Self-fixturing system for a vacuum interrupter
A vacuum interrupter includes end covers having a curved or looped portion, which serves to connect a coil segment of the vacuum interrupter to a ceramic envelope of the vacuum interrupter, and thereby help maintain a vacuum seal for the interrupter. The curved portion acts as a spring when the vacuum interrupter is exposed to heat, thereby absorbing any expansion or contraction in the length of the vacuum interrupter due to the heating or cooling. The curved portion also protects an end of the ceramic envelope from any build-up of metallic arcing products and eliminates the need for elaborate fixturing during assembly. Additionally, a guide may be affixed to the end cover, the guide having ears which ride in a slot in a moving rod of the vacuum interrupter, to thereby prevent a twisting of a bellows of the interrupter during a brazing process. Thus, no elaborate fixturing is necessary to prevent this twisting.
1. An end cover for a vacuum interrupter, the end cover comprising:
a substantially annular first portion, the first portion being attached to a substantially cylindrical hollow body of the vacuum interrupter;
a concave second portion, the second portion being concentric to the first portion and concave with respect to the body; and
a substantially annular third portion, the third portion being concentric with the first portion,
wherein at least a portion of the concave second portion is positioned along an axis defined between electrical contacts of the vacuum interrupter and a joint at which the end cover is attached to the hollow body, and wherein the axis defines an opening of a shield that encloses the electrical contacts, such that the concave second portion shields the joint from electrical stress associated with movement of the electrical contacts during an operation of the vacuum interrupter.
2. The end cover of claim 1 wherein at least a first section of the first portion is substantially in a plane of the third portion.
3. The end cover of claim 2 wherein all of the first portion is substantially in the plane of the third portion, and substantially perpendicular to the body.
4. An end cover for a vacuum interrupter, the end cover comprising:
a substantially annular first portion, the first portion being attached to a substantially cylindrical hollow body of the vacuum interrupter;
a concave second portion, the second portion being concentric to the first portion and concave with respect to the body; and
a substantially annular third portion, the third portion being concentric with the first portion,
wherein a section of the first portion is tapered away from a plane of the third portion, in a direction of the concave second portion, and attached to the body.
5. The end cover of claim 1 wherein the body is primarily composed of ceramic.
6. The end cover of claim 1 further comprising a fourth portion that extends over the second portion.
7. The end cover of claim 1 wherein the third portion is attached to a substantially cylindrical electrode support structure that is concentric with the body.
8. An end cover for a vacuum interrupter, the end cover comprising:
a substantially annular first portion, the first portion being attached to a substantially cylindrical hollow body of the vacuum interrupter;
a concave second portion, the second portion being concentric to the first portion and concave with respect to the body; and
a substantially annular third portion, the third portion being concentric with the first portion,
wherein a substantially annular hollow guide is attached to the third portion, the guide including protruding portions extending into an interior thereof, the protruding portions riding in corresponding slots formed in a moving rod that is slidable through the end cover and the guide and operable to actuate a moving electrode of the vacuum interrupter.
9. The end cover of claim 8 wherein the protruding portions are composed primarily of steel.
10. The end cover of claim 1 wherein the third portion is attached to, and sandwiched between, a support structure for an electrode of the vacuum interrupter and a female-threaded metallic base.
11. A vacuum interrupter having an end cover, the end cover comprising:
a substantially circular outer perimeter portion;
an inner portion that is concentric with the outer perimeter portion; and
a continuously curved portion protruding into a body of the vacuum interrupter and joining the outer perimeter portion to the inner portion,
wherein at least a portion of the continuously curved portion is positioned along an axis defined between electrical contacts of the vacuum interrupter and a joint at which the end cover is attached to an insulating body encasing the vacuum interrupter, and wherein the axis defines an opening of a shield that encloses the electrical contacts, such that the continuously curved portion shields the joint from electrical stress associated with movement of the electrical contacts during an operation of the vacuum interrupter.
12. The vacuum interrupter of claim 11 wherein the inner portion is substantially within a plane, and further wherein at least a first portion of the outer perimeter portion is substantially within the plane of the inner portion.
13. The vacuum interrupter of claim 12 wherein substantially all of the outer perimeter portion is substantially within the plane of the inner portion.
14. A vacuum interrupter having an end cover, the end cover comprising:
a substantially circular outer perimeter portion;
an inner portion that is concentric with the outer perimeter portion; and
a continuously curved portion protruding into a body of the vacuum interrupter and joining the outer perimeter portion to the inner portion,
wherein a portion of the outer perimeter portion is tapered away from a plane of the inner portion, in a direction of the curved portion, and attached to the insulating body of the vacuum interrupter.
15. The vacuum interrupter of claim 11 wherein the outer perimeter portion and the inner portion are substantially perpendicular to the insulating body of the vacuum interrupter.
16. The vacuum interrupter of claim 11 further comprising a covering portion that extends over the curved portion.
17. The vacuum interrupter of claim 11 wherein the inner portion is attached to a substantially cylindrical electrode support structure that is concentric with the body.
18. A vacuum interrupter having an end cover, the end cover comprising:
a substantially circular outer perimeter portion;
an inner portion that is concentric with the outer perimeter portion; and
a continuously curved portion protruding into a body of the vacuum interrupter and joining the outer perimeter portion to the inner portion,
wherein a substantially annular hollow guide is attached to the inner portion and includes protruding portions extending into an interior thereof, the protruding portions riding in corresponding slots formed in a moving rod that is slidable through the end cover and the guide and operable to actuate a moving electrode of the vacuum interrupter.
19. The vacuum interrupter of claim 11 wherein the inner portion is attached to, and sandwiched between, a support structure for an electrode of the vacuum interrupter and a female-threaded metallic base.