Patent GB-640325-A (GB)
Title: Means for pressing or forming cavities in blocks, bricks and other moulded articles or parts
IPC: B28B7/32
Filed: 1948-02-23
Abstract: 640,325. Presses for moulding bricks &c. LOCATELLI, A. V. Feb. 23, 1948, No. 5236. Convention date, Nov. 28, 1946. [Class 87 (ii)] A press for producing hollow articles from clay, argillaceous earths, &c. comprises a box 24 containing stationary depending punches 33, Fig. 3, associated with inflatable tubes or chambers 34, and having a vertically-movable platform 17 operated by fluid pressure, in combination with rotary supporting columns 7 carrying moulds 1, which, by the rotation of the columns, are alternately brought to positions outside the press for discharging and refilling and then swung into positions over the platform of the press, being then lifted by the platform into the box containing the punches so that the material in the raised moulds is pierced by the punches and can be acted upon by the inflatable tubes or chambers, the subsequent operation of the press causing the moulds to be lowered and then swung to one side. Each mould box 1 may consist of separable side walls and bottom held together by a steel band tightened by a screw. The bottom 2 has holes 3 to receive the punches 33. Collapsable handles 4 on the boxes are normally held by springs in the horizontal position and rest on U-shaped supporting arms 6 fixed to the four rotary columns 7. The arms may collapse into recesses in the sides of the box. The columns 7 rotate simultaneously, but two at each side in opposite senses, so that the pair of boxes 1 lying in the press, Fig. 5, may be swung outwardly at the same time as the other pair are swung into the pressing position. For this purpose the columns 7 have toothed pinions 10 engaged by a rack 11 passing between them, the rack being moved by a hydraulic cylinder 14. The platform 17 may be raised and lowered between vertical guides 18 by means of a hydraulic cylinder 22. It has apertures 35 corresponding to the punches 33 and to the apertures 3 in the boxes. The compression box 24 is formed of four steel plates rigidly connected by flanges at two diagonal corners and, at the other two diagonal corners, by running bolts passing through corner flanges 27 permitting a small separation of the two halves of the box formed by the pairs of rigidly connected plates. The compression box may be moved vertically for a limited amount upon two rods 25 passing between the flanges 27. The upper and lower edges of the box are conically chamfered at 31, 56 and, when the press is in the raised position, these chamfered edges engage corresponding conical recesses 32, 57 respectively in a stationary cover-plate 23 and the platform 17, causing the two halves of the box to close together. In the lowered position conical collars 29, 30 on the rods 25 co-operate with the lugs 27 and force the two halves of the box apart. The punches 33 are rigidly mounted on two plates 36, hung, by means of further plates 37 and girders 38, from the underside of the fixed cover-plate 23. Each punch consists of a head portion screwed on to a body portion 39, the body portion being rigidly screwed into a fluid pressure supply pipe 45 and secured to the plate 36 by a nut 43. The edges of a double-walled inflatable rubber tube 34 are clamped between shoulders on the body portion 39 and nuts 43, 46, lock-nuts 47, 48 being provided. The air pipes from the punches lead to a distributer box 51 which controls the punches and the two hydraulic cylinders. When the press is in the raised position with the punches 33 penetrating the apertures 3, 35, the rubber tubes are inflated to compress the material in the mould boxes. The internal surfaces of the moulds are lined with two or more fine-mesh gauzes 58 to allow expulsion of water from the moulds. A thin sheet of metal may be placed as a middle partition in the mould boxes. Specification 636,745 is referred to.