US PATENT SUBCLASS 137 / 537
.~.~.~.~ Spring under tension

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

Internet Version by PATENTEC © 1999      Terms of Use


137 /   HD   FLUID HANDLING

455  DF  LINE CONDITION CHANGE RESPONSIVE VALVES {11}
511  DF  .~ Direct response valves (i.e., check valve type) {14}
528  DF  .~.~ Reciprocating valves {5}
535  DF  .~.~.~ Spring biased {5}
537.~.~.~.~ Spring under tension

DEFINITION

Classification: 137/537

(under subclass 535) Valves in which the resilient member is placed under tension to hold the valve normally closed.

SEE OR SEARCH CLASS

267, Spring Devices,

69+, for elastic extension devices, per se, especially subclasses 73+ for tension springs.