Patent Yard Sign in
Expired Canadian patentCanada

Guided drilling system with shock absorber

CA 2203736 C · Owner: Van Berkel, Lambertus H. · Inventors: Hoover, David Lloyd; Young, Donald D.; Van Berkel, Lambertus H.

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

There is provided a guided drilling system and an in-the-hole shock absorber adapted thereto. The guided drilling system includes a drill string configured to continuously and accurately bore a hole in the ground without the need to periodically break the connection of the drill string. In order to protect the components of the drilling system a hollow core shock absorber for percussive drill strings has been designed. A centrally disposed coil spring transmits the necessary thrust to a percussive hammer while providing a resilient cushion for vibration displacement Pressurized fluid flows through the center of the shock absorber through a poppet valve.

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 April 25, 1997 and granted December 23, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 25, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 25, 2019.
  • 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 25, 1997
GrantedDecember 23, 2003
Term endedApril 25, 2017
Patent numberCA 2203736 C
Classification (IPC)E21B7/02 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedApril 25, 1997Patent grantedDec 23, 2003Term endedApril 25, 2017

Sources & verification

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