Plastic article or earthenware shaping or treating: apparatus – Press forming apparatus having opposed press members
Patent
1991-09-16
1993-08-10
Heitbrink, Tim
Plastic article or earthenware shaping or treating: apparatus
Press forming apparatus having opposed press members
92249, 100267, 4254501, B29C 4564
Patent
active
052343359
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulically, pneumatically or "mechanically" drivenpower unit and its application in a die or compression press, particularly for producing wide-bodied compressed articles.
A problem generally encountered in the manufacture of wide-bodied compressed articles is that, in order to produce as uniform a pressure as possible over the entire surface area of a piece to be compressed, the press molds must be relatively rigid and heavy in construction and, in addition, they usually require a plurality of separate pistons for producing a compressive force. One solution for eliminating this problem is described in the Applicant's earlier PCT application WO 89/02986.
SUMMARY OF THE INVENTION
The invention provides a hydraulically, pneumatically or mechanically driven power unit, particularly in a die press, in a manner that the actual molding surfaces can be made as thin and lightweight as possible and, in addition, that a piece to be pressed will be subjected to a pressure as uniform as possible over its entire surface area. In order to achieve this, a power unit of the invention is characterized in that an elastomer space is filled with elastomer by casting elastomer in situ. The application of a power unit of the invention in a die press especially for manufacturing wide-bodied compressed pieces, the press having at least two body sections and at least two molding surfaces to be pressed against each other for effecting the pressing of a compressed piece in a mold cavity therebetween, is characterized in that the power unit is adapted to carry at least one of the mold surfaces relative to its body section towards the other mold surface in a per se known manner through the intermediary of a support layer, said support layer being located in a region between the mold surface and the elastomer space and/or a press plate. The support layer is preferably elastic, made, e.g., of a two-component silicone or polyurethane.
One benefit gained by the application of a power unit of the invention in a die press is the uniform distribution of compression pressure through the intermediary of an elastic support layer over the entire surface area of a piece to be pressed.
Although a power unit of the invention is in this context described in association with a die press, it can of course be applied to many other machine parts and devices, such as couplings, brakes, connectors, sealings etc. One benefit offered by a power unit of the invention is e.g., that the system can be designed as a closed system and the risk of hydraulic oil spill is minimized, especially in "mechanical" application.
In view of the operation of a power unit, an essential feature is e.g., that elastomer does not adhere in the elastomer space and/or to the walls of elastomer passages so as to permit a moderate movement of elastomer in the elastomer space and/or passages under pressure. Elastomer behaves almost as a fluid in a sense that it is incompresssible, a difference from fluid being, however, that elastomer is self-restoring after the action of pressure is stopped. The conducted preliminary tests have indicated that a pressure of over 100 bars, nearly a complete equalization of pressure occurs in a passage having a diameter of about 5 mm and a length of about 500 mm throughout the entire passage. The non-adherence of elastomer to the walls of passages and elastomer spaces can be enhanced e.g., by means of various lubricants which are compatible with a particularly employed elastomer. Elastomer passages/spaces must usually be designed larger in volume than corresponding fluid passages. However, if necessary, the elastomer can be joined e.g., with a separate sealing layer or with a mechanical piston for a pressurizing medium by using an appropriate medium, such as Chemosil X 5201, available e.g., from Henkel AG (FRG). In addition, the elastomer space must be designed in a manner that elastomer cannot work its way out of the space. This design is effected e.g., in a manner that the region be
REFERENCES:
patent: 2756707 (1956-07-01), Peters
patent: 2783727 (1957-03-01), Hoffman
patent: 3120205 (1964-02-01), Pfeiffer et al.
patent: 4093175 (1978-06-01), Putzer et al.
patent: 4344313 (1982-08-01), Chachin et al.
Meals, R. N. et al, Silicones, Reinhold, N.Y. (1959) pp. 130, 131, 132.
Heitbrink Tim
Unicraft Oy
LandOfFree
Hydraulically, pneumatically or mechanically driven power unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulically, pneumatically or mechanically driven power unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulically, pneumatically or mechanically driven power unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1721448