Patent Publication Number: US-7222389-B2

Title: Recovery tank for a floor cleaning device

Description:
This application is a continuation application claiming priority to application Ser. No. 11/032,969 filed on Jan. 11, 2005 which claims priority to application Ser. No. 09/955,713 filed on Sep. 18, 2001 issued as U.S. Pat. No. 6,842,942 on Jan. 18, 2004. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a recovery tank for a floor cleaning unit. 
   2. Background Information 
   In some floor cleaning units, a cleaning solution is distributed on the floor or cleaning surface and then removed, along with dirt entrained in the solution, by a suction nozzle. The soiled liquid and the debris then travels to a recovery tank where the liquid is separated from the working air. In the relatively large recovery tanks of the canister style wet pickup suction cleaners, the liquid laden working air is allowed to expand and slow down upon entering the tank. This expansion and slowing of the working air is typically sufficient to adequately separate the liquid from the working air. However, recovery tanks for the upright floor cleaning units or small floor cleaning units are generally small with little room. In these tanks, the liquid laden working air travels much too fast for the liquid to expand and adequately separate from the air, unless specific structures in the tank is provided to cause the liquid to separate. Also, it is desirable to increase the rate of air flow through the suction nozzle to improve the suction of the floor cleaning unit. However, this also increases the speed at which the liquid laden working air travels through the recovery tank. It is further desirable to use the same recovery tank when the floor cleaning unit is used to dry vacuum the floor. Finally, the recovery tank should be designed and constructed to prevent liquid from entering the suction motor area. 
   Hence it is an object of the present invention to provide a recovery tank for use with floor cleaning units that has enhanced air and water separation to accommodate a high rate of airflow into the recovery tank. 
   It is another object of the present invention to provide a recovery tank for use with floor cleaning units that also dry vacuum the floor. 
   It is another object of the present invention to provide a recovery tank that prevents liquid form entering the suction motor and possibly damaging it. 
   SUMMARY OF THE INVENTION 
   The foregoing and other objects of the present invention will be readily apparent from the following description and the attached drawings. In one embodiment of the present invention, a recovery tank is provided for a floor cleaning unit. The recovery tank comprises an inlet opening and a duct fluidly connected to the inlet. The duct extends horizontally within the tank adjacent a side wall the recovery tank for directing air and liquid from the inlet opening in two opposing directions. A lid covers the tank and has an outlet opening for directing air out of the recovery tank. A pair of shields depends downwardly from the lid and extends from the duct to the side wall of the recovery tank. The outlet opening of the lid is located between the shields such that the shields prevent liquid from coming out of the duct and entering the outlet opening of the lid. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described, by way of example, with reference to the attached drawings, of which: 
       FIG. 1  is a perspective view of the hard floor cleaning unit of one embodiment according to the present invention; 
       FIG. 2A  is an exploded view of the bottom portion of the base assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 2B  is an exploded view of the front upper portion of the base assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 2C  is an exploded view of the rear upper portion of the base assembly of the hard floor cleaning unit of  FIG. 1  with the carriage assembly included for illustrative purposes; 
       FIG. 3A  is an exploded view of the handle assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 3B  is an exploded view of the upper handle portion of the handle assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 3C  is an elevational view taken along line  3 C— 3 C of  FIG. 3A ; 
       FIG. 4  is a side elevational cross sectional view taken vertically through the lower portion of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 5  is a side elevational cross sectional view taken vertically through the upper portion of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 6  is an exploded view of the nozzle assembly for the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 7  is a sectional view of the nozzle assembly taken along line  7 — 7  of  FIG. 2B ; 
       FIG. 8A  is a partial sectional view of the base assembly of the hard floor cleaning unit taken along line  8 C— 8 C of  FIG. 1 , but with the slide latches slid outwardly away from the channel of the frame; 
       FIG. 8B  is a partial sectional view similar to  FIG. 8A , except that the slide latches are slide inwardly into the channel of the frame; 
       FIG. 8C  is a partial sectional view taken of the base assembly of the hard floor cleaning unit taken along line  8 C— 8 C of  FIG. 1 ; 
       FIG. 9A  is a sectional view of the base assembly taken along line  9 A— 9 A of  FIG. 8B . 
       FIG. 9B  is a sectional view similar to  FIG. 9A  except that the slide latch is slid inwardly to the position shown in  FIG. 8C ; 
       FIG. 10A  is a bottom front perspective view of the base assembly of the floor cleaning unit of  FIG. 1  with the nozzle assembly and brush block assembly removed for illustrated purposes; 
       FIG. 10B  is a view similar to  FIG. 10A  but with the wheel carriage pivoted in a position further away from the frame of the base assembly. 
       FIG. 11A  is a partial sectional view taken along line  11 A— 11 A of  FIG. 10B , illustrating the principle elements used to raise and lower the nozzle assembly and brush block assembly of the hard floor cleaning unit of  FIG. 1  and to indicate such positions; 
       FIG. 11B  is a view similar to  FIG. 11A  but with the left pedal depressed to move the slide block outwardly to raise the nozzle assembly and brush block assembly; 
       FIG. 11C  is a view similar to  FIG. 11B  but with the left pedal released to allow the spring to move the slide block slightly outward; 
       FIG. 12  is a partial sectional view of the left pedal taken along  12 — 12  of  FIG. 11A . 
       FIG. 13A  is a partial sectional top view of the nozzle lifting assembly and left pedal taken horizontally through a portion of the slide block and illustrating the left pedal being depressed to move the slide block inwardly to raise the nozzle assembly; 
       FIG. 13B  is a view similar to  FIG. 13A  but with the left pedal released and the slide block, rotor, and spring in different positions illustrating the results from such action; 
       FIG. 13C  is a view similar to  FIG. 13A  but with the slide block, rotor, and spring in different positions, indicative of the nozzle assembly being lowered; 
       FIG. 14A  is a partial front elevational view of the right handle release pedal, lock plate, lower portion of the handle assembly, and other elements of the hard floor cleaning unit of  FIG. 1  used to releasably lock the handle assembly in the upright position; 
       FIG. 14B  is a view similar to  14 A but with the right handle release pedal depressed to pivot the lock plate away from the right ear of the handle assembly; 
       FIG. 15A  is an elevational view taken along line  15 A— 15 A of  FIG. 14B ; 
       FIG. 15B  is a view similar to  15 A but with the handle assembly locked in the upright position; 
       FIG. 16  is a an elevational view taken along line  16 — 16  of  FIG. 14B ; 
       FIG. 17  is a fragmentary bottom view of the forward portion of the hard floor cleaning unit of  FIG. 1  illustrating the nozzle assembly and brush block assembly; 
       FIG. 17A  is a sectional view taken along line  17 A— 17 A of  FIG. 17 ; 
       FIG. 18  is a side diagrammatic side view of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 19  is an exploded view of the brush block assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 20A  is a front top perspective view of the brush block assembly with the latches and push buttons assembled for removing the brush block assembly; 
       FIG. 20B  is a view similar to  FIG. 20A  but with the push button depressed and the latches disengaged from the brush block assembly; 
       FIG. 20C  is a view similar to  FIG. 20B  but with the brush block assembly separated from the latches; 
       FIG. 21  is an exploded view of the distributor with latches of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 22  is an elevational view taken along line  22 — 22  of  FIG. 21 ; 
       FIG. 23  is a an exploded view of the nozzle lifting assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 24  is an exploded view of the brush motor assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 24A  is an exploded view taken along line  24 A— 24 A of  FIG. 24 ; 
       FIG. 25  is an exploded of the recovery tank of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 25A  is a side elevational view of the lid of the recovery tank of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 25B  is a partial sectional view taken along line  25 B— 25 B of  FIG. 25A ; 
       FIG. 25C  is front elevational view of the lid of the recovery tank; 
       FIG. 26  is an enlarged sectional view of the latch of the recovery tank identified in  FIG. 4 ; 
       FIG. 27  is an exploded view of the suction motor assembly of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 28  is an exploded view of the power switch assembly of the hard floor-cleaning unit of  FIG. 1 ; 
       FIG. 29  is an exploded view of the supply tank of the of the hard floor cleaning unit of  FIG. 1 ; 
       FIG. 29  is a sectional view taken along line  19 A– 29 A of  FIG. 1 ; 
       FIG. 30A  is a perspective view of the base assembly of the hard floor cleaning unit of  FIG. 1  with the nozzle assembly and cover removed and portions cutaway for illustrative purposes; 
       FIG. 30B  is a view similar to  FIG. 30A  but with the brush block assembly lowered; 
       FIG. 30C  is an enlarged view of the cut away portion of  FIG. 30A , but with the brush block assembly locked in the raised position; 
       FIG. 30D  is a view similar to  FIG. 30A  but with a compression spring being used to bias the indicator plate instead of a torsion spring; 
       FIG. 31  is an elevational view taken along line  31 — 31  of  FIG. 30C ; 
       FIG. 31A  is a sectional view taken along line  31 A— 31 A of  FIG. 31 ; 
       FIG. 31B  is a view similar to  FIG. 31A  but with the brush lifting lever, pocket portion, cable and other related elements in a position that lowers the brush block assembly; 
       FIG. 32  is a partial front sectional view of the upper portion of the lower body shell of the hard floor cleaning unit of  FIG. 1  with portions removed for illustrative purposes; 
       FIG. 32A  is a view similar to  FIG. 32  but with the cap in a position to causes depression of the push button microswitch to energize the brush motor; 
       FIG. 33  is a partial sectional view taken along line  33 — 33  of  FIG. 1 ; 
       FIG. 33A  is view similar to  FIG. 33  but showing different means to secure the spring to the slide button; 
       FIG. 34  is fragmentary perspective view of a hard floor cleaning unit according to another embodiment of the present invention; 
       FIG. 34A  is an exploded view of the hard floor cleaning unit of  FIG. 34 ; 
       FIG. 35  is perspective view taken along line  35 — 35  of  FIG. 34  with the frame, nozzle assembly, and cover removed for illustrative purposes; 
       FIG. 36  is a partial elevational view taken along line  36 — 36  of  FIG. 34  with the nozzle assembly removed and portions of the frame cut away for illustrative purposes; 
       FIG. 37A  is a sectional view taken along line  37 A— 37 A of  FIG. 35 ; 
       FIG. 37B  is a view similar to  FIG. 37A  but with the pedal depressed; 
       FIG. 38  is a perspective view of still another embodiment of the hard floor cleaning unit according to the present invention; 
       FIG. 39A  is a right perspective view of the base assembly of the hard floor cleaning unit of  FIG. 38  with the cover and central duct removed for illustrative purposes; and 
       FIG. 39B  is a left perspective view of the base assembly of the hard floor cleaning unit of  FIG. 38  with the cover and central duct removed for illustrative purposes. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings,  FIG. 1  depicts a perspective view of an upright hard floor-cleaning unit  40  of one embodiment of the present invention. The hard floor cleaning unit  40  comprises an upright handle assembly  42  pivotally connected to the rear portion of a base assembly  44  that moves and cleans along a surface. In particular, as shown in  FIG. 2C , a pair of trunnions  46 , laterally extending from respective right and left ears  48 ,  49  integrally formed on the lower end on the handle assembly  42 , journal into caps  50  mounted on the rear of the frame  52  of the base assembly  44  to form the pivotal connection. Referring back to  FIG. 1 , the base assembly  44  includes a nozzle assembly  62  for recovery particles and/or fluid from the floor and a brush block assembly  216  ( FIG. 2A ) for scrubbing the floor. The handle assembly  42  includes a recovery tank  53  for collecting the particles and/or fluid picked up by the nozzle assembly  62  and a solution tank  43  containing cleaning solution for distribution on the floor. 
