| 摘要 |
<PICT:0963376/C6-C7/1> <PICT:0963376/C6-C7/2> <PICT:0963376/C6-C7/3> A method of making electrical contact blades 10 having limited regions, embracing the contact-making areas plated with precious metal comprises applying to a 0.020 inch strip, of preferably phosphor bronze, bands 19, 20 of plating-resistant varnish, e.g. by roller or spraying means, blanking the strip to form a succession of contacts 16 connected by tags 17 showing positioning perforations 18, immersing a length of the strip in a plating solution so that the right hand contact portion 11 only is immersed up to the mid-point of the resist strip 19 and plating by the electroless or electrolytic method the exposed areas thereof with, e.g., gold or platinum to a thickness of 0.0002-0.0003 inch. Subsequently the strip is cleaned and if necessary the plating resistant removed, prior to dipping the left hand tag portions 13 of the strip into a molten tinning bath and passing the strip through a press tool to blank and form the finished blade 10 therefrom. The plating-resistant bands may be applied to the strip after the initial blanking operation. The blades may be used in multi-point plugs and shelf jacks for telephone systems.
|
