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US 5,348,425 AGranted
Piston cylinder device with a protective coating and method of producing such a coating
OwnerRobert W. Heiligerinventor
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OwnerRobert W. Heiligerinventor
Estimating the term…
A method is described for protecting piston cylinder devices against corrosion by a pressure resistant thermoset or cured material coating. At least the outer and inner cylindrical surfaces, for example, of a mine prop, that cooperate with a sealing device, are coated with a three-dimensionally cross-linked, cured or thermoset material having a sufficient thickness on the one hand for providing the intended protection against corrosion and on the other hand to avoid excessive radially directed elastic deformations of the coating. An additive is included in the coating to improve the dry lubricating characteristics, and thus the cooperation between the coating and the sealing devices. The three-dimensionally interlinked thermoset material fills all surface irregularities so that gas and water pockets, for example, in a mine prop, are avoided.
A method for producing a protective thermoset coating at least on one surface that cooperates with a sealing device in a piston cylinder unit wherein said at least one surface is in sliding contact with said sealing device, comprising the following steps:
A piston cylinder device, comprising an outer cylindrical pipe section with an inwardly facing first cylindrical surface and a piston with an outwardly facing second cylindrical surface, sealing means in sliding contact with at least one of said first and second cylindrical surfaces, a protective thermoset, cured coating of a three-dimensionally cross-linked powder-based thermosetting material including a lubricant additive in said coating on at least one of said first and second cylindrical surfaces for improving a dry sliding characteristic of said sliding contact, said coating having a thickness within the range of about 100 .mu.m to about 500 .mu.m, said lubricant additive being dispersed and embedded in said coating, said thermoset, cured coating comprising macro-molecules formed by said three-dimensional cross-linking and said cured coating being substantially non-compressible and substantially impervious to gases, water and water vapor.
A mine prop, comprising a piston cylinder device including at least one outer cylindrical pipe (5) and an inner cylindrical pipe (6) slidingly guided in said outer cylindrical pipe, a piston (7) connected to an inner end of said inner cylindrical pipe, piston sealing means (34) in sliding, guided contact with an inner surface of said outer cylindrical pipe (5), at least one further sealing means (4) in sliding contact with an outer surface of said inner cylindrical pipe (6), a sleeve ring (8) connecting said further sealing means (4) with an upper end of said outer cylindrical pipe (5), a first protective, thermoset coating at least on said inner surface of said outer cylindrical pipe, a second protective, thermoset coating at least on said outer surface of said inner cylindrical pipe, each of said first and second protective coatings comprising a thermoset, cured coating of a three-dimensionally cross-linked powder-based thermosetting material including a lubricant additive in said coating on at least one of said first and second cylindrical surfaces for improving a dry sliding characteristic of said sliding contact, said coating having a thickness within the range of about 100 .mu.m to about 500 .mu.m, said lubricant additive being dispersed and embedded in said coating, said thermoset, cured coating comprising macro-molecules formed by said three-dimensional cross-linking and said cured coating being substantially non-compressible and substantially impervious to gases, water and water vapor.
Dependencies are inferred from the claim text.