# US 2025/0084579 A1 · Improvements relating to laundry apparatus and/or their control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0084579 A1 - Document ID: US20250084579A1 - Status: Published application - Kind: A1 - Application number: 18/720,462 - Filed: 2022-12-16 - Published: 2025-03-13 - Earliest claimed: 2021-12-16 - Assignees: Fisher & Paykel Appliances Limited - Applicants: Fisher & Paykel Appliances Limited - Inventors: Christopher Harold Matulis; Jamal Azhar Koya; Ethan Russell Bos - Web page: https://patentgrep.com/patent/US20250084579A1 ## CPC - D06F 33/48: Preventing or reducing imbalance or noise - D06F 23/02: and rotating or oscillating about a horizontal axis - D06F 34/16: Imbalance - D06F 37/36: for rotating the receptacle at more than one speed {(D06F37/304, D06F37/308 take precedence)} - D06F 2103/24: Spin speed; Drum movements - D06F 2103/26: Imbalance; Noise level - D06F 2103/46: of the motor driving the drum - D06F 2105/48: Drum speed - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES ## Abstract A method of mitigating an out of balance washing load in a washing machine with a horizontal axis drum comprising: determining an indication of an angular position, and optionally a radial position, of a OOB mass of the washing machine drum, and controlling rotational speed of the drum so that, as the drum and OOB mass rotates, a rotational speed of the drum is varied relative to a usual speed based on the OOB mass so that an outward radial force on the washing load reduces below the inwards radial force and/or of gravity. ## Claims ### Claim 1 A method of mitigating an out of balance laundry load in a laundry machine with a horizontal axis drum, comprising the steps of: spinning the drum above a satellisation speed of the laundry load; and within a single revolution of the drum, varying the drum speed by sequentially decreasing and then increasing the drum speed below and then above satellisation speed, to selectively allow at least some of the laundry load to drop under gravity. ### Claim 2 (depends on 1) The method of claim 1 wherein the rate at which drum speed is decreased to a speed below satellisation speed is more rapid than the rate at which drum speed is subsequently increased to a speed above satellisation speed. ### Claim 3 (depends on 1) The method of claim 1 further comprising the step of: determining a position (which is optionally an angular position) of an out of balance mass of the out of balance laundry load. ### Claim 4 (depends on 3) The method of claim 3 wherein the step of varying the drum speed coincides rotation of the drum below satellisation speed with the position of the out of balance mass being at, near, or passing through, a high point in its rotation about the horizontal axis of the drum. ### Claim 5 (depends on 3) The method of claim 3 further comprising the step of: determining a target zone with an angular extent relative to the angular position of the out of balance mass, and optionally with a radial extent relative to the radius of the drum; and wherein, within a single revolution of the drum, drum speed is varied by sequentially decreasing and then increasing the drum speed below and then above satellisation speed, to selectively cause laundry load located within the target zone to drop under gravity. ### Claim 6 (depends on 5) The method of claim 5 wherein the angular extent of the target zone is between about 0-90 degrees in either direction relative to the position of the out of balance mass; or optionally between about 0-45 degrees, about 0-30 degrees, about 0-15 degrees, or about 0-5 degrees in either direction relative to the position of the out of balance mass. ### Claim 7 (depends on 5) The method of claim 5 wherein the radial extent of the target zone is between about 25-100 percent of the radius of the drum; or optionally between about 40-100 percent, about 60-100 percent, about 80-100 percent, or about 90-100 percent of the radius of the drum. ### Claim 8 (depends on 3) The method claim 3 wherein one or more selected from the following are used as inputs from which to determine the position of the out of balance mass. a. motor torque, power, current, speed, or voltage; and/or b. a time (relative to a reference time point); and/or c. drum speed, drum angular position, drum linear acceleration and/or drum angular acceleration. ### Claim 9 (depends on 3) The method of claim 3 wherein the position of the out of balance mass is determined using: a. sensor data, optionally selected from one or more of data from an accelerometer or gyroscope; and/or b. motor data, optionally selected from one or more of motor torque, power, current, speed or voltage. ### Claim 10 (depends on 9) The method of claim 9 wherein the position of the out of balance mass is determined using only motor data. ### Claim 11 (depends on 1) The method of claim 1 wherein, during the step of varying the drum speed by sequentially decreasing and then increasing the drum speed below and then above satellisation speed, the rotational speed of the drum is controlled using a control signal with a profile that varies from a previous normal and/or constant control signal profile, and optionally has a pulsed profile. ### Claim 12 (depends on 11) The method of claim 11 wherein the control signal varies based on one or more selected from: a. motor torque, power, current, speed, or voltage; and/or b. a time (relative to a reference time point); and/or c. drum speed, drum angular position, drum linear acceleration and/or drum angular acceleration; and/or d. the mass of the laundry load; and/or e. the size/diameter of the drum; ### Claim 13 (depends on 11) The method of claim 11 wherein the control signal comprises one or more selected from: a. an angular start position/angular span/angular stop position of rotational speed decrease and subsequent speed increase; b. a time (relative to a reference time point) at which rotational speed decrease and subsequent speed increase is initiated and/or concluded; c. a slope or rate of rotational speed decrease and subsequent speed increase; and/or d. a magnitude or amplitude of rotational speed decrease and subsequent speed increase. ### Claim 14 (depends on 11) The method of claim 11 wherein the control signal profile creates a rotational speed profile of the rotating drum that selectively causes laundry load in the drum to drop under gravity; and optionally wherein the control signal profile creates a rotational speed profile of the rotating drum that selectively causes laundry load in the target zone to drop under gravity. ### Claim 15 (canceled) ### Claim 16 (canceled) ### Claim 17 (canceled) ### Claim 18 A method of mitigating an out of balance washing load in a washing machine with a horizontal axis drum comprising: determining an indication of an OOB mass of the washing machine drum, and controlling rotational speed of the drum so that, as the drum and OOB mass rotates, a rotational speed of the drum is varied, within one revolution of the drum, relative to a usual speed based on the OOB mass so that an outward radial force on the washing load reduces below the inwards radial force and/or of gravity. ### Claim 19 (canceled) ### Claim 20 (canceled) ### Claim 21 (canceled) ### Claim 22 (canceled) ### Claim 23 (depends on 18) A method according to claim 18 wherein the rotational speed of the drum is controlled using a control signal with a profile that varies from a normal control signal. ### Claim 24 (canceled) ### Claim 25 (canceled) ### Claim 26 (depends on 23) A method according to claim 23 wherein the control signal profile creates a rotational speed profile of the rotating drum that creates a target region which redistributes an OOB mass and/or washing load in the target region. ### Claim 27 (depends on 26) A method according to claim 26 wherein the target region comprises and angular span and a radial extent. ### Claim 28 (depends on 18) A laundry apparatus comprising: a drum, a motor to rotate the drum, one or more sensors, and a controller that receives input from the sensors and controls the motor to rotate the drum, wherein the controller is configured to mitigate an out of balance washing load according to claim 18. ### Claim 29 (depends on 1) The method of claim 1 wherein the drum is spun at a constant speed above satellisation speed prior to, and optionally following, the step of varying drum speed within a single revolution of the drum.