   Generally, the hard floor cleaning unit  40  can be used for two modes of cleaning, the dry and wet mode as best illustrated in  FIG. 18 . In the dry mode, the nozzle assembly  62  and brush block assembly  216  are raised to allow pick up of large loose particles. In the wet mode as shown by the phantom lines, the nozzle assembly  62  is lowered to collect the fluid and pick it up. Also, in the wet mode, the brush block assembly  216  can be lowered, if desired, to scrub the floor. Both the nozzle assembly  62  and the brush block assembly  216  are removable from the base assembly  44 . Further details of the cleaning unit  40  are discussed below. 
   Turning to the lower portion of the base assembly  42  as shown in  FIG. 2A , the frame  52  is generally unitary molded and includes two laterally displaced rear wheels  54 . Each wheel  54  is rotatably connected to a cantilevered axle  56  that is journaled into the frame  52  and retained therein by an e-ring  58  secured around the axle  56 . Soft elastomeric tires  60  are molded over the wheels  54  to prevent the scratching on various floor surfaces. Elastomeric bumper strips  51  are overmolded on the lower edges of frame  52  surrounding the brush block assembly  216 . 
   As depicted in  FIGS. 6 and 7 , the nozzle assembly  62  includes an elastomeric squeegee  66  attached around a retainer  76  that is mounted to the bottom of the translucent nozzle body  68 . The nozzle body  68  is composed of a rigid material such as, for example, plastic. The squeegee  66  includes front and rear integrally molded blades or lips  70 ,  72  ( FIG. 7 ) that have bumps  74  along the outer surface of the bottom edges. The bumps  74  raise the leading squeegee lip to allow air and liquid to flow beneath the lip between the bumps. Yet, the trailing lip bends out and cleanly wipes the floor with its inside straight edge to keep liquid in the high suction area between the lips  70 ,  72 . The bumps are formed only adjacent the bottom edges of the lips  70 ,  72 , so that there is a relatively thin cross section of each of the lips  70 ,  72  between the bumps  74  and bottom edge of the nozzle body  68 . This provides a highly flexible thin section in the bending area for good wiping action for the trailing lip and to insure the leading lip bends sufficiently to raise it on the bumps  74 . Such a design is shown in U.S. Pat. No. 3,520,012; the disclosure of which is incorporated herein by reference. Integrally molded with the squeegee  66  is a bumper or furniture guard  64 . 
   With continued reference to  FIG. 6 , the squeegee  66  is attached around the frame  80  of the elongated retainer  76  by over molding it there around. Integrally formed retaining tabs  81  are seated in slots formed in the frame  80  to provide added reinforcement. The retainer  76  includes a plurality of separator plates  78  integrally molded between the front and rear portions of the frame  80  of the retainer  76 . A pair of mounting members  82  is integrally molded on opposite sides of the frame  80  at its upper side and have apertures  84  for receiving screws  88 . A cylindrically shaped spacer  86  is integrally molded on the center separator plate  78  of the retainer  76 . The nozzle body  68  has a pair of bosses  90  with inner longitudinal bores  94  extending downwardly from the underside of the nozzle body  68  on opposite sides. The retainer  76  and squeegee  66  are inserted into the underside of the nozzle body  68  such that the apertures  84  of the mounting members  82  register with the bores  94  in the bosses  90  and a rear central aperture  92  of the nozzle body  68  registers with a lateral aperture  96  of the spacer  86 . Screws  88  are then inserted through the apertures  84  of the mounting members  82  and through the bores  94  in the bosses  90 . A screw  89  is also inserted through the rear central aperture  92  of the nozzle body  68  and the lateral aperture  96  in the spacer  86  of the retainer  76 . The spacer  86  and separator plates  78  maintain alignment and sealing of the squeegee  66  with the nozzle body  68  to insure proper airflow through them. 
   As shown in  FIG. 17 , a channel  98  is formed on the underside of each mounting member  82  and is flushed or slightly below the nozzle channel  100 , when the nozzle assembly  62  is placed on the floor, to direct the air and water flow through the nozzle channel  100 . The nozzle channel  100  converges into a rear centrally located outlet  102  ( FIG. 6 ). A spacer  86  is attached to the outlet  102  as seen in  FIG. 6 , and is fluidly connected to a rectangularly shaped translucent base duct or channel  106  as depicted in  FIG. 4 . The spacer  86  has a pocket portion  87  for engagement by a tongue  85  (also depicted in  FIG. 2B ) extending forwardly from the frame  52  for added support of the nozzle assembly  62 . 
   As best illustrated in  FIGS. 2B and 4 , the floor suction nozzle assembly  62  is removably attached to the frame  52  and fluidly connected to a base duct  106 . The base duct  106  comprises upper and lower portions that are welded together. An elastic flexible grommet  108  for sealing is fitted around the front inlet of the base duct  106  to seal the passageway between the spacer  104  and base duct  106  when they are fluidly connected together. 
   Referring back to  FIG. 6 , the nozzle assembly  62  includes a pair of slide latches  110  on opposite sides of the nozzle assembly  62  for removably securing the nozzle assembly  62  to the frame  52  ( FIG. 2B ). Specifically, each slide latch  110  includes a lateral tongue member  112  that is slidingly inserted into a holder  114  attached to the rear side of the nozzle body  68 . The upper button portion  122  of the latch  110  includes a hook  116  depending downwardly therefrom that engages a stop member  118 , projecting on the upper surface of the holder  114 , to prevent the latch  110  from disengaging from the holder  114 . An oval shaped recess  120  is formed in the top surface of the upper button portion  122  for engagement by a user. With reference to  FIGS. 9A and 9B , the tongue member  112  includes a slot  128  formed therein for slidingly receiving a u-shaped protrusion  124  formed on the upper surface of a front step  123  of the frame  52 . The tongue member  112  includes an L-shaped guide rib  126  integrally formed on its underside and extending inwardly from the outer end of the tongue member  112 . 
   When connecting the nozzle assembly  62  ( FIG. 2B ) to the frame  52 , each slide latch  110  is first slid outwardly until the hook  116  engages the stop member  118  as best illustrated in  FIG. 8A . The nozzle assembly  62  is then positioned so that the spacer  104  is aligned with the grommet  108  as previously mentioned. As seen in  FIG. 8B , each latch  110  is then slid inwardly so that the tongue member  112  extends partially through a lateral channel  130  formed in the frame  52 . As the slide latch  110  is slid further, the hook  116  cams against a beveled channel rib  132  on the top wall  133  of the channel  130 , deflecting upwardly over the channel rib  132  and catching it as shown in  FIG. 8C . Also, as depicted in  FIGS. 9A and 9B , when each latch  110  is slid inwardly to lock the nozzle assembly  62  to the base  94 , the rib  126  cams against the beveled protrusion  124  to guide or move the nozzle assembly  62  rearward, as depicted by the arrows in  FIG. 9B , such that it forms a close fit to the frame  52 , thereby sealingly engaging the spacer  104  to the grommet  108  as seen in  FIG. 4 . 
   Referring to  FIGS. 10A ,  10 B,  11 A–C,  13 A–C and  23 , a lifting mechanism  134  raises and lowers the nozzle assembly  62  ( FIG. 6 ) for use in respective dry and wet modes. As depicted in  FIGS. 10A and 10B , the lifting mechanism  134  includes a wheel carriage assembly  136  positioned in a complimentary recessed area formed in the bottom side of the frame  52  and pivotally connected at the rearward end of the recessed area by trunnions  137  ( FIG. 23 ). 
   Referring to  FIG. 23 , the wheel carriage assembly  136  also includes two pairs of wheels  138  in contact with the floor with each pair riding on stainless steel axles  131  that are snapped into the bottom of the base  140  of the wheel carriage assembly  136  about a horizontal axis. The wheels  138  have soft over molded treads to prevent scratching on various floor surfaces. Further, adjacent front and rear wheels  138  are spaced from each other to keep the nozzle level when traveling over uneven portions of the floor such as grout lines. The top side  142  of the base  140  of the wheel carriage assembly  136  has a raised unshaped frame  144  for securely receiving a coiled compression spring  146 . An arm is integrally formed with the top side  142  of the base  140  and extends upwardly. A rotor  148  is rotatably connected to the top side  142  of the base  140  through a boss or bearing  150 . 
   A slide block  152  is slidably mounted to the top side  142  of the base  140  by screws  143  extending through a pair of elongated longitudinal slots  147  and threading into a pair of bosses  145 . The screws  143  extend through washers  133 , which are positioned between the slide block  152  and heads  151  of the screws  143 . The washers  133  are secured to the screws  143  by suitable means such as, for example, welding. The washers  133  radially extend beyond the front and rear ends  127 ,  129  of the slots  147  to secure the slide block  152  to the top side  142  of the base  140 . Thus, the slide block slides along the longitudinal axis of the slots  147 , yet is secured to the base  140  of the wheel carriage  136 . The slide block  152  is fitted over the rotor  148 , spring  146  and frame  144  securing them thereto. A pair of ramp portions  154  is formed on the top side  142  of the slide block  152  for camming against a corresponding pair of cam followers  156  ( FIGS. 10A and 10B ), extending downwardly from the frame  144  of the base assembly  44 , depending on the longitudinal position of the slide block  152 . 
