Patent GB-1127219-A (GB)
Title: Molding apparatus and method for concrete products
IPC: B28B23/02
Filed: 1966-05-17
Abstract: 1,127,219. Moulding concrete planks. V. E. O. HENNIG. 17 May, 1966 [19 May, 1965], No. 21811/66. Heading B5A. A method of moulding concrete planks comprises depositing elongated mould troughs 1 on inclined slope rails 9, rigging prestressing wires (16) and inflatable rubber core members (24) therein, at a rigging station (Fig. 1), pouring dry concrete mix from a travelling hopper 49 at a pouring station into the moulds which are simultaneously vibrated while being isolated by lifting from the rails 9, then moving the moulds to an initial curing station under a canopy 53 followed by curing in an oven at a temperature in excess of 135 F., hot air being blown around and through the planks, after removal of the cores; water sprays (62) and reservoirs (58) (Figs. 11, 12, not shown) ensuring that the air is humid, one blower for the air being arranged directly opposite the bores in the planks. In the curing oven blowers (60) and heaters (59) for the circulated air are displaced vertically and horizontally to facilitate good circulation. The moulds move under gravity down the inclined rails. The moulds then pass from the oven, are cooled by a spray 561 and the planks are then stripped from the moulds after bending the walls thereof upwardly outwardly and the base concavely upwardly, the planks being stored and the moulds cleaned prior to the commencement of another cycle. Each mould includes wheels engaging the rails 9, rotating chocks (11) (Figs. 6, 7) being used to check movement of each mould at the various stations. Prestressing the wires 16.-The wires (16) pass through grooves (34) in an end wall (35) of the trough (Fig. 9) and are stressed exteriorly by jacks, the tension being retained by vices (37) held in housings (38), led round a U-shaped return member (32) (Fig. 10) exteriorly of the opposite mould end. The wires (16) are held in pace downwardly depending legs (31) of a bridge (30) (Fig. 5) and by passage through holes in a central partition comprising spaced plates (17) with a filling of polystyrene (18) (Fig. 3, not shown). The partition locates inflatable rubber cores (24) which are maintained against floating in the uncured element by hard wire loops (25) also being attached thereto to facilitate removal of a cured plank. The cores are removed either at the initial setting station or in the oven, the bridge (30) also being removed at the former station and the grooves left thereby being filled with a concrete mix. Mould lifting mechanism. Fig. 7.-At the pouring station fluid-operated jacks 40 parallel to either side rail raise a beam 39, upstanding lugs 41 thereon locating in loops 42 protruding from side flanges 5 of the mould, the wheels 7 thereof being raised clear of the rails. Stabilizing columns 40, 47 comprising resilient collars 48 counteract the effect of an eccentric motor 43 vibrating the beam. In a modification (Fig. 8) the beam is raised by inflatable cushions (51) on columns (52) disposed outwardly of columns (40), (47). During vibration the hopper 49 traverses the length of the mould on both directions on rails (50) (Fig. 1).