Xenon arc lamp with compressive ceramic to metal seals
AssigneeVarian Associates, Inc.
InventorsEdwin T. Chan, Stanley R. Jepson
Life of this patent
Estimating the term…
Abstract
A high pressure arc lamp envelope having an anode portion and cathode portion, separated by a ceramic insulator, is configured to prevent the high pressure from causing tensile stresses in the ceramic and its associated hermetic seals. The window seal is configured to reduce tensile stresses in the window and to place the metal-to-window bond of the seal in compression.
Claims14
An envelope for an arc lamp, said envelope being capable of containing a gas therewithin at a pressure higher than atmospheric pressure, said envelope comprising:
- a first metallic member having an inwardly projecting flange portion,
- a second metallic member having an outwardly projecting flange portion,
- the outwardly projecting flange portion of said second metallic member being received within said first metallic member, the inwardly projecting flange portion of said first metallic member being disposed to overlap the outwardly projecting flange portion of said second metallic member, said overlapping flange portions of said first and second metallic members being radially spaced apart to define a generally annular region between said first and second metallic members,
- a ceramic member disposed in said annular region, and
- means for hermetically sealing said ceramic member to said inwardly and outwardly projecting flange portions so that said ceramic member is under compression when said envelope contains a gas at a pressure higher than atmospheric pressure.
In an arc lamp comprising a metallic envelope member and a window, an outer surface of said window being a portion of the exterior of an enclosure for containing a gas at higher than atmospheric pressure, sealing means for providing a hermetic seal between said metallic envelope member and said window, said sealing means comprising:
- a knife-edge member disposed between said metallic envelope member and said window, said knife-edge member being in contact with said window only where a first edge of said knife-edge member abuts a peripheral portion of the outer surface of said window, said window being spaced apart from said metallic envelope member, a second edge of said knife-edge member abutting an inwardly projecting flange portion of said metallic envelope member.
Dependencies are inferred from the claim text.