   As illustrated in  FIG. 2C , a foot pedal  158  is hinged to the frame  52  of the base assembly  44  at its inner end and has a leg  160  depending downwardly from the bottom of the pedal  158 . A torsion spring  162 , secured between the inner end of the foot pedal  158  and frame  52 , upwardly biases the foot pedal  158 . In particular, as best illustrated in  FIG. 12 , the torsion spring  162  is inserted around a pin  161  integrally molded to the inner side of the pedal  158 . Alternatively, the spring  162  could be seated into a recessed portion of the frame  52  as seen in  FIG. 30D . The leg  160  terminates outwardly adjacent a strike member  153  depending upwardly on the left end of the slide block  152  as best illustrated in  FIGS. 10A and 11A . Depressing the pedal  158  downwardly rotates the leg  160  to engage the strike member  153  and laterally push the sliding block  152  such that the ramp portions  154  engage the cam followers  156 , which ride up the ramp portions  154  as best depicted in  FIG. 11B . This action moves the frame  52  upwardly with respect to the wheel carriage assembly  136 , pivoting at the rear end of the wheel carriage assembly  136  as depicted in  FIG. 10B . Hence, the nozzle assembly  62  is raised off the floor as shown in  FIG. 18 . As depicted in  FIG. 11C , the frame  52  remains in the raised position due to the rotor  148  position, after the pedal  158  is released and urged upwardly back by the torsion spring  162  ( FIG. 12 ). Depressing the pedal  158  again permits the spring  146  ( FIG. 23 ) to move the sliding block  152  back outwardly in the lateral direction so that the cam followers  156  ride down the ramp portions  154  and lower the frame  52  as seen in  FIGS. 11A and 10B . Thus, the nozzle assembly  62  lowers on the floor as shown by the phantom lines of  FIG. 18 . 
   In particular, as illustrated in  FIGS. 13A ,  13 B, and  13 C, the rotor  148  engages respective front and rear rib cages  164 ,  166  formed on the underside of the sliding block  152  to perform these actions. Specifically, as depicted in  FIG. 13A , when the leg  160  of the pedal  158 , upon being depressed, pushes the sliding block  152  laterally inward to raise the nozzle assembly  62  ( FIG. 18 ), the front rib cage  164  will engage a first notch  168  on the pedal  158  to rotate the rotor  148 . The rotor  148  is rotated until a second notch  170  of the rotor  148  engages the rear rib cage  166  as depicted in  FIG. 13B . When the pedal  158  is released, which disengages the leg  160  from the strike member  153 , the coiled compression spring  146  moves the slide block  152  back slightiy so that the rear rib cage  166  rotates the rotor  148   50  that the front rib cage  164  is aligned with the outer side  171  of the rotor  148  between the notches,  168 ,  170 . In this position the engagement of the rear rib cage  166  with the second notch  170  prevents further rotation of rotor  148 . 
   Depressing the pedal  158  again, moves the slide block  152  inwardly such that the rear rib cage  166  moves out of the way of the second notch  170  and the front rib cage  164  engages the outer side  171  of the rotor  148  rotating it such that the second notch  170  rotates past the rear rib cage  166 . At this position as shown in  FIG. 13C , there is no interference to prevent the slide block  152  from moving back to its original position. Thus, upon releasing the pedal  158 , the coiled compression spring  146  moves the slide block  152  outward. This action lowers the nozzle assembly  62  as depicted by the phantom lines in  FIG. 18 . It should be apparent that upon depressing the pedal  158  again to raise the nozzle assembly  62 , the front rib cage  164  now engages the second notch  170  and the first notch  168  engages the rear rib cage  166  but in all other aspects the raising and lowering operation will be similar, since the notches are similarly shaped. Alternatively, a pin index mechanism could be substituted for the rotor  148 . 
   As depicted in  FIGS. 1 and 2C , a hood or cover  172  snap fits onto the frame  52  and includes dry mode and wet mode openings or windows  174  and  176 , respectively, for viewing a colored area on the top surface of an indicator plate  178  ( FIG. 2B ) to inform the user that the hard floor cleaner is in either the dry mode or wet mode. In particular as shown in  FIG. 2B , the indicator plate  178  is spring loaded and rotatably connected on the frame via an integrally formed pin  180  ( FIGS. 11A–C ) extending downwardly through an aperture in the frame  52  near the left side of the frame  52  rearwardly adjacent the nozzle assembly  62 . The indicator plate  178  further includes a downwardly depending leg  179  extending through a curved guide slot  184  formed in the frame  52 . A torsion spring  182  is inserted around a raised hub portion  181  integrally molded on the top of the indicator plate  178 . 
   Referring to  FIGS. 11A–C , the spring has its front end  186  extending into a protrusion  187  formed on top of the frame  52  and its rear end  185  extending into a rear aperture in the indicator plate  178  of the spring. With this arrangement, the spring  182  urges the leg  179  of the indicator plate  178  inwardly against an upper inner offset portion  183  of the striking portion  153  on the left end of the slide block  152 . In operation, when the slide block  152  moves laterally inward to raise the nozzle assembly  62  ( FIG. 18 ), the leg  179 , urged by the spring  182 , slides inwardly along the curved guide slot  184  to the position shown in  FIG. 11C . Hence, the indicator plate  178  rotates to the position shown in  FIG. 30A  such that the colored area of the indicator plate  178  is positioned under the dry mode opening  174  ( FIG. 1 ). When the slide block  152  is moved laterally outward to lower the nozzle assembly  62  ( FIG. 18 ), the leg  179 , urged by the spring  182 , slides outwardly along the curved guide slot  184  to the position shown in  FIG. 11A  thereby rotating the indicator plate  178  to the position shown in  FIG. 30B  such that the colored area of the indicator plate  178  is positioned under the wet mode opening  176 . Alternatively, as depicted in  FIG. 30D , a compression spring  182 ′ with one end inserted around the hub portion  181  of indicator plate  178  and the other end inserted around the protrusion  187  could be used instead of the torsion spring  182 . 
   Also, the nozzle assembly  62  is raised when the handle assembly  42  is pivoted in the upright position to prevent deformation of the squeegee  66  during storage as depicted by the phantom lines in  FIG. 4 . Specifically as depicted in  FIG. 2C , the left ear  49  extending from the bottom of the handle assembly  42  interfaces with a raised left cam member  188  on the top of the wheel carriage assembly  136 . In operation, as depicted in  FIG. 16 , when the handle assembly  42  is pivoted in the upright position, the ear  49  cams against the cam member  188  to raise the frame  52  ( FIG. 2C ) from the wheel carriage  136 . 
   As depicted in  FIG. 2C , a lock plate  190  is pivotally connected to the frame  52  via a central lever  192  and includes an inwardly extending stop member  194  to prevent the handle assembly  42  from inadvertently pivoting back down. In particular, with reference to  FIGS. 15A and 15B , a torsion spring  196 , inserted around the lever  198 , is secured between the frame  52  and lock plate  190  and biases the stop member  194  to extend inwardly and abut the right ear  48 . As the handle assembly  42  is raised as shown in  FIG. 15A , the curved portion  208  of the right ear  48  cams against the stop member  194  deflecting it downwardly until the stop member  194  catches the flat front side  204  of the right ear  48 . At this position as shown in  FIG. 15B , the stop member  194  is flexed back from the biasing force of the spring  196  and laterally abuts the straight front side  204  of the right ear  48 , preventing the handle assembly  42  from moving back down. The front side of the lock plate  190  interfaces with the frame  52  providing a limit for twisting or deflection of the handle assembly  42 . This places the lock plate  190  in compression. As shown in  FIG. 2C , a handle release pedal  206 , hinged to the frame  52  at its inner end, is provided to move the stop member  194  out of the way of the right ear  48  to allow the handle assembly  42  to pivot downwardly. In particular, as best illustrated in  FIGS. 14A and 14B , upon depressing the pedal  206 , a downwardly depending leg  210  of the pedal  206  cams upwardly against an outwardly extending tongue member  212  of the lock plate  190 , thereby pivoting the stop member  194  downwardly and outwardly away from the right ear  48 . Thus, the handle assembly  42  is free to pivot downward and lower. A torsion spring  214 , secured between the inner end of the foot pedal  206  and frame  52  ( FIG. 2C ), urges the handle release pedal  206  back up to its original position. In particular, as best illustrated in  FIG. 15B , the torsion spring  214  is inserted around a pin  215  integrally molded to the inner side of the pedal  206 . Alternatively, the spring  214  could be seated into a recessed portion of the frame  52 . 
   As depicted in  FIG. 2A , a brush block assembly  216  is removably secured to the base assembly  44  for agitating the surface to be cleaned. In particular, as depicted in  FIG. 19 , the brush block assembly  216  comprises a brush support plate  218  having six spaced apart openings  220 A,  220 B,  220 C,  220 D,  220 E, and  220 F. Fixedly received within the openings  220  are bushings  222 A,  222 B,  222 C,  222 D,  222 E, and  222 F which in turn rotatingly receive axial shafts  224 A,  224 B,  224 C,  224 D,  224 E, and  224 F of gear brushes  226 A,  226 B,  226 C,  226 D,  226 E, and  226 F. The gear brushes  226 A–F rotate on a vertical axis. A drive shaft  225  having a square cross section is welded to the axial shaft  224 B of the gear brush  226 B adjacent the right outer brush  226 A. Each of the gear brushes  226  is basically configured as a spur gear having ten teeth  228  that intermesh such that when one gear brush  226  rotates, all other gear brushes  226  rotate accordingly. The center hub of gear brushes  226  forms a hollow downwardly projecting brush cup  230  having a multiplicity of openings  232  circumscribing the bottom thereof. 
   During manufacturing of the brush assembly  216 , the gear brush axial shafts  224  are first inserted into the appropriate bushing  222  and with gear brushes  226  in their uppermost position and, with gear teeth  228  intermeshed between the gear brushes  226 . Each gear tooth  228  has a blind bore, extending to offset portion  233  into which bristle bundles  234  are compressively inserted. Bristle bundles  235  are also compressively inserted into the front corners of the brush support plate  218  for edge cleaning. 
