Abstract:
A floor cleaning apparatus includes a housing and a dirt collection vessel carried on that housing. The dirt collection vessel includes a dirty air inlet, a clean air inlet, a dirt collection chamber and a clean air outlet. A filter is received in the dirt collection vessel. A suction generator is carried on the housing. The floor cleaning apparatus also includes a flow control valve assembly. The flow control valve assembly is selectively displaceable between a first position wherein dirt and debris are captured in the dirt collection vessel and a second position wherein clean air is drawn through at least a portion of the filter to clean the filter. An activator is provided for automatically displacing the flow control valve assembly between the first and second positions.

Description:
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/780,211 filed on 8 Mar. 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 electro-mechanical 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 in situ. 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 described herein, a floor cleaning apparatus is provided. That floor cleaning apparatus includes a housing. A dirt collection vessel is held in the housing. The dirt collection vessel includes a dirty air inlet, a clean air inlet, a dirt collection chamber and a clean air outlet. A filter is received in the dirt collection vessel. Further, a suction generator is carried on the housing. The floor cleaning apparatus also includes a flow control valve assembly. The flow control valve assembly is selectively displaceable between (a) a first position wherein dirt and debris are captured in the dirt collection vessel and (b) a second position wherein clean air is drawn through at least a portion of the filter to clean the filter. An activator automatically displaces the flow control valve assembly between the first and second positions. 
     More specifically describing the invention, the activator may take the form of a timer. In another embodiment, the activator is a position sensor. That position sensor may be connected to the control handle. In yet another embodiment, the activator is a performance sensor. The performance sensor may take the form of an air pressure sensor or a dirt volume sensor. In yet another embodiment, the activator is a switch that initiates filter cleaning when the floor cleaning apparatus is first turned on. Alternatively, that switch may initiate filter cleaning when the floor cleaning apparatus is turned off. 
     The housing of the floor cleaning apparatus includes a nozzle assembly and a canister assembly. A suction inlet is provided on the nozzle assembly. A rotary agitator may be carried on the nozzle assembly adjacent to suction inlet. Further, the dirt collection vessel is carried on the canister assembly. That canister assembly is pivotably connected to the nozzle assembly. In addition, the floor cleaning apparatus may include a manual activator so that the operator can clean the filter at any desired time. Further, the flow control valve assembly includes a first flow valve for selectively opening and closing the clean air inlet and a second flow valve for selectively closing and opening the dirty air outlet. 
     In accordance with an additional aspect of the present invention a method is provided for cleaning a filter in situ in a floor cleaning apparatus. The method may be broadly described as including the step of providing the floor cleaning apparatus with two modes of operation. Those modes of operation include a floor cleaning mode wherein dirt and debris are collected in a dirt collection vessel and a filter cleaning mode wherein dirt and debris are cleaned from the filter. In addition, the method may include the step of automatically activating the filter cleaning mode upon sensing a predetermined condition. 
     The activating of the filter cleaning mode may occur upon turning the floor cleaning apparatus off or on. Alternatively, the activating of the filter cleaning mode may occur upon the sensing of the position of a control handle or the sensing of a predetermined operating condition. Further, the activating of the filter cleaning mode may occur upon the sensing of the operation of the floor cleaning apparatus for a predetermined period of time. 
     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 perspective, partially broken-away view of the floor cleaning apparatus of the present invention; 
         FIG. 2  is a detailed perspective view of the assembled dirt collection vessel; 
         FIG. 3  is an exploded perspective view of the dirt collection vessel, filter and flow control valve assembly of the present invention; 
         FIG. 4  is a cross-sectional view of the dirt collection vessel, filter and flow control valve assembly in the first position allowing for normal vacuum cleaner operation; 
         FIG. 5  is a cross-sectional view similar to  FIG. 4  but illustrating the flow control valve assembly in the second position allowing cleaning of a section of the filter; and 
         FIG. 6  is a detailed top perspective view of the filter assembly. 
     
    
    
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawing figures. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is now made to  FIG. 1  which illustrates the floor cleaning apparatus  10  of the present invention. In the illustrated embodiment, the floor cleaning apparatus  10  comprises an upright vacuum cleaner. It should be appreciated, however, that the apparatus  10  may just as easily be a canister vacuum cleaner, a handheld vacuum cleaner or even an extractor. 
     As illustrated, the apparatus  10  includes a housing  12  including both a nozzle assembly  14  and a canister assembly  16 . The nozzle assembly  14  includes a suction inlet  18  through which air entrained with dirt and debris is drawn into the vacuum cleaner  10 . A rotary agitator  20  is mounted to the nozzle assembly  14  and extends across the suction inlet  18 . 
