US20070174993A1

US20070174993A1 - Filter cleaning system for floor cleaning apparatus

Info

Publication number: US20070174993A1
Application number: US11/644,059
Authority: US
Inventors: Kerry L. Dever; Jeffrey M. Elrod
Original assignee: Panasonic Corp of North America
Current assignee: Panasonic Corp of North America
Priority date: 2006-02-02
Filing date: 2006-12-22
Publication date: 2007-08-02

Abstract

A floor cleaning apparatus includes a housing. A dirt collection vessel with filter and a suction generator are carried on the housing. The floor cleaning apparatus also includes a four port/two position directional control valve and a valve actuator. The valve actuator selectively displaces the directional control valve between a first position wherein dirt and debris is captured in the dirt collection vessel by the filter and a second position wherein clean air purges dirt and debris from the filter into the dirt collection vessel.

Description

This application claims the benefit of U.S. provisional patent application Ser. No. 60/764,417 filed Feb. 2, 2006.

TECHNICAL FIELD

The present invention relates generally to the floor care equipment field and, more particularly, to a vacuum cleaner, extractor or the like equipped with a pneumatic mechanism for cleaning dirt and debris from the filter including, particularly, fine dirt particles from the pores of the filter in order to enhance filter cleaning efficiency and extend filter service life.

BACKGROUND OF THE INVENTION

A vacuum cleaner is an electromechanical appliance utilized to effect the dry removal of dust, dirt and other small debris from carpets, rugs, fabrics or other surfaces in domestic, commercial and industrial environments. In order to achieve the desired dirt and dust removal, most vacuum cleaners incorporate a rotary agitator. The rotary agitator is provided to beat dirt and debris from the nap of the carpet or rug while a pressure drop or vacuum is used to force air entrained with this dirt and debris into the nozzle of the vacuum cleaner. The particulate laden air is then drawn into a dirt collection vessel. The air is then drawn through a filter before being directed through the motor of the suction generator to provide cooling. Finally, the air is filtered to remove any fine particles of carbon from the brushes of that motor or other dirt that might remain in the airstream before being exhausted back into the environment.
Often the dirt collection vessel is designed to produce cyclonic airflow by providing that vessel with a dirt chamber having a cylindrical sidewall and a tangentially directed air inlet. This arrangement forces the air to swirl around the dirt collection chamber in the manner of a cyclone. The centrifugal force that is produced causes dirt and debris to move toward and against the cylindrical sidewall of the chamber while relatively clean air may be drawn off from the center of the chamber through the filter toward the suction generator.
Under most operating conditions most or all of the dirt and debris is removed from the airstream by the cyclonic airflow. At times, however, some dirt and debris remains entrapped within the airstream. Typically, that dirt and debris is relatively fine dirt particles of light weight which are not as susceptible to the centrifugal separation force produced by the cyclonic airflow. Over time such fine particles may become entrapped and fill the pores of the filter media thereby restricting airflow and reducing the cleaning efficiency of the vacuum cleaner. Eventually the cleaning efficiency of the vacuum cleaner becomes so impaired it is necessary for the operator to either clean or change the filter in order to achieve the desired level of cleaning. The present invention relates to a vacuum cleaner, extractor or the like equipped with a more efficient and effective filter cleaning mechanism. Advantageously, the present invention allows one to quickly and easily clean dirt and debris from a filter including particularly fine particles from the pores of the filter. As a result each filter has a longer service life and the apparatus may be operated at a higher cleaning efficiency over the entire length of that extended service life.

