(under the class definition) Apparatus in which there is provided either a movable vane or abutment that slides relative to the working member or cylinder respectively in a direction generally toward or away from the axis of rotation and other than in a radial plane containing the axis of rotation of the working member.
(1) Note. A sliding vane or abutment is considered to slide radially when a plane thereof including or parallel to the plane of a side face thereof is coincident with a radial plane of the working member. Where the sliding vane or abutment has nonparallel sides, it is considered to slide radially if the median plane thereof is coincident with the radial plane of the working member.
