Abstract:
Floor care apparatus is disclosed wherein a powered brush assembly having a multiplicity of rotary brushes is suspended within the apparatus such that the brush assembly floats freely upon the surface being cleaned without supporting any of the machine&#39;s weight. The rotary brushes are generally configured as spur gears and function in a gear train wherein one brush drives all other gear brushes in the system. Axially projecting brush bristles are embedded in each gear tooth such that there is no unbrushed area between adjacent brushes in the brush line. The portion of the gear tooth wherein the bristles are embedded includes a recessed profile to allow for circumferential expansion of the tooth, upon insertion of the brush bristles, thereby preventing gear tooth interference. The brush assembly is particularly suitable for hot water carpet extractors of the upright design.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a division of U.S. Ser. No. 08/678,496 filed on Jul. 9, 1996, now U.S. Pat. No. 6,009,593, issued Jan. 4, 2000. 
     This application claims the benefit of U.S. Provisional Application No. 60/003,265 filed Aug. 11, 1995. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a carpet extractor and more particularly to a floating powered brush assembly for use with an upright extractor (of the type taught in co-owned U.S. Pat. No. 5,406,673) having powered floor cleaning brushes. 
     Heretofore carpet extractors having powered brushes to assist scrubbing of the surface being cleaned have generally affixed the powered brush and/or brushes to the main body of the machine in such a way that, except for the rotary motion of the brush, the brush assembly did not move relative to the main body. Thus the rotary action of the powered brush tends to lift the liquid suction nozzle upward and away from the surface being cleaned resulting in lost efficiency of the system as a whole. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The herein invention overcomes the above stated disadvantage of prior art extractors by disclosing a novel, free floating, powered, brush assembly and associated fluid supply system whereby the brush assembly is free to float atop the surface being cleaned in such a way that the brush assembly supports none of the extractor&#39;s weight nor imparts any forces to the machine that would otherwise tend to lift the liquid recovery suction nozzle upward from the surface being cleaned. 
     The present invention teaches a floating brush support system particularly useful for supporting a multiplicity of laterally disposed cup-like scrubbing brushes rotatable about, generally parallel, vertically aligned, axis of rotation. 
     The brush assembly generally comprises an elongate brush support beam having integrally molded, spaced apart, vertically aligned cylindrical bearings each receiving therein a vertically directed axle shaft of an associated rotary scrubbing brush. 
     The rotary brushes generally comprise a spur gear configuration having tufts of brush bristles retained within each gear tooth and directed axially downward toward the surface being cleaned. The spur gear configurations, of each rotary brush, intermesh with the adjacent rotary brush thereby creating a gear train such that rotating any one rotary brush causes the entire gear train to rotate thereby powering all brushes with one driving brush. The intermeshing of the brush gear teeth and their associated brush bristles assures that no unbrushed area will be present between adjacent brushes. 
     The axial thickness of each gear tooth includes an upper and lower profile. The upper profile provides the tooth involute that engages the tooth involute of the adjacent gear brush. The lower profile is inwardly offset from the upper profile to allow circumferential expansion (or bulging) of the profile upon insertion of the brush bristles that otherwise may cause binding or interference between intermeshing gear teeth. 
     A gear brush guard, affixed to the gear support beam, surrounds the periphery of all brushes and is provided with an internally directed flange at the bottom of the guard sidewall extending inward beyond the outer locus of the gear teeth thereby restricting each gear brush within its associated cylindrical bearing on the support beam. 
     Preferably four outwardly directed tangs, two on either side of the peripheral brush guard, engage vertically disposed guide slots in the brush assembly cavity of the extractor base module thereby permitting the brush assembly to translate or float vertically while retaining the brush assembly therein. To assist and guide the brush assembly as it floats vertically, a vertically directed flange is integrally molded onto the brush support beam, one at each end, which slidingly engage vertically disposed tracks or slots integrally molded into the end walls of the brush assembly cavity. None of the machine&#39;s weight is supported by the floating brush assembly. Generous tolerances between all moving parts namely: between the brush axles and cylindrical bearings, between the lower gear tooth surface and the brush guard peripheral flange, and the support beam vertical guide flanges and guide slots are provided such that the brush assembly may float in skewed positions and that the gear brush axle shafts may slightly tilt omnidirectionally from the vertical thereby permitting the scrubbing gear brushes to follow and remain engaged with any unevenness of the surface being scrubbed or to automatically adjust for carpet height 
     The brush assembly further comprises a unique “snap together” structure for ease of assembly on a typical mass production assembly line. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     FIG. 1 is a perspective view of an upright carpet extractor base module incorporating the present invention. 