   Further, as seen in  FIG. 17 , closely packed bristle bundles  237  are also compressively inserted into blind bores located in the center of each of the gear brushes  226  for added agitation and cleaning in the middle of the gear brush  226 . Specifically, an outer ring of nine bristle bundles  237  concentrically surrounds an inner ring of five bristle bundles  237 . The spacing of adjacent bristle bundles  237  located in the center of the gear is shorter than the bristle bundles  234  in the offset portion  233 . The center bristle bundles  237  provide several features. They support the brush block assembly  216 , preventing it from tilting, thereby promoting the application of even pressure on the floor from all of the bristle bundles  234 ,  235 , and  237 . Such support also significantly reduces the deflection or bending of the outer bristle bundles, thereby significantly minimizing the spraying or splattering of the cleaning solution from them. They further add to the brush or bristle density of the brush block assembly  216 , thereby providing more scrubbing on the floor. Each bristle is crimped instead of straight so that when the bundles are formed, more scrubbing coverage is provided. Such crimping on the bristles in the bundles also reduces deflection of the bristles as they scrub, thereby minimizing the spraying or splattering of cleaning solution from the bristles. 
   Referring back to  FIG. 19 , a gear guard  236  snap fits into a brush support plate  218 . Specifically, upwardly extending locking tabs  238  on the gear guard  236  catch onto steps  240  integrally molded to the lower surface of the brush support plate  218 . During assembly of the gear guard  236  to the brush support plate  218 , the locking tabs  238  deflect laterally extending cantilevered tangs  242  integrally formed in the brush support plate  218  to allow the locking tabs  238  to extend therethrough. The tangs  242  will then flex back to their initial position, closely adjacent the locking tabs  238 , to prevent the locking tabs  238  from disengaging off of the steps  240 . 
   With continued reference to  FIG. 19 , the brush support plate  218  includes a plurality of troughs  244 A,  244 B,  244 C,  244 D for receiving the cleaning solution that flows from a distributor  246  ( FIG. 2A ) positioned thereon. Cleaning solution received in the toughs  244  flows through openings  248  in them and into the brush cups  230  of the brushes  226 . Once deposited within the brush cup  230 , the cleaning solution flows outward toward the surface being cleaned through openings  232  in the bottom of the brush cups. The cups  230  contain the cleaning solution as the gear brushes  226  rotate and thus prevent solution from being sprayed outward over the top of the gear brush. The gear guard  236  is designed to withstand impact and prohibit cleaning solution from resting on its inner lip  231 . In particular, the bottom surface  241  of the inner lip  231  inclines downwardly to the edge of the inner lip  231  to direct the flow of cleaning solution off the inner lip  231 . 
   Further, as depicted in  FIG. 17A , the bottom side  259  of each of the two inner troughs  244 B,  244 C is gabled or convexly curved from left to right to direct the flow of cleaning solution to the openings  248 . The bottom side  261  of each of the outer troughs  244 A,  244 D is inclined downwardly to the opening  248  to also direct the flow of cleaning solution to the opening  248 . As depicted in  FIG. 2A , the distributor  246  is positioned on the brush support plate  218  and includes respective upper and lower plates  250 ,  252  sealingly secured to each other by, for example, hot plate welding them together. The brush support plate  218  includes respective front and rear stop members  254 ,  255  positioned closely adjacent the front and rear ends of the distributor  246  to limit the front and rear lateral movement of the brush block assembly  216  with respect to the distributor  246 . Additionally, front and rear lateral extensions  256  ( FIG. 22 ) of the lower plate  252  are seated between adjacent right and left center stop members  257 ,  258 , respectively to aid in minimizing lateral movement of the brush block assembly  216  along its longitudinal axis with respect to the distributor  246 . 
   Referring to  FIG. 21 , the lower plate  252  of the distributor  246  has a channel  260  with orifices  262  formed therein. The orifices are aligned over the troughs  244  of the brush support plate  218 . The upper plate  250  includes a tubular elbow connector  245  welded onto the upper surface of the upper plate  250 . The elbow connector  245  is fluidly connected to the distributor supply hose  328 . The outlet of the elbow connector  245  is aligned over a rear branch  261  of the channel of the lower plate  252 . Cleaning solution flows from the supply hose  328  through the elbow connector  245  to a rear branch  264  of the channel  260  and then through the orifices  262  to the troughs  244  ( FIG. 19 ). A pair of hooks  710  integrally molded with the upper plate  250  of the distributor  246  extends from its upper surface. 
   As depicted in  FIG. 2A , the brush block assembly  216  is removably connected to the distributor  246  and both are received in a complementary cavity  265  formed on the underside of the frame  52  rearwardly adjacent the nozzle assembly  62 . The hooks  710  of the distributor  246  hang onto forwardly extending arms  714  of a brush lifting lever  718  which is positioned on the frame  52 , thereby floatingly supporting the distributor  246  and brush block assembly  216  to the frame  52 . The mechanism to remove the brush block assembly  216  is described as follows. A pair of latch members  266 ,  267  are rotatably connected to the lower plate  252 . The latches are mirror images with respect to each other, but are similar in all other respects. Thus, similar reference numbers in them will be used to describe similar parts. Referring to  FIG. 21 , for ease of assembly, each latch member  266  comprises a center circular key portion  268  with opposite extensions  270  that are received in a complimentary slot  272  formed in the lower plate  252 . As depicted in  FIG. 22 , the bottom surface  251  of the lower plate  252  has diagonally opposite front and rear ramps  274 ,  276  and diagonally opposite protrusions  282 ,  284  formed thereon. 
   As best illustrated in  FIG. 21 , when installed, the key portion  268  is aligned and inserted into slot  272 , and the latch member  266  or  267  is turned flexing slightly outward from the lower plate  252  as its upper surface rides up on respective diagonally opposite front and rear ramps  274 ,  276  ( FIG. 22 ). As depicted in  FIGS. 10A and 10B , the latch member  266  or  267  is turned until radially extending opposite front and rear legs  278 ,  280 , respectively, are seated between the vertical walls of their corresponding ramps  274 ,  276  and front and rear protrusions  282 ,  284  formed on the lower plate  252 . As best illustrated in  FIG. 21 , the extensions  270  will extend over the lower surface of the lower plate  252  interlocking the latch member  266  or  267  to the lower plate  252  thereby preventing it from vertically separating from the lower plate  252  and riding up over the ramps  274 ,  276  ( FIG. 22 ). Each of the front legs  278  has a nub  293  integrally molded on its upper surface. The front and rear legs  278 ,  280  also have respective front and rear elastic L-shaped fingers  286 ,  288  extending inwardly from the distal ends of the legs and located on diagonally opposite ends of the latch member  266  or  267 . As seen in  FIGS. 10A and 10B , the fingers  286 ,  288  abut the respective protrusions  282 ,  284  thereby providing a biasing force. Thus, the elasticity of the fingers  286 ,  288  will allow the latch member  266  or  267  to rotate when sufficient lateral force is applied to overcome the biasing force of the fingers  286 ,  288 . 
   As depicted in  FIG. 19 , the brush support plate  218  includes two pairs of integrally molded front and rear hook members  290 ,  292  extending upwardly from its upper surface. The nose  291  of the front hook member  290  is oriented inwardly and the nose  291  of the rear member  292  is oriented outwardly, opposite to that of the front hook member  290 . As best illustrated in  FIGS. 20A ,  20 B, and  2 CC, each pair is associated with a latch member  266  or  267 . The front and rear hook members  290 ,  292  slidingly engage the upper surface of front and rear legs  278 ,  280 , respectively. The front and rear hook members  290 ,  292  associated with each latch member  266  or  267  are also located diagonally across from each other. 
   Referring to  FIG. 2B , a pair of push buttons  296  is used to disengage the hook members  290 ,  292  from the latch members  266 ,  267 . In particular, each button  296  is hinged to the frame  52  by a pin  297  integrally molded on the inner end of the button  296  with respect to the frame  52 . Each button  296  further includes an integrally molded cantilevered finger  298  extending laterally inward from the inner end. A cap  295  snap fits on the frame  52  over the finger  298  and pin  297  thereby securing the button  296  to the frame  52 . The finger  298  biases the button  296  upwardly. The button  296  has a leg  299  depending downwardly with respect to the frame  52  from the underside of the button  296 . As best depicted in  FIGS. 20A and 20B , the leg  299  terminates adjacent the outer side of the nub  293  of the front leg  278  of the latch member  266  or  267 . The nub  293  ensures that the leg  299  engages the latch member  266  or  267  when the button  296  is depressed. Thus, as shown in  FIG. 20B , when each button  296  is depressed with sufficient force to overcome the biasing force of the finger  298  of the button  296 , it pivots about the pin  297  and moves the leg  299  of the button  296  inwardly. The movement of leg  299  inwardly moves the latch member  266  or  267  to laterally rotate in a direction such that its front and rear legs  278 ,  280 , respectively, slidingly disengage from their respective hooks, when sufficient lateral force is imparted to the front leg  278  of the latch member  266  or  267  to overcome the biasing force of the fingers  286 ,  288  ( FIG. 21 ) of the latch member  266  or  267 . 
   Thus, as illustrated in  FIG. 20C , upon such disengagement, the brush block assembly  216  freely falls out of the cavity  265  ( FIG. 2A ) by gravity. When the buttons  296  are no longer depressed, the biasing force from the fingers  286 ,  288  of the latch members  266 ,  267  and fingers  298  of the buttons  296  cause the buttons  296  and latch members  266 ,  267  to return to their initial positions. As best illustrated in  FIG. 2A , the brush block assembly  216  is reinstalled to the latch members  266 ,  267  by simply positioning the brush block assembly  216  in the cavity, aligning the drive shaft  225  with the gear opening of a brush motor assembly  500 , and pushing the brush block assembly  216  upwardly until the hook members  290 ,  292  catch or engage the legs  278 ,  280  of the latch members  266 ,  267 . In particular, each of the hook members  290 ,  292  includes an incline portion  291  ( FIG. 19 ) on each of their noses  294  ( FIG. 19 ) that rides along its corresponding leg  278  or  280 , thereby rotating each of the legs  278 ,  280  away from the nose  294  allowing the nose  294  to pass through. After the nose  294  passes through, the biasing force of the fingers  286 ,  288  will rotate the latch so that the legs slidingly engage the hook members  290 ,  292  underneath the nose  294 . 
   As shown in  FIG. 2A , the brush motor assembly  500  is mounted on the underside of the frame  52  directly above the wheel carriage assembly  136 . Turning to  FIG. 24 , the brush motor assembly  500  comprises a generally L-shaped motor housing  502  that includes an upper cover  504  that is snap connected to the lower cover  506 . In particular, u-shaped locking tabs  503  integrally formed on the upper cover  504  engage catches  505  formed on the lower cover  506 . Screws (not shown) secure the brush motor assembly  500  to the frame  52 . Seated within the housing  502  is a grounded, internally rectified DC motor  508  and a gear train  510 . A worm  512  is press fitted onto the shaft  514  of the motor  508 . A worm gear  516  having thirty teeth  518  is mounted on an axial shaft  519  and engages the worm  512 . A spur gear  522  is also mounted on the axial shaft  519  above the worm gear  516 . 