     The canister assembly  16  includes a handle  22  having a handgrip  24 . An actuator switch  26  for turning the vacuum cleaner on and off is provided adjacent the handgrip. In addition the canister assembly  16  includes a cavity or receiver  28  for receiving and holding a dirt collection vessel  30 . A suction generator  32  is mounted in a compartment in the canister assembly  16 . During operation, the rotary agitator  20  beats dirt and debris from the nap of the rug or carpet being cleaned. The suction generator  32  draws air entrained with that dirt and debris through the suction inlet  18  into the dirt collection vessel  30 . The dirt and debris is trapped in the dirt collection vessel  30  and the now relatively clean air passes through and over the motor of the suction generator  32  to provide cooling before being exhausted through an exhaust port (not shown) back into the environment. 
     As best illustrated in  FIGS. 2 and 3 , the dirt collection vessel  30  comprises a dirt cup section  36  and a lid section  38 . The dirt cup section  36  comprises a sidewall  35 , a bottom wall  37  and a packing ring  39 . In the illustrated embodiment, the bottom wall  37  is a “dump door” connected by a hinge  31  to the side wall  35 . A bracket  33  and fastener  29  complete the hinged connection. A latch  150  secures the bottom wall  37  in the closed position. A sliding latch release  152  is displaced downwardly to release the latch  150  and open the bottom wall  37  in order to dump dirt and debris from the dirt collection vessel in a manner described in greater detail in co-pending U.S. patent application Ser. No. 11/104,711 filed 13 Apr. 2005. 
     The lid section  38  comprises a first element  40 , a second element  42  and a third element  43 . The first element  40  includes the dirty air inlet  44  and a filter cavity  46 . The second element  42  includes a clean air outlet  48 . The third element  43  receives a pivoting handle  51  for conveniently carrying the dirt collection vessel  30 . The first element  40  is connected to the side wall  35  by the screws  160 . The third element  43  is connected to the second element  42  by the screws  162 . 
     A filter, generally designated by reference numeral  52 , is received in the filter cavity  46  of the first element  40 . The filter  52  includes a sidewall  54 , a hub  56  and multiple partitions  58  extending between the hub and the sidewall (see also  FIG. 6 ). The partitions  58  serve to divide the filter  52  into multiple sections  60 . A filter media  62 , of a type well known in the art, extends between the sidewall  54 , hub  56  and partitions  58  defining each section  60 . Gaskets  166  and  168  provide a seal between the hub  56  and the side wall  54  of the filter  52  and the supporting lid element  40 . 
     A prefilter  66  and an inner support  64  extend downwardly in the dirt cup section  36  from the first element  40  to the bottom wall  37 . A gasket  164  provides an airtight seal between the support  64  and the bottom wall  37 . The prefilter  66  includes a series of intake apertures  68  that allow airflow in a manner that will be described in greater detail below. 
     In the illustrated embodiment, the dirt collection vessel  30  is designed to produce cyclonic airflow and thereby use centrifugal force to improve the efficiency with which dirt and debris are removed from the airstream. More specifically, as clearly illustrated in  FIG. 3 , the dirt cup section  36 , the lid section  38 , the inner support  64 , the prefilter  66  and the filter  52  are all substantially cylindrical in shape. As illustrated in  FIGS. 4 and 5 , the inner support  64  and prefilter  66  are concentrically received in the sidewall  35  of the dirt cup section  36 . The filter  52  is concentrically received in the filter cavity  46  of the first element  40  of the lid section  38 . The dirty air inlet  44  is tangentially directed into the annular space formed between (a) the first element  40  and sidewall  35  on the outside and (b) the inner support  64  and prefilter  66  on the inside. The airstream flows around the annular space in a circular or vortex pattern generating centrifugal force that causes dirt and debris in the airstream to move outwardly toward the sidewall  35  thereby causing the dirt and debris to collect in the dirt cup section  36 . Simultaneously, the relatively clean air is drawn through the intake apertures  68  provided in the prefilter  66  along the inner wall of the annular space where it is then directed upwardly through the filter  52 . Specifically, the air passes through the filter media  62  where any fine dirt and debris remaining in the airstream is stopped while clean air passes through the media on through the clean air outlet  48  to the suction generator  32 . The direction of airflow during normal vacuum cleaner operation is shown by action arrows in  FIG. 4 . 
     The flow control system of the present invention will now be described in detail. The flow control system includes an actuator such as a drive motor  70  that is connected to a first drive gear  72 . The first drive gear  72  meshes with a second drive gear  74  carried in the lid  38 . The second drive gear  74  is connected to an air guide  76  by the screws  75 . The air guide  76  has a concavity  78  that holds a clean air inlet valve comprising a valve body  80  and biasing spring  82 . When in the normal operating position illustrated in  FIG. 4 , the valve body  80  engages and closes the clean air inlet  50  defined by the central aperture in the second drive gear  74 . As further illustrated in the drawing figures the air guide  76  includes an air guide passage  84  that defines an arc of A°. 
