Patent Abstract:
An extraction cleaning machine has a solution dispensing system and a recovery system for applying a cleaning solution to a surface and recovering the solution from the surface, and an agitation brush assembly for agitating the surface. The agitation brush assembly can include friction-type or other dampers for reducing brush bounce, and biasing elements for maintaining a constant downward force on the brush. The brush can have multiple helical rows of tufted bristles, preferably at least four rows, or can comprise a continuous helix of bristles in a twisted-wire spindle. The brush can further have a removable fabric cover for mounting over a bristle brush for contacting a surface being cleaned. The brush assembly can function in an upright extraction cleaning machine with or without an above floor cleaning tool, a hand-held extractor, or a hand-held attachment to a canister extractor or an above floor tool in upright extractor.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/302,526, filed Jul. 2, 2001 

   BACKGROUND OF INVENTION 
   1. Field of the Invention 
   The invention relates to extraction cleaning machines incorporating agitation brushes. In one of its aspects, the invention relates to an extraction cleaning machine incorporating a multi-row agitation brush. In another of its aspects, the invention relates to extraction cleaning machines incorporating a twist-wire agitation brush. In yet another of its aspects, the invention relates to extraction cleaning machines incorporating an agitation brush dampening mechanism. In yet another of its aspects, the invention relates to an extraction cleaning machines incorporating an agitation brush that applies a predetermined force to a carpet. 
   2. Description of Related Art 
   Extraction cleaning machines are used for removing dirt from surfaces such as carpeting, upholstery, drapes and the like. Known extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al.; an upright unit as disclosed in U.S. Pat. No. 6,134,744 to Kasen et al. and U.S. Pat. No. 6,167,587 to Kasper et al.; and a hand-held unit as disclosed in U.S. Pat. No. 5,367,740 to McCray. 
   Vacuum cleaning machines are also used for removing dirt from surfaces. Vacuum cleaning machines have rotating brushes to agitate the surface, thus enhancing cleaning effectiveness. Brushes can be in the form of multiple rows of bristles as disclosed in U.S. Pat. No. 2,659,921 to Osborn, and twist-wire type bristles in U.S. Pat. No. 1,205,162 to Clements. 
   SUMMARY OF INVENTION 
   An extraction cleaning machine has a housing with a solution dispensing system and a solution recovery system mounted thereto for applying a cleaning solution to a surface being cleaned and recovering the solution from the surface, and an agitation brush for agitation of the surface being cleaned. A drive motor is mounted in the housing and is connected to the agitation brush for rotation of the elongated agitation brush about the longitudinal axis. 
   In one embodiment, the elongated agitation brush is selected from a multi-row, helically arranged bristle brush and a helically arranged twisted wire brush. The helically arranged bristle brush has at least four rows of bristles. The helically arranged twist wire brush comprises a continuous helical array of radially extending bristles bound by a pair of twisted wires forming a spindle. 
   In another embodiment, the elongated agitation brush is mounted to the housing through a pair of arms which are pivotally attached at one end to the housing and rotatably support the elongated brush roll at another end thereof. A spring is mounted between the arms and the housing to bias the elongated brush roll with respect to the housing into contact with the surface to be cleaned. In a preferred embodiment, at least one of the arms has a resiliently mounted projection which against a surface of the housing to resist transient vibrations of the elongated agitation brush with respect to the housing. The resiliently mounted projection is mounted on an integrally formed flexible tab on the at least one arm. 
   In another embodiment, a torsional spring provides a rotational bias about pivot pins located on brush arms to force the agitation brush toward the surface to be cleaned. In alternate embodiments, downward force of the brush can also be accomplished with a compression spring or cantilever beam spring mounted between the brush arm and the base housing. 
   In another embodiment, a cover encircles the elongated agitation brush and is removably mounted thereto for contacting the surface to be cleaned. Desirably, the elongated cover is a fabric and is secured onto the elongated agitation brush with a hook and pile fastener. 
   In one embodiment, the housing is a hand held deep cleaner housing. In another embodiment, the housing comprises a base including a pair of wheels for movement along a surface to be cleaned, and further includes a handle pivotally mounted to the base for manipulation of the base along a floor surface to be cleaned. In yet another embodiment, the working air conduit includes a flexible hose which is joined at one end to the housing and further comprising a hand tool mounted to a free end of the flexible hose, and the suction nozzle and the elongated agitation brush are mounted in the hand tool. In this embodiment, a turbine motor can be mounted in the hand tool to drive the agitation brush. 
