Patent GB-845856-A (GB)
Title: Hydraulic press for the moulding of bricks or blocks
IPC: B28B3/00
Filed: 1959-05-04
Abstract: 845,856. Presses for moulding bricks &c. LOCATELLI, A. V. May 4, 1959 [Sept. 29, 1958], No. 15104/59. Class 87(2). A hydraulically operated brick moulding press having punches to make perforations in the bricks, a vertically movable platform operated by hydraulic pressure and vertical columns on which the moulds swing between filling and pressing positions, is provided with moulds which consist each of four displaceable sides and a removable bottom and with means whereby, when the perforation of the materials in the moulds has been completed by the punches, the bottom is automatically removed and, after the mould has been moved to a position outside the press, the sides of the mould are automatically caused to separate and the mould to expand to release a moulded brick or block. A pair of opposite walls 29 of the mould are hinged between the other pair 33 and are bevelled at their top edges to cause one pair to move outwards as the other pair moves outwards. An elastic encircling member 35 tends to reclose the mould. Handles 30 on the mould walls 29 rest on arms 3 supported from columns 4 with sleeves 4a which rotate simultaneously so that the pair of moulds lying in the press, Fig. 2, may be swung outwards as the other pair are swung into the pressing position. For this purpose the sleeves 4a have toothed pinions 5 engaged by a rack 6 passing between them, the rack being moved by a hydraulic cylinder 9. To open the mould, extensions 38 from the handles 30 are forced apart by levers operated by a pressure cylinder. A compression box 31 is formed of four steel plates rigidly connected by flanges at two diagonal corners and, at the other two diagonal corners, by pins passing through corner flanges permitting a small separation of the two rigid halves. The cover 19 and upper edge of the compression box are bevelled to interfit so that, during the ascent of the platform 10 the moulds enter the box and the walls close by sliding on the pins through the comer flanges to grip the moulds. Each punch 13 comprises a metallic core 27 screwed to a compressed air tube 20 and covered with a double-walled inflatable tube 26a, 26b; and rubber balls 26e, to guard against breakage due to repeated blows. When the platform 10 rises it carries upwards two empty moulds, seen on the right in Fig. 2, and the two moulds containing material to be moulded, which has depressions in it for the punches 13 to enter. The depressions are made by punches 47 similar to the punches 13, depending from material-holding boxes 49 which may be vibrated to assist material to fall through holes in the base into the empty moulds. As the platform 10 rises and the moulds enter the compression box 31 the empty moulds are carried up on frames 44 by arms 101, 102 which enter grooves 103 in the mould walls 29. The empty moulds have no bottoms, but, when they have reached the top of their travel, base plates 24 are swung up under them and are latched by the engagement of teeth 60 with leaf springs 59, Fig. 16. Normally each base 24 is held in the position A, where it remains so long as an arm 40 on its pivot shaft 26 is held by a tooth 41 on one of the rotatable vertical sleeves 4a. When the sleeve 4a turns to carry the moulds into position the arm 40 is released and the base 24 is held only by another arm 42 which engages a block 46 on a vertical shaft 69. When the moulds reach their top position a pneumatic cylinder and piston 66, 54, Fig. 4, are actuated and cause linkage 55, 58 to move the shaft 69 and cause release of the base plates 24 from position A. After the moulds are filled and material compressed, air pressure is released from the cylinder 54 and springs 67 pull a cable 63 which pulls away the springs 59 and releases the base plates, which are raised back to the position A by the operation of a tooth 68 on the arms 42. Accumulated material is freed from the spaces between the punches, as the moulds are raised, by a grid of wires 72. Air pressure for the inflatable punches is supplied by a two-stage compressor 81, 87, Fig. 18, and, when a cock 95 is in the position E, high-pressure air is supplied to the punches. When the punches have compressed the material the cock is turned to F and air returns to the cylinder 87, pressure in the pipe 96 dropping to a lower value, at which point a cock 99 opens and low-pressure air is supplied to the pre-compressing punches 47.