     The air flow control system also includes a static air guide  86  that is held in the lid  38  overlying the filter  52 . A seal  167  is provided between the air guide and the filter  52 . The static air guide  86  includes a central aperture  88  and a series of radially arrayed partitions  90  defining a series of air pathways also having an arc of A°. As noted above, the filter  52  includes partitions  58  that divide the filter into equal sections  60  each having an arc of A°. It should be appreciated that the partitions  90  in the static air guide  86  are aligned with the partitions  58  in the filter  52 . Accordingly, the air pathways  92  in the static air guide  86  are each aligned with a single section  60  of the filter  52 . 
     In the illustrated embodiment, the filter  52  includes eight partitions  58  dividing the filter  52  into eight equal sections  60 , each spanning a 45° arc. Similarly, the static air guide  86  includes eight partitions  90  dividing the guide into eight air pathways  92  each spanning an arc of 45°. Further the air guide passage  84  in the air guide  76  also spans an arc of 45°. As will be described in greater detail below the air guide  76  is precisely rotated to bring the air guide passage  84  in perfect alignment with a single air pathway  92  of the static air guide  86  and thus a single section  60  of the filter  52  during each movement cycle. 
     As further illustrated, the air guide  76  includes a first cam  94  projecting from the bottom wall thereof. The cam  94  includes eight cam profiles, one for each section  60  of the filter  52 . The cam  94  engages a cam follower  96  (also with eight matching profiles) that is connected by means of a telescoping shaft to a flow control valve  100 . More specifically, the telescoping shaft  98  comprises a first section  102  connected to the cam follower  96  and a second section  104  having a bore  106  that telescopingly receives the first section  102 . A compression spring  108  received in the bore  106  engages the first section  102  of the shaft and biases the telescoping shaft  98  into an extended position. A second compression spring  110  is received in the hub  112  of the element  40 . This compression spring  110  engages the bottom of the cam follower  96  and biases the cam follower  96  into engagement with the cam  94 . A cap seal  170  and expander  172  seal around the shaft  98  and the element  40  to prevent any passage of air. 
     The flow control valve  100  comprises a flexible tubular diaphragm  114  supported at a first or upper end by a first open air guide  116  and a second or lower end by a second open air guide  118 . The air guide  116  is secured to the element  40  and is static. In contrast, the second open air guide  118  is fastened to the distal end of the second section  104  of the telescoping shaft  98 . 
     During normal vacuum cleaner operation, the rotary agitator  20  functions to beat dirt and debris from the nap of an underlying carpet being cleaned. That dirt and debris is then drawn by the suction generator  32  through the inlet  44  into the dirt collection vessel  30 . As the airstream flows in cyclonic fashion around the side wall  35 , dirt and debris are collected in the dirt collection vessel  30 . The relatively clean air is then drawn through the apertures  68  in the prefilter  66  (see action arrow A in  FIG. 4 ) up through the filter  52 . The filter media  62  allows the passage of clean air but prevents the passage of any relatively fine dust particles that might remain in the airstream. The now clean air then passes upwardly through the static air guide  86  (note action arrow B) and then passes through the air outlet  48 . The air then travels through a conduit to the suction generator  32 . From there the clean air passes over the motor of the suction generator  32  to provide cooling before being exhausted to the environment through a final filter and exhaust port (not shown) back into the environment. 
     As the vacuum cleaner  10  operates, the fine dirt particles not removed from the airstream by the cyclonic action in the dirt cup section  36  are stripped from the airstream and trapped by the filter media  62  of the filter  52 . Over time, these fine particles begin to close off the pores in the filter media  62  thereby restricting airflow. This not only causes the motor of the suction generator  32  to run hotter and at a lower efficiency, it also reduces airflow thereby adversely affecting the cleaning efficiency of the vacuum cleaner  10 . Consequently, the airflow may become so restricted as to prevent the vacuum cleaner from cleaning properly. It is then necessary to either clean or replace the filter  52 . 
