Patent Yard Sign in
Expired Canadian patentCanada

Differential hydraulic jack with damping system for the control of electric circuit-breakers

CA 1287040 C · Owner: Gratzmuller, Claude Alain · Inventors: Gratzmuller, Claude Alain

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

A differential hydraulic jack with a damping system for the control of electric circuit-breakers is provided with a floating ring which produces a damping action at the end of travel and is also provided with a damping extension stud which forms part of the jack piston and penetrates into the damping ring. No provision is made on the jack piston for any packing ring forming a seal with the jack cylinder. The damping ring carries two projecting lips constituting a double valve which forms a leak-tight seal with the bottom face of the jack piston and the internal face of the cylinder end. At the end of travel of the piston the damping, ring forms a double sealing valve for shutting-off the …

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 July 30, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 30, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 12, 1988
GrantedJuly 30, 1991
Term endedJuly 30, 2008
Patent numberCA 1287040 C
Classification (IPC)F15B15/22 +1 more

Timeline

Timeline From CIPO dates

1989199119931995199719992001200320052007Application filedApril 12, 1988Patent grantedJuly 30, 1991Term endedJuly 30, 2008

Sources & verification

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