US PATENT SUBCLASS 417 / 545
.~ Valved piston

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use


417 /   HD   PUMPS

437  DF  EXPANSIBLE CHAMBER TYPE {40}
545.~ Valved piston {7}
546  DF  .~.~> Piston contains inlet and outlet valves
547  DF  .~.~> Fluid conduit fixed to piston
548  DF  .~.~> Having rigidly attached imperforate wall member
549  DF  .~.~> Having separate means biasing valve closed
550  DF  .~.~> Flexible
551  DF  .~.~> Hinged
552  DF  .~.~> Reciprocating {2}

DEFINITION

Classification: 417/545

(under subclass 437) Apparatus in which the pumping chamber is defined in part by a piston, said piston or element rigid therewith (e.g., piston rod) having a pump fluid conducting passage formed therein and the means for controlling fluid flow into or out of the chamber includes a movable valve member in flow controlling relationship with said passage, said valve member being located within or carried by said piston or element rigid therewith.

(1) Note. For classification under this definition, the expansible chamber pump must be provided with a pump fluid conducting passage which is physically located within the piston or element rigid therewith. A pump having relatively movable piston portions for controlling flow from one side of the piston to the other via a flow path formed between the

piston and a cylinder sidewall (i.e., pump fluid flows around the piston) is excluded under this definition; see subclasses 555.1+, below, and the search note therein to Class 92 for such subject matter.

SEE OR SEARCH THIS CLASS, SUBCLASS:

244+, for successive stage pumps and particularly subclasses 259+ for those including a valved piston and see the notes in subclass 244 for the distinction between these subclasses.

467, for a valved piston in which the valve is mechanically actuated.

484, for a valved oscillating-type pumping member. 495, for a valved piston combined with pumping member controlled inlet or discharge ports.

511, for a piston carried distributor in which either the piston or distributor frictionally engages the pumping chamber wall and the distributor or piston, respectively, is integral with the drive rod of the pump.

523+, for a plural chamber pump having a valved pumping member.