(under the class definition) Apparatus comprising a cylinder and a piston reciprocally mounted therein, and in which a relatively small unobstructed space or passage is provided between the side wall of the piston and the adjacent cylinder wall, said space or passage extending from one end of the piston side wall portion to the opposite end thereof to allow working fluid to flow from the chamber formed at one end of the piston side wall portion to the chamber formed at the opposite end thereof.
SEE OR SEARCH CLASS
188, Brakes,
316, for an internal resistance fluid brake comprising a cylinder and piston, and passage means between the cylinder wall and piston side wall to allow restricted flow of fluid from one end of the piston to the other as the piston moves in the cylinder.
277, Seal for a Joint or Juncture, for a generic sealing means or process,
411+, for a dynamic close proximity seal (e.g., contactless, fluent, etc.) having a gap or clearance.