   Testing has shown that extraction type cleaning in combination with the brush configurations described herein provide an unexpected improvement in cleaning performance when compared to extraction cleaners with other types of agitation brushes. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     In the drawings: 
       FIG. 1  is a perspective view of an extraction cleaning machine according to the invention. 
       FIG. 2  is an exploded view of a base module of the extraction cleaning machine shown in  FIG. 1 . 
       FIG. 3  is a partial sectional side view of the foot module of the extraction cleaning machine of  FIG. 1 . 
       FIG. 4  is an exploded view of a floating brush assembly for the extraction cleaning machine of  FIG. 1 . 
       FIG. 5  is a front view of an agitation brush according to the invention. 
       FIG. 6  is a partial cross-sectional view of another embodiment of a twist-wire brush according to the invention. 
       FIG. 7  is a perspective view of a further embodiment of an extraction cleaning machine according to the invention. 
       FIG. 8  is a front view of the extraction cleaning machine of  FIG. 7 . 
       FIG. 9  is a perspective view of a hand-held attachment for an extraction cleaning machine according to the invention. 
       FIG. 10  is a bottom view of the hand-held attachment of  FIG. 9  showing an agitation brush. 
       FIG. 11  is a perspective view of an agitation brush including a removable cover according to the invention. 
   

   DETAILED DESCRIPTION 
   Referring now to the drawings and to  FIG. 1  in particular, an upright extraction cleaning machine  12  according to the invention is shown. The machine  12  is a portable surface cleaning apparatus including a base module  14  adapted to roll across a surface to be cleaned and an upright handle assembly  16  pivotally mounted to a portion of the base module  14 . 
   As best shown in  FIGS. 1–3 , the base module  14  includes a lower housing portion  15  and an upper housing portion  17 , which together define an interior for housing components and a well  730  for receiving a tank assembly (not shown). The upper housing portion  17  receives a transparent facing  19  for defining a first working air conduit  704  and a suction nozzle  34 , which is disposed at a front portion of the base module  14  adjacent the surface being cleaned for recovering fluid therefrom. The handle assembly  16  has a closed loop grip  18  provided at the uppermost portion thereof and a combination hose and cord wrap  20  that is adapted to support an accessory hose  22  and a electrical cord (not shown) when either is not in use. A latch assembly  21  is pivotally mounted to the rear portion of the base module  14  adjacent the rotational union of the handle assembly  16  therewith for releasably locking the handle assembly  16  in its upright position. 
   As shown in  FIG. 2 , the base module  14  houses a drive motor  196  that is connected to a source of electricity by the electrical cord. A motor compartment  500  within the base module  14  is a clamshell-shaped housing for holding a motor assembly in place and preventing rotation thereof. The clamshell motor compartment  500  includes an upper half  502  and a lower half  504 . The upper half  502  is removable from the lower half  504 , which is integral to the extraction cleaner base module  14 . Thus, a bottom wall of the lower half  504  is the bottom surface of the extraction cleaner base module  14 . An arm  651  extends upwardly from the motor housing  500  in the base module  14  to support the flow indicator  650 , which is mounted to an upper end thereof. An opening  653  in the upper housing portion  17  receives the flow indicator  650  when that portion is mounted to the lower housing portion  15 . 
   The motor compartment  500  includes a large circular impeller fan housing  510  and a smaller motor housing  512 , further having a generally T-shaped cross section. The impeller fan housing  510  surrounds an inner housing  41  defining a vacuum source  40 , which is created preferably by an impeller (not shown) disposed within the housing  41 . The housing  41  includes a large aperture  516  for mounting a vacuum intake duct  530 , which is sealed to the aperture  516  by a gasket  520 . The smaller motor housing  512  includes a small aperture  524  for receiving therethrough a motor drive shaft  198 . A stretch belt  204  is received on the motor drive shaft  198  outside of the clamshell motor compartment  500 . 
   The drive shaft  198  of the drive motor  196  is connected to an interim drive shaft  200  of a solution pump  202  by the stretch belt  204 , which in turn, is connected to a rotatably mounted agitation brush  606  by a timing belt  208 , as best illustrated in  FIGS. 5 and 6 . On the opposite side of the motor  196 , the motor drive shaft  198  supports the impeller (not shown) within the impeller housing  41 , which provides the vacuum source  40  and is mounted inside the housing  510  of the motor compartment  500 . With this configuration, a single drive motor  196  is adapted to provide driving force for the impeller, the solution pump  202 , and the agitation brush  606 . 
