Reed switches and process for making them

Abstract

A reed switch is made by forming an envelope tube, non-circular in cross-section, with a known internal heightwise dimension, forming a reed element with two end-bearing portions at least one of which is part of a contact section of the reed element and an intermediate sealing-bearing section between and entirely out of a plane defined by the end-bearing portions of the reed, the distance between the plane and a bearing surface of the sealing-bearing section being greater than the internal heightwise dimension of the envelope tube; inserting the reed element into an open end of the envelope tube sufficiently far to cause both of the end-bearing portions and the bearing surface of the sealing-bearing section to bear against the inside wall of the envelope tube, the end-bearing portion of the contact section of the reed element bearing with a force greater than the force ultimately to be exerted by that portion in the finished switch; sealing at least a part of the sealing section in the envelope tube to seal said tube and form the reed switch envelope, and relieving at least a part of the pressure exerted upon the inside wall by the end-bearing portion of the contact section of the reed. The resulting reed switch has at least one reed element with two end-bearing portions bearing upon undistorted areas of the inside wall of the envelope and a sealing section sealed in the envelope, the force with which the end portion of the contact section or sections bears against the envelope wall being less than the force with which it bore during the reed switch forming process.