Patent GB-662638-A (GB)
Title: Process and apparatus for manufacturing profiled pieces of cementitious material
IPC: B28B7/46
Filed: 1948-01-28
Abstract: 662,638. Moulding fibro-cement articles. SALVANESCHI, P. Jan. 28, 1948 [March 4, 1944], No. 2590/48. Class 87(ii) Apparatus for moulding metal reinforced asbestos cement blocks in which pre-determined parts of each block may have a richer mixture giving higher resistance to bending &c. forces at those positions, comprises a hollow porous inner walled mould 5, Figs. 1, 3, having compartments 55-59 in the hollow sides, a movable table 14 reciprocated by a rack 63 and pinion 64, adapted to support the mould so that the compartments may be communicated through holes 18 and by means of a piston 16 with a cylinder 15, a funnel or hopper 1 having a bottom 2 adapted to form a countermould, and a further countermould 4. The cylinder 15 may be exhausted of air and water by means of a vacuum pump (not shown) attached to the passage 67. The countermoulds are reciprocated in a vertical direction to give sinusoidal vibrations and the guide shoe 35 is attached to the hopper 1. The piston 16 is mounted with air-tight clearance inside the cylinder 15 and is held fast relatively to the hopper by a rod 17 adjustably attached to the base 62. In the manufacture of an I-beam, supports or cores 19, 20, Fig. 2, of slightly less cross-sectional area than the desired block are secured to the mould to form ends and support metal reinforcements 26, 27 and 28, 29, or metal frames. In operation the mould, which is of metal and lined with wire netting, is positioned on the table which is then moved to the right until the core 20 is level with the left-hand end of countermould 2. In this position, compartment 55 is already in communication via hole 18 with the cylinder 15. The mixture is fed into the hopper 1, the cylinder 15 is connected to the vacuum pump, shafts 42, 50 of the vibrating mechanism are rotated, and the pinion 64 is revolved to cause the table and cylinder to move to the left. The material fed into the mould from the hopper is compressed by the countermoulds 2, 4, and the compartments 56, 57, 58, 59 are opened to suction one by one. The process continues until the mould reaches a position beyond the countermould 4, at which point the process is stopped, the cores 19, 20, withdrawn, and the moulded block removed, upside down, on a wooden board. The mould is then replaced and the table repositioned for another cycle. The hopper may at different times during the moulding of a block be fed with materials of different fibre content, or it may be divided lengthwise by a partition arranged vertically and perpendicular to the wall 2, the compartments so formed acting as funnels communicating at the bottom and containing different mixtures. The hopper may, however, be fed with mixtures through separate valve-controlled pipes. In a modification, the mould jacket may have only one compartment and be directly connected to the vacuum pump. It is also possible to discard the hopper, the mould being filled wholly with the mixture arid then worked with the vibrating counter mould 4, adjusting the suction effect at each run. Further modifications describe the rod 17 supporting piston 16, as being slidably mounted and moved by the sliding mould, and only parts of the hopper may be vibrated if so required. Additional countermoulds may be used having vibrations in directions different from those shown in Fig. 1. Specification 609,026 is referred to.