Two-coordinate locating device for a ultrasonic search probe

Claim 2

In a system for scanning an arcuate surface with an ultrasonic search probe to detect the existence of cracks and other flaws therein, means for continuously locating the polar coordinates of the probe relative to an actual fixed reference point radially spaced outwardly of a theoretical given point on the arcuate surface, comprising, a reel releasably mounted to the arcuate surface in spaced relation to the fixed reference point for rotation about an axis parallel to the plane tangent to the arcuate surface at the given point thereon, a flexible cable having one end wound on said reel and the other end thereof connected to the probe, spring means responsive to the rotation of said reel for imparting a constant torque thereto in opposition to the unwinding of said cable therefrom, a first incremental encoder rotatably responsive to the winding and unwinding of said cable from said reel for generating electrical counting pulses in direct relation to the length of said cable unwound from said reel during the scanning movement of the search probe, a second incremental encoder mounted at right angles to said first encoder and rotatably responsive to the angular movement of the probe for generating electrical counting pulses in direct relation to the extent of the angle between the probe and a line through the fixed reference point normal to the axis of rotation of said reel, and means for visually presenting the output of each of said first and second encoders throughout the scanning movement of the probe.

Claim 3

The locating means defined in claim 1 including switch means for permanently recording the visual presentation of the output of said encoders during the traverse of the probe over a crack in the arcuate surface.

Claim 4

The locating means defined in claim 1 wherein said spring means comprises, a first rotatable spool forming a portion of said reel, a second rotatable spool spaced from Said first spool in parallel relation thereto, and a negator spring partially wound around each of said first and second spools and biased to resist the unwinding thereof from said second spool.

Claim 5

The locating means defined in claim 3 including a guide arm disposed between the arcuate surface and said second incremental encoder, one end of said arm coupled to said second encoder and the other end of said arm having an opening therethrough for passage of said cable into connection with the search probe whereby the angular scanning movement thereof over the arcuate surface actuates said guide arm to rotate said second encoder for generating the electrical counting pulses utilized to indicate the extent of the angular coordinate of the probe.

Claim 6

The locating means defined in claim 4 including pulley means rotatably responsive to the winding and unwinding movement of said cable on said reel comprising, a first rotatable pulley spaced from said first spool in position to maintain the portion of said cable therebetween normal to the axis of rotation of said reel, a second rotatable pulley disposed in common alignment with said first and second spools and in frictional engagement with said cable, and a third rotatable pulley spaced from said first and second pulleys in position to maintain the portion of said cable between said third pulley and said opening in said guide arm in parallel relative with the portion of said cable between said first spool and said first pulley.

Claim 7

In a system for scanning the exterior surface of a tube with an ultrasonic probe to detect the existence of cracks and other flaws therein, means for continuously locating the polar coordinates of the probe in relation to a fixed reference point on the locating means, comprising, a reel releasably mounted in spaced relation to one end of the tube for rotation about an axis parallel to the plane tangent to the exterior of the tube at a point in radial alignment with the fixed reference point, a flexible cable having one end wound on said reel and the other end thereof connected to the probe, spring means responsive to the rotation of said reel for imparting a constant torque thereto in opposition to the unwinding movement of said cable, a first incremental encoder having a central shaft rotatably responsive to the winding and unwinding of said cable from said reel for generating electrical counting pulses in direct relation to the length of said cable unwound from said reel during the scanning movement of the search probe, a second incremental encoder having a central shaft disposed at right angles to said first encoder shaft in axial alignment with the fixed reference point and rotatably responsive to the angular movement of the probe for generating electrical counting pulses in direct relation to the extent of the angle between the probe and a line through the fixed reference point normal to the axis of rotation of said reel, and means for visually presenting the output of each of said encoders throughout the scanning movement of the probe.

Claim 8

In a system for scanning the exterior surface of a tube with an ultrasonic probe to detect the existence of cracks and other flaws therein, means for continuously locating the polar coordinates of the probe in relation to a fixed reference point on the locating means, comprising, a reel releasably mounted in spaced relation to one end of the tube for rotation about an axis parallel to the plane tangent to the exterior of the tube at a point in radial alignment with the fixed reference point, a flexible cable having one end wound on said reel and the other end thereof connected to the probe, spring means responsive to the rotation of said reel for imparting a constant torque thereto in opposition to the unwinding movement of said cable, a first incremental encoder having a central shaft rotatably responsive to the winding and unwinding of said cable from said reel for generating electrical counting pulses in direct relation to the length of said cable unwound from said reel during the scanning movement of the search probe, a second incremental encoder having a central shaft disposed at right angles to said first encoder shaft in axial alignment with the fixed reference point and rotatably responsive to the angular movement of the probe for generating electrical counting pulses in direct relation to the extent of the angle between the probe and a line through the fixed reference point normal to the axis of rotation of said reel, and means for visually presenting the output of each of said encoders throughout the scanning movement of the probe.

Claim 9

The locating means defined in claim 6 including means for releasably mounting said reel to one end of the tube, comprising, a cross-bar terminating in magnetic blocks at each end thereof for clamping engagement with the exterior surface of the tube, means for adjusting the position of said blocks relative to said cross-bar to prevent contact between said cross-bar and the exterior surface of the tube, and a pair of spaced plates projecting from said cross-bar in position to rotatably receive said reel therebetween.