     The present invention allows the filter  52  to be cleaned in situ in a very convenient and efficient manner before any substantial loss of cleaning power or efficiency occurs. Specifically, the motor  70  is activated to rotate the air guide  76  through an arc of 45° by means of the meshing gears  72 ,  74 . Precise rotation may be provided by a stepper motor or a permanent magnet direct current motor in combination with a sensor and sensor target such as a magnet  120  fastened to or held in a cavity on the drive gear  74 . An annular bearing  122  and cooperating bearing plate  124  ensure free rotation of the drive gear  74 . As the rotation is completed the air guide passage  84  in the air guide  76  is aligned with one of the air pathways  92  in the static air guide  86  and, accordingly, one of the sections  60  of the filter  52 . The rotation of the drive gear  74  simultaneously causes the cam  94  on the bottom of the air guide  76  to rotate from the position shown in the  FIG. 4  to the position shown in  FIG. 5 . As this occurs, the cam follower  96  follows the cam  94  causing the telescoping shaft  98  to be displaced downwardly. This in turn causes the second open air guide  118  of the flow control valve  100  to engage the top of the support  64 . As this occurs the diaphragm  114  is expanded and the air pathway for normal operation illustrated by action arrow A in  FIG. 4  is interrupted (compare  FIG. 5  to  FIG. 4 ). The telescoping shaft  98  accommodates any discrepancy that may exist in the height of the cam  94  and the distance the second open air guide  118  is moved to engage the top of the support  64 . 
     When the valve  100  closes the normal airflow pathway, no air may be drawn by the suction generator through the prefilter  66  or the suction inlet  18 . As the negative pressure builds, the biasing force of the spring  82  is overcome and the valve body  80  is displaced to open the clean air inlet  50  in the drive gear  74 . As a consequence, clean air is drawn through the inlet  50  past the valve body  80 . That clean air then passes through the air guide passage  84  in the air guide  76  and the aligned air pathway  92  in the static air guide  86  (see action arrow C in  FIG. 5 ). The clean air is then drawn through a single section  60  of the filter  52  in a direction reverse to normal flow so as to remove fine dust particles from the pores of the filter media  62 . As a result of a pressure drop, those fine dust particles settle in the bottom of the support  64  (note action arrow D) while the airstream travels back through the other sections  62  of the filter  52  not aligned with the passage  84  of the air guide  76  (note action arrow E). The airstream then travels back through the air pathways  92  of the static air guide  86  (i.e. those not aligned with the air guide passage  84 ) before passing out of the dirt collection vessel  30  through the outlet  48 . The airstream is then drawn through the suction generator  32  before being exhausted back into the environment. 
     During a cleaning cycle, the sections  60  of the filter  52  are sequentially cleaned in the manner described above as the air guide  76  is rotated into alignment with each air pathway  92  and each filter section  60 . The cleaning cycle may last, for example, from about one to about 30 seconds and more typically from about 3 to about 15 seconds. After rotating the air guide  76  precisely through 360°, the drive motor  70  stops and the flow control valve  100  is opened as illustrated in  FIG. 4 . When this occurs, airflow is restored to the suction inlet  18  and the spring  82  biases the valve body  80  so as to close the clean air inlet  50  and restore airflow for normal vacuum cleaner operation. 
     The motor  70  is activated by means of an activator  300  as schematically illustrated in  FIG. 3 . The activator  300  may assume a number of forms. In one possible embodiment, the activator  300  is a timer that times the operation of the suction generator  32  of the vacuum cleaner  10 . After the suction generator  32  is operated for a predetermined period of time, such as, for example 15 minutes, the timer  300  activates the motor  70  to initiate the filter cleaning cycle. 
     In another possible embodiment, the activator  300  is a position sensor. In this embodiment, the position sensor  300  detects the position of the handle  22 . Upon detecting the return of the handle  22  into the upright, storage position from the lowered, use position, the position sensor activates the motor  70  to initiate the filter cleaning cycle. 
     In yet another embodiment, a timer is added to the position sensor so that the activator  300  only functions to initiate the cleaning cycle when the handle  22  is returned to the upright position after a predetermined time of operation has lapsed since the last filter cleaning. 
     In still another embodiment the activator  300  is a performance sensor. The performance sensor  300  may, for example, be an air pressure sensor for sensing air pressure between the dirt collection vessel  30  and the suction generator  32  or a dirt volume sensor for detecting the level of dirt in the dirt cup. Upon reaching a predetermined pressure or level of dirt, such an activator  300  functions to activate the motor  70  and initiate the cleaning cycle. 
     In yet another alternative embodiment, the activator  300  is a switch. The switch  300  may function to initiate the filter cleaning cycle when the vacuum cleaner  10  is first switched on or when the vacuum cleaner is switched off. 
     Still further, the vacuum cleaner  10  may include a manual activator switch  300 . The manual switch  300  may be engaged by the user at any desired time in order to initiate the cleaning cycle. Obviously, a manual switch of this nature may be provided on the vacuum cleaner in addition to any of the other activators previously discussed if desired to allow the user to override the automatic system to initiate the cleaning cycle. 
     The foregoing description of preferred embodiments 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. 
     The embodiments were 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.