Ball lock punch retainer
CA 2077901 C · Owner: Wellman, Charles G. · Inventors: Wellman, Charles G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved punch retainer is disclosed in which a backing plate extends over a relatively large surface area to dissipate force from a punch. A punch retainer body and the backing plate are permanently connected to each other and include passages which are finally ground after the two have been permanently connected. With this arrangement it is, ensured that passages within the backing plate and retainer body are all properly aligned during formation of the punch retainer. Since the backing plate dissipates force over a relatively large surface area, the punch retainer may be used in heavier applications than prior art punch retainers. A spring passage is closed off by a seal received in …
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 April 5, 1991 and granted March 14, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 5, 2013.
- 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.