Method and device for the saving of electrical energy for the drive of an hydraulic lift
CA 2088893 C · Owner: Nagel, Heinz-Dieter · Inventors: Nagel, Heinz-Dieter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
With this method and this device for the saving of electrical energy for the drive, of an hydraulic lift, it is possible to drive the lift cage in the upward direction with, practically constant power for any loading. The maximum nominal speed in upward, direction is chosen for a loading which according to experience occurs most frequently. The required size of the drive is designed in accordance with this choice. The hoist, speed is reduced correspondingly for higher loads and increased correspondingly for, lower loads. The variable hoist speed is achieved either through an adjustable pump (8), of variable displacement volume and controlled by a pressure-regulating valve (14) or, …
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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 February 5, 1993 and granted November 25, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 5, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 5, 2015.
- 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.