   Referring to  FIG. 24A , the central hub  524  of the worm gear  516  defines an upwardly extending hollow cylindrical portion that has three notches  526  formed at its distal end. The spur gear  522  has a hub portion  523  formed on its underside in which three integrally molded ribs  528  extend radially therefrom. The ribs  528  engage the notches  526  so that the worm gear  516  can rotate the spur gear  522 . Turning back to  FIG. 24 , the axial shaft  520  is pressed into pockets  530  formed in the lower cover  506  and received in pockets  530  formed in the upper cover  504  to balance and minimize wobbling of the worm gear  516 , thereby maintaining engagement of the teeth  517  with the worm  512  as the worm gear  516  rotates. The worm gear  516  generally has the largest diameter and the most teeth of the gears in the gear train  510  so as to provide speed reduction. Although the present worm gear  516  has thirty teeth  518 , the diameter and number of teeth can be altered to provide the desired speed reduction. 
   The teeth  518  of the spur gear  522  intermesh with teeth  518  of an adjacent spur gear  522  which in turn intermeshes with teeth  518  of an adjacent spur gear  522  which finally intermeshes with teeth  518  of the remaining spur gear  532 . The middle spur gears  522  have axial shafts  520  which are also pressed into pockets  530  formed in the lower cover  506  and received in pockets  530  formed in the upper cover  504  to minimize wobbling and maintain engagement with their respective adjacent spur gears  522 ,  532 . The last spur gear  532  in the gear train  519  has a square opening for receiving the drive shaft  225  of the gear brush  224  in the brush block assembly  216 . A power cord  552  electrically connects the motor  508  through a microswitch  534  ( FIG. 32 ) to a power source (not shown). Thus, when the motor  508  is energized, the worm  512  rotates the worm gear  516  and hence spur gears  522 ,  532  which in turn rotates the drive shaft  225 . Rotation of the drive shaft  225  then rotates the gear brushes  226  in the brush block assembly  216  as seen in  FIGS. 17A and 19 . 
   Referring to  FIG. 3A , handle assembly  42  basically comprises an upper handle portion  312 , lower body shell  314 . The upper handle portion  312  tapers upwardly into a narrow closed looped handgrip  372  at its upper end. A carrying handgrip  308  is also snap connected into the rear wall of the upper handle portion  312  to aid in carrying the hard floor cleaning unit  40 . A front cover  311  is secured to the lower body shell  314 . An upper cord holder  310  is snap connected into the rear wall of the upper handle portion  312  as also illustrated in  FIG. 5 . A lower cord holder  303  is screwed to the rear wall of the lower body shell  314 . 
   A combined air/water separator and recovery tank  53  is removably seated within a cavity  306  of the lower body shell  314  upon the bottom side of the lower body shell  314 . A bottom cover  535  of the recovery tank  53  screws into the lower body shell  314 . As depicted in  FIG. 4 , positioned rearwardly of the recovery tank  53  is a corrugated translucent plastic hose  536  and recovery duct  538 . The hose  536  is fluidly connected downstream to the translucent recovery duct  538  by a connector  540  and is sealed thereto by an O-ring  542  ( FIG. 3A ). A mounting bracket  539  (also shown in  FIG. 3A ) fits over the connector  540  and mounts the recovery duct  538  and hose  536  to the lower body shell  314 . The hose  536  is fluidly connected upstream to the base duct  106  by a hose mounting bracket  544  mounted to the base duct  106 . The hose  536  is flexible, yielding to permit pivoting of the handle assembly  42 . 
   Referring to  FIG. 3A , the recovery duct  538  has grooves  546  that snap connect onto locking tabs  548  ( FIG. 3C ) extending from the center of the rear inner side of the lower body shell  314 . The recovery duct  538  is generally rectangular shaped and slightly flattened yet laterally elongated to provide additional room to accommodate the recovery tank  53  while allowing adequate flow of liquid and air therethrough. As depicted in  FIG. 3C , raised channel portions  549 ,  550 ,  551  extend from the center of the rear inner side of the lower body shell  314  for securely receiving the supply tube  328 , brush cable  730 , and power cord  552 , respectively. The translucent recovery duct  538  covers these elements for protection, yet provides visibility of these components for service. 
   Referring to  FIG. 25 , the recovery tank  53  includes an inverted cup shaped handle  628  integrally molded to its front wall  602 . The recovery tank  53  further includes a lid  554  located above the handle  628 . The lid  554  includes an upper portion  555  mounted to a lower portion  556  with a rope seal  578  there between as also seen in  FIG. 25A . A rectangular shaped retainer  558  is integrally formed on the top surface of the upper portion  555  of the lid  554  and surrounds the center tank exhaust opening  560 . An integrally molded screen  582  covers the exhaust opening  560 . A pleated filter  562  integrally molded to a seal  564  is seated in the retainer  558 . A cover  566  with an outlet opening  568  formed therein covers the seal  564  and filter  562 . The lid  554  is secured to the recovery tank  53  by a lid locking plate  570  and an integrally molded locking tang  517  ( FIGS. 4 and 25A ). The lid locking plate  570  is hingedly snap connected to the lid  554  and has two smaller slots  580  for securely receiving locking tabs  572  projecting from the recovery tank  53  by a snap connection. As best illustrated in  FIG. 4 , the locking tang  517  engages a groove  573  ( FIG. 25 ) formed on the inner side of the front wall recovery tank  53 . Referring to  FIG. 25C , a rear recovery channel  574  having right and left oudets  576 ,  577  is formed in the lower portion  556  of the lid  554 . The channel  574  is in fluid communication with the recovery tube inlet  584  that is formed at the top side of the lid  554 . The inlet  584  is fluidly connected through a seal  598  ( FIG. 25A ) to the recovery duct  538  as depicted in  FIG. 4 . 
   As best illustrated in  FIG. 25B , when the hard floor cleaner unit  40  is used in the wet mode, the extracted soiled cleaning liquid enters the inlet  584  and travels downward impinging upon the bottom  590  and inner sides of the channel  574  as it moves along the right and left branches  586 ,  588  of the channel  574  to slow down its velocity for air/water separation. The bottom  590  of the channel  574  is slightly gabled to aid in directing the liquid to the right and left outlets  576 ,  577  ( FIG. 25C ). 
   The cross sectional areas of the branches,  586 ,  588  increase downstream to further slow down the liquid and help separation. Referring to  FIG. 25C , a pair of downwardly depending shields  592 R,  592 L extends forwardly from the front wall of the channel  574 . As depicted in  FIG. 25C , each shield  592  is slightly angled outward and also includes more pronounced outwardly angled drip edges  594 R,  594 L on the bottom ends. An additional drip edge  596  runs along the rear bottom side of the channel  574 . The shields  592 R,  592 L and drip edges  594 R,  594 L, and  596  aid in separation of the liquid and minimize the amount of liquid entering the exhaust opening  560 . Adjacent the outlets  576 ,  577  of the channel  574  are upper deflectors  600 R,  600 L extending forwardly therefrom. 
   As best illustrated in  FIG. 4 , these deflectors  600 R,  600 L ( FIG. 25C ) in combination with the shields  592 R,  592 L direct a portion of the liquid to impinge onto the inner surface of the front wall  602  of the recovery tank  53  and collect down on the bottom  601  of the recovery tank  53 , thereby separating the liquid from the air and thus, minimizing the amount of water near the exhaust opening  560 . The remaining portion of the liquid exits the duct through the oudets  576 ,  577  ( FIG. 25C ) and is impinged onto their associated inner sidewalls  604 R,  604 L ( FIG. 25 ) of the recovery tank  53  and also collects down on the bottom  601  of the recovery tank  53 . Air separated from the liquid flows through the exhaust opening  560 , is filtered by the screen  582  and pleated filter  562 , and exits through the oudet opening  568  ( FIG. 25 ) in the cover  566 . 
   Referring to  FIGS. 4 and 25C , a float assembly  606  comprises a bottom float  608  connected by a stem  610  to an upper portion defining a seal  612 . The seal  612  is pivotally connected to the underside of the lid  554  ( FIG. 25C ) and drops down to open the exhaust opening  560 . This design prevents water from traveling from the float  608  to the seal  612 . When the liquid level in the recovery tank  53  reaches a full level, the float  608  will move upward thereby pivotally moving the seal  612  upward to cover the neck  614  of the exhaust opening  560  as shown in the phantom lines of  FIG. 4 . In this position, the seal  612  closes the exhaust opening  560  to prevent the liquid from entering the motor area. When the hard floor cleaning unit  40  is used in the dry mode, the large objects drawn into the recovery tank  53  by the suction motor assembly  632  collect on the bottom  601  and small objects or particles such as dust are filtered out by the screen  582  and pleated filter  562  and prevented from entering the motor area. 
   As previously mentioned, the recovery tank  53  removably securely seats into the cavity  306  of the lower body shell  314  as depicted in  FIG. 4 . In particular, this is accomplished as follows. Referring to  FIG. 25 , a U-shaped vertically extending shield  616  is integrally molded on the top surface of the upper portion  555  of the lid  554 . A retaining housing or slot  618  is integrally molded to the rear inner side of the shield  616  for receiving a spring-loaded latch  620 . A coiled spring  622  is positioned between the top side of the lid  554  and latch  620  to bias the latch  620  upwardly. A lateral opening  624  in the shield  616  allows access to an arcuate lateral ledge  626  formed on the front of the latch  620 . As depicted in  FIG. 25C , the ledge  626  is positioned near the center of the opening for placement of a thumb or finger of a user. As best illustrated in  FIG. 26 , the upper end  630  of the latch  620  is beveled and cams against the lower edge  304  of the front cover  311  of the lower body shell to urge the latch downward as illustrated by the phantom lines, upon placing the recovery tank ( FIG. 4 ) into the cavity  306 . Once past the lower edge  304 , the biasing force in the coiled spring  622  will urge the latch  620  upwardly behind the lower edge  304 . This allows the recovery tank  53  to seat into the cavity  306  as shown in  FIG. 4 . Alternatively, instead of the coiled spring  622 , an integrally molded elastic member extending downwardly from the bottom end of the latch  620  could also bias the latch  620  upwardly. 
