Device for the injection molding of plastic objects enclosing hollow spaces and process for operating it
US5750155A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1995 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | May 5, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/1734
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The proposal is for a device for injection molding plastic items enclosing hollow spaces with which a further pressurised medium like air, gas or a fluid can be introduced through a hollow needle (5) at a point differing from the nozzle into a mould (1), the mould hollow or cavity (4) of which can be filled with molten pastic through a nozzle. There is a needle core (9) which can be moved axially to a limited extent in the hollow needle (5) and it is possible via this needle core (9) to vary the cross-section of or open and close the aperture (16) of the hollow needle (6) opening into the mould hollow or cavity (4). The needle core (9) bears a thickened head or plate (10) in front of the end of the aperture in the hollow needle, the outside diameter of which corresponds at least approximately to the outside diameter of the hollow needle, so that it forms, with the aperture end (6) of the hollow needle (5), a radially directed splitting valve. In relation to the hollow needle (5), the needle core (9) is axially supported by spring means (23). It is important here that these spring means (23) continuously engage with the needle core (9) in the closing direction of the aperture of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.