   As best seen in  FIGS. 2 ,  3 , and  4 , the rotatably mounted agitation brush  606  is adapted for floor-responsive adjustment by a floating brush assembly  400  mounted within an agitation brush housing  26  disposed within a forward portion of the base module  14 . The floating movement of the agitation brush  606  is a horizontally oriented arcuate path for reciprocation toward and outward of the agitation brush housing  26 . Ends  452  of an agitation brush shaft  606  are received in bearings  454 , which in turn, are press fit into inwardly extending bosses  456  to provide a pair of opposed articulating arm members  458 . Alternatively, stub shafts (not shown) can extend from the arm members  458  and the ends  452  can be replaced with bearings similar to  454  for rotational installation of the brush  606  on the arm members  458 . 
   Each arm member  458  comprises a back plate  460  with a pivot pin  462  provided at the rear of the plate  460 . In addition, a laterally extending belt guard  466  is preferably integrally formed with the articulating arm  458 . The belt guard  466 , which extends laterally inwardly enough to cover the timing belt  208 , minimizes the lodging of threads and other foreign material in the timing belt  208  and protects the carpet or other surface positioned below the base assembly  14  from the rotating belt  208 . 
   As best shown in  FIGS. 3 and 4 , the timing belt  208  is reeved through a pulley  216  mounted at one end of the brush  606  and a pulley  222  on the interim drive shaft  200  of the pump  202 , which includes a separate pulley  220  through which is reeved the stretch belt  204 , which, in turn, extends around the drive shaft  198  of the motor  196 . Further, the pulley  220  has a convex cross section of its periphery, whereby it is adapted to receive the smooth stretch belt  204 , while the pulley  222  has a toothed perimeter adapted for registration with the teeth in the timing belt  208 . 
   The pivot pins  462  of the arm member  458  are rotatably supported secured in a bearing (not shown) mount integrally formed with an internal wall of the agitation brush housing  26 . Further, the pivot pins  462  are held in the bearing by a support  478  on the non-belt side of the base module  14  and the arm  258  of the second belt access door  252  on the belt side of the base module. Both the arm  258  and support  478  are secured to the agitation brush housing  26  by a conventional fastener (not shown) inserted through an aperture in each part. The arm members  458  are preferably limited in their downward movement relative to the agitation brush housing  26  by the length of the timing belt  208  as well as the engagement of the brush guards  466  with the arm  258  and the support  478 . As the floating brush assembly  400  extends further and further downwardly, the belt  208  will stretch and resist further downward movement. Eventually, the brush guards  466  on each arm  458  will contact respectively the arm  258  and the support  478 , which prevents any further downward movement. 
   With this floating agitation brush assembly  400 , the cleaning machine  12  according to the invention can almost instantaneously adapt to varying carpet naps or other inconsistencies on the surface being cleaned. The arm members  458  also allow the rotating brush  606  to drop below the normal floor plane to, for example, provide contact with a bare floor. 
   The upright extraction cleaning machine described above is disclosed in more detail in U.S. Pat. No. 6,167,587, which is incorporated herein by reference in its entirety. 
   Referring now to  FIG. 4 , arm member  458  includes a U-shaped slot  470  defining an integral resilient tab  472 . Resilient tab  472  includes a friction projection  474  extending from outer face of plate  460 . The plate  460  maintains a tight tolerance with the sidewall of the base module, such that friction projection  474  resiliently bears against the sidewall of the base module under the influence of resilient tab  472 . In this manner, the friction projection  474  resists transient vibrations of the agitation brush assembly such as brush “bounce” caused by contact of the brush assembly with an uneven floor surface. 
   Referring to  FIGS. 3 and 4 , a torsion spring  476  is illustrated for mounting on pivot pins  462  to provide a rotational bias about pivot pins  462  to direct agitation brush  606  toward the surface being cleaned. In lieu of the torsion spring  476 , a forward ramped surface  414  of an elevator assembly  410  can be attached to a rearward portion of arm member  458 . Compression spring assembly  406  biases the elevator assembly  410  rearward relative to the base housing. In operation, when the upright handle  16  is placed in the upright position, the elevator assembly  410  is moved forward compressing the spring assembly  406  and lifting the arm member  458 . When the upright handle  16  is lowered, the spring assembly  406  forces the elevator assembly  410  rearward, pulling the arm member  458  with it, therefore biasing the brush  458  against the surface to be cleaned. The operation of the elevator assembly  410  is described more completely in U.S. Pat. No. 6,167,587 which is incorporated herein by reference in its entirety. In the alternative, it is anticipated that a compression spring situated between the brush housing and the arm member  458 , at an end of arm member  458  distal from pivot pins  462 , can provide the same downward bias to the agitation brush  606 . Likewise, a cantilever beam spring mounted to one of the arm member  458  and the brush housing and bearing against the other of the arm member  458  and the brush housing can provide a downward bias to the agitation brush  606 . A downward bias can also be accomplished by increasing the weight of the brush  606  to reduce its susceptibility to bounce or float away from the surface being cleaned, thus improving cleaning performance. 
