Motor Control for a Vacuum Cleaner

• US 20110005023A1
• Filed: 09/22/2010
• Published: 01/13/2011
• Est. Priority Date: 01/05/2006
• Status: Active Grant

• Current Assignee: Kirby OPCO LLC
• Original Assignee: John A. Lambert, Terry L. Zahuranec
• Inventors: Zahuranec, Terry L., Lambert, John A.
• Granted Patent: US 8,099,825 B2
• Time in Patent Office: Days
• US Class Current: 15/319
• CPC Class Codes: A47L 9/19 Means for monitoring filtering operation
• CPC Class Codes: A47L 9/2805 Parameters or conditions being sensed
• CPC Class Codes: A47L 9/2842 Suction motors or blowers
• CPC Class Codes: A47L 9/2857 User input or output elements for control, e.g. buttons, switches or displays

Abstract

A vacuum cleaner includes a nozzle, an air-filtering dirt receptacle, and a motor. A fan of the vacuum cleaner is configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface. A controller of the vacuum cleaner provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value.

Claims

1. A vacuum cleaner comprising:

a nozzle;

an air-filtering dirt receptacle;

a motor;

a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and

a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value.

2. The cleaner of claim 1 wherein the notification directs the user to empty the receptacle.

3. The cleaner of claim 1 wherein the notification directs the user to replace the receptacle.

4. The cleaner of claim 1 wherein the controller powers the motor with constant voltage.

5. The cleaner of claim 1 wherein the controller is configured to control the motor to maintain a constant motor temperature.

6. The cleaner of claim 1 wherein the receptacle includes a filter bag.

7. The cleaner of claim 1 wherein the controller powers the motor to rotate at different user selectable speed settings, and the threshold value is different for each speed setting.

8. The cleaner of claim 1 wherein the controller is configured to vary a ratio of on-time to total-time of pulse width modulated (PWM) voltage applied to the motor to maintain a parameter of motor operation at a constant value, and the motor current dropping below the threshold is indicated by the value of the PWM ratio.

9. The cleaner of claim 8 wherein the parameter is motor speed, and the controller provides the notification when the ratio drops below a predetermined value.