     FIG. 2 is a left side elevational view of the base module, as seen in FIG. 1, having the forward portion thereof cut away to illustrate the general positioning of the brush assembly therein. 
     FIG. 3 illustrates the forward portion of the base module, illustrated in FIG. 1, having the top cover portion removed. 
     FIG. 4 is an exploded view illustrating the basic subassemblies which form the present invention. 
     FIG. 5 is an exploded view of the brush assembly seen in FIG.  4 . 
     FIG. 6 presents a sectional view taken along line  6 — 6  in FIG. 3 showing the brush assembly in its lowest position. 
     FIG. 6A presents a sectional view taken along line  6 — 6  in FIG. 3 showing the brush assembly in its uppermost position. 
     FIG. 7 is a bottom view as seen along line  7 — 7  in FIG.  4 . FIG. 8 is a sectional view taken along line  8 — 8  in FIG.  6 . 
     FIG. 9 is a sectional view as taken along line  9 — 9  in FIG. 3 with the brushes removed. 
     FIG. 10 is a sectional view taken along line  10 — 10  in FIG.  9 . 
     FIG. 11 is a sectional view taken along line  11 — 11  in FIG.  9 . 
     FIG. 12 is a sectional view taken along line  12 — 12  in FIG. 4 with the brushes shown in phantom. 
     FIG. 13 is a perspective view of one gear brush with all but one of the brush bristle bundles removed. 
     FIG. 14 is a bottom view of the gear brush illustrated in FIG. 13 with all but one of the brush bristle bundles removed. 
     FIG. 15 is a cross-sectional view taken along line  15 — 15  in FIG. 14 with all but one of the brush bristle bundles removed. 
     FIG. 16 is an elevational view taken along line  16 — 16  in FIG.  7 . 
     FIG. 17 is an elevational view taken along line  17 — 17  in FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, the present invention relates to a base module  10  for an upright carpet extractor. The upper portion of a typical upright carpet extractor suitable for use in combination with the herein described base module  10  may be found in co-owned U.S. Pat. No. 5,406,673 issued on Apr. 18, 1995, titled “Tank Carry Handle and Securement Latch”, the contents of which are included herein by reference. 
     Base module  10  comprises a lower housing  12  and an upper housing  14  which generally separate along parting line  13 . Suction nozzle  16  and suction inlet  18  are part of the upper housing  14  similar to the suction nozzle structure as taught in the above referenced co-owned patent. 
     As principally illustrated in FIGS. 2,  3 , and  4 , lower housing  12  has suspended therein a floating carpet scrubbing brush assembly  20 . FIGS. 3 and 4 illustrate the forward portion of lower housing  12  with the upper housing, including the suction nozzle  16 , removed for clarity. The brush assembly may be powered by an air driven turbine  15 , or any other suitable motive power means typically used in the industry, through a suitable gear drive train or transmission  54 . A suitable air turbine driven gear train is taught in co-owned U.S. Pat. No. 5,443,362 issued on Aug. 22, 1995 and titled “Air Turbine”. 
     Turning now to FIGS. 5 and 6, brush assembly  20  comprises brush support beam  22  having five spaced apart, integrally molded, cylindrical bearings  24 A,  24 B,  24 C,  24 D and  24 E. Rotatingly received within bearings  24  are axial shafts  26 A,  26 B,  26 C,  26 D and  26 E of gear brushes  25 A,  25 B,  25 C,  25 D and  25 E. It is to be noted that the axial shafts of brush gears  25 C and  25 E include extensions  28  and  29 , respectfully, for purposes to be described below. 
