CLEANING APPLIANCE

• US 20180125221A1
• Filed: 11/03/2017
• Published: 05/10/2018
• Est. Priority Date: 11/04/2016
• Status: Active Grant

• Current Assignee: Dyson Technology Limited (Beeswax Holdings UK Limited)
• Original Assignee: Dyson Technology Limited (Beeswax Holdings UK Limited)
• Inventors: WRONSKI, Robert Stefan, GUTKOWSKI, Martin Szymon, MAY, Alexander David
• Granted Patent: US 10,588,399 B2
• Time in Patent Office: Days
• CPC Class Codes: A46B 11/0055 with a reciprocating piston or plunger acting as the pressurising means
• CPC Class Codes: A61C 17/02 Rinsing or air-blowing devices, e.g. using fluid jets or comprising liquid medication combined with receptacles for spittle A61C17/14; combined with power-driven cleaning or polishing devices A61C17/16
• CPC Class Codes: A61C 17/0202 Hand-pieces
• CPC Class Codes: A61C 17/028 with intermittent liquid flow
• CPC Class Codes: A61C 17/221 Control arrangements therefor
• CPC Class Codes: A61C 17/227 with reservoirs, e.g. for toothpaste
• CPC Class Codes: A61C 17/28 with rinsing means
• CPC Class Codes: A61C 17/36 with rinsing means

Abstract

A fluid delivery system of a dental cleaning appliance includes a pump for drawing a working fluid through a fluid inlet, a hydraulic actuator for receiving working fluid from the pump, a drive for actuating the pump, and a nozzle having a fluid outlet for ejecting working fluid from the appliance. The drive includes a motor and a control circuit for operating the motor. The control circuit is configured to detect stalling of the motor in response to the load applied to the pump by the pressurized working fluid stored in the accumulator, and to deactivate the motor when stalling of the motor has been detected.

Claims

1. A dental cleaning appliance comprising:

a fluid delivery system comprising a fluid inlet, a pump for drawing a working fluid through the fluid inlet, a drive for actuating the pump, and a nozzle having a fluid outlet for ejecting working fluid from the appliance; and

wherein the drive comprises a motor and a control circuit for operating the motor, and wherein the control circuit is configured to detect stalling of the motor and to deactivate the motor when stalling of the motor has been detected.

2. The appliance of claim 1, wherein the control circuit is configured to detect stalling of the motor from a voltage generated by the motor.

3. The appliance of claim 2, wherein the control circuit is configured to detect stalling of the motor by measuring a back electromotive force across a coil of the motor.

4. The appliance of claim 1, wherein the motor is configured to stall when the pressure of pumped working fluid is in the range from 3 to 10 bar, preferably in the range from 5 to 8 bar.

5. The appliance of claim 1, wherein the drive comprises a linear actuator coupled to the motor, wherein the control circuit is configured to drive the motor to move the actuator.

6. The appliance of claim 1, wherein the motor is a stepper motor.

7. The appliance of claim 6, wherein the motor is a linear stepper motor.

8. The appliance of claim 1, wherein the pump is a piston pump.

9. The appliance of claim 1, wherein the pump is a double acting pump.

10. The appliance of claim 1, comprising a fluid chamber for receiving working fluid from the pump.

11. The appliance of claim 10, wherein the fluid chamber has a capacity in the range from 0.1 to 1 ml.

12. The appliance of claim 10, comprising a hydraulic accumulator, and wherein the accumulator comprises said fluid chamber.

13. The appliance of claim 12, wherein the accumulator is a gas-charged accumulator.

14. The appliance of claim 11, comprising a valve having an open position for enabling a burst of working fluid to be delivered from the fluid chamber to the nozzle and a closed position for enabling the fluid chamber to be replenished under the action of the pump.

15. The appliance of claim 14, wherein the valve is located downstream from the fluid chamber.

16. The appliance of claim 14, wherein the valve is a solenoid valve.

17. The appliance of claim 1, comprising a fluid reservoir for storing working fluid, and wherein the pump is arranged to draw working fluid from the fluid reservoir.

18. The appliance of claim 17, wherein the fluid reservoir has a capacity in the range from 5 to 50 ml.