Pneumatic percussion hammer
CA 1295604 C · Owner: Lister, William · Inventors: Lister, William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A pneumatic percussion hammer for rock drilling has a tubular casing (10) with a top sub (23) for connection to the outer tube of a double tube drill stem, an air feed pipe (19) from the top sub (3) extending co-axially into the casing and co-axially about an air outflow pipe (21) for connection to the inner tube of the drill stem, its lower end being slidable in an air passage (38) through a bit (31) of which the shank (32) is slidable, a driver sub (33) at the lower casing and is topped by an anvil (35), this passage (43) having ducts (39) being to the exterior of the bit the air, outflow pipe having ducts (44) to the bottom of the bit (31). A tubular piston (27) slidable in the casing …
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
- Granted February 11, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 11, 2009.
- 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.