GB622207A - Improvements in methods of coating or encasing substantially cylindrical objects by a pressure moulding process and mould arrangement for use in carrying out such methods - Google Patents

Abstract

622,207. Injection-moulding machines. GRAVESEN, C. C. Jan. 7, 1946, No. 615. Convention date,.Jan. 5, 1945. [Class 87 (ii)] A cylindrical object, such as a condenser, is wholly encased in plastic material by first encasing one end and some or all of the side of the object and then covering the other end and any remaining part of the side. In one method, Figs. 1 and 3, the condenser 5 is slidably mounted in an end guide 9 which with a piston 8 forms one end of a mould cavity 4. The other end of the cavity is formed by a stopper 10, which may either abut against the face of or fit in one of several holes in a rotatable ring 11 mounted on a mould block 1 of an injection-moulding machine. In operation, the mould blocks 1, 2 are brought together, and material is then injected into the mould, which causes the guide 9 to move to the right. When the guide is nearly clear of the condenser, it is stopped, by means not shown, and the injection is also temporarily stopped. The block 2, together with a ring 3, is then withdrawn, the movement of the piston 8 being delayed for a time sufficient to cause the dead head to be sheared where it joins the coating. Also during the early part of this movement the main part of the dead head is held against the block 1 by a plunger 16, to ensure that the dead head is removed from the ring 3. The dead head is later removed by an ejector rod working in the plunger 16. The ring 11 is then rotated to bring one of its holes in line with the stopper 10. The blocks 1, 2 are brought together again, see Fig. 3, and more plastic material is injected to enclose the rest of the condenser. The coated condenser is ejected axially. In a modification, Fig. 4, material is injected through an inlet 15 to cause a stopper 13 to move to the left and thus, through a connecting member 14, cause a piston 8 to eject the condenser 5 out of a guide 12. When the condenser has left the guide by a short distance, the movement of the condenser is stopped, e.g. by the member 14 striking an abutment. The piston 8 is then moved to the right, e.g. by providing a spring connection or a releasing device between the piston 8 and the member 14, to allow the end of the condenser to be coated.