Gravity gradiometer accelerometers
CA 2293217 A1 · Owner: Lee, James Beresford · Inventors: Lee, James Beresford; O'Keefe, Graeme Joseph; Goodwin, Graham Clifford
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention concerns improvements to gravity gradient instruments (GGI) and in particular to the accelerometers that are paired within these instruments. Accelerometers (1) have a proof mass (2) suspended by a spring (3) within a magnetic field. An internal feedback loop (6) provides a signal related to movement of the proof mass back through a reaction coil (7) retaining the proof mass in the magnetic field, to maintain the proof mass stationary. An external feedback loop (17) adjusts the accelerometer scale factor. The internal feedback loop provides second order compensation to the proof mass and the spring stiffness. In a further aspect the invention is a method of matching …
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 June 11, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 11, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 11, 2020.
- 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.