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Expired Canadian patentCanada

Spiral staircase arrangement

CA 1280574 C · Owner: Saskatchewan Economic Development Corporation · Inventors: Scholler, Siegfried

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

22 -, "SPIRAL STAIRCASE ARRANGEMENT " ABSTRACT OF THE DISCLOSURE, A spiral staircase is formed from post pieces and treads with the treads each having a collar portion which cooperates with the post pieces to form a complete post. The collars are rotatable relative to the post portions to allow the treads to be aligned for transportation. The post portions and collars are clamped together by a longitudinal screw with end caps closing the end post portions. The upper end cap has an opening therein so that a pourable settable liquid reinforced with glass-fiber can be poured down the hole post with the treads arranged spirally to integrate the collars and post portions into a complete rigid …

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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 26, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 26, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 17, 1986
GrantedFebruary 26, 1991
Term endedFebruary 26, 2008
Patent numberCA 1280574 C
Classification (IPC)E04F11/02

Timeline

Timeline From CIPO dates

19871990199319961999200220052008Application filedNov 17, 1986Patent grantedFeb 26, 1991Term endedFeb 26, 2008

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.