Expansion joint , ∨ Expansion coupling Meaning, Definition & Usage

Definitions
  1. (Mech. & Engin.), a yielding joint or coupling for so uniting parts of a machine or structure that expansion, as by heat, is prevented from causing injurious strains; as by heat, is prevented from causing injurious strains; as: (a) A side or set of rollers, at the end of bridge truss, to support it but allow end play. (b) A telescopic joint in a steam pipe, to permit one part of the pipe to slide within the other. (c) A clamp for holding a locomotive frame to the boiler while allowing lengthwise motion.

Webster 1913