Weld thickness monitoring in resistance welding apparatus
AssigneeMetal Box Public Limited Company
InventorsStephen J. Haigh, Martin J. Melville, Martin J. Melville
Life of this patent
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Abstract
Apparatus, for measuring the thickness of a welding seam produced by resistance welding between a resiliently mounted upper roll and a lower roll, comprises a source of light mounted laterally of the resiliently mounted roll and a light collector mounted to receive such light as is not eclipsed by the periphery of the roll so that variation in the amount of light received as the roll periphery interrupts the light is indicative of weld thickness. The light received is preferably converted by means to an electrical signal which is analyzed to discern the quality of the weld.
Claims19
Resistance welding apparatus for welding a workpiece arranged to be displaced along a predetermined path, said apparatus comprising:
- a pair of cooperating electrodes;
- means mounting said electrodes on opposite sides of said path;
- means urging the electrodes towards one another;
- a gap defining member;
- means mounting the gap defining member in a fixed positional relationship with one said electrode and located facing the outer surface of the other electrode to define a gap between the said outer surface and the gap defining member, the said outer surface being faced, being inclined to a line extending perpendicular to the path where said outer surface passes between the electrodes whereby the size gap will vary as a function of the instantaneous thickness of the workpiece between the electrodes;
- and
- monitoring means for monitoring the size of said gap and thereby the thickness of said workpiece.
Resistance welding apparatus comprising
- first and second mutually co-operable electrodes, said first electrode being arcuate and the second electrode a rotary wheel,
- means mounting said first electrode immovable in bodily position,
- means mounting said second electrode for guided movement towards and away from the first electrode, and
- means for sensing the displacement of the periphery of the second electrode at a position where the periphery is inclined to the direction of movement of the second electrode and for generating a signal which is a function of the relative displacement between the electrodes and therefore also a function of weld thickness present between the electrodes.
Resistance welding apparatus comprising first and second mutually co-operable electrodes, said first electrode being arcuate and the second electrode a rotary wheel;
- means mounting said second electrode for guided movement towards and away from the first electrode;
- a light source located laterally of the periphery of the second electrode to direct light towards a position where the periphery is inclined to the direction of movement of the second electrode;
- and
- a light collector located on the opposite side of the second electrode from the light source to receive light and in a position where light from the light source directed at light collector is partially eclipsed by the second electrode, the collector thereby generating a signal which is a function of the relative displacement between the electrodes and therefore also a function of weld thickness present between the electrodes.
Dependencies are inferred from the claim text.