GB1215821A - Improvements in press mechanism for moulding or casting machines - Google Patents

Abstract

1,215,821. Mould closure device. ATELIERS DE CONSTRUCTIONS MECANIQUES ET DE CHAUDRONNERIE CORPET - LOUVET & CIE. 22 Jan., 1968 [24 Jan., 1967], No. 3163/68. Heading B5A. [Also in Division B3] In an injection transfer or compression moulding machine or a pressure die-casting machine (see Division B3), a die plate 14 is moved to a die plate 11 (fixed on the machine frame 10) by at least one hydraulic jack 30 secured to the frame 10 by way of a bearing support 22 adjustably secured by nuts 26 to fixed bearers 15 on which slide the die plate 14 and a crosshead 40 with a toggle mechanism 62 connected between them; when the die parts are closed together by the jack 30, a wedge 88 is lowered (to stop reverse movement of the crosshead and die plate 14) adjacent an inclined' end face 87 of a bar 86 on the crosshead and then the toggle 62 is actuated by an hydraulic control jack 44 (connected to the crosshead by tie bars 42) to lock the die parts 12, 13 together. The locking force is determined by adjusting the length of the jack rod 53, 57 (of a piston 52) by a screw connection in an enlargement 56 of the rod. The plate 14 rests on an adjustable foot 18 on a slideway 20. The bearers 15 may be vertical. The control jack 44 has rollers 48 running on rails 49 extending from the bearing support 22. In the open position shown, the working piston 52 is maintained at the cylinder end by fluid pressure (from an inlet 82) between the piston and an abutment piston 75 through which the rod 53 freely passes and which has a wider end 76 whose face 78 is subject to the same fluid pressure so that the piston 75 is held against a shoulder 80. When the pressure is switched from the inlet 82 to an inlet 81, the piston 52 is moved to abut the small end of the abutment piston 75 and a head 61 on the rod extension 57 is moved away from the crosshead 40 so that outer arms 64, 72 of the toggle linkage are brought nearly to horizontal alignment, Fig. 2 (not shown). The die parts 12, 13 are then brought together by the hydraulic jack(s) 30 and the wedge 88 can be lowered by a jack 90 to prevent return movement of the die plate 14 because the crosshead 40 is moved by the enlargement 56 on the rod 53, 57. Then, when pressure is removed from the piston face 78, the working piston 52 can move further right (by pushing the abutment piston 75) so that the toggle links are actuated further to align the links 64, 72 horizontally, Fig. 3 (not shown), and thus the locking pressure is applied as determined by the adjusted combined length of rods 53 and 57. Moulding (or casting) then takes place. The weaker force of the jack(s) 30 is sufficient during cooling. The toggle linkage is then opened, the wedge 88 removed and the die plate 14 moved back by the jack(s) 30. An ejector 100 carried by the plate 14 has adjustable rods. (not shown) for abutting the bearing support 22 at the reversing movement to eject the moulding (or casting). The locking pressure may be accurately determined by a comparator indicating the tensile force in the bearers 15.