Valve nozzle for injection molding
US4681528A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 1986 |
| Grant date | Jul 21, 1987 |
| Priority date | — |
| Expiry date | Jun 13, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/234
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection molding valve nozzle comprises a nozzle head with a gate dividing a flow passage into two sections, a spool slidably attached to the gate and including axial grooves in its outer surface and a spring for urging the spool rearward. The valve nozzle is so arranged that the gate is closed by the spool because the grooves do not reach the gate upon lower pressure of resins below a certain level, but that the spool may slide forward to extend the grooves over the gate, communicating a front passage with a rear passage upon higher resin pressure above a certain level and that when the pressure differential between the front and rear passages decreases or the resin pressure descends below a certain level, the spool slides rearward by the spring for closing the gate. Thus, the gate is closed by the spool until the resin pressure rises up to a certain level. The engaging portions of the gate and the spool may be made long depending on the pressure and viscosity of the resin so that the gap between the gate and the spool can be determined to be approximately 10 .mu.m. Therefore, easy manufacturing of the valve nozzle is realized. Further, although the resins flow into the gap, t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.