GB795422A - Molding press - Google Patents

Abstract

795,422. Injection-moulding machines. AETNA-STANDARD ENGINEERING CO. June 26, 1956 [July 27, 1955], No. 19736/56. Class 87(2). A press comprises a lower platen 15 carried by a vertically-reciprocable hydraulic ram 12, a tilting head 23 carrying an upper platen 26, and a tilting intermediate press plate 67. The head and plate are tiltable so that parts carried thereby may be visible and accessible. Side clamps 50 releasably secure the head in closed position. The invention is illustrated in connection with a transfer moulding press in which a lower die 17 is mounted on platen 15, an upper die 68 is carried by the intermediate press plate 67, and pressing plungers 28 are carried by the head 23. When the press is closed by raising the ram 12, the plate 67 is lifted and the plungers 28 press rubber stock 93 through passages in die 68 into mould cavities formed in dies 17 and 68. The head 23 is mounted on brackets 24 supported by bearings on a stationary shaft 21 carried by uprights 20. The head 23 carries also a bracket 30 connected to a pin 31 at the end of a piston rod 32 reciprocable by hydraulic cylinder and piston 23. When rod 32 is pulled down, the head tilts. The intermediate press plate 67 is similarly mounted on the shaft 21, being tilted by means of hydraulic cylinder and piston mechanisms. The head and intermediate plate may be held in the tilted positions either by pressure in their hydraulic cylinders, or by latch members 38, 81 (the latter not shown). At the end of the moulding operation, the lower platen 15 and the ram 12 are pulled downwardly by hydraulic cylinder and piston mechanisms 62 acting on arms 61 attached to the platen 15, and the side clamps 50 are turned about their pivots 51, to release the head 23, by the engagement of cams 59 on the arms 61 with rollers 65 on the side clamps. (The clamps are closed for the moulding operation by the engagement of rollers 58 on brackets 60 on the arms 61 with cams 59 on the clamps.) Lowering of the platen 15 separates the die 68 from either the lower die 17 or from the die members 28 on the upper platen. In the first alternative, separation of the two dies results from the fact that the platen 15 can move down further than the plate 67, In the second alternative, fluid pressure cylinders 90 on the upper head 23 actuate piston rods 91 engaging the plate 67, to move the latter away from the upper platen.