Claim 10

The locating means defined in claim 7 wherein said spring means comprises, a spool portion adjacent one end of said reel, a separate spool rotatably mounted between said spaced plates in spaced alignment with said spool portion of said reel, and a negator spring having one end thereof wound around said spool and the other end thereof wound around said spool portIon of said reel in the direction in which the bias thereof resists the rotation imparted to said reel by the unwinding of said flexible cable therefrom.

Claim 11

The locating means defined in claim 8 including, a plate intermediate said pair of spaced plates, and pulley means between said intermediate plate and one of said spaced plates for supporting said flexible cable, said pulley means comprising, a first rotatable pulley spaced from said reel and disposed to position the portion of said cable therebetween normal to the axis of rotation of said reel, a second pulley spaced from said first pulley and from said reel for rotation about an axis disposed in the plane common to the axes of both said separate spool and said spool portion of said reel, said second pulley being thereby positioned to rotate in response to the frictional engagement of said cable therewith, and a third pulley spaced from said first and second pulleys in offset relation thereto for supporting the portion of said cable extending from said second pulley in parallel relation to the portion between said first pulley and said reel.

Claim 12

In a system for scanning the exterior surface of a tube with an ultrasonic probe to detect the existence of cracks and other flaws therein, means for continuously locating the polar coordinates of the probe relative to a fixed reference point radially spaced outwardly of a given point on the exterior surface of the tube, comprising, a reel releasably mounted in spaced relation to one end of the tube for rotation about an axis disposed in parallel relation to the plane tangent to the exterior surface of the tube at the given point thereon, said reel having first and second spool portions in juxtaposed relation, a rotatable spool spaced from said reel in parallel relation thereto, a flexible cable having one end wound on said second spool portion of said reel and the other end thereof extending into connection with the probe, pulley means for supporting said cable for passage through the fixed reference point in a direction normal to the axis of rotation of said reel, a negator spring having one end wound on said spool and the other end thereof wound on said first spool portion of said reel, said spring responsive to the rotation of said reel during the unwinding of said cable therefrom for imparting a constant torque thereto arranged to restore said cable to the unwound position thereof, a first incremental encoder having a central shaft coupled to said pulley means for simultaneous rotation therewith whereby the movement of said cable relative to said reel generates electrical counting pulses in direct relation to the changes in the length of said cable from the fixed reference point to the search probe, a second incremental encoder having a central shaft disposed at right angles to the axis of said shaft of said first encoder in the plane passing through the fixed reference point and rotatably responsive to the angular movement of the search probe for generating electrical counting pulses in direct relation to the extent of the angle between the probe and a line through the fixed reference point normal to the axis of rotation of said reel, and means for visually presenting the output of each of said encoders throughout the scanning movement of the probe.

Claim 13

In a system for scanning the exterior surface of a tube with an ultrasonic probe to detect the existence of cracks and other flaws therein, means for continuously locating the polar coordinates of the probe relative to a fixed reference point radially spaced outwardly of a given point on the exterior surface of the tube, comprising, a reel releasably mounted in spaced relation to one end of the tube for rotation about an axis disposed in parallel relation to the plane tangent to the exterior surface of the tube at the given point thereon, said reel having first and second spool portions in juxtaposed relation, a rotatable spool spaced from said reel in parallel relation thereto, a flexible cable having one end wound on said second spool portion of said reel and the other end thereof extending into connection with the probe, pulley means for supporting said cable for passage through the fixed reference point in a direction normal to the axis of rotation of said reel, a negator spring having one end wound on said spool and the other end thereof wound on said first spool portion of said reel, said spring responsive to the rotation of said reel during the unwinding of said cable therefrom for imparting a constant torque thereto arranged to restore said cable to the unwound position thereof, a first incremental encoder having a central shaft coupled to said pulley means for simultaneous rotation therewith whereby the movement of said cable relative to said reel generates electrical counting pulses in direct relation to the changes in the length of said cable from the fixed reference point to the search probe, a second incremental encoder having a central shaft disposed at right angles to the axis of said shaft of said first encoder in the plane passing through the fixed reference point and rotatably responsive to the angular movement of the search probe for generating electrical counting pulses in direct relation to the extent of the angle between the probe and a line through the fixed reference point normal to the axis of rotation of said reel, and means for visually presenting the output of each of said encoders throughout the scanning movement of the probe.

Claim 14

The locating means defined in claim 10 including means for releasably mounting said reel on one end of the tube, comprising, a cross-bar having an arcuate face on one side thereof, an adjusting element pivoted to each end of said cross-bar, a magnetic block pivoted to the outer end of each of said adjusting elements for clamping engagement with the exterior surface of the tube at locations equally distant from the given point thereon, screw means for locking said elements and said magnetic blocks in positions for locating said arcuate face out of contact with the exterior surface of the tube, and a pair of plates fixed To said cross-bar to project beyond the end of the tube in spaced apart relation for rotatably receiving said reel therebetween.

Claim 15

The locating means defined in claim 10 including a guide arm disposed between the exterior surface of the tube and said second encoder, said guide arm comprising, a first end fixedly engaged with said central shaft of said second encoder, a second end parallel to said first end and having an opening therethrough for passage of said cable into connection with the search probe, and a linear section connected to said ends whreby said guide arm is pivoted by the angular coordinate of the scanning movement of the probe to rotate said second encoder for generating the electrical counting pulses indicative of the extent of the angular coordinate of the position of the probe.

Claim 16

The locating means defined in claim 12 wherein said linear section of said guide arm is connected to said ends for bending movement relative thereto only in the plane common to both said linear section and said ends thereby permitting said cable to conform to the curvature of the tube during movement of the probe therearound.