Seal for a joint or juncture – Seal between fixed parts or static contact against... – Contact seal for other than internal combustion engine – or...
Reexamination Certificate
1998-12-01
2001-01-16
Knight, Anthony (Department: 3626)
Seal for a joint or juncture
Seal between fixed parts or static contact against...
Contact seal for other than internal combustion engine, or...
C277S641000, C277S650000, C411S372000, C411S533000, C411S542000
Reexamination Certificate
active
06173969
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a sealing ring, which at its two mutually opposite axial sides respectively possesses an annular sealing section and which has an annular base body, which is manufactured of synthetic resin and is adapted to endow the sealing ring with dimensional stability, and furthermore possesses an annular sealing body arranged concentrically in relation to the base body and having rubber-elastic properties.
DESCRIPTION OF THE PRIOR ART.
A sealing ring of this type is for example disclosed in the German patent publication 3,918,891. This known sealing ring has an L-shaped base body made of metal or a rigid synthetic resin, on which the annular sealing body is fixed. The sealing ring is axially placed between two faces (herein referred as the sealed faces) between which a sealing effect is to be produced on the two components, the sealing body being acted upon in the fitted condition from axially opposite sides by the sealed faces. The two sealing sections, causing the sealing action, of the sealing ring are provided on the sealing body, whereas the base body performs a purely supporting function and prevents crushing of the sealing body.
Although the known sealing ring has excellent properties in use, it is relative expensive to manufacture. Furthermore a substantial thrust force must be exerted in order to deform the sealing body sufficiently so that it engages the associated sealed faces at the two sealing sections.
SHORT SUMMARY OF THE INVENTION
One object of the invention is to provide a sealing ring which while ensuring a reliable sealing ring action is simpler and cheaper to produce.
In order to achieve these and/or other objects appearing from the present specification, claims and drawings, in the present invention the base body is made to of thermoplastic synthetic resin and its one axial side itself directly constitutes the first sealing section and the sealing body forming the second sealing section is made of elastomeric synthetic resin material and is permanently molded on the axial side, which is opposite the first sealing section, with the formation of a dual-material injection molding on the base body.
It is in this manner that the invention leads to a sealing ring consisting completely of synthetic resin, which can be manufactured very simply and economically as a dual-material injection molding. For the material of the base body thermoplastic synthetic resin is employed, which possesses sufficient strength and rigidity in order to provide the sealing ring with the desired dimensional stability. As a sealing body elastomeric material is employed, which is integrally and permanently formed on the base body by injection molding. The arrangement is such that the base body does not solely function as a carrier for the sealing body, but also represents a sealing body, on which one of the two annular sealing sections is formed. Although the base body does not possess the same ability to deform as the sealing body, the resiliency is sufficient to perform a reliable sealing effect on sealed faces with a high surface quality. The elastomeric body on the contrary is also suitable for sealing against sealed faces with a high degree of roughness so that the sealing ring is more particularly suitable for initial fitting to equipment, which is composed of components produced by the manufacturer itself together with parts from other sources, whereas as regards the parts produced by the manufacturer a high surface quality may be ensured quite readily, whereas in the case of which the parts from other sources variations in surface roughness may be expected.
If after a long period of use the thrust forces acting on the sealing sections should be reduced owing to creep of the thermoplastic material, this will be compensated for by the elastic deformation capacity of the elastomeric body. Accordingly leaks are unlikely even after long periods of use.
Further advantageous developments of the invention are defined in the claims.
In order to optimize the sealing properties of the thermoplastic base body the first sealing section provided on it may have at least one annular axial projection, which more particularly has an encircling sealing edge so that linear engagement on the sealed face of the associated component may be achieved, this leading to an even better sealing action owing to the higher surface pressing force.
If required it is readily possible for several, concentrically arranged axial projections to be present, which in cooperation with the associated sealed face may also lead to a labyrinth sealing effect.
Functionally adjacent to the inner periphery of the sealing ring it is convenient to provide several peripherally distributed holding projections, which ensure a locking of the sealing ring in place without any possibility of loss, when for example the sealing ring is slipped onto a male thread of a screw part. The holding projections may in this case also possess a centering action and prevent transverse displacement in relation to the associated component so that the sealing sections arc always correctly aligned with the opposite sealed faces.
In the case of the holding projections it is a question preferably of elastomeric parts formed integrally with the sealing body, such projections being formed by injection molding on the radially inwardly directed inner peripheral face of the base body.
The sealing ring is more especially suitable for use between two axially facing sealed faces, which are provided on two fluid power components to be connected together. One of the components may in this respect be a screw part, as for instance a plug or a screwed component, which possesses a spigot-like threaded part provided with an external screw thread adapted for instance to be screwed into a female thread of another component, as for example a valve or a fluid power cylinder. The sealing ring is in this case directly slipped over the threaded part coaxially, the holding projections also present ensuring locking on the threaded part.
The sealing ring can be so inserted that the component cooperating with the sealing body normally is free of contact with the base body. However the design may also be such that on the axial side bearing the sealing body the base body has at least one supporting face, which the associated component may engage, when the elastomeric sealing body is deformed.
Further advantageous developments and convenient forms of the invention will be understood from the following detailed descriptive disclosure of a preferred embodiment thereof in conjunction with the accompanying drawings.
REFERENCES:
patent: 2373443 (1945-04-01), Armington
patent: 3930656 (1976-01-01), Jelinek
patent: 4468042 (1984-08-01), Peppert et al.
patent: 4692928 (1987-09-01), Abele
patent: 4778321 (1988-10-01), Okawa
patent: 5172919 (1992-12-01), Takasaki et al.
patent: 5342096 (1994-08-01), Bachle et al.
patent: 5390939 (1995-02-01), Terauchi et al.
patent: 5536018 (1996-07-01), Szott
patent: 5564714 (1996-10-01), Katsuno et al.
patent: 39 18 891 (1990-09-01), None
patent: 0 177 709 A 1 (1986-04-01), None
patent: 739 490 (1955-11-01), None
Kees Ulrich
Stoll Kurt
Festo AG & Co.
Hoffman & Baron LLP
Knight Anthony
Patel Vishal
LandOfFree
Sealing ring does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sealing ring, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sealing ring will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2491170