Bruce L Pfund

US Patent:

56866526, Nov 11, 1997

Filed:

Sep 9, 1996

Appl. No.:

8/707851

Inventors:

Bruce Pfund - Westerly RI

International Classification:

G01M 700

US Classification:

73 1204

Abstract:

A portable test hammer apparatus that produces repeatable and adjustable impacts to make traditional "tap testing" more reliable and quantified. The apparatus includes an impactor head device having a housing sized to be held in a human hand and engageable with the structural member, a plurality of adaptor bases, each readily mounted on the housing, an impactor head disposed within the housing for reciprocating movement therein, and a fluid piston assembly for moving the impactor head from a retracted position within the housing to a projected position in which the impactor head impacts the structural member. Impactor devices can be rapidly slid across test surfaces on non-marring feet, vacuum adhered to the test surface, or both. The apparatus further includes a rugged acoustic transducer for generating and transmitting an electrical signal based on the acoustic signature of the strike of the impactor head against the structural member. An acoustic spectral analyzer characterizes the acoustic signatures of the impacts, with extensive filtering and modeling options that configure the processing to best emphasize differences between intact and damaged test areas.