| 摘要 |
<p>Apparatus for welding longitudinal seams in can bodies includes a lower electrode wheel 10 mounted on an arm 18 and an upper electrode wheel 12 mounted on an arm 20. Metal Blanks bent into a tubular form are supplied to the nip between wheels 10,12. The apparatus also includes a transducer 40 for detecting vertical displacement of wheel 12, a pair of pick-ups 46,48 for detecting the rotational positions of wheels 12,10, and a single processing circuit. In order to determine the profile of one of the wheels 10,12, the output of transducer 40 is divided into a set of traces, each of which corresponds to a single rotation of the wheel. The traces are then averaged to produce an averaged trace, which represents the profile of the wheel. In order to determine weld thickness, the profile of each wheel, in turn, is subtracted from the output of transducer 40 to produce a corrected output which provides a good indication of weld thickness.</p> |
