Means for rotating ball valves between open and closed positions
CA 2122913 C · Owner: Kemp, Willard E. · Inventors: Kemp, Willard E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A ball valve (10) has a stem (28) to rotate a ball member (20) with a lower key or lug (29) received within a slot or opening (26) forming a keyway in the ball member (20). As shown particularly in (Figures 2 and 3), relieved or cutaway surfaces (52 54, 56) are provided between lug (29) and the outer spherical surface (24) of ball member (20) so that a torque exerted by rotation of the stem (28) contacts surfaces (34, 36) of the slot (26) along opposed corners (48) which are spaced a distance T1 from the outer spherical surface (24) of ball valve member (20) thereby removing or minimizing any stress concentrations adjacent outer spherical surface (24).
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 October 21, 1992 and granted October 15, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 21, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 21, 2014.
- 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.