Hollow stackable building block
CA 2029710 C · Owner: Lewis, John F. · Inventors: Lewis, John F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A lightweight, hollow building block is disclosed. The building block preferably has a rectangular base and an open pentagonal top. Two adjacent sides of the block form right angles with the base and the top. The three remaining adjacent sides are inclined outwardly from the base at an angle which permits the blocks to be stacked one inside another. When four such blocks are arranged in a double-wide and double-long pattern they form a rectangular, vertical sided building unit. A building is constructed from the blocks by laying a course at the time and preferably filling the open upturned blocks in each course with some locally available filler material to lend weight and stability to the …
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 9, 1990 and granted August 2, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 2012.
- 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.