Actuating mechanism for gate valve of injection nozzle
US4173448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1978 |
| Grant date | Nov 6, 1979 |
| Priority date | — |
| Expiry date | Jan 6, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/2875
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection gate of a mold cavity comprises an elongate valve rod which passes axially through a flow channel for molten plastic material and is guided in an extension of a thin-walled steel cylinder open at its opposite end toward an adjoining manifold plate. The rod extremity remote from the gate is secured to a tubular neck of a piston inside the cylinder whose stroke length is a fraction of the axial height of the cylinder's interior, a clearance around this neck providing space for drooling plastic while the length of the neck and of the peripheral cylinder wall serves for thermally insulating the manifold plate from the flow channel. The piston has a head sliding within an internal annular shoulder of the cylinder wall, proximal to the manifold plate, which is traversed by axially oriented bores communicating with the aforementioned clearance whereby pressure fluid such as compressed air can be selectively admitted from conduits in the manifold plate to either side of the piston head for reciprocating same together with the valve rod. A plurality of such valve-control pistons can be connected to these conduits in parallel for simultaneous actuation by the air pressure applie…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.