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Expired Canadian patentCanada

Combination lift piston/axial port unloader arrangement for a screw compressor

CA 2074444 C · Owner: American Standard International Inc. · Inventors: Linnert, Peter J.

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Abstract From the Canadian patent

Title, COMBINATION LIFT PISTON/AXIAL, PORT UNLOADER ARRANGEMENT FOR A SCREW COMPRESSOR, Inventor, PETER J. LINNERT Abstract, An unloading arrangement for a rotary screw compressor includes discrete and different unloading apparatus associated with the male and female rotors respectively. The unloading apparatus associated with the male rotor is an axial piston continuous unloader movably disposed in a bore which is remote from but in flow communication, through a series of ports, with the compressor's working chamber. The unloading apparatus associated with the female rotor is a step unloader which, when opened, unloads the compressor in a single relatively large capacity step. The …

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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 July 22, 1992 and granted June 14, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 22, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 22, 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.
FiledJuly 22, 1992
GrantedJune 14, 1994
Term endedJuly 22, 2012
Patent numberCA 2074444 C
Classification (IPC)F04C2/08 +2 more

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedJuly 22, 1992Patent grantedJune 14, 1994Term endedJuly 22, 2012

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.