Alfred M Clark

Author:

Alfred Clark

ISBN #:

0121754405

Author:

Alfred Clark

ISBN #:

0121754502

Author:

Alfred T. Clark

ISBN #:

0538717599

Author:

Alfred W. Clark

ISBN #:

0306308797

Author:

Alfred Joseph Clark

ISBN #:

0443012571

US Patent:

56523890, Jul 29, 1997

Filed:

May 22, 1996

Appl. No.:

8/651597

Inventors:

Stephen R. Schaps - Tempe AZ
Alfred V. Clark - Boulder CO
Brian Barnes - Tempe AZ

Assignee:

The United States of America as represented by the Secretary of Commerce - Washington DC

International Classification:

G01N 2904
G01N 2926

US Classification:

73643

Abstract:

The present invention is directed toward a method and apparatus for the ncontact inspection of workpieces having a plate-like portion of the first part joined via an inertia weld to the end of a second part extending away from the plate-like portion. The apparatus and method are particularly apt for the non-contact inspection of driver inflator igniter canisters for airbag applications, such canisters having a spool-shaped structure with outer walls which restrict access to the internal inertia welds for inspection. To achieve non-contact inspection, the invention comprises electromagnetic acoustic transducer means which generate a pulsed inspection signal and a detection signal. In one embodiment, the inspection signal comprises shear acoustic waves which are polarized parallel to the outer surface of the second member (e. g. , the central web member of an inflator igniter canister), and a pulse/echo detection approach is employed. Separate electromagnetic acoustic transducer assemblies are utilized to generate the inspection and detection signals, with the transmit assembly being positioned between the detection assembly and workpiece.