Hydraulic speed controls for die closing unit of injection molding machine
US4565116A · kind A · utility
Inventor
Key dates
| Filing date | Oct 14, 1983 |
| Grant date | Jan 21, 1986 |
| Priority date | — |
| Expiry date | Oct 14, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/6771
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A hydraulic actuator assembly for a push-type die closing unit of an injection molding machine which has a central, internally bypassable power piston, lateral cylinders for rapid opening travel and a rearward stationary plunger for rapid closing travel, the lateral travel cylinders and the pressure spaces of the power cylinder creating a differential effect under which a small external flow volume of pressurized fluid is required from the pump to produce rapid opening and closing travel while a much larger internal flow volume passes through a flow connection between the cylinders. A program-controlled proportional-response throttle valve in this flow connection gives an accurate and steady control over the travel speeds, especially during deceleration. The throttle valve also makes it possible to obtain a forcible initial die opening movement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.