Device for moulding and coating pipes and like articles

摘要

In apparatus for coating pipes &c., the pipe is mounted for rotation and the coating is supplied by a hopper, having at its outlet a strickle having a curved surface which is parallel either to the external surface of the pipe on to a plane tangential to this surface and which determines the thickness of the coating. In Fig. 2, a concrete pipe having reinforcement 2 wound round it is coated by concrete from a hopper 33 and a shoot 7, the lower part 7b of which is curved to form a strickle parallel to the plane tangential to the pipe. The concrete passes between the pipe and an apron 24 which is moved at the same speed and direction as the pipe on rollers 15-20. Staves 30 are forced in front of the concrete and are released at the roller 16. Vibrators 11a, 11b and 12 assist the flow of the concrete and remove air. When the coating is complete, the pipe is removed by shifting the vibrator 12 aside and releasing the apron 24 by lifting a counterweight 27. The apron may be heated by steam jets 28. In a modification, Fig. 4, the pipe 41 is rotated on rollers 45, one of which is driven. When the pipe has been placed on the rollers the concrete hopper 49 is lowered so as to rest on it by means of a plate 54 pivoted to one side of the hopper outlet, the other side of which is formed into a strickle 56, the surface of which is curved parallel with the pipe. The hopper is carried on counterweighted slings 59. A vibrator comprises a rod 65 mounted in rubber journals and carrying fins 69 and having a pneumatic vibrator on its end external to the hopper. The plate 54 is hinged upwardly to allow the concrete covering to be completed. A modification is shown in which four hoppers are used to coat one pipe. A smoothing plate having a vibrator may be hinged to the strickle 56.