Invalidity dossier
US 4237356
Electrical compression switch with contact movement assistor
Current assignee: BBC Brown Boveri AG Switzerland
Added 9/24/2026, 2:09:44 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US 4,237,356 A
Title: Electrical compression switch with contact movement assistor
Patent number: US 4,237,356 A
Application number: US05/787,215
Inventor: Klaus Ragaller
Assignee: BBC Brown Boveri AG (Switzerland)
Priority/filing date: 1977-04-13
Publication (grant) date: 1980-12-02
Status listed: Expired – Lifetime (anticipated expiration 1997-12-02)
Purpose
The invention concerns a method and apparatus to assist the drive of at least one moving switch part in an electric compression switch. A quenching-medium flow is generated during switching-off by a compression device, primarily a piston coacting with a quenching-medium compression chamber, and the arc across the switch components is quenched by that flow. As explained in the excerpt, breaking increasingly heavy currents requires external drives with correspondingly greater motive forces; the invention aims to reduce that demand.
Plain-language scope
Quenching medium is highly compressed by one end of a piston (preferably a differential-diameter piston) and released to act on the arc. A portion of the medium, heated by the arc and put under increasing pressure, expands in a quenching-medium expansion chamber, moving the piston's other end and part of the chamber boundary apart. During the final period of switch-off, that portion is diverted to a lower-pressure region, preferably the switch's quenching chamber. The preferred form uses a tubular differential-diameter piston whose smaller-area end faces the high-pressure side and larger-area end the low-pressure side, so a relatively low pressure rise can be amplified into a much higher compression-chamber pressure. A non-return valve may be arranged between the compression and expansion chambers. In one described species, the differential-diameter piston is stationary; FIGS. 3a–3c show on/off positions.
What the excerpt does not establish
The supplied text is partial: the description is cut off mid-sentence in the discussion of FIG. 3b, and the claims and abstract are not reproduced. It therefore does not establish the full claim scope, all described embodiments, or the complete figures.
Generated 10/1/2026, 9:40:47 PM
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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