SUMMARY OF THE INVENTION

In accordance with the purposes of the present invention as described herein, an improved floor cleaning apparatus is provided. That apparatus comprises a housing, a dirt collection vessel with filter carried on the housing and a suction generator carried on the housing. The floor cleaning apparatus further includes a four port/two position directional control valve and a valve actuator. The valve actuator functions to selectively displace the directional control valve between a first position wherein dirt and debris is captured in the dirt collection vessel by the filter and a second position wherein clean air purges dirt and debris from the filter into the dirt collection vessel.
In one possible embodiment of the present invention the valve actuator is a solenoid. The solenoid is connected to a rotary solenoid switch. The housing rides over the floor on a series of wheels. The rotary solenoid switch is connected to one of those wheels. In one possible embodiment two gears connect the rotary solenoid switch with the wheel.
The dirt collection vessel includes an air inlet and an air outlet. A first conduit connects the air outlet with the directional control valve. A motor prefilter is provided in that first conduit.
The suction generator is provided in a motor compartment including an intake plenum and an exhaust plenum. A second conduit connects the exhaust plenum with an exhaust port. An exhaust filter is provided in the second conduit. In one possible embodiment a check valve is provided in the second conduit as well.
The housing includes a nozzle assembly and a canister assembly. The nozzle assembly includes a suction inlet. At least one rotary agitator is carried by the nozzle assembly adjacent the suction inlet. A flexible hose connects the nozzle assembly with the canister assembly. In addition the nozzle assembly includes a control wand.
In the following description there is shown and described several preferred embodiments of this invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing incorporated in and forming a part of this specification, illustrates several aspects of the present invention, and together with the description serves to explain certain principles of the invention. In the drawing:

FIG. 1 is a partially cutaway, perspective view illustrating one possible embodiment of the floor cleaning apparatus of the present invention;

FIG. 2 is a schematical top plan view illustrating the airflow pathway when the directional control valve is in a first or floor cleaning position; and

FIG. 3 is a schematical top plan view similar to FIG. 2 but illustrating the airflow path when the directional control valve is in the second or filter cleaning position.

Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIG. 1 illustrating the floor cleaning apparatus 10 of the present invention in the form of a canister vacuum cleaner It should be appreciated that a canister vacuum cleaner is only representative of the floor cleaning apparatus 10 which may in fact assume other forms including, for example, an upright vacuum cleaner or even an extractor.
The floor cleaning apparatus 10 comprises a housing including a canister assembly 12 and nozzle assembly 14. The nozzle assembly 14 includes a suction inlet 16. A rotary agitator 18 extends across the suction inlet 16. In the illustrated embodiment the rotary agitator 18 is driven by an agitator motor 20. Brushes, wipers, bristle tufts, beater bars or other cleaning structures project from the rotary agitator 18 and function to beat dirt and debris from an underlying carpet as the agitator is rotated at high speeds.
The nozzle assembly 14 also includes a wand 22 incorporating a control handle 24 having a hand grip 26 and operator controls 28. The operator controls 28 allow the operator to selectively control the operation of the vacuum cleaner 10 in a manner that is well known in the art.
A flexible hose 30 connects the nozzle assembly 14 with the canister assembly 12 and simultaneously provides a conduit for the passage of dirt and debris from the suction inlet 16 to a dirt collection vessel 32 carried on the nozzle assembly 14 (see also FIGS. 2 and 3).
As best illustrated in FIGS. 2 and 3, the dirt collection vessel 32 includes an air inlet 34 and an air outlet 36. In the illustrated embodiment the dirt collection vessel 32 is substantially cylindrical in shape and the air inlet 34 is tangentially directed along the sidewall. The air outlet 36 is axially aligned in the bottom of the dirt collection vessel 32. A main filter 40 covers the air outlet 36. The main filter 40 is preferably cylindrical in shape and is concentrically received in the dirt collection vessel 32. Such a structural arrangement produces cyclonic airflow within the dirt collection vessel. This produces a centrifugal force which functions to separate dirt and debris from the airstream and increases cleaning efficiencies in a manner known in the art.
A suction generator 42 is carried by the canister assembly 12 in an internal motor compartment 44. A partition 46 divides the motor compartment 44 into an intake plenum 48 and an exhaust plenum 50.
A four port/two position directional control valve 52 is provided to control airflow through the floor cleaning apparatus 10. A first conduit 54 connects the air outlet of the dirt collection vessel 32 with the directional control valve 52. If desired, a secondary filter 56 may be provided in the first conduit 54 between the air outlet 36 and the directional control valve 52. This filter functions to insure that no dirt and debris is drawn into the suction generator 42 during vacuum cleaner operation.
A second conduit 58 connects the directional control valve 52 with an exhaust port 60. A final or exhaust filter 62 such as a HEPA filter may be provided in the second conduit 58 adjacent the exhaust port 60.
A valve actuator 64 functions to selectively displace the directional control valve 52 between a first position, illustrated in FIG. 2, wherein dirt and debris is captured in the dirt collection vessel 32 by the filter 40 and a second position, illustrated in FIG. 3, wherein clean air purges dirt and debris from the filter into the dirt collection vessel.
In the illustrated embodiment the valve actuator 64 is a solenoid. The solenoid 64 is connected to a rotary solenoid switch 68. The rotary solenoid switch 68 is connected in turn by the gears 70, 72 to one of the wheels 74 upon which the canister assembly 12 is supported to roll across the floor.
During vacuum cleaner operation the directional control valve 52 is normally in the first or floor cleaning position illustrated in FIG. 2. When in this position the suction generator draws air entrained with dirt and debris through the suction inlet 16, the wand 22, the flexible hose 30 and the air inlet 34 into the dirt collection vessel 32. Dirt and debris is captured in the dirt collection vessel 32 and relatively clean air is then drawn through the main filter 40 through the first conduit 54, the secondary filter 56 and the control valve 52 into the intake plenum 48 (note action arrows). From there the airstream passes over the motor of the suction generator 42 in order to provide cooling before passing from the exhaust plenum 50 back through the directional control valve 52 and the second conduit 58. From there the airstream passes through the exhaust filter 62, which captures any remaining fine particles such as carbon particles from the windings of the suction generator motor, before passing through the exhaust port 60 back into the environment. Over time, some dirt and debris D collects on the filter 40.
As the operator cleans the floor, the floor cleaning apparatus 10, and more particularly, the canister assembly 12 is pulled along the floor across a room. As this occurs the wheel 74 rotates. This rotational motion is transmitted through the gears 70, 72 to the rotary solenoid switch 68. Once the canister assembly 12 has been rolled a predetermined distance, the rotary solenoid switch 68 activates the solenoid 64 causing the directional control valve 52 to be displaced into the second or filter cleaning position illustrated in FIG. 3. In this position the suction generator 42 draws air through a check valve 76 into the second conduit 58. Next the air travels through the directional control valve 52 into the intake plenum 48 (note action arrow). From there the air passes over the motor of the suction generator 42 into the exhaust plenum 50. At this point it is directed by the directional control valve 52 through the first conduit 54 and the outlet 36 to the main filter 40. The air then passes outwardly through the main filter 40 purging dirt and debris D from the filter including tiny particles capable of filling the pores of the filter material and reducing the airflow through the filter and the cleaning efficiency of the floor cleaning apparatus 10.
The rotary solenoid switch 68 is designed to provide only momentary energization of the solenoid 64 and switching of the directional control valve 52 which is then promptly returned by the spring 78 to the normal or floor cleaning position illustrated in FIG. 2. Accordingly, the airflow reversal takes the form of a pulse or short burst of air sufficient in duration to purge the main filter 40 and deposit the residue in the dirt collection vessel 32 but not such that the contents of the dirt collection vessel are blown back through the flexible hose 30. Of course, if desired, an optional check valve (not shown) could be provided in the air inlet 34, the coupling for the hose 30 or anywhere in between in order to prevent possible blowback. situ in the vacuum cleaner. Specifically, the method includes the steps of (a) providing a valve for periodically reversing air flow through the filter, (b) providing an actuator for that valve and (c) connecting the actuator to a wheel of the vacuum cleaner so that the filter is cleaned after the vacuum cleaner rolls a predetermined distance over the ground or floor.
The foregoing description of a preferred embodiment of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, while the dirt collection vessel 32 illustrated in the drawing figures provides for cyclonic airflow, the vessel need not do so and may assume substantially any shape. In addition, while the main filter 40 is illustrated as being positioned in the dirt collection vessel 32, it could be positioned downstream from that vessel if desired. Further, while one rotary agitator 18 is illustrated in the drawing figures, the nozzle assembly could carry multiple rotary agitators if desired. In addition, while the valve actuator illustrated and described is a solenoid 64, it should be appreciated that the actuator could take another form. For example, the actuator could be a slider-crank type mechanism either in conjunction with a gear system or a spring-return rack and pinion. In another possible embodiment the actuator could simply take the form of a timing circuit that would electronically energize the solenoid after the floor cleaning apparatus 10 has been operated in the normal or floor cleaning mode for a predetermined period of time.
The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims and their fair and broad interpretation in any way.

