Ceramic tube for high-intensity discharge lamp and method of producing the same
AssigneeNGK Insulators, Ltd.
InventorsSugio Miyazawa, Keiichiro Watanabe, Tsuneaki Ohashi
Life of this patent
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Abstract
The present invention relates to a ceramic tube for a high-intensity discharge lamp, comprising a hollow member and a plug member. The hollow member contains a substantially cylindrical body and a closure for closing one end of the body, and the plug member is inserted into an insertion opening formed at the other end of the body. Before the insertion of the plug member, the insertion opening has a tapered portion with a diameter decreasing in the direction from the open end to the inside at least in an area into which the plug member is inserted. After the insertion of the plug member, an outer wall of the plug member is bonded to an inner wall of the insertion opening.
Claims14
A ceramic tube for a high-intensity discharge lamp, comprising:
- a hollow member and a plug member, each containing an electrode insert into which an electrode is inserted;
- wherein the hollow member comprises a substantially cylindrical body having an opening at one end of the body and a closure for closing another end of the body;
- wherein the plug member comprises a disc-shaped portion with a substantially constant outer diameter;
- wherein the plug member is inserted into the opening of the hollow member;
- wherein, before the insertion of the plug member, the opening has a tapered portion with a diameter decreasing in a direction from an inlet to an inside of the hollow member at least in an area into which the plug member is inserted;
- and
- wherein, after the insertion of the plug member, an outer wall of the plug member is bonded to an inner wall of the opening.
A method of producing a ceramic tube for a high-intensity discharge lamp comprising a hollow member and a plug member, each containing an electrode insert into which an electrode is inserted,
- wherein the hollow member comprises a substantially cylindrical body having an opening at one end of the body and a closure for closing another end of the body,
- wherein the plug member is inserted into the opening,
- wherein the hollow member has a tapered, diameter-decreasing portion with a diameter decreasing in a direction from an inlet of the opening for the plug member to an inside of the hollow member at least in an area into which the plug member is inserted,
- wherein the plug member has a disc-shaped portion with a substantially constant outer diameter, and
- wherein an inner wall of the tapered, diameter-decreasing portion is at an angle of 0.5° to 4° to an outer wall of the disc-shaped portion of the plug member,
- the method comprising the steps of:
- inserting the disc-shaped portion to the opening;
- and
- bonding the outer wall of the plug member to the inner wall of the opening.
Dependencies are inferred from the claim text.