GB779081A - Improvements in pipe making machines - Google Patents

Abstract

779,081. Pipe-making machines. TONIOLO, L. May 13, 1955, No. 13966/55. Class 99(2) In a machine for making pipes of asbestos and cement, or other fibrous materials and hvdraulic binders, mandrels 18a, ... 18d, (Fig. 4), are fed along rails 30 from the rear of the machine to the pipe-making position by a motion parallel to and in the same direction of movement of a lower felt 14. and, with the pipes formed thereon, are removed from the machine by a continuation of the same movement. The machine is of the type comprising a cylinder 10, Fig. 1, which takes up from a tank 12 a thin film of the pipe-making material and transfers the material to the felt 14 which is moved by a motor-driven cylinder 16, the pipe being formed on a mandrel 18 located between the felt 14 and an upper felt 20 and held in position in the machine by rollers 22, 24. As shown in Fig. 4, each of a number of mandrels 18a, 18b &c. which are longer than the cylinder 16, roll along a pair of sloping guide rails 30 to the position 18d between the cylinder 16 and the pressure rollers 22, 24, the rails extending beyond the pipemaking section of the machine to a calendering section and then to a section where the pipes are removed from the mandrels. Each mandrel is stopped in the pipe-making position by a device comprising pairs of arms 44, 46, Fig. 6, which carry rollers 50, 52 engageable with the bare ends of the mandrels and adjustable to any position along the arms to accommodate mandrels of different diameters. A mandrel 18 on reaching the pipe-making position is stopped by the arms 44 which are raised at an angle of 45 degrees and the arms 46 are then raised to prevent backward movement of the mandrel; the pressure rollers 22, 24 are lowered to enable the making of a pipe to proceed, the arms 44, 46 also being lowered during this operation. In modifications, (a), Fig. 7 (not shown), the roller 24 is spring-loaded and stops a mandrel at the pipe-making position, arms 46 being raised to prevent the mandrel moving backwards and the rollers 22, 24 being lowered to exert pressure on the pipe being made; alternatively, the roller 24 is connected to a lever and counter-weight, or replaced by two short rollers engaging the bare ends of the mandrel so that the felt 20 is guided only by the roller 22, and (b) there is a single pressure roller 22, Fig. 8, and a roller 54 held against the mandrel 18 by a lever ,and counterweight, or a spring or pneumatic piston-cylinder device, and adjustable through an angle of 45 degres to accommodate different sizes of mandrels, the arms 44 being employed to stop the mandrel at the pipe-making position.