     During manufacture of brush assembly  20 , the gear brush axial shafts  26  are first inserted into the appropriate bearing  24  and with gear brushes  25  in their uppermost position, with gear teeth  78  intermeshed, gear guards  32 A and  32 B are attached to support beam  22 , as described below, thereby forming brush assembly  20 , as illustrated in FIG.  4 . Once assembled the periperal lips  33 A and  33 B, on each gear guard  32 A and  32 B respectively, extend inwardly beyond the lower portion  84  (see FIG. 13) of gear teeth  78  thereby surrounding the row of rotary brushes and retaining each gear brush within the confines of the surrounding gear guards. Thus each brush may float vertically, with respect to support beam  22 , limited in its uppermost travel by abutment of brush  25  with the lower portion of bearing  24  and limited in its lowermost travel by abutment of teeth  78  with lips  33  of gear guards  32 . Also by providing a loose fit between the gear brush axial shaft  26  and bearing  24  each brush  25  may also tilt slightly with respect to the vertical axis. 
     Gear guards  32 A and  32 B are identical in construction so as to be interchangeable on either side of brush support beam  22 . To facilitate “snap together” assembly of each gear guard to the brush support beam, each gear guard  32  is provided with three integrally formed, horizontally extending, locking tabs  34 , as best seen on gear guard  32 B in FIG. 5, extending parallel to and below the top cover plates  36 A and  36 B of gear guards  32 A and  32 B. Further each gear guard ( 32 A and  32 B) is provided guide and alignment openings  38  for receipt therein (upon assembling the brush assembly) of extended tabs  39  of brush support beam  22 . 
     As the gear guards are brought together about brush support beam  22  and its associated gear brushes  25 , tangs  34 , on both gear guards  32 A and  32 B, slide under extended tabs  39 , of brush support beam  22 , engaging slots  41  thereby locking gear guards  32 A and  32 B to brush support beam  22  as illustrated in FIGS. 11 and 12. It is to be noted that when assembled, extended tangs  39  are sandwiched between the gear guard top cover plate  36 A and  36 B and its associated tang  34 , as seen in FIG. 12, thereby providing lateral stability to the gear guards. 
     Integral to and extending upward from the opposite lateral ends of brush support beam  22  are “T” shaped rails  42  and  43 . T-rails  42  and  43  are slidably received within vertical guide slots  46  and  47  integrally molded into lower base module housing  12 , as best seen in FIGS. 3,  9 , and  10 , whereby brush assembly  20  may freely move or float in the vertical direction within the brush assembly cavity  48  of housing  12 . 
     During assembly of base module  10 , brush assembly  20  is inserted vertically into cavity  48  with T-rails  42  and  43  slidably engaging guide slots  46  and  47  respectfully. As brush assembly  20  is inserted into cavity  48 , tabs  51  on gear guards  32 A and B snap into vertically elongated openings  53  and grooves  57  respectively of housing  12 . As illustrated in FIGS. 2,  3 ,  9 ,  11 ,  16 , and  17 , outwardly projecting tangs  51  from gear guard  32 A slidingly engage vertical slots  53  of housing  12  and tangs  51 , projecting from gear guard  32 B, slidingly engage grooves  57  thereby floatingly retaining brush assembly  20  within cavity  48 . 
     Gear brush  25 C and  25 E (see FIG. 5) are provided with axle shaft extensions  28  and  29 , respectively, having a square lateral cross-section. Axle shaft  28  is slidably received within drive gear  52  contained within gear box  54  as illustrated in FIG.  6 . Gear  52  is preferably powered by air turbine  15  through an appropriate gear train, such as that disclosed in co-owned U.S. Pat. No. 5,443,362 identified above and incorporated herein by reference. As brush assembly  20  moves vertically, with respect to lower housing  12 , axle shaft  28  is slidably received within drive gear  52  as illustrated in FIG.  6 A. 
     Gear brush rotation indicator  44  is fixedly attached to shaft extension  29  of gear brush  25 E and extends upward through opening  56  in the top  45  of brush cavity  48  of lower housing  12  so as to be visible to the operator through clear lens  19  of upper housing  14  as seen in FIG.  1 . 
