Speed control device for dc motors
CA 2233837 C · Owner: Ready Welder Co. · Inventors: Rebold, Jerome I.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A speed control device is provided such that the speed of DC motors is controlled to remain constant with varying voltages supplied from a power source. A given application for such a speed control device is in the use of portable hand-held Metal Inert, Gas (MIG) welders. The power requirements of a portable MIG welder are twofold. Power is required for the generation of a welding current to enable the workpieces to be sufficiently heated and thus, welded together and power is also required to drive a wire spooler which provides wire at a constant rate leading to accurate and consistent welds. The speed control device provided ensures constant power delivery for both powerrequirements …
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 March 31, 1998 and granted February 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 31, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 31, 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.