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US 4,631,771 AGranted
Clothes washing machines
AssigneeFisher & Paykel Limited
InventorsIain A. Anderson, Christopher J. Gaelic, Phillipa L. Elliott
Life of this patent
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AssigneeFisher & Paykel Limited
InventorsIain A. Anderson, Christopher J. Gaelic, Phillipa L. Elliott
Estimating the term…
A clothes washing machine includes a container within which a spin tub is rotatably mounted, an agitator mounted within that spin tub, driving means including a reversible electric motor to drive the spin tub and agitator, and controls are provided to cause the spin tub to commence a spinning phase of the clothes washing cycle, to cause the spin tub and its contents to accelerate through the critical speed (lateral resonance speed) to a holding speed not greatly above that critical speed, and to cause that holding speed to be maintained for a sufficient length of time as to prevent or substantially reduce the creation of suds or foam caused by cleaning additives such as detergents in the washing liquid until conditions for suds forming have been substantially eliminated. Alternatively or additionally a hot water admission water valve and a cold water admission valve are provided and further controls to control motion of the clothes in association with control of the hot water admission valve in a manner such that the clothes are slowly or gently moved during admission of hot water into the container of the laundry machine.
A method of operating a clothes washing machine of the type which includes a container within which a spin tub is rotatably mounted, an agitator mounted within that spin tub, driving means including a reversible electric motor energized to drive said spin tub and agitator, said method comprising the steps of causing said spin tub to commence a spinning phase of the clothes washing cycle, accelerating the spin tub and its contents through the critical speed (lateral resonance speed) to a holding speed not greatly above that critical speed, and holding the speed at that holding speed for a sufficient length of time as to prevent or substantially reduce the creation of suds or foam caused by cleaning additives such as detergents in the washing liquid until conditions for suds forming have been substantially eliminated, applying increased power to said motor after said sufficient length of time has expired to accelerate said spin tub towards a further speed lower than a full spin speed, sensing whether there is excessive friction resisting attaining or maintaining said further speed under available motor torque from the energized motor and then effecting further steps selected from either the step of maintaining said further speed, when attained, for a period of about 10 seconds and subsequently applying further increased power to said motor to cause the full speed spinning for a desired period of time and subsequently stopping spinning, or the step of switching off power to said motor in the event that said further speed is not reached or maintained under said available motor torque.
A clothes washing machine of the type which includes a container within which a spin tub is rotatably mounted, an agitator mounted within that spin tub, driving means including a reversible electric motor to drive said spin tub and agitator, wherein control means including sensing means are provided to cause said spin tub to commence a spinning phase of the clothes washing cycle, to cause the spin tub and its contents to accelerate through the critical speed (lateral resonance speed) to a holding speed not greatly above that critical speed, and to cause that holding speed to be maintained for a sufficient length of time as to prevent or substantially reduce the creation of suds or foam caused by cleaning additives such as detergents in the washing liquid until conditions for suds forming have been substantially eliminated, said control means causing said motor to be actuated to accelerate said spin tub after said sufficient length of time toward a further speed which is lower than the full spin speed, said sensing means sensing whether said further speed is attained within a predetermined time, attainment of said further speed resulting in said control means being actuated to cause said spin tub to be accelerated to full spin speed after holding said further speed for about 10 seconds and lack of said attainment resulting in said control means being actuated to switch off power to said motor.
A method as claimed in claim 22 wherein said holding speed is about 50 to 100 R.P.M.
A method of operating a clothes washing machine of the type which includes a container within which a spin tub is rotatably mounted, an agitator mounted within that spin tub, driving means including a reversible electric motor energized to drive said spin tub and agitator, said method comprising the steps of causing said spin tub to commence a spinning phase of the clothes washing cycle, accelerating the spin tub and its contents through the critical speed (lateral resosance speed) to a holding speed not greatly above that critical speed, and holding the speed at that holding speed for a sufficient length of time as to prevent or substantially reduce the creation of suds or foam caused by cleaning additives such as detergents in the washing liquid until conditions for suds forming have been substantially eliminated, applying increased power to the said motor after said sufficient length of time has expired to accelerate said spin tub towards a further speed lower than a full spin speed, sensing the speed of the spin tub to sense whether said further speed is attained in a substantially predetermined time and then effecting further steps selected from the steps of maintaining said further speed, when attained, for a period of about 10 seconds and subsequently applying further increased power to the motor to cause the full speed spinning, for a desired period of time and subsequently stopping the spinning and switching off power to said motor in the event that said further speed is not reached in said substantially predetermined time.
Dependencies are inferred from the claim text.