(under subclass 13) Apparatus in which the expansible chamber is defined in part by a deformable wall, movement of said deformable wall being caused by or effecting expansion and contraction of the chamber.
(1) Note. The deformable wall of the above definition may be either (1) fabricated of flexible material or (2) formed by a plurality or relatively movable rigid members hinged together in a manner such that relative pivotal movement thereof is caused by or effects expansion and contraction of the chamber.
