US PATENT SUBCLASS 251 / 26
.~.~ Alternative pressure sources or pilot valve


Current as of: June, 1999
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251 /   HD   VALVES AND VALVE ACTUATION

12  DF  FLUID ACTUATED OR RETARDED {12}
25  DF  .~ Pilot or servo type motor {8}
26.~.~ Alternative pressure sources or pilot valve


DEFINITION

Classification: 251/26

(under subclass 25) Subject matter in which the servo-motor may receive fluid from any one of two or more sources of fluid pressure or in which two or more pilot valves are employed for a single servo unit, one pilot valve duplicating the function of another pilot valve.

SEE OR SEARCH THIS CLASS, SUBCLASS:

19, for servo-systems having an additional pilot valve which compels reclosing of the main valve irrespective of the position of the first pilot valve.

25+, for servo-systems in which there are two or more pilot valves not duplicative of their functions and not classifiable in subclasses 29 and 31, such as inlet and outlet valves.

29, for pilot valves controlling fluid flow to a fluid actuated pilot valve.

31, for servo-systems in which a plurality of pilot valves control a corresponding number of servo units.

SEE OR SEARCH CLASS 137, Fluid Handling,

65+, for plural servo-motor control valves in a speed responsive prime mover control.