   Referring to  FIG. 4 , to remove the recovery tank  53  from the cavity  306  in the lower body shell  314 , a user grasps the handle  628  with his fingers and pushes down on the lateral ledge  626  of the latch  620  with his thumb until the upper end of the latch  620  moves below the lower edge  304  ( FIG. 26 ) of the front cover  311  to unlock the recovery tank  53  therefrom. Using the handle  628 , the user then pulls the recovery tank  53  out of the cavity  306 . Referring to  FIG. 25 , to empty the recovered liquid from the recovery tank  53 , a user lifts the lid locking plate  570  outward to unsnap it from the locking tabs  572  thereby unlocking the lid  554  from the recovery tank  53 , and then simply removes the lid  554  and empties the recovered liquid from the recovery tank  53 . 
   As shown in  FIG. 3A  suction source in the form of a bypass suction motor assembly  632  is received within the lower body shell  314  and covered by the front cover  311 . In particular with reference to  FIGS. 4 and 27 , the suction motor assembly  632  generally comprises a motor/fan mechanism  634  that is positioned in a fan housing  636 . An elastomeric vibration mounting O-ring  638  fits around a flange  640  of the fan housing  636 . An impeller  642  is rotatably connected to the bottom of the fan housing  636  and extends into an impeller housing  644 . The O-ring  638  of the fan housing  636  rests upon a support step  637  ( FIG. 27 ) of the lower impeller housing  644 . A gasket  650  is secured around the impeller housing  644  just below a flange portion  647 . As depicted in  FIG. 4 , the gasket  650  has an annular groove  652  ( FIG. 27 ) that cooperates with a support ledge  648  integrally formed on the inner side of the front cover  311  and lower housing  314  to support the motor/fan mechanism  634 . 
   As depicted in  FIG. 4 , a motor cover  654  surrounds the motor/fan mechanism  634  and is mounted to the flange portion  647  of the impeller housing  644  thereby defining motor cooling exhaust manifolds  656  around the bottom of the fan housing  636 . Motor cooling air is drawn through a rear vent  658  in the lower body shell  314  to air inlets  661  ( FIG. 27 ) of the motor cover and air inlets  662  ( FIG. 27 ) in the fan housing  636  by a cooling fan  649  of the motor/fan mechanism  634 . The air cools the motor/fan mechanism  634  and exhausts into the exhaust manifolds  656 . Referring to  FIG. 3A , the heated air then exits upwardly through exhaust air outlets  664  ( FIG. 27 ) in the motor cover  654  and then through exhaust vents  666  mounted on the front cover  311  of the lower body shell  314 . The exhaust vents  666  are oriented to direct the air upwardly away from the floor and thereby prohibit any moisture from entering the motor/fan mechanism  634 . Turning to  FIG. 27 , the motor cover  654  includes vertical sealing plates  668  positioned adjacent the ends of the manifolds  656  that prevent the exhaust air from entering back up into the inlets  662  of the fan housing  636 . 
   With continued reference to  FIG. 27 , the impeller housing  644  includes a bottom portion  670  mounted thereto and which includes an opening  678  and an air inlet port  672  aligned over the eye of the impeller  642 . A molded in grilled guard  674  on the bottom of the opening  678  (shown separated for illustrative purposes) restricts large objects from entering the eye of the impeller  642 . Referring to  FIG. 4 , the air inlet port  672  extends downwardly to the opening  568  ( FIG. 25 ) in the lid cover  566  of the pleated filter  562 . The bottom of the inlet port  672  is beveled to register with the cover  566  of the filter  562 . A gasket  673  is fitted around the inlet port  672  to seal it to the cover  566 . The impeller  642  draws clean air filtered by the pleated filter  562  into the inlet port  672 , where it then exhausts through the side of the impeller  642  and bottom slit in the impeller housing  644 , where it is then directed downward exiting between the recovery tank  53  and the lower body shell  314 . 
   As depicted in  FIG. 3A  main power switch assembly  682  is electrically connected to the suction motor assembly  632  and power supply (not shown) and thus, is used to turn on and off the suction motor assembly  632 . The switch assembly  682  includes a mounting plate  684  ( FIG. 28 ) mounted to the lower body shell  314  adjacent the motor assembly  632 . Referring to  FIG. 28 , a circuit breaker  686  secured to the mounting plate  684  includes a reset button  688  extending up through an opening in the top of the mounting plate  684 . Receptacles  685  are attached to prongs  687  extending downward from the bottom of the circuit breaker  686 . Guide channels  690 A,  690 B formed on the mounting plate  684  slidably receives a switch lever  692 . The lever  692  has a flap  694  extending over the reset button  688  of the circuit breaker  686 . The switch button  696  from a switch body  698  extends through an aperture  700  in the lever  692  and aperture  702  in the mounting plate  684 . A slide button  704  located on the exterior side of the lower body shell  314  snap fits into a second aperture  706  formed in the lever  692 . 
   Thus, movement of the slide button  704  longitudinally with respect to the handle assembly  42  will correspondingly move the switch button  696  longitudinally turning it on and off, and also reset the circuit breaker  686  when slid down. Thus, when the slide button  704  is slid up to the on position, the motor  635  in the motor/fan assembly  634  is energized, and when the slide button  704  is slid down to the off position, the motor  635  is de-energized and the flap  694  engages the reset button  688 , resetting the circuit breaker  686  when tripped. 
   As generally illustrated in  FIG. 3A , the lower body shell  314  has integrally molded therein a top support shelf  318  that has mounted thereto a cleaning solution reservoir assembly  320 . Reservoir  320  receives and holds a quantity of cleaning solution from a supply tank  43  for distribution to the supply tube  328  as further described below. The handle assembly  42  is completed by fixedly attaching the upper handle  312  to the lower body shell  314  by telescopingly sliding upper handle  312  downward such that its lower lip  307  fits into a recess area  309  of the front cover  311 . 
   Referring now to  FIG. 29A , cleaning solution reservoir assembly  320  includes a bottom concave lower basin  324  having a supply tube  328  exiting therefrom. Supply tube  328  provides a valved release of cleaning solution from the reservoir volume  334  and the supply tank  43  to the cleaning solution distributor  246 . As shown in  FIGS. 3A and 29A , the supply tube  328  is covered with a jacket  553  within the area of the motor assembly  632  ( FIG. 3A ) to ensure that no leakage from a possible rupture of the tube will enter the area. 
   As depicted in  FIG. 29A , a cover plate  332  is sealingly mounted to lower basin  324  thereby forming reservoir volume  334  which supply tank  43  floods with cleaning solution through inlet port  336 . Extending axially upward through inlet port  336  is pin  338  which acts to open the supply valve  440  of the supply tank  43  as the tank  43  is placed upon the support shelf  318  and secured in place. The structure and operation of the supply valve  440  is described further below. 
   Cleaning solution is released, upon operator demand, into tube  328  through solution release valve  340  which comprises valve seat  342  positioned in basin  324  of bowl  344  integrally formed with top cover  332 . The basin  324  of bowl  344  extends across discharge port  346  such that valve seat  342  is aligned to open thereinto. An opening  348 , within the wall of bowl  344 , permits the free flow of cleaning solution from reservoir  334  into bowl  344 . An elastomeric valve member  350  comprises an elongate piston  352  extending through valve seat  342  having a bulbous nose  354  at the distal end thereof within discharge port  346 . The valve member  350  is preferably made of an elastomeric material. The opposite end of piston  352  includes a downwardly sloped circular flange  356 , the peripheral end of which frictionally and sealingly engages the upper circular rim  358  of bowl  344  thereby preventing leakage of cleaning solution. The flange  356  acts to bias piston  352  upward thereby urging nose  354  into sealing engagement with valve seat  342  preventing the flow of cleaning solution from bowl  344  into discharge port  346  and tube  328 . 
   The solution release valve  340  is operated by pressing downward upon the elastomeric release valve member  350  by a push rod  360  thereby deflecting the center of flange  356  downward urging nose  354  downward and away from valve seat  342  permitting the passage of cleaning solution therethrough into discharge port  346  and tube  328 . Energy stored within flange  356 , as a result of being deflected downward will, upon release of the force applied to push rod  360 , return the valve to its normally closed position as illustrated in  FIG. 29A . Such an arrangement is similar to that disclosed in U.S. Pat. No. 5,500,977; the disclosure of which is incorporated by reference. 
   Referring now to  FIGS. 3B and 5 , extending upward through handle assembly  42  is the articulated push rod  360 . Push rod  360  is positioned within the handle assembly  42  by means of integrally molded spacers  364  dimensioned and located as necessary. Integrally formed lateral hook arms  367  on the push rod  360  slidingly engage a guide channel  365  integrally formed in the inner side of the upper handle  312  and extending longitudinally with respect to the upper handle  312 . This arrangement aids in guiding the push rod  360  directly over the valve member  350  ( FIG. 29A ) as it moves longitudinally. The upper end  366  of push rod  360  is pivotally attached to trigger  368 . Specifically, a lateral pin  371  integrally molded on the trigger pivotally snaps into a detent  363  ( FIG. 3B ) formed in the upper end  366 . 
   The trigger  368  is pivotally attached to the handgrip  372  at a pivot  370 . In particular as depicted in  FIG. 3B , the pivot  370  of handgrip  372  snappingly receives lateral integrally molded pins  370 A of trigger  368 . Integrally molded onto trigger  368  and extending upwardly are two elastic arms  369 , one on each lateral side thereof. Elastic arms  369  produce a biasing force and urge trigger  368  and the attached articulated push rod  360  towards the valve closed mode as illustrated in  FIG. 29A . Elastic arms  369  are engineered to support the weight of the push rod  360  such that no force is applied to elastomeric valve member  350  ( FIG. 29A ). Upon the operator squeezing the trigger  368 , elastic arms  369  yield thereby permitting counterclockwise rotation of trigger  368  about the pivot  370  with a resulting downward movement of the push rod  360 . Turning to  FIG. 29A , this action opens the solution release valve  340  causing gravitational flow of cleaning solution from the reservoir  334  to the tube  328 . Upon release of the trigger  368  ( FIG. 5 ), energy stored in the system returns the valve  340  to the closed mode. 
