Fail-safe valve actuator
CA 1266853 C · Owner: Karr, Michael A. Jr. · Inventors: Karr, Michael A. Jr.; Zwiegel, John M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fail-safe valve actuator includes a hydraulic piston (17) and cylinder (15) for driving the valve stem (9) and gate member (35) of a gate valve into a first flow control state responsive to sufficient pressure delivered by a fluid or gas supply line (92). Upon failure or other loss of sufficient control line pressure, a volute spring (7) drives the cylinder (15) and hence, the stem (9) and gate member (35) axially outward resulting in, the valve being moved into a second flow control state. Retaining rings (94, 102) are provided to retain the volute spring in a precompressed state during disassembly of the actuator for servicing.
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 March 20, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 20, 2007.
- 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.