Electromagnetic shield-type doorway for buildings and electromagnetic shielding system therefor
CA 1308185 C · Owner: Takahashi, Takeshi · Inventors: Nagata, Koji; Nakamura, Masatake; Takahashi, Takeshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electromagnetic shield-type doorway for a building is provided with two doors having a curved passageway between them. By lengthening the passageway to such an extent that the two doors cannot be opened simultaneously, electric waves can be blocked at either of the doors. The electromagnetic shielding effect can be enhanced by installing a revolving door in the passageway and attaching electrically conductive brushes to at least the lower edge and one side edge of the revolving door to fill the gaps at these edges. In a system for electromagnetically shielding a building a doorway passageway of the building is partitioned by three or more doorways each having an electromagnetic shielding …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted September 29, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 29, 2009.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.