(A) This class relates to devices which include an expansiblechamber, said chamber having a wall portion thereof (i.e., a workingmember) movable in a to and fro motion to vary the volume of thechamber, and having a fluid conducting passage means in communicationwith the chamber for introducing or withdrawing fluid therefrom,said device being the type in which:
(1) The introduction of fluid into the chamber or the withdrawalof fluid from the chamber acts upon the movable wall portion andeffects a movement thereof in a direction to change the volume ofthe chamber and produce a mechanical force output which is employedto do work (e.g., motor) or
(2) Application of a mechanical force to the movable wallportion effects a movement of such movable wall portion in a directionto change the volume of the chamber to draw fluid into or expelfluid from the chamber (e.g., pump).
(B) This class also takes miscellaneous subcombinations ofmotors or pumps disclosed as being of the type having a chamberas indicated in part A, above, not involving control of the workingfluid and not provided for in other classes, (e.g., bellows walls,diaphragms or pistons).
(C) This class excludes means to control the fluid to or fromthe chamber, except in the case of a sealing means for a workingmember which is adapted under certain conditions of operation toflex away from the encompassing chamber wall to allow fluid passagebetween said means and the chamber wall.