Patent · US Expired

Clamping unit for injection molding machine

US5052910A · kind A · utility

38Cited by
3References
18Claims
0Family size

Inventor

Key dates

Filing dateDec 13, 1989
Grant dateOct 1, 1991
Priority date
Expiry dateDec 13, 2009

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C2045/6785
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A clamping unit has a hydraulic actuating assembly including at least two locking cylinders provided with respective locking pistons, which are connected by piston rods to a movable mold carrier. Each locking cylinder contains a high-pressure chamber and a low-pressure chamber, which are adapted to communicate with each other through overflow passages formed in the associated locking piston. The overflow passages can be shut off by valve members. The hydraulic actuating assembly has an axis of symmetry, on which a drive cylinder and a buffer cylinder are centered. The drive cylinder serves to close and open the injection mold. The buffer cylinder is connected to the movable mold carrier and has a buffer chamber, which communicates with the low-pressure chambers of the locking cylinders. The locking cylinders and the buffer cylinder have steel tubes, which are connected at both ends to common cylinder covers to constitute a unit. The drive cylinder is coaxially surrounded by the steel tube of the buffer cylinder. The steel tubes of at least two locking cylinders are symmetrical to the drive cylinder.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.