Patent GB-429144-A (GB)
Title: Improvements in moulding presses for the production of compact moulded bodies from ceramic masses, concrete or like material
IPC: B28B3/02
Filed: 1934-08-31
Abstract: 429,144. Moulding-presses. LUX, E., 26, Billerbrinkhohe, and DANIELS, J., 25, Felgendreherstrasse, both in Essen, Germany.-(Assignees of Koppers Ges., H. ; 29, Moltkestrasse, Essen, Germany) Aug. 31, 1934, Nos. 25174 and 25175. Convention dates, Aug. 31, 1933 and Aug. 10, 1934. [Class 87 (ii)] In a moulding-press in which the mould is mounted between a movable lower ram and a top abutment, the mould walls are movable parallel to the stroke of the ram and independently of the ram in both directions during the pressing-operation, with the object of securing uniform pressure throughout the whole thickness and extent of the moulded article. In the illustrated form the main details comprise an abutment 5 movable laterally on rails 15 into and out of the pressing position, a lower ram 7 carried by the hydraulic cylinder 1, and mould walls 6 connected through rods 9 to pistons 10 working in cylinders underneath larger floating pistons 12 which serve as stops for the pistons 10 so long as pressure is maintained in their cylinders. In operation, commencing from the point at which the mould walls have been lowered right down over the ram 7 to eject a moulded article, the walls are raised to the charging position by admitting fluid underneath the pistons 10 until they abut against the lower end of the pistons 12 which are held to their seats by pressure at this stage. In this position the ram 7 projects slightly into the lower end of the walls, but the abutment 5 is still clear of the upper side of the walls and is moved laterally while the charge is supplied and then is replaced. The pistons 12 are now opened to exhaust so that on supplying additional fluid to the pistons 10 the walls move upwardly over the abutment until the projections 8 thereon contact the surfaces 21. At this stage the ram 7 is raised to apply pressure to the bottom of the material and simultaneously pressure is admitted above the pistons 10 to move the walls downwards until one of a pair of cams 27, 28 strikes a reversing-lever 24 which opens the top side of pistons 10 to exhaust and admits pressure to the lower side, thus moving the walls upward again until the cams again actuate the reversing- lever. This oscillatory movement continues under the increasing pressure on the material by the ram until finally the walls cannot move far enough in either direction to actuate the reversing-lever and take up a final position in which the material is subjected to equal pressure throughout its thickness. The main piston-controlling mechanism 30, the use of which automatically cuts out the reversing- lever 24, is now actuated to lower the walls over the ram to eject the moulded article which is removed laterally. The ram is then lowered to its initial position ready for another cycle of operations. Fig. 2 shows a modification in which the mould walls move upwards with the ram 7 at the commencement of the pressing- operation. The pistons 10 are provided with hoods 31 resting in their lowest positions on stops 34 corresponding to the filling-position of the mould. When the mould is filled, an initial upward movement of the walls engages the abutment 5 before the main pressing-operation commences. To effect this, the upper side of the hoods 31 are opened to exhaust while pressure is applied to the under side of the pistons 10, thus raising both pistons and hoods into contact with the lower sides of the pistons 12. At this stage the main ram 7 is actuated, and the pistons 12 opened to exhaust, thus allowing the pistons and hoods to raise the mould walls with the ram by raising the pistons 12. The subsequent procedure is similar to that already described. Figs. 3 and 5 show a modified construction in which the moulding table 41 is vibrated or jigged by suitable mechanism 42. Pressure is applied by a deadweight 47 which can be raised by rack-andpinion mechanism 74 at the completion of the operation. The mould walls 57, which are adjustable both in length and breadth, are operated by two mechanisms, (1) screw mechanism 70 which is attached to them temporarily by wedges to raise them at the end of the operation to strip the moulded block ; and (2) the double-piston mechanism shown in Fig. 5 to which the walls are secured detachably during the moulding-operation by sliding plates 56 furnished with key-hole slots. By admitting fluid above the pistons 62, the mould walls can be lowered relatively to the base, while by admitting fluid to the cylinder 64 they can be raised. This up-and-down movement of the mould walls is repeated during the whole time that the mass is being consolidated by the jigging - mechanism alternately raising and lowering the mould base against the dead weight pressure, and this jigging movement is transmitted to the mould walls and superimposed upon the other movements imparted to them. At the completion of the operation, after the plates 56 have been operated to release the walls and the latter raised by the screwmechanism, the pressure-plate 47 then is raised by the rack-and-pinion mechanism, and finally the hooks of lifting-mechanism (not shown) are inserted into the slots 44 of the moulding- table 41 so as to raise the moulded article and the pallet-plate 45 as an integer for delivery. The fluid supply-pipes 67 are coiled to permit the jigging-movement of the apparatus and the exhaust passage is throttled so that exhaust is always effected under pressure, thus preventing any uncontrolled movement of the walls.