Claims

1. A floor cleaning apparatus, comprising:

a housing;

a dirt collection vessel with filter carried on said housing;

a suction generator carried on said housing;

a four port/two position directional control valve; and

a valve actuator for selectively displacing said directional control valve between a first position wherein dirt and debris is captured in said dirt collection vessel by said filter and a second position wherein clean air purges dirt and debris from said filter into said dirt collection vessel.

2. The floor cleaning apparatus of claim 1, wherein said valve actuator is a solenoid.

3. The floor cleaning apparatus of claim 2, wherein said solenoid is connected to a rotary solenoid switch.

4. The floor cleaning apparatus of claim 3, wherein said housing includes at least one wheel for riding over a floor.

5. The floor cleaning apparatus of claim 4, wherein said rotary solenoid switch is connected to said at least one wheel.

6. The floor cleaning apparatus of claim 5, wherein at least two gears connect said rotary solenoid switch with said at least one wheel.

7. The floor cleaning apparatus of claim 6, further including a check valve.

8. The floor cleaning apparatus of claim 7, wherein said dirt collection vessel includes an air inlet and an air outlet and said apparatus further includes a first conduit connecting said air outlet with said directional control valve.

9. The floor cleaning apparatus of claim 8, wherein a motor prefilter is provided in said first conduit.

10. The floor cleaning apparatus of claim 9, wherein said suction generator is provided in a motor compartment including an intake plenum and an exhaust plenum

11. The floor cleaning apparatus of claim 10, further including a second conduit connecting said exhaust plenum with an exhaust port.

12. The floor cleaning apparatus of claim 11, wherein an exhaust filter is provided in said second conduit.

13. The floor cleaning apparatus of claim 12, wherein said check valve is provided in said second conduit.

14. The floor cleaning apparatus of claim 1, wherein said housing includes a nozzle assembly and a canister assembly.

15. The floor cleaning apparatus of claim 14, wherein said nozzle assembly includes a suction inlet.

16. The floor cleaning apparatus of claim 15, wherein at least one rotary agitator is carried by said nozzle assembly adjacent said suction inlet.

17. The floor cleaning apparatus of claim 16, wherein a flexible hose connects said nozzle assembly and said canister assembly.

18. The floor cleaning apparatus of claim 17, wherein said nozzle assembly includes a control wand.

19. A floor cleaning apparatus, comprising:

a housing;

a dirt collection vessel carried on said housing;

a filter carried on said housing;

a suction generator carried on said housing;

at least one wheel connected to said housing and supporting said housing on a floor;

a directional control valve carried on said housing; and

a valve actuator for selectively displacing said directional control valve between a first position wherein dirt and debris is collected in said dirt collection vessel and on said filter and a second position wherein clean air purges dirt and debris from said filter into said dirt collection vessel, said valve actuator being connected to said at least one wheel.

20. The apparatus of claim 19, wherein said valve actuator is a solenoid and said solenoid is connected to a rotary solenoid switch connected to said at least one wheel.

21. A method of cleaning a filter in situ in a vacuum cleaner supported on a ground engaging wheel, comprising;

providing a valve for periodically reversing air flow through said filter;

providing an actuator for said valve; and

connecting said actuator to said wheel whereby said filter is cleaned after said vacuum cleaner rolls a predetermined distance over the ground.