Abstract: A subminiature lamp assembly utilizes a high temperature polymer which directly surrounds and is cemented to the glass envelope. The polymer may preferably derive support from a metal base. The polymeric material is somewhat rigid and can be manually handled and used to manipulate the subminiature lamp as a handle to facilitate bulb changout. A fluoroelastomer is a preferable type of elastomer which has the chemically resistive properties and ability to withstand high temperature which can be advantageously employed. The elastomer used for the seal supported lamp assembly provides (1) extended axial length sealing, (2) heat resistance, (3) ease of handling, (4) increased resistance to invasion and chemical attack (5) eliminates contact corrosion, and (6) reduces lamp failure modes.

Abstract: A low-wattage metal-halide discharge lamp has a tube of the double ended type that forms a bulb or envelope, a pair of electrodes, e.g., an anode and a cathode, which penetrate into an arc chamber inside the envelope, and a suitable amount of mercury plus one or more metal halide salts. The electrodes are each formed of a refractory metal, i.e., tungsten wire, extending through the respective necks into the arc chamber. The electrodes are of a composite design i.e., in the form of a club, with a lead-in wire of small diameter supported in the associated neck, and a post member of greater diameter supported on the lead-end wire. The post members are supported of contact with the necks and also out of contact with the bulb wall. The larger size of the post member allows heat at the tip to diffuse back into the post member, so that the metal tip will not evaporate. The narrow lead-in wire keeps most of the heat in the bulb, so that flow of heat out of the neck portions is limited.