GB189801117A - Improvements in the Manufacture of Tiles and the like, and in Apparatus therefor. - Google Patents

Abstract

1117. Price, W. Jan. 14. Moulding tiles.- Relates to plungers or dies provided with expanding and contracting slides for producing dovetail or undercut recesses in the backs of facing-tiles. In the arrangement shown in Fig. 4, a frame or tie A carrying the slide D is made with dovetailed perforations, and the plungerhead B is made with wedge-shaped projections b which enter the perforations of the die. The slides are made with horizontal recesses L, which engage with guide-ribs of the die, and dovetail grooves d<1> which engage with keys of the plunger. Springs F are interposed between the die-plate and the plunger-head to separate them when the pressure is taken off the dust in the mould. The dust is first compressed gently to allow the air to escape, and the force is afterwards augmented to cause the die and plunger to come together, expand the slides D, and compress the dust into a compact solid mass. The contraction of the slides when the plunger is raised allows the tile M to be raised without injuring the sharp edges of the recesses. The die-plate is connected to the plunger by slotted guide-plates at opposite sides. In a modification shown in Fig. 11, the springs are dispensed with, and the plunger-rod P is connected to the die A by a stud R, arranged to slide in a hole in the head B. In another arrangement, the plunger-rod passes loosely through the head, and is screwed into the die-plate. The die with the slides may be attached to the upper plunger instead of the lower. Fig. 8 shows the form of the slot in an upper die-plate, and Fig. 10 shows a slide constructed of two parts D, d adjustably connected together by two parallel screws U. These screws slide horizontally in guide-slots T in the die-plate when the slides are expanded or retracted. The plates D may be of any suitable shape in plan, and the wedge-shaped or tapered projections and recesses of the plungerhead and die-plate may be of a rounded, oval, or other suitable shape in cross-section.