Reed switch construction
AssigneeCorning Glass Works
InventorDavid W. Morgan
Life of this patent
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Abstract
A reed switch construction is described embodying magnetic metal reeds and an improved glass envelope. The envelope is drawn from an infrared absorbing glass having a steep viscosity curve which permits forming a seal between the metal reeds and the glass envelope with infrared heating at a temperature sufficiently low to avoid damaging the reeds.
Claims5
A reed switch embodying reeds composed of a magnetic, cobalt-iron-vanadium alloy having a thermal coefficient of expansion within the range of 95-105 .times. 10.sup.-.sup.7 (25.degree.-300.degree.C.), and a tubular glass envelope having an expansion coefficient matching that of the alloy below the glass setting point and being hermetically sealed to the reeds, the envelope being drawn from a glass having a working temperature below 950.degree.C. and being composed essentially of, in percent by weight as calculated from the glass batch on an oxide bases, 46-54% SiO.sub.2, 2-8% B.sub.2 O.sub.3, 0-4% Li.sub.2 O, 0-12% Na.sub.2 O, 0-10% K.sub.2 O, the total content of Li.sub.2 O + Na.sub.2 O + K.sub.2 O being 8-13%, 0-6% CaO, 13-20% BaO, 5-10% ZnO, the total content of CaO + BaO + ZnO being 25-35%, 0-2% TiO.sub.2, 0-4% ZrO.sub.2, and 0.5-5.0% Fe.sub.2 O.sub.3.
Dependencies are inferred from the claim text.