US PATENT SUBCLASS 307 / 138
.~.~.~ Polarity reversing


Current as of: June, 1999
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307 /   HD   ELECTRICAL TRANSMISSION OR INTERCONNECTION SYSTEMS

112  DF  SWITCHING SYSTEMS {5}
134  DF  .~ With operation facilitating feature {2}
137  DF  .~.~ Switch contact conditioning {1}
138.~.~.~ Polarity reversing


DEFINITION

Classification: 307/138

(under subclass 137) Subject matter having means to reverse the polarity of the contacts during use.

(1) Note. This subclass relates, for example, to those systems in which polarity reversing of the contacts is used to prevent a transfer of metal continuously from one contact to the other with resultant pitting and buildup.