GB593853A - Swivel-jointed article and method of producing the same - Google Patents

Abstract

593,853. Injection-moulding. PLASCO, Ltd. (Crown Fastener Corporation). June 15, 1945, No. 15240. [Class 87 (ii)] [Also in Groups XXII and XXV] A swivel of the type in which a headed pin 10, Fig. 3, fits within a socket 7 in an enlarged end portion of a loop 5 is made by moulding plastic material between similar dies 14, Fig. 1, with three cavities, two 15 and 16 in the shape of the swivel parts joined by neck 17 with tube 18 to nozzle 19 and the third 22 equivalent to the upper part of cavity 15. A core pin 21 with or without a bushing 8 of metal, fibre, or a different plastic, is inserted to form the aperture 7 and in the first operation an easily removeable dummy member is inserted in the cavity 22. Material is injected, a casting made, the pin 21 and the dummy removed and the moulded piece 5 moved down to the lower cavity 22. A second casting is made wherein the pin 10 of member 9 is formed within the socket of the first casting and contracts on cooling to give a swivel joint. The parts 17 and 18 may be broken away or neck 17 left if a chain is to be made. Alternate castings may be in different colours. One die has a member 23 to engage the loop 5 and prevent displacement of the casting when the core pin 21 is removed, Fig. 2 (not shown), and has aligning portions 24.