Laundry machines and/or flow control systems and/or methods of controlling operations of laundry machines and/or flow control systems and/or methods of control using pulse width modulation
CA 2044994 C · Owner: Shacklock, Frank Whitney · Inventors: Shacklock, Frank Whitney; Greenman, Murray
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The temperature or some other specific characteristic of a mixture of the two liquids in a mixing chamber (14) is controlled by a microprocessor (8) which controls the supply of power to solenoid actuated valves (10 and 11) to control the quantities of liquids admitted to the chamber (14) so that a desired temperature is achieved using a pulse width modulation control method. The pulse width modulation method requires only one microprocessor timer and provides a substantially constant supply of power to one valve while varying the power supplied to the other valve to control the temperature of the liquids.
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 19, 1991 and granted September 14, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 19, 2013.
- 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.