초록 ▼

Method and apparatus of making socketed pipe-fittings of synthetic plastics material by injection moulding. Prior to starting the injection moulding process a sealing ring is held in somewhat pinched condition with reduced outer diameter at the level of means to be formed on the socket for receiving

Method and apparatus of making socketed pipe-fittings of synthetic plastics material by injection moulding. Prior to starting the injection moulding process a sealing ring is held in somewhat pinched condition with reduced outer diameter at the level of means to be formed on the socket for receiving the sealing ring. During the injection moulding process the sealing ring is held in this condition and is isolated from the moulding cavity. After sufficient, but incomplete cooling of the socket formed, the sealing ring receiving means are partially and temporarily deformed, and the sealing ring is released to enable it to spring into the partially deformed ring receiving means. Thereafter the ring receiving means reassume their original form, thereby firmly gripping the sealing ring.

대표청구항 ▼

A method of making a pipe fitting of synthetic plastics material by injecting moulding, said pipe fitting comprising a socket including means for receiving a sealing ring, characterized by, prior to the injection moulding process, placing a sealing ring in slightly pinched condition with reduced out

A method of making a pipe fitting of synthetic plastics material by injecting moulding, said pipe fitting comprising a socket including means for receiving a sealing ring, characterized by, prior to the injection moulding process, placing a sealing ring in slightly pinched condition with reduced outer diameter at the level of the means to be formed on the socket for receiving the sealing ring, and holding it in this position during the injecting moulding process, the sealing ring being isolated from the moulding cavity during the injection moulding process; and after sufficient, but incomplete cooling of the moulded socket, temporarily and partially deforming the means for receiving the sealing ring, and releasing the sealing ring to permit the same to spring into the partially deformed ring receiving means, which thereafter reassume their original shape, thereby gripping the sealing ring.