The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 1991
Filed:
Jun. 26, 1989
Applicant:
Inventor:
Christopher N West, Somerset, GB;
Assignee:
Westland Helicopters Limited, Somerset, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01M / ;
U.S. Cl.
CPC ...
73 407 ; 73104 ; 416 61 ;
Abstract
A method for detecting a crack in the main load bearing spar of a hilicopter rotor blade consists of attaching a capillary tube along an external surface of the spar and connecting the interior of the tube to a supply of colored liquid contained in a reservoir at a root end of the blade, whereby a crack in the spar causes a corresponding crack in the capillary tube resulting in visible leakage of the colored liquid.