Prefabricated modular heiical escape structure for multiple story buildings
CA 1048461 A · Owner: Van Byelvelt, Rudi · Inventors: Welcker, Willy H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A double helical earthquake and fire escape structure for multiple story buildings formed mainly of a plurality of prefabricated sections of precast concrete. Two identically formed upper sectional units and two identically formed lower units are arranged in facing relationship to each other for each floor of the building. Complementary portions of the assembled units combine to form a pair of oppositely disposed entrances on each floor leading to two separate helical slides arranged about a separately formed central circular smokestack. The units are provided with steel members adjacent their edges which are connected together and secured to a surrounding supporting steel framework. Two …
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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 February 13, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 13, 1996.
- 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.