   As best illustrated in  FIG. 3A , removably positioned over the top support shelf  318  of the lower body shell  314  and top side of the front cover  311  is a cleaning solution supply tank  43 . As seen in  FIG. 29 , supply tank  43  basically comprises a deeply hollowed upper body  410  and a relatively planer bottom plate  412  which is adhesively secured, about its periphery, to the upper body  410 . The bottom plate  412  is provided with suitable recessed areas  413  and  415 . As seen in  FIG. 3A , these recessed areas  413 ,  415  ( FIG. 29 ) index upon and receive therein corresponding raised portions  313  and  315  on the top side of the front cover  311  of handle assembly  42 , when supply tank  43  is placed thereon. In effect, the raised portions  313 ,  315  and reservoir  320  support the supply tank  43 . A pair of recessed grip areas  476  formed on opposite sides of the outer wall of the upper body  410  have raised projections or bumps  478  formed thereon to aid in gripping the supply tank  43 . 
   Referring to  FIG. 29A , incorporated into bottom plate  412  of tank  43  is the supply valve  440  comprising valve seat  442  having an elongate plunger  444  extending coaxially upward therethrough. Plunger  444  having an outside diameter less than the inside diameter of valve seat  442  is provided with at least two flutes  446  ( FIG. 29 ) to maintain alignment of plunger  444  within valve seat  442  as plunger  444  axially translates therein and permits the passage of fluid therethrough when plunger  444  is in the open position. 
   An open frame housing  454  is located atop valve seat  442  having a vertically extending bore  456  slidingly receiving therein the upper shank portion of plunger  444 . An elastomeric circumferential seal  448  circumscribes plunger  444  for sealingly engaging valve seat  442 . Seal  448  is urged against valve seat  442  by action of compression spring  452 , circumscribing plunger  444 , and positioned between frame  454  and seal  448 . The supply valve  440  is normally in the closed position. However, as supply tank  43  is placed upon the support shelf  318  of handle  42 , pin  338  of the cleaning solution supply reservoir  320  aligns with plunger  444  and is received within flutes  446 , as best illustrated in  FIG. 29A , thereby forcing plunger  444 , upward compressing spring  452 , and opening valve seat  442  permitting cleaning solution to flow from the supply tank  43  into reservoir  320 . Upon removal of the supply tank  43  from support shelf  318  the energy stored within compression spring  452  closes valve seat  442 . A supply tank seal  480  ( FIG. 32 ) seals the supply valve  440  upon removal and placement of the supply tank  43  from the support shelf  318 . 
   Referring now to  FIG. 29 , located at the top of the supply tank  43  is a fill opening  416  through which the supply tank  43  may be conveniently filled with cleaning solution. To assure that the ambient pressure within the supply tank  43  remains equal to atmospheric, as cleaning solution is drawn from the supply tank  43 , an elastomeric umbrella valve  426  is provided in the top of cap  420  comprising a multiplicity of air breathing orifices. Referring to  FIG. 5 , as the ambient pressure within the supply tank  43  drops, by discharge of cleaning solution from therein, atmospheric pressure acting upon the top side of umbrella valve  426  causes the peripheral edge  428  to unseat from surface  432  of cap  420  thereby permitting the flow of atmospheric air into the supply tank  43  until the ambient pressure therein equals atmospheric. Once the pressure on both sides of the umbrella valve equalize, the energy stored by deflection of the umbrella valve causes the peripheral edge  428  ( FIG. 29 ) to reseat itself against surface  432  thereby preventing leakage of cleaning solution through orifices during operation of the extractor. 
   Referring to  FIG. 29 , cap  420  and flat circular seal  418  sealingly close fill is opening  416 . Cap  420  incorporates an inverted cup portion  422  which serves as a convenient measuring cup for mixing an appropriate amount of concentrated cleaning solution with water in tank  43 . When cap  420  is inverted and used as a measuring cup, liquid pressure against umbrella valve  426  further urges peripheral edge  428  against surface  432  ( FIG. 5 ) thereby providing a leak free container. Such an arrangement is similar to that disclosed in U.S. Pat. No. 5,500,977; the disclosure of which is incorporated by reference. 
   The solution supply tank  43  includes a tank securement latch  462  of approximately similar construction and function as that of the recovery tank to provide a convenient means for removably securing the supply tank from the cavity  468  ( FIG. 3A ) of the upper handle portion  312  ( FIG. 3A ). Specifically, a retaining housing or slot  458  is mounted to the inner side of the front wall  460  of the supply tank  43  for slidably receiving and retaining a spring-loaded latch  462 . A coiled spring  464 , positioned between the bottom of the retaining housing  458  and latch  462 , biases the latch  462  upwardly. Additionally, a u-shaped plastic spring  465 , integrally formed with latch  462  and extending downwardly from the bottom end of the latch  462 , aids in biasing the latch  462  upwardly. The upper end  466  of the latch  462  is beveled. 
   Thus with reference to  FIG. 3A , upon insertion of the supply tank  43  assembly into the cavity  468 , a downward extending rib  470  of the upper handle  312  just above the cavity  468  cams against the upper end  466  urging the latch  462  downward and thereby allowing the supply tank  43  to seat into the cavity  468 . Once past the rib  470 , the biasing force in the coiled spring  464  ( FIG. 29 ) will urge the latch  462  upwardly behind the edge  470  thereby locking the supply tank  43  within the cavity  468 . A lateral opening  472  formed in the inner side of the front wall  460  allows access to an arcuate laterally extending ledge  474  (also shown in  FIG. 29 ) integrally formed on the front of the latch  462  and positioned near the center of the opening  472  for placement of a thumb or finger of a user. To remove the supply tank  43  from the cavity  468  in the upper handle  321 , a user grasps the grip areas  476  with his fingers and pushes down on the ledge  474  of the latch  462  with his index finger until the upper end  466  of the latch  462  moves below the edge  470  to unlock the supply tank  43  from the cavity  468 . Using the grip areas  476 , the user then pulls the supply tank  43  out of the cavity  468 . Alternatively, the u-shaped plastic spring  465  could be designed to alone bias the latch  462  upwardly. 
     FIGS. 2A ,  30 A,  30 B,  30 C,  31 ,  31 A,  31 B, and  32  illustrate the brush lifting mechanism, which will be herein described. Referring to  FIGS. 2A ,  30 A,  30 B, a pair of hooks  710  integrally molded with the upper plate  250  of the distributor  246  extends from its upper surface  247 , as previously mentioned. The hooks  710  hang onto forwardly extending arms  714  integrally molded on a rod portion  716  of a brush lifting lever  718 . A ring member  719  is integrally molded on the rod portion  716  and extends rearwardly. The rod portion  716  is rotatingly positioned in a complimentary recess in the top portion of the frame  52  such that rotating the lever  718  clockwise when viewed from the left side raises the arms  714  and hence brush block assembly  216 , as seen in  FIG. 30A , and rotating the lever  718  counter clockwise lowers the arms  714  and brush block assembly  216  as seen in  FIG. 30B . 
   As best depicted in  FIG. 2A , integrally molded or attached to the upper surface  247  of the upper plate  250  are upwardly extending guide members  718  which, along with the arms  714 , slidingly interface with the frame  52  to guide and minimize lateral movement of the distributor  246  as it is raised and lowered, thereby preventing the hooks  710  from unhooking off the arms  714 . Inner upstanding walls  708  ( FIG. 17A ) of the frame  52  positioned outwardly adjacent the hooks  710  also aid in performing this function. A pocket portion  720  having an arcuately shaped bottom defining opposite front and rear gripping members  722 ,  724  slidably engages around to the rod portion  716 . 
   As depicted in  FIG. 31 , a transverse groove  726  is formed across the lower end of the rod portion  716 . The groove  726  slidably receives a tongue  728  integrally molded and extending rearwardly from the front gripping member  722  of the pocket portion  720 . When the brush block assembly  216  ( FIG. 30B ) is raised, the pocket portion  720  moves rearwardly so that the tongue  728  engages the front edge of the groove  726  to rotate the rod portion  716  clockwise (when viewed from the left side). This action moves the arms  714 , hooks  710 , and brush block assembly  216  upward as depicted in  FIG. 30B . To lower the brush block assembly  216 , the pocket portion  720  is moved forward, which allows the weight of the brush block assembly  216  to rotate the rod portion  720  counterclockwise and hence lower the brush block assembly  216  for scrubbing as depicted in  FIG. 30A . Hence, the rod portion  716  and tongue  726  are rotated in the position shown in  FIG. 31B . 
   When the nozzle assembly  62  is raised off the floor as depicted in  FIG. 18 , the brush assembly  216  is locked in its raised position, thereby prevented from being lowered. To accomplish this action as depicted in  FIG. 30C , a snap pin  149  extends through the ring member  719  and aperture  141  ( FIG. 23 ) of the upwardly extending arm  141  of the wheel carriage ( FIG. 23 ) pivotally securing them together. Thus, when the lifting lever  718  is raised with respect to the wheel carriage  136 , the arm  141  lowers the ring member  719  of the lifting lever  718 , thereby rotating the rod portion  716  clockwise and lifting the brush block assembly  216 . At this position as depicted in  FIG. 30C , the pin  149  holds down the ring member  719  preventing it from pivoting upwardly, and thereby preventing the brush block assembly  216  from lowering. At this position as depicted in  FIG. 31A , the pocket portion  720  is free to pivot forwardly, since the tongue  728  can slide along the length of the groove  726 . In effect, the cooperation of the tongue  728  and groove  726  acts as a lost motion mechanism to keep the brush block assembly raised and also to avoid stressing the wire portion  376  of the cable  730  in the event the pocket portion  720  is moved forward from, for example, a user sliding a brush slide button  762  ( FIG. 30B ) down to the wet scrub position as will be explained in further detail below. 
   As shown in  FIG. 2A , the cable  730  and related elements are used to move the pocket portion  720  forward and rearward to lower and raise the brush block assembly  216 , and in combination with a microswitch  534  ( FIG. 3A ) to energize and denergize the brush motor  508  ( FIG. 24 ) when the brush block assembly  216  is lowered and raised, respectively. In particular, a ball  732  at the lower end of the cable  730  is securely seated in the pocket portion  720  by a projection  734  ( FIG. 2C ) formed on the underside of the hood  172  ( FIG. 2C ) bearing against it. The cable  730  includes a Bowden-type wire portion  736  slidably received in a shell  738 . As depicted in  FIGS. 30A and 30B , the cable  730  is seated in a raised channel  740  formed in the upper surface of the upper portion of the frame  52  rearwardly adjacent the pocket portion  720  to minimize lateral movement of the cable  730 . 
