Cushion member for joint

摘要

The structure of the joint between co-operating cushioning elements 2a, 2b, is in that a ridge defining a cushioning member 2 bulged at the top thereof is formed at one end and a groove 24 corresponding to said ridge at the other end and said ridge and said groove are integrated by engaging them. By the integration, the strength of the joint is increased. In the case of jointing a plurality of arcuate members 2a, 2b to form the cushion member 2, the arcuate members differ in hardness among them are used arranging the softest arcuate members 2a at the portion where the compressive deformation is the largest. This suppresses an excessive concentration of stress at the pipe joint portion in curved jacking. The sectional shape of the cushion member 2 is in that at least one side of the cushion member 2 is uneven having a slope, a groove or a stepped portion.