Repetitive make=and=break switch with silver contacts - of spherical and plane forms allowing compensatory metal transfer and criss=crossed pattern of furrows

摘要

The fixed contact studs are formed of Ag-CdO or Ag-Ni alloy with a preponderance of Ag. The moving contacts are the ends of a bridge impelled by a contact carrier and spring urging the partially spherical ends into contact with the studs. The bridge may be cold-stamped from a thin conductive sheet with edges folded to form a U-section for additional rigidity. The moving contact surfaces are coated with a 20-micron thin film of pure Ag, pref. occupying a pattern of criss-crossed furrows. Currents up to 10 A can be made and broken repeatedly without appreciable degradation of contact quality, some stud alloy being transferred into the furrows to counteract loss of Ag from the moving contact film.