Vacuum cleaner with filter clogging indicating means

• US 6,167,588 B1
• Filed: 08/02/1999
• Issued: 01/02/2001
• Est. Priority Date: 12/20/1996
• Status: Expired due to Term

• Current Assignee: Dyson Technology Limited (Beeswax Holdings UK Limited)
• Original Assignee: Notetry Limited
• Inventors: Dyson, James
• Primary Examiner(s): Warden, Sr., Robert J.
• Assistant Examiner(s): Snider, Theresa T.
• Application Number:
  US09/331,466
• Time in Patent Office: 519 Days
• Field of Search: 153/19, 153/39, 153/47
• US Class Current: 15/339
• 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 9/2821 Pressure, vacuum level or airflow
• 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
• CPC Class Codes: A47L 9/2889 Safety or protection devices or systems, e.g. for prevention of motor over-heating or for protection of the user

Abstract

The invention provides a vacuum cleaner having an airflow path, dust separating apparatus (16) arranged in the airflow path and a motor (24) arranged in the airflow path downstream of the dust separating apparatus (16), a pre-motor filter (20) located immediately upstream of the motor (24) and downstream and separate from the dust separating apparatus (16), and a bleed valve (18) located upstream of the pre-motor filter (20) to allow air to be bled into the airflow path in the event of a blockage occurring upstream of the bleed valve (18), wherein signalling means (30, 32, 34) responsive to a change in an operating condition of the motor (24) are provided to indicate that a blockage has occurred at or downstream of the pre-motor filter (20).

Claims

1. A vacuum cleaner comprising dust separating apparatus arranged in an airflow path, a motor arranged in the airflow path downstream of the dust separating apparatus, a pre-motor filter located upstream of the motor and downstream of and separate from the dust separating apparatus, a bleed valve located upstream of the pre-motor filter to allow air to be bled into the airflow path in the event of a blockage occurring upstream of the bleed valve, a sensor which senses a temperature or pressure in the airflow path at or near the motor and a signaling device responsive to a change in the temperature or pressure sensed by the sensor which indicates a blockage of the pre-motor filter.

2. A vacuum cleaner as claimed in claim 1, wherein the sensor is a temperature sensor.

3. A vacuum cleaner as claimed in claim 2, wherein the signalling device is connected to a switch and provides a signal when the operating temperature of the motor exceeds a predetermined temperature.

4. A vacuum cleaner as claimed in claim 2 wherein the motor comprises a thermo-trip switch and the signalling device is connected to the thermo-trip switch.

5. A vacuum cleaner as claimed in claim 1, wherein the motor is arranged in a motor housing and the sensor is capable of sensing the ambient temperature within the motor housing.

6. A vacuum cleaner as claimed in claim 5, wherein the signalling device is connected to a switch and provides a signal when the ambient temperature within the motor housing exceeds a predetermined temperature.

7. A vacuum cleaner as claimed in claim 1, wherein the sensor is a pressure sensor which senses the vacuum pressure of airflow passing the motor.

8. A vacuum cleaner as claimed in claim 7, wherein the signalling device is connected to a switch and provides a signal when the vacuum pressure of the airflow exceeds a predetermined pressure.

9. A vacuum cleaner as claimed in claim 1, wherein the signalling device is visual.

10. A vacuum cleaner as claimed in claim 9, wherein the signalling device comprises a signal light or illuminated sign.

11. A vacuum cleaner as claimed in claim 9 or 10, wherein the signalling device is provided adjacent or in the vicinity of means for switching the motor of the vacuum cleaner on and off.

12. A vacuum cleaner as claimed in claim 1, wherein the signalling device is audible.

13. A vacuum cleaner as claimed in claim 1, wherein the signaling device provides a signal which indicates that the pre-motor filter may require to be changed.

14. A vacuum cleaner as claim in claim 1 wherein a post-motor filter is also provided, the post-motor filter being located downstream of the motor.

15. A vacuum cleaner as claimed in claim 1 wherein the motor is connected to operate irrespective of whether or not the signalling device is operated.

16. A vacuum cleaner as claimed in claim 1 wherein the dust separating apparatus comprise a cyclonic separator.