Agricultural depth control system including cross plumbed series cylinders
CA 2015352 C · Owner: Deere & Company · Inventors: Barber, Dennis Ray
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A hydraulic control system is provided which includes a pair of transversely spaced rockshaft cylinders which are plumbed in parallel and connected to opposite ends of a rockshaft on the central portion or main frame of a wide implement such as a field cultivator or chisel plow. The left-hand rockshaft cylinder is connected in series with a right-hand outer cylinder located near the right end of the implement. The right-hand rockshaft cylinder is connected in series with a left-hand outer cylinder on the opposite side of the implement. When a ground condition exists which causes for example, the left side of the implement to dig more deeply and the left-hand wing cylinder to retract 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
- Filed April 25, 1990 and granted April 9, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 25, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 25, 2012.
- 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.