Detecting apparatus including resilient moisture absorbent roller means for locatingdiscontinuities in non-conductive coatings on conductive objects

Claim 1

IN A COATING DISCONTINUITY DETECTOR, MEANS ADAPTED FOR SUPPORTING AN ELONGATED, ELECTRICALLY CONDUCTIVE OBJECT HAVING AN OUTER, GENERALLY CYLINDDRICAL, NON-CONDUCTIVE COATING THEREON; A SCANNER ASSEMBLY INCLUDING AN ANNULAR SERIES OF INDIVIDUALLY ROTATABLE ROLLERS, EACH LOCATED FOR LONGITUDINAL ROLLING ENGAGEMENT WITH THE COATING OF AN OBJECT SUPPORTED BY SAID SUPORTING MEANS, SAID SUPPORTING MEANS AND SAID ASSEMLBY BEING ADAPTED TO PERMIT RELATIVE SHIFTING OF THE ASSEMBLY AND SAID OBJECT, LONGITUDINALLY OF THE LATTER, NORMALLY INTERRUPTED ELECTRICAL CIRCUIT MEANS FOR INDICATING COATING DISCONTINUITIES ELECTRICALLY COUPLED WITH SAID ROLLERS AND ADAPTED FOR CONNECTION TO SAID OBJECT; AND MEANS FOR DISTRIBUTING AN ELECTRICALLY CONDUCTIVE FLUID TO SAID ROLLERS, SAID ROLLERS BEING CONSTRUCTED OF RESILEINT, FLUID ABSORBENT MATERIAL AND EACH HAVING A PERIPHERAL SURFACE CONTOURED FOR COMPLEMENTALLY ENGAGING SAID COATING CIRCUMFERENTIALLY THEREOF, SAID SURFACES BEING DISPOSED FOR CONTACTING THE ENTIRE CIRCUMFERENTIAL EXTENT OF SAID COATING WHEREBY UPON RELATIVE SHIFTING OF THE ASSEMBLY AND THE OBJECT, UPON DISTRIBUTION OF SAID FLUID TO SAID ROLLERS AND UPON CONNECTION OF SAID CIRCUIT MEANS TO SAID OBJECT, A CIRCUMFERENCE ENCOMPASSING, LONGITUDINALLY SHIFTING BRIDGE OF SAID LIQUID IS FORMED BETWEEN THE COATING AND THE ROLLERS FOR CLOSING SAID CIRCUIT MEANS WHENEVER A DISCONTINUITY IN THE COATING IS TRANSVERSED BY THE BRIDGE REGARDLESS OF FLUCTUATIONS IN THE DIAMETER OF SAID OBJECT.