     Referring to FIGS. 2,  9 ,  16 , and  17 , brush assembly  20  floats freely within cavity  48  of lower housing  12 . The lower limit of brush assembly  20 , as illustrated in FIG. 9, is controlled by tangs  51  which engage the bottom ledge  49  and  50  of slots  53  and grooves  57 . The upper travel of brush assembly  20  is limited by abutment of the brush assembly against the top portion  45  of cavity  48 . 
     Further, as brush assembly  20  floats vertically within cavity  48  T-rails  42  and  43  slidingly engaging slots  46  and  47  respectively of lower housing  12  thereby maintaining alignment of brush assembly  20  within cavity  48  and transferring the forces applied to brush assembly  20 , by movement of extractor  10  forward and rearward, to lower housing  12 . T-rails  42  and  43  are configured so as to permit brush assembly  20  to assume a laterally skewed or canted (one end higher than the other) relationship with respect to cavity  48  as it moves vertically. 
     Referring to FIGS. 1 and 2, base module  10  is principally supported upon rear wheels  17  and suction inlet  18  of suction nozzle  16 . Thus brush assembly  20 , by reason of the above described floating structure, is suspended within cavity  48  of lower housing  12  whereby brush assembly  20  bears none of the extractor weight and permits brushes  25  to “float” atop the surface being cleaned as they rotate. The weight of the extractor is supported by rear wheels  17  and suction inlet  18 . With the extractor center of gravity forward of rear wheels  17  and the floating characteristic of brush assembly  20 , suction inlet  18  will be in contact with the surface being cleaned thereby assuring maximum recovery of dispensed cleaning solution. 
     The structure described hereinabove is preferably constructed with generous and loose tolerances that permit brush assembly  20  as a unit and the individual gear brushes  25  to separately move in other than vertical straight lines and thereby operate in skewed positions as may be dictated by the unevenness of the surface being cleaned. 
     Cleaning solution supply manifold  60  is positioned above brush assembly  20  and affixed to lower housing  12 , as illustrated in FIGS. 3,  6 , and  7 . Liquid cleaning solution is supplied to nipple  62  on manifold  60  by way of a flexible tube such as, for example, illustrated in co-owned U.S. Pat. No. 5,406,673. Cleaning solution flows throughout manifold channel  64  to discharge orifices  66 A,  66 B,  66 C,  66 D and  66 E in the bottom thereof as shown in FIGS. 7 and 8. Brush support beam  22  includes a laterally extending trough-like floor  68 , as best seen in FIGS. 9 and 12, separated into five zones or troughs  71 A,  71 B,  71 C,  71 D, and  71 E by walls  72 A,  72 B,  72 C,  72 D,  72 E, and  72 F as best illustrated in FIG.  5 . 
     As can be seen in FIGS. 6 and 6A, liquid cleaning solution cascadingly flows, by gravity, from manifold orifice  66 A into trough  71 A, from orifice  66 B into trough  71 B, from orifice  66 C into trough  71 C, from orifice  66 D into trough  71 D and from orifice  66 E into trough  71 E. In the configuration as illustrated in FIGS. 6 and 6A, no fluid flows into trough  71 C′. The purpose of trough  71 C′ is to provide symmetry to support beam  22  such that beam  22  requires no specific orientation during assembly. Beam  22  may be positioned as shown in the figures or rotated 180°. When rotated 180° trough  71 C′ then receives fluid from orifice  66 C and supplies brush  25 C through conduit  74 C′ with trough  71 C becoming non-functional. 
     Cleaning solution received in troughs  71 A,  71 B,  71 C,  71 D, and  71 E flows through fluid supply conduits  74 A,  74 B,  74 C,  74 D, and  74 E, respectively, and into center cups  77 A,  77 B,  77 C,  77 D, and  77 E of brushes  25 A,  25 B,  25 C,  25 D, and  25 E as best seen in FIG.  6 . Once deposited within brush cup  25 , the cleaning solution flows outward toward the surface being cleaned through openings  81 A,  81 B,  81 C,  81 D, and  81 E in the bottom of brush cups  77 A,  77 B,  77 C,  77 D, and  77 E, respectively. 