   As depicted in  FIG. 32 , the cable  730  is routed to the lower body shell  314 , such that the wire portion  736  of the cable  730  extends into a cylindrical cap  742  and attaches to an upper enclosed end portion of the cap  742  by, for example, molding or die casting it to the cap  742 . The cylindrical cap  742  slidingly extends through an opening in the top support shelf  318  of the lower body shell  314  and through a coiled spring  746 . A washer  748  is inserted around the cap  742  and covers the spring  746 . An elastic e-shaped ring  749  is inserted into an annular groove formed circumferentially around the cap  742  just above the washer  748 , to keep the spring  746  from urging the washer  748  out the cap  742 . A rubber boot  752  mounted to the top support shelf  318  of the lower body shell  314  via mounting piece  754 , covers the cap  742 , spring  746 , washer  748  and ring member  719 , thereby sealing them from moisture. An articulated push rod  756  has a lower end  758  abutting the top  751  of the boot  752 . 
   The microswitch  534  is mounted in the lower body shell  314  inwardly adjacent the cap  742  below the top support shelf  318  via a switch cover  766  ( FIG. 3A ), capturing it in place. The microswitch  534  is electrically connected through the power switch assembly  682  ( FIG. 3A ) to the power supply (not shown) and to the power cord  552  ( FIG. 24 ) of the brush motor  508  ( FIG. 24 ) to energize and deenergize the motor  508 . An elastic lever arm  786  is snap connected to the microswitch  534  and abuts a spring-loaded push button  772  on the microswitch  534 . A roller  770  is rotatably connected at the distal end of the lever arm  768 . 
   Referring to  FIG. 33 , the slide button  762  slides up and down along an elongated groove  776  formed near the lower end of the handgrip  372  ( FIG. 3B ) to move the push rod  756 . In particular, the slide button  762  includes a pair of rearward depending outwardly flared legs  781  that slidingly receive opposite side edges of an inner frame  786  surrounding the groove and integrally formed with the upper handle  312 . A u-shaped spring  778  is fitted around and under rearward depending tabs  780  of the slide button  762 . The middle portion  782  of the u-shaped spring  778  bears against a lateral rear rib  788  of the slide button  762 . Upper and lower pairs of notches or detents  790 ,  792  are formed on opposite sides of the inner frame  786  for receiving complimentary outer offset portions  794  formed on opposite legs  796  of the u-shaped spring  778 . 
   Thus, pushing the slide button  762  down to its lower position with respect to the handle urges the offset portions  794  to seat into the lower pair of detents  792  and pushing the slide button  762  upwardly to its upper position urges the offset portions  794  to seat into the upper pair detents  790 . A nose member  784  is attached to the rear surface of the slide button  762  below the rib  788 . A laterally extending arm member  798  is integrally formed with the nose member  784  and pivotally snaps into a detent  774  ( FIG. 3B ) formed in the upper end  760  of the push rod  756 . Alternatively, as depicted in  FIG. 33A , the spring is supported and mounted to the slide button via a screw  783  inserted through a tab  787 , attached on the middle portion  782  of the spring  778 , and screwed to the rear side of the slide button  762 . 
   Thus, pushing down on the slide button  762  will move the push rod  756  downward which in turn pushes on the cap  752  moving it and the wire  736  of the cable  730  downwardly. This causes two actions. One being that the ball portion  732  moves the pocket portion  724  forward rotating the brush lifting lever  718  about a quarter turn counterclockwise thereby lowering the brush block assembly  216  as depicted in  FIG. 30B . The other being that the cap  742 , as seen in  FIG. 32A  cams against the roller  770  of the lever arm  768  of the microswitch  534 , moving the lever arm  768  such that it presses down on the push button  772  of a microswitch  534  to energize the brush motor  508  ( FIG. 24 ) and rotate the brushes  226  ( FIG. 19 ) for scrubbing. When the slide button  762  is slid back upwardly, the ball portion  732  moves rearward rotating the brush lifting lever  718  clockwise back a quarter turn thereby lifting the brush block assembly  716 . Also, as seen in  FIG. 32 , the cap  742  moves up away from the roller  770 , thereby releasing the lever arm  768  from pressing down on the push button  772  of the microswitch  534 . Thus, the brush motor  508  ( FIG. 24 ) is deenergized and the brushes  226  are not rotated when lifted. Alternatively, the unit could be designed to operate the brushes  226  when suction is not applied to the floor. 
   With reference to  FIG. 1 , to operate the hard floor cleaner unit  40  in the dry mode to vacuum dust, dirt and other particulates on the floor, the user depresses the right pedal  206  to lower the handle assembly  42 . In the event that the handle is already lowered, but the nozzle assembly  62  is lowered, the user depresses the left pedal to raise the nozzle assembly  62  off the floor. Then, the slide button  704  on the power switch assembly  682  is slid down to activate the suction motor assembly  632  ( FIG. 27 ) to provide suction. The user grasps the handgrip  372  and moves the hard floor cleaner unit  40  over the floor to clean it. After vacuuming the floor in the dry mode (or whenever vacuuming in the wet mode is desired), the user then depresses the left pedal  158  to lower the nozzle assembly  62  on the floor in contact with it in the wet mode to collect and pick up particles on the hard floor. 
   Referring to  FIG. 30B , if scrubbing of the floor is desired, the user slides the slide button  762  on the hand grip  372  downward to the on position which lowers the brush block assembly  216  on the floor and energizes the brush motor  508  ( FIG. 24 ) to rotate the brushes  226  ( FIG. 19 ) to scrub the floor. Squeezing the trigger  368  on the handgrip  372  distributes cleaning solution through the brushes  226  ( FIG. 19 ) and to the floor for cleaning. For hardwood floors, a cleaning solution specifically design to protect the wood can be used. It should be noted that the nozzle assembly  62  could be removed, as previously mentioned, if scrubbing of the floor is desired with no suction applied to it. Referring back to  FIG. 1 , after cleaning the hard floor, the user slides the slide button  704  of the power switch assembly  682  up to turn off the unit  40 . To store the unit  40 , the handle assembly  42  is pivoted in the upright position, which in turn raises the nozzle assembly  62  off the floor as depicted in the phantom lines of  FIG. 4 . 
     FIGS. 34 ,  35 ,  36 A,  36 B, and  37  illustrate another embodiment of the nozzle lifting mechanism and brush lifting mechanism for a hard floor cleaning unit  810 . Referring to  FIG. 34 , the cleaning unit  810  comprises an upright handle assembly  812  pivotally connected to the rear portion of a base assembly  814  that moves and cleans along a surface. The handle assembly  812  is generally similar to that of the previous embodiment except that the brush block assembly  816  ( FIG. 35 ) is activated and lifted by a foot pedal  818 L on the base assembly  814 , which will be further explained. As depicted in  FIG. 34A , the base assembly  810  includes a nozzle assembly  820  removably connected to the frame  822 , which is covered by a hood  827 . Rear wheels  824  are rotatably connected to axles  826  journaled into the frame  822 . Left and right pedals  818 L,  818 R include downward depending leg portions  860  that slidably engage vertical channels  858  formed in the side of the frame  822 . A brush block assembly  816  fits into a complimentary cavity  828  of the frame  822  rearwardly adjacent the nozzle assembly  820 . A distributor plate  830  is removably secured on the brush block assembly  816 . Attached to the front end of the distributor plate  830  is a lateral pin  832  extending forwardly. A pin  834  is also attached to the inside of the front wall  836  of the frame  822  and laterally extends rearward. 
   Referring to  FIG. 35 , a lever  838  is pivotally connected to the pin  834 . In particular, the pin  834  extends into a sleeve  840  formed in the lever  838 . The right end of the lever  838  defines a hook portion  842  that is positioned just under the pin  832  of the distributor plate  830 . A brush motor  846  with cover  847  is mounted to the underside of the frame  822  and includes a drive slot (not shown), which receives a drive shaft  883  ( FIG. 34A ) of the brush block  816  for driving the brushes  817  for rotation. A microswitch  844  is mounted to the inside of the front wall  836  of the frame  822  above the lever  838  and is electrically connected between a power source (not shown) and the brush motor  846 . In this position, the lever  838  is spaced from the spring-loaded push button  855  of a microswitch  844 , which is in a normally close circuit condition. 
   A shaft member  848  oriented perpendicular with respect to the lever  838  is rotatably connected to the cleaning unit  810 . A pair of front and rear ears  850 ,  852  are integrally formed on opposite ends of the shaft member  848  and extend inwardly. The front ear  850  bears upon the left end of the lever  838  and the rear ear  852  is positioned just under a forwardly extending projection  854  formed on a left pedal  818 L. The shaft member  848  extends through a torsion spring  856 , secured to the frame  822  that biases the ears  850 ,  852  upwardly. Depressing the left pedal  818 L downwardly will cause the projection  854  to cam on the rear ear  852  rotating it downwardly, thereby also causing the front ear  850  to rotate downwardly and cam down on the left portion  864  of the lever  838 . This action pivots the lever  838  clockwise thereby moving the hook portion  842  and brush block assembly  816  upwardly. In addition, the lever  838  presses the push button  855  on the microswitch  844 , which opens the circuit in the microswitch  844 , thereby breaking the electrical connection between the brush motor  846  and power supply. Hence, the brush motor  846  deenergizes and turns off the brush block assembly  816 . 
   Pushing the pedal  818 L again and then removing the pushing force moves the pedal  818 L upward such that the projection  854  moves away from the rear ear  852  of the shaft member  848 , thereby allowing the shaft member  848  to rotate the front ear  850  upwardly from the biasing force of the spring  856 . The upward rotation of the front ear  850  away from the left end of the lever  838  allows the right end of the lever  838  to pivot downward from the weight of the brush block assembly  816 , thereby lowering the brush block assembly  816 . The lever  838  then moves away from the push button  855  of the microswitch  844 , thereby closing the circuit in the microswitch  844 , which in turn energizes the brush motor  846  to rotate the brushes  817  on the brush block assembly  816  for scrubbing. Additionally with reference to  FIG. 34A , as a backup to the microswitch  844 , a second microswitch  843 , electrically connected between the power source and brush motor  846 , could be mounted on the cover  847  of brush motor  846  and positioned over the distributor plate  830  such that a raised portion  841  on the distributor presses the switch button  845  to open circuit and de-energize the brush motor  846  upon the brush block assembly  816  being raised. 
   Referring to  FIG. 36 , a mechanism for lifting the nozzle assembly  820  is disclosed. A wheel carriage  865  is pivotally connected to the underside of the frame  822 . In particular, a rear pair of trunnions  868  ( FIG. 34A ) located on opposite sides of the wheel carriage  865  journals through the frame  822 . A pair of wheels  870  is rotatably connected on opposite ends of a stationary axