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Machine translation
1. (WO1980001843) METHOD AND APPARATUS FOR TESTING METAL TAPES
Latest bibliographic data on file with the International Bureau   

Pub. No.:    WO/1980/001843    International Application No.:    PCT/US1980/000141
Publication Date: 04.09.1980 International Filing Date: 11.02.1980
IPC:
G01N 27/82 (2006.01), G01R 33/12 (2006.01)
Applicants:
Inventors:
Priority Data:
13657 21.02.1979 US
Title (EN) METHOD AND APPARATUS FOR TESTING METAL TAPES
(FR) METHODE ET APPAREIL DE CONTROLE DE BANDES METALLIQUES
Abstract: front page image
(EN)Magnetic flux is induced in the tape (10) by applying a magnetic field to the tape. Where there is a perforation (12) or a crack (14) air gaps are created and magnetic flux (15, 18) radiates outwardly from the tape across these air gaps. The presence of the crack (14) is detected by sensing the radiating flux (15, 18) at two distances from the tape. At one distance (30), close to the tape, the total flux is the sum of the flux from the crack and the perforation. At the other distance (32), further from the tape, the flux is solely that produced by the perforation. A coil (36, 38) is placed at each position to sense the flux. The tape (10) is moved, which causes the flux (15, 18) to intersect the coils (36, 38). The intersection produces an output signal (40) from each coil (36, 38). The signal (40) produced by the coil (38) further from the tape is subtracted from the signal (40) produced by the coil (36) closer to the tape; the difference being a signal (58) caused by the additional flux produced by the crack (14). An alarm (94) is sounded and an indicator (88) lights when the signal is present.
(FR)Un flux magnetique est induit dans la bande (10) en appliquant un champ magnetique sur celle-ci. La ou existe une perforation (12) ou une fissure (14), se creent des lacunes et un flux magnetique (15, 18) irradie vers l"exterieur a partir de la bande au travers de ces lacunes. La presence de la fissure (14) est detectee en captant le flux radiant (15, 18) a deux distances differentes de la bande. A une distance (30), proche de la bande, le flux total est la somme du flux provenant de la fissure et de la perforation. A l"autre distance (32), plus loin de la bande, le flux est seulement celui qui est produit par la perforation. Une bobine (36, 38) est placee a chaque position pour capter le flux. La bande (10) est deplacee, exposant les bobines (36, 38) au flux (15, 18). L"exposition produit un signal de sortie (40) de chaque bobine (36, 38). Le signal (40) produit par la bobine (38) la plus eloignee de la bande est soustrait du signal (40) produit par la bobine (36) la plus proche de la bande; la difference donne un signal (58) provoque par le flux supplementaire produit par la fissure (14). Une alarme sonore (94) se met en route et un indicateur (88) s"allume lorsque le signal se produit.
Designated States:
Publication Language: English (EN)
Filing Language: English (EN)