipe body, at the same time further compressing the body. The socket of the pipe however is not lined. When the head of the piston is clear of the former the blades are retracted by the engagement of the lever 71 with the stop 74, the motor 19 is automatically reversed and the piston returned at a faster speed to smooth the lining. Specification 661,290, [Group V], is referred to.