Mold-clamping mechanism for injection-molding machine
US4230442A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1979 |
| Grant date | Oct 28, 1980 |
| Priority date | — |
| Expiry date | Aug 21, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/6714
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A thrust member on column secured to a movable platen of an injection-molding machine, surrounded by a mounting frame with laterally withdrawable shutters which enter behind the thrust member in the terminal phase of a mold-closing stroke for transmitting to the thrust member a supplemental clamping force, is linked with a hydraulically actuated plunger or driving piston via a lost-motion coupling. The clamping force is supplied through one or more annular pistons received in respective cylinder chambers of a stationary housing linked via tie rods with a fixed platen. Upon the release of the clamping force, a counter-vailing hydraulic force is developed between the column and the driving piston, whose forward displacement is limited by a fixed abutment, to break open the mold with a larger hydraulic force. The annular clamping pistons remain spaced from the adjoining housing walls in their retracted positions to allow for an extra rearward shift if, through a malfunction, the shutters are trapped between their mounting frame and the column.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.