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Series-welding heads on a common mechanical carrier are individually fine-positioned by independent control of electromagnets operating with permanent magnets in the heads.
English (United States)
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Fine Positioning of Series Welding Heads
Series-welding heads on a common mechanical carrier are individually fine-
positioned by independent control of electromagnets operating with permanent
magnets in the heads.
Metal sheet or bar workpieces 10, 11 are joined together by passing a
welding current between electrodes 12, 13 carried on identical welding heads 14, 15. Both heads are rigidly attached to a common mechanical carrier 16 for gross
position control in a conventional manner. To achieve fine control of position and
pressure, electrodes 12 and 13 are individually movable over a small vertical
In the partially cutaway view of head 15, bearings 17 support shaft 18 in
housing 19. Permanent magnet 20 repels shaft-mounted magnet 21 for
cushioning before electrode 13 comes into contact with workpiece 10. As
housing 19 continues to move downward, the repulsion between magnet 21 and
another permanent magnet 22 applies pressure to electrode 13. At this point, a
control current may be passed through electromagnet coil 23, wound in core 24,
to attract shaft-mounted armature 25 and apply further pressure to electrode 13.
Electrode 12 may be similarly controlled by a second control circuit for attracting
armature 26. Since the two control currents may be separately regulated,
independent fine positioning and pressures may be achieved for electrodes 12,
13 even though the heads 14, 15 are mechanically fixed to each other.