Tube inspection system with interlaced scanning

Claim 2

The combination of a tube transport line for moving a tube axially, a drive station for simultaneously moving said tube axially along said line and rotating said tube about its axis, an inspection station positioned on said line, said inspection station including a pair of search units positioned on diametrically opposite sides of said tube, said search units being spaced a predetermined distance from each other and said tube, receiving means coupled to the search units to produce at least one signal corresponding to a dimension of said tube, means in said receiving means for producing signals corresponding to the distances between the search units and the adjacent sides of the tube and signals corresponding to the thicknesses of said sides of the tube, and means in said receiving means for producing an inside diameter signal corresponding to the difference between the sum of said signals and a signal corresponding to the distance between said search units.

Claim 3

The combination of a transport line for carrying an axially elongated workpiece axially therealong, drive means for simultaneously rotating and axially advancing said workpiece in said transport line, a first inspection station on said transport line, a group of ultrasonic search units in said first inspection station, each of said search units being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, positioning means in said first inspection station for positioning all of the search units in said group with their beams incident upon the workpiece in a common plane and at uniformly circumferentially spaced intervals therearound whereby all of the beams in the group scan the workpiece along equally spaced interlaced helical paths and propagate longitudinally through the workpiece in a forward direction, a second inspection station on said transport line and separated from the first inspection station, a group of ultrasonic search units in said second inspection station, each of said search units in said second group being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, positioning means in said second group for positioning all of the search units in said second group with their beams incident upon the workpiece in a second common plane and at uniformly circumferentially spaced intervals therearound whereby the beams in the second group scan the workpiece along equally spaced interlaced helical paths and propagate longitudinally through the workpiece in a rearward direction, a third inspection station on said transport line and separated from the other inspection stations, a group of ultrasonic search units in said second inspection station, each of said search units in said third group being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, positioning means in said third inspection station for positioning all of the search units in said third group with their beams incident upon the workpiece in a common plane and at uniformly circumferentially spaced intervals therearound whereby the beams in the third group scan the workpiece along equally spaced interlaced helical paths and propagate circumferentially around the workpiece in a right hand direction, a fourth inspection station on said transport line and separated from the other inspection stations, a group of ultrasonic search units in said fourth inspection station, each of said search units in said fourth group being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, and positioning means in said fourth inspection station for positioning all of the search units in said fourth group with their beams incident upon the workpiece in a common plane and at uniformly circumferentially spaced intervals therearound whereby the beams in the fourth group scan the workpiece along equally spaced interlaced helical paths and propagate circumferentially around the workpiece in a left hand direction.

Claim 4

The combination of a transport line for carrying an axially elongated workpiece axially therealong, drive means for simultaneously rotating and axially advancing said workpiece in said transport line, a first inspection station on said transport line, a group of ultrasonic search units in said first inspection station, each of said search units being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, positioning means in said first inspection station for positioning all of the search units in said group with their beams incident upon the workpiece in a common plane and at uniformly circumferentially spaced intervals therearound whereby all of the beams in the group scan the workpiece along equally spaced interlaced helical paths and propagate longitudinally through the workpiece in a forward direction, a second inspection station on said transport line and separated from the first inspection station, a group of ultrasonic search units in said second inspection station, each of said search units in said second group being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, positioning means in said second group for positioning all of the search units in said second group with their beams incident upon the workpiece in a second common plane and at uniformly circumferentially spaced intervals therearound whereby the beams in the second group scan the workpiece along equally spaced interlaced helical paths and propagate longitudinally through the workpiece in a rearward direction, a third inspection station on said transport line and separated from the other inspection stations, a group of ultrasonic search units in said second inspection station, each of said search units in said third group being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, positioning means in said third inspection station for positioning all of the search units in said third group with their beams incident upon the workpiece in a common plane and at uniformly circumferentially spaced intervals therearound whereby the beams in the third group scan the workpiece along equally spaced interlaced helical paths and propagate circumferentially around the workpiece in a right hand direction, a fourth inspection station on said transport line and separated from the other inspection stations, a group of ultrasonic search units in said fourth inspection station, each of said search units in said fourth group being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width, and positioning means in said fourth inspection station for positioning all of the search units in said fourth group with their beams incident upon the workpiece in a common plane and at uniformly circumferentially spaced intervals therearound whereby the beams in the fourth group scan the workpiece along equally spaced interlaced helical paths and propagate circumferentially around the workpiece in a left hand direction.

Claim 5

The combination of: a transport line for carrying an axially elongated workpiece axially therealong; drive means for simultaneously rotating and axially advancing said workpiece in said transport line; at least first and second inspection stations on said transport line; a plurality of ultrasonic search units mounted at said first inspection station, each of said search units being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width; positioning means at said first inspection station for positioning all of said plurality of search units thereat to direct their respective ultrasonic beams so as to be incident upon said workpiece at uniformly circumferentially spaced intervals defining a common plane transverse to the axis of said workpiece and obliquely inclined relative to said axis to cause said plurality of beams to scan said workpiece along equally spaced interlaced helical paths which after entering said workpiece at said common plane propagate longitudinally along said workpiece for greatest sensitivity to workpiece defects oriented transversely to the workpiece axis; another plurality of ultrasonic search units mounted at said second inspection station, each of said plurality of search units mounted at said second station being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width; and positioning means at said second station for positioning all of the search units mounted thereat to direct their respective ultrasonic beams so as to be incident upon said workpiece at uniformly circumferentially spaced locations therearound defining a common plane transverse to the workpiece axis, said positioning means at said second inspection station further positioning all of said search units thereat to direct the respective ultrasonic beams along directions laterally offset from an intersection with the axis of said workpiece but transverse thereto such that the beams from said search units at said second inspection station scan said workpiece along equally spaced interlaced helical paths which propagate circumferentially around said workpiece for greatest sensitivity to workpiece defects oriented longitudinally thereof.

Claim 6

The combination of: a transport line for carrying an axially elongated workpiece axially therealong; drive means for simultaneously rotating and axially advancing said workpiece in said transport line; at least first and second inspection stations on said transport line; a plurality of ultrasonic search units mounted at said first inspection station, each of said search units being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width; positioning means at said first inspection station for positioning all of said plurality of search units thereat to direct their respective ultrasonic beams so as to be incident upon said workpiece at uniformly circumferentially spaced intervals defining a common plane transverse to the axis of said workpiece and obliquely inclined relative to said axis to cause said plurality of beams to scan said workpiece along equally spaced interlaced helical paths which after entering said workpiece at said common plane propagate longitudinally along said workpiece for greatest sensitivity to workpiece defects oriented transversely to the workpiece axis; another plurality of ultrasonic search units mounted at said second inspection station, each of said plurality of search units mounted at said second station being adapted to transmit and receive ultrasonic energy along a beam having a predetermined width; and positioning means at said second station for positioning all of the search units mounted thereat to direct their respective ultrasonic beams so as to be incident upon said workpiece at uniformly circumferentially spaced locations therearound defining a common plane transverse to the workpiece axis, said positioning means at said second inspection station further positioning all of said search units thereat to direct the respective ultrasonic beams along directions laterally offset from an intersection with the axis of said workpiece but transverse thereto such that the beams from said search units at said second inspection station scan said workpiece along equally spaced interlaced helical paths which propagate circumferentially around said workpiece for greatest sensitivity to workpiece defects oriented longitudinally thereof.