US 12,465,184 B2
Vacuum cleaner
Mark Philip Taylor, Bristol (GB); Andrew David Chadwick, Surrey (GB); Nolan Thomas McCann, Oakton, VA (US); Mehdi Salehifar, Swindon (GB); Thomas James Richards, Swindon (GB); and Angel Isidoro Nieto, Bristol (GB)
Assigned to Dyson Technology Limited, Wiltshire (GB)
Appl. No. 17/042,665
Filed by Dyson Technology Limited, Wiltshire (GB)
PCT Filed Feb. 25, 2019, PCT No. PCT/GB2019/050505
§ 371(c)(1), (2) Date Sep. 28, 2020,
PCT Pub. No. WO2019/186100, PCT Pub. Date Oct. 3, 2019.
Claims priority of application No. 1805267 (GB), filed on Mar. 29, 2018.
Prior Publication US 2021/0059492 A1, Mar. 4, 2021
Int. Cl. A47L 9/28 (2006.01); A47L 9/04 (2006.01)
CPC A47L 9/2842 (2013.01) [A47L 9/0411 (2013.01); A47L 9/0466 (2013.01); A47L 9/2831 (2013.01); A47L 9/2847 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A vacuum cleaner comprising:
a cleaner head defining a suction chamber and having an agitator arranged to be rotated by an agitator motor;
a dirt separator;
a vacuum motor arranged to draw air into the suction chamber and then into the dirt separator; and
a controller configured to selectively operate in a first mode, a second mode, and a third mode, wherein while in the first mode, the controller is configured to:
monitor an electrical load of the agitator motor, compare a magnitude of the electrical load to a threshold range, and selectively adjust the electrical power delivered to the vacuum motor,
wherein the controller is configured to at least one of: gradually increase the electrical power delivered to the vacuum motor to a predetermined upper power level when the electrical load is greater than an upper limit of the threshold range, and gradually decrease the electrical power delivered to the vacuum motor to a predetermined lower power level, that is greater than zero, when the electrical load is smaller than a lower limit of the threshold range,
wherein the controller is configured to retain a record of the power level that was being delivered to the vacuum motor when the vacuum cleaner was last turned off, and is configured to resume delivery of that power level to the vacuum motor when the vacuum cleaner is next turned on, and
compare the magnitude of the electrical load to a spike threshold, which is higher than the upper limit of the threshold range,
wherein the controller is configured to provide a rapid step decrease in the power delivered to the predetermined lower power level in response to determining that the electrical load is larger than the spike threshold, initiate a time delay, and following the expiration of the time delay, compare the magnitude of the electrical load to the spike threshold to determine whether the electrical load remains larger than the spike threshold,
wherein while in the second mode, the controller is configured to supply a minimum predetermined power level to the vacuum motor, the minimum predetermined power level being below the predetermined lower power level and greater than zero, and
wherein while in the third mode, the controller is configured to supply a maximum predetermined power level to the vacuum cleaner when the controller is in the third mode, the maximum predetermined power level being above the predetermined upper power level.