End construction with hollow beam construction for a drum
CA 2020678 C · Owner: Carpenter, Herbert L. Jr. · Inventors: Carpenter, Herbert L. Jr.; Hale, James A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A barrel or drum preferably of fibre, with metal chimes responsive to longitudinal compressive forces is provided. The compressive forces urge a diagonal flange of the chimes towards the horizontal thereby expanding the outer circumference of the flange of the chime. The outer circumference of the flange of the chime has a rectangular or looped (tear-drop shaped) high strength hollow beam construction so as to increase the stiffness or "stretch resistance" of the flange.
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 July 6, 1990 and granted March 9, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 6, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 6, 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.