Injection nozzle provided with shut-off means
US4272236A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1979 |
| Grant date | Jun 9, 1981 |
| Priority date | — |
| Expiry date | Dec 14, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/231
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A nozzle for the introduction of liquefied plastic material into a mold has a channel terminating at one end in an injection orifice and adjoining at its other end a reduced bore serving for the guidance of a valve pin slidable with all-around clearance in that channel, the pin having a rear extremity projecting from its guide bore. A passage for the admission of liquefied molding material under pressure enters the channel at its junction with the reduced guide bore, rearwardly of a set of skew fins of the pin serving for additional guidance thereof in the channel and for imparting relative rotary motion to the flow and the pin. The orifice is blocked at the end of an injection operation by a pusher acting upon the projecting rear extremity; it is unblocked, upon withdrawal of the pusher, by the pressure of the molding material in the channel upon a forwardly facing annular shoulder of the pin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.