     It is preferred that brush bristles  86  be of a soft texture such that when rotating and in contact with the surface being cleaned the brush bristles bend whereby the bottom of brush cup  77  is in contact with the surface being cleaned. Thus the cleaning solution being dispensed through openings  81  flows directly onto the surface being cleaned. A circumferential rim or edge  88  is provided about the bottom periphery of cup  77  to prevent the centrifuging of cleaning solution radially outward. The preferred operational speed of brushes  25  has been found to be between 500 to 900 RPM for a brush of approximately two inches in diameter. 
     For uniform distribution of cleaning solution on carpeted or other surfaces being cleaned, it is desirable that each brush  25 A,  25 B,  25 C,  25 D and  25 E receive a steady and equal flow rate of cleaning solution. Therefore, the size of orifices  66 A,  66 B,  66 C,  66 D, and  66 E are preferably determined by empirical testing. It has been found, for the manifold configuration as illustrated herein, that orifice  66 B required a slightly larger diameter than that of the other four which are of equal size. 
     In order to minimize the lead-time required to stop the flow of cleaning solution to the brushes, conduits  74  A,  74 B,  74 C,  74 D, and  74 E are oversized so as to be more than adequate to convey the flow rate being dispensed by orifices  66  into brush cups  77  thereby assuring that dispensed cleaning solution immediately flows through conduits  74  into brush cups  77  and exits through openings  81  onto the surface being cleaned and does not collect or back-up in troughs  71  A,  71 B,  71 C,  71 D, or  71 E. 
     Referring to FIGS. 5,  13 ,  14 , and  15 , gear brushes  25 C and  25 E are identical to brushes  25 A,  25 B, and  25 D in all respects except that brushes  25 A,  25 B, and  25 D do not include key shaft  28  or  29 . It is necessary for brush  25 C to have extended key shaft  28  as it is the preferred, power driven gear brush which drives the gear brush train. Gear brush  25 E includes key shaft  29  so that gear brush rotation indicator  44  may be placed thereon to provide visual verification to the operator that the gear brushes are, in fact, rotating during use. 
     Each gear brush  25  is basically configured as a spur gear preferably having ten teeth which intermesh, as seen in figures , 6 , and  6 A such that when center gear brush  25 C rotates all other gear brushes rotate accordingly. Ihe center hub of gear brushes  25  forms a hollow downwardly projecting cup  77  having a multiplicity of openings  81  circumscribing the bottom thereof. 
     Each gear tooth  78  has an upper tooth profile  82  and a lower profile  84  which approximates upper profile  82 . However, profile  84  is smaller in size and slightly indented from profile  82 , as seen in FIGS. 13,  14 , and  15 , forming an offset  83 . Only profile  82  of gear tooth  78  is intended to drivingly engage the corresponding tooth profile of the adjacent gear brush. 
     Each gear tooth  78  has a blind bore  79 , extending to offset  83 , into which bristle bundles  86  are compressively inserted. Upon insertion of bristle bundles  86  into blind bores  79  lower profile  84  of tooth  78  may be expected to expand or bulge in the area of bore  79 . Thus the offset  83  is sufficiently sized to prevent the bulge, in lower profile  84 , from extending beyond the upper profile  82  and thus assuring that the gear teeth of adjacent gear brushes, upon intermeshing, do not bind or otherwise interfere with one another. Alternatively a downwardly extending circular (or any other convenient configuration) boss may be used to receive the bristle bundles and perform the function of alleviating gear binding. 
     The invention has been described with reference to the preferred embodiment having five rotary brushes. However, obvious modifications and alterations (including increasing or decreasing the number of brushes) will occur to others upon a reading and understanding of the specification. It is also to be understood that although the preferred embodiment disclosed hereinabove teaches rotary brushes having intermeshing spur gear configurations it is not to be considered outside the scope of our invention to use other types of brushes, such as a horizontal roll brush, and alternative drive means such as a belt drive etc. It is our intention to include all such modifications, alterations and equivalents in so far as they come within the scope of the appended claims or the equivalents thereof.