Method of forming a socket end on a plastic pipe and a molding device for use of the method
US4279853A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1979 |
| Grant date | Jul 21, 1981 |
| Priority date | — |
| Expiry date | Sep 28, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/218
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
For the purpose of making a joint socket comprising at least two portions, namely a portion for receiving a plastic pipe end and another portion into which a rubber ring is fitted, a method of heating and softening a plastic pipe end and enlarging the radius of the softened pipe end to twice its size which includes, an inwardly slanted portion between a first outwardly slanted portion and a second outwardly slanted portion whose radius becomes smaller as it comes nearer to the front end thereof. As the result, the frictional resistance between an improved core and the radius enlarged softened pipe is reduced to a value which enables the method to be carried out such that wall-thickened sockets can be made without loss of wall thickness subsequent to the radius enlarging process. The core for forming a molding space includes the first outwardly slanted portion, the inwardly slanted portion and the second outwardly slanted portion and which are necessary to perform the method can be expanded and shrunk so as to pass through the small and large radius portions of the molded socket and has a self-locking mechanism capable of resisting the resistance caused between the forcedly fed pipe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.