Corrugated cardboard tube and load bearing tables using the same
CA 2136503 C · Owner: Yoshii, Hisashi · Inventors: Yoshii, Hisashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A corrugated cardboard tube (1A) includes a tubular laminar structure of single-lined corrugated cardboard which includes a plurality of strips of singlelined corrugated cardboard (2) spirally wound into a substantially cylindrical configuration to form corresponding single-lined corrugated cardboard layers (31to 36) overlapping and bonded with each other in a radial direction. Each of thestrips of single-lined corrugated cardboard (2) is composed of an elongated liner sheet (2b) and a corrugated sheet (2a) having a plurality of parallel ridges (2d) and furrows, and being spirally turned in a direction perpendicular to the ridges (2d). The corrugated cardboard tube (1A) is used as a load …
Read the whole patent
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
- Filed November 23, 1994 and granted November 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 23, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 23, 2016.
- 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.