O-ring seal for rock bit bearings
CA 2096300 C · Owner: Smith International, Inc. · Inventors: Denton, Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A dynamic O-ring seal for retaining the lubrication around a rock bit bearing for drilling subterranean formations has a composition comprising 100 parts by weight highly-saturated nitrile elastomer furnace black in the range of from 40 to 70 parts by weight, peroxide curing agent in the range of from 7 to parts by weight, graphite in the range of from 10 to parts lay weight, zinc oxide or magnesium oxide in the range of from 4 to 7 parts by weight stearic acid, in the range of from 0.5 to 2 parts by weight and, sufficient plasticizer to provide a Shore hardness no more than A 80.
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 May 14, 1993 and granted March 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 14, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 14, 2015.
- 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.