   Referring to  FIG. 5 , the agitation brush  606  comprises multiple rows  608  of bristles  610  formed in tufts  612 . The increase in the number and density of bristles on the surface of the agitation brush has been found to increase the cleaning effectiveness of the brush  606 . In the illustrated embodiment, there are four rows  800 ,  802 ,  804 ,  806  of bristles in a generally longitudinally sinusoidal configuration. The number of rows  608  of bristles can vary depending on the function of the machine. We have discovered that at least three rows of bristles  608  has surprisingly enhanced cleaning compared with a single or even a double row of bristles. Typically, there will be 4–6 rows  608  of bristles, preferably five rows. 
   Referring now to  FIG. 6 , a further embodiment of a twist-wire agitation brush  480  is shown comprising an array of continuous helical bristles  482  bound by a twist-wire spindle  484 . The twist-wire spindle  484  provides the advantage of a flexible brush  480  for conformance to the surface being cleaned and therefore equalization of the brushing force applied to the surface. The twist-wire agitation brush  480  also has the advantage of being lighter in weight, requiring lighter weight support structure and a less powerful brush drive motor. Especially in combination with the spring bias feature illustrated in  FIG. 4 , the twist-wire brush  480  has the advantage of lower weight and better conformance to the surface being cleaned while maintaining firm contact to effectively clean the surface. The twist-wire spindle  484  can be formed of material such as galvanized steel, aluminum or stainless steel, the material selected in order to ensure compatibility with the preferred cleaning compounds for the application. 
   Referring to  FIG. 11 , a further embodiment of an agitation brush according to the invention includes a removable/replaceable fabric cover  700  secured about multi-row bristle brush  606 . The fabric cover has an outer surface  702  for contacting a surface being cleaned. The fabric cover  700  is secured at a first end  704  to the brush roll by way of a slot or fastener  710  and wrapped firmly about the outside diameter of the rows of bristles  608  until it laps over itself and is secured by known fasteners  712  such as hooks, snaps, buttons or hook-and-loop fasteners. The fabric cover  700  can be formed of any one of a number of cloth or textile materials such as terry cloth, corduroy or other materials of varying porosity or surface texture. The fabric cover  700  is easily removable for cleaning or replacement. The fabric cover  700  can be fabricated to be reversible as a given side becomes dirty or worn, or with each side having a different texture. Fabric covers have been shown to provide cleaning advantages in some applications, but can become dirty or wear out quickly, requiring a ready method of removal and replacement. 
   A further application of the twist-wire brush  480  of  FIG. 6 , the agitation brush  606  with multiple rows  608  of  FIG. 5 , and fabric cover  700  of  FIG. 11  is in a hand-held extraction cleaner, as shown in  FIGS. 7 and 8 . It is anticipated that the twist-wire brush  480 , the agitation brush  606 , or the fabric cover  700  can be used in the hand-held extraction cleaner  1710 . Those features of the hand-held extraction cleaner  1710  shown in the figures but not further discussed herein are described in U.S. Provisional Application Ser. No. 60/239,670, filed Oct. 12, 2000 and U.S. Pat. No. 6,125,498 issued Oct. 3, 2000, all of which are incorporated herein by reference in their entirety. 
   A further application of the twist-wire brush  480  of  FIG. 6 , the agitation brush with multiple rows  608  of  FIG. 5 , and fabric cover  700  of  FIG. 11  is in a hand-held attachment  1810  for an extraction cleaner, as shown in  FIGS. 9 and 10 . The hand-held attachment  1810  attaches at a first end  1830  to a hose (not shown) fluidly connected to an extraction cleaner such as a canister extraction cleaner or an upper right extraction cleaner, the hose including a suction conduit and a fluid supply conduit. The suction conduit is selectively fluidly connected to a suction nozzle  1840  or to a turbine  1820  for driving an agitation brush  606 , the attachment  1810  including a selector slide  1825  for directing the suction air flow to the turbine  1820  or suction nozzle  1840 . The fluid supply conduit is fluidly connected to a spray nozzle  1850 . It anticipated that the twist-wire brush  480  can be used in place of the agitation brush  606  in the hand-held attachment  1810 . 
   While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. Reasonable variation and modification are possible within the scope of the foregoing disclosure of the invention without departing from the spirit of the invention.

Technology Classification (CPC): 0