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US 4,038,578 AGranted
Short-arc discharge lamp with electrode support structure
AssigneeU.S. Philips Corporation
InventorPetrus Johannes Mathijssen
Life of this patent
Estimating the term…
Abstract
Rare gas-filled short arc discharge lamps comprise in the neck-shaped portions of the lamp envelope a supporting member for the electrode pin which is connected neither to the wall of the lamp envelope, nor to the electrode pin. The supporting member is fixed against axial displacement. The member may consist of quartz glass, ceramic, a high-melting point metal. Due to this construction the manufacture of lamps is considerably simplified and critical steps are avoided.
Claims7
A short-arc discharge lamp comprising:
- an envelope, two opposed electrodes, a rigid electrode pin supporting each electrode and a rare gas filling, said envelope having a portion enclosing the discharge space and two neck-shaped portions via which said electrode pins to said electrodes extends to support said electrodes, said electrode pins extending through the wall of the lamp envelope in a vacuum-tight manner said lamp further including a cylindrical supporting member disposed about each of said electrode pins within one of said neck-shaped portions said cylindrical supporting member having an inside diameter greater then said electrode pin and an outside diameter less than the inside diameter of said neck-shaped portions in which said supporting member is disposed when said lamp is not operating and means to fix the supporting member against axial displacement with respect to the electrode pin about which said supporting member is disposed, the difference in the inside diameter of said supporting member and said neck-shaped portion allowing for differential expansion with changes in temperature.
Dependencies are inferred from the claim text.