Electrically operated injection apparatus
US6193499A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1999 |
| Grant date | Feb 27, 2001 |
| Priority date | — |
| Expiry date | Feb 12, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/536
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A two-stage, electrically-powered injection unit for an injection molding machine is disclosed. The injection unit includes an extruder for plasticating material, and a separate melt accumulator to receive the plasticated material. The accumulator includes an injection plunger that is slidably positioned to inject the plasticated material from the accumulator into a mold. The plunger is rotated and translated by an electrically-driven linear actuator, such as a roller screw mechanism. The plunger extends outwardly of the accumulator barrel at the commencement of an injection stroke and is peripherally supported by a bushing at the outer end of the accumulator barrel. The outwardly-extending portion of the plunger can also be supported by a movable intermediate support member to minimize lateral deflection of the plunger and enable a longer injection stroke to be employed. The injection pressure imposed upon the plasticated material can be varied from a relatively low initial injection pressure, to minimize plunger lateral deflection, to a relatively higher injection pressure as the length of the portion of the plunger that extends outwardly of the accumulator barrel decreases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.