Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
245 words
A method of non-destructive quality testing of spot welds comprising the following steps of: (a) exposing a test weld nugget zone to a primary electromagnetic field to induce therein eddy currents, said eddy currents producing a secondary electromagnetic field which interacts with the primary electromagnetic field to form a resultant electromagnetic field; (b) displacing said primary electromagnetic field in a direction parallel to the surface of contact of the welded parts and between points located on either side of the test weld zone where the weld nugget is disposed; (c) measuring the phase angle between the resultant and primary electromagnetic fields at each of the points characterized by the maximum of the primary electromagnetic field and lying on the same line parallel to the surface of the welded junction being tested in the zone of the weld nugget, in the region disposed between the points located on either side of the weld junction being tested wherein the weld nugget is disposed, and establishing the maximum and minimum phase angle values; (d) evaluating the weld nugget thickness from the difference between the maximum phase angle value measured in the portion of the test weld zone where there is no weld nugget and the minimum phase angle value in the portion of the test weld zone where there is a weld nugget; and (e) evaluating the weld nugget diameter from the length of the zone within the limits in which the phase angle has its minimum value.
Claim 2
Independent Claim
245 words
A method of non-destructive quality testing of spot welds comprising the following steps of: (a) exposing a test weld nugget zone to a primary electromagnetic field to induce therein eddy currents, said eddy currents producing a secondary electromagnetic field which interacts with the primary electromagnetic field to form a resultant electromagnetic field; (b) displacing said primary electromagnetic field in a direction parallel to the surface of contact of the welded parts and between points located on either side of the test weld zone where the weld nugget is disposed; (c) measuring the phase angle between the resultant and primary electromagnetic fields at each of the points characterized by the maximum of the primary electromagnetic field and lying on the same line parallel to the surface of the welded junction being tested in the zone of the weld nugget, in the region disposed between the points located on either side of the weld junction being tested wherein the weld nugget is disposed, and establishing the maximum and minimum phase angle values; (d) evaluating the weld nugget thickness from the difference between the maximum phase angle value measured in the portion of the test weld zone where there is no weld nugget and the minimum phase angle value in the portion of the test weld zone where there is a weld nugget; and (e) evaluating the weld nugget diameter from the length of the zone within the limits in which the phase angle has its minimum value.
Claim 3
Independent Claim
145 words
An apparatus for non-destructive quality testing of spot welds, comprising: (a) a sinusoidal voltage generator; (b) a reference channel having a phase shifter with its input connected to the output of said sinusoidal voltage generator; (c) a measuring channel having an unbalanced bridge circuit and having its input connected to the output of said sinusoidal voltage generator; (d) a phase meter having its inputs connected to the outputs of said phase shifter and unbalanced bridge circuit; (e) an eddy current transducer arranged in one of the branches of said unbalanced bridge circuit; (f) means for mechanically displacing said eddy current transducer in a plane parallel to the surface of contact of the welded parts; (g) means connected to said phase meter for measuring the thickness of a weld nugget; and (h) means connected to said phase meter for measuring the diameter of a weld nugget.
Claim 4
Independent Claim
145 words
An apparatus for non-destructive quality testing of spot welds, comprising: (a) a sinusoidal voltage generator; (b) a reference channel having a phase shifter with its input connected to the output of said sinusoidal voltage generator; (c) a measuring channel having an unbalanced bridge circuit and having its input connected to the output of said sinusoidal voltage generator; (d) a phase meter having its inputs connected to the outputs of said phase shifter and unbalanced bridge circuit; (e) an eddy current transducer arranged in one of the branches of said unbalanced bridge circuit; (f) means for mechanically displacing said eddy current transducer in a plane parallel to the surface of contact of the welded parts; (g) means connected to said phase meter for measuring the thickness of a weld nugget; and (h) means connected to said phase meter for measuring the diameter of a weld nugget.
Claim 5
Dependent Claim
20 words
An apparatus as defined in claim 2, further comprising an attenuator connected between said phase meter and said measuring means.
Claim 6
Dependent Claim
20 words
An apparatus as defined in claim 3, further comprising a matching amplifier connected between said attenuator and said measuring means.
Claim 7
Dependent Claim
17 words
An apparatus as defined in claim 4, further comprising a display unit connected to said matching amplifier.