Moisture indicator for wet pick-up suction cleaner

• US 6,812,847 B1
• Filed: 08/25/2000
• Issued: 11/02/2004
• Est. Priority Date: 08/25/2000
• Status: Expired due to Term

• Current Assignee: Healthy Gain Investments Limited
• Original Assignee: Hoover Company (Whirlpool Corporation)
• Inventors: Schneider, Ronald D., Salem, Jay M., Gordon, Evan A.
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/648,204
• Time in Patent Office: 1,530 Days
• Field of Search: 340/604, 340/618, 340/620, 340/619, 340/621, 340/622, 340/602, 733/04.R, 733/04.C, 153/39, 153/19, 153/20, 153/53, 406/34, 406/35
• US Class Current: 340/604
• CPC Class Codes: A47L 11/34 Machines for treating carpets in position by liquid, foam, or vapour, e.g. by steam
• CPC Class Codes: A47L 11/4044 Vacuuming or pick-up tools; Squeegees
• CPC Class Codes: A47L 11/4058 for adjusting the height of the tool
• CPC Class Codes: A47L 7/0038 with means for emptying the tanks
• CPC Class Codes: A47L 7/0042 Gaskets; Sealing means
• 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
• 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 moisture sensor and indicator for a wet pickup vacuum cleaner, more particularly a wet extraction type carpet cleaner, is positioned in the suction duct to sense when water droplets or moisture is traveling through the suction duct. An indicator is activated to indicate to the operator that water is being extracted from the carpet. The sensor may alternatively be located in the bottom of the floor-engaging portion where it contracts the floor. When the degree of moisture in the carpet exceeds a predetermined threshold an indicator is activated to indicate to the operator that the floor is still wet and to continue extracting moisture from the floor. Alternatively, the moisture sensor can be used as a safety device on a dry pickup vacuum cleaner. When moisture is detected within the suction duct, the motor-fan assembly of the dry pickup vacuum cleaner is disabled to prevent a potentially hazardous condition.

Claims

1. A moisture indicator system for a suction cleaner, comprising:

a base;

a handle pivotally mounted to the base;

a nozzle on the base;

a recovery tank removably positionable on one of the base and handle;

a motor fan assembly mounted on the base for drawing a moisture laden air stream from the nozzle to the recovery tank;

a suction duct between a nozzle and recovery tank;

a bend in the suction duct between the nozzle and the recovery tank; and

a moisture sensor located downstream of the bend,

wherein the moisture laden air stream impinges on the moisture sensor after it passes through the bend in the suction duct.

2. The moisture indicator system of claim 1, wherein the bend forms substantially a right angle.

3. The moisture indicator system of claim 1, further comprising:

a controller,

wherein the moisture sensor generates continuous signals to the controller.

4. The moisture sensor of claim 3, wherein the signals are proportional to the conductivity of the moisture laden air stream.

5. The moisture sensor of claim 4, the controller further having a smoothing circuit for translating the continuous signals into a discrete signal.

6. The moisture sensor of claim 5, wherein the smoothing circuit further includes a schmitt trigger comparator.

7. The moisture sensor of claim 5, wherein the discrete signal is used to power a first LED.

8. The moisture sensor of claim 7, wherein the first LED is powered when the discrete signal is above a predetermined threshold value.

9. The moisture sensor of claim 7, wherein the first LED is substantially red.

10. The moisture sensor of claim 7, wherein the LED is positioned on the base.

11. The moisture sensor of claim 7, wherein the second LED is substantially green.

12. The moisture sensor of claim 7, wherein the second LED is positioned on the base.

13. The moisture sensor of claim 5, wherein the discrete signal is used to power a second LED indicator.

14. The moisture sensor of claim 13, wherein a second LED is powered when the discrete signal is below a predetermined threshold value.

15. A method of operating a suction cleaner, having a suction duct between a nozzle and recovery tank, and a bend in the suction duct between the nozzle and the recovery tank, comprising the steps of:

positioning a moisture sensor downstream of the bend for generating an indication signal; and

impinging a moisture laden air stream on the moisture sensor.

16. The method of claim 15, further comprising the steps of moving the moisture laden air stream through substantially a right angle prior to the impinging step.

17. The method of claim 16, further comprising the step of generating continuous signals with a controller during the impinging step.

18. The method of claim 17, wherein the generating step further includes the step of determining the conductivity of the moisture laden air stream.

19. The method of claim 18, further comprising the step of smoothing the continuous conductivity signals to create a discrete signal.

20. The method of claim 19, further comprising the step of driving one or more LED with the discrete signal.