摘要 |
A novel coupling member which comprises a hollow, generally tubular metal member which is heat-shrinkable or can be rendered heat-shrinkable in the radial direction and is provided on its inner surface with at least three teeth in the form of radially extending rings, the distance (t) between any pair of adjacent teeth being less than 0.95 d and less than 4 w, where d is the internal diameter of the tubular member, and w is the wall thickness of the tubular member, there being at least one tooth either side of the tooth nearest the center of the tubular member, the distance from the center of the member to the tooth nearest the center of the member being from 0 to 0.3 d and the distance between the two teeth adjacent the tooth nearest the center of the member being more than the smaller of 0.4 d and 3 w. Such a coupling member can be expanded by mandrel expansion methods without danger of damaging the teeth.
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