US Patent 10907291 Laundry appliance and operating method

A method of operating a laundry washing (or washing and drying) machine, and a machine so operated, for determining whether an undetached laundry ring is present within the drum at the end of a washing cycle. The method includes rotating the drum at first and second rotational speeds, respectively below and above the threshold speed at which the load is centrifugally held against the drum's surface, measuring motor current/torque at each speed and comparing the measured values. Optionally, a percentage change in current/torque can be calculated and the existence of the ring detected if the percentage change is above/below a predetermined threshold value. Optionally, speed variation of the drum at each threshold speed can be determined and this information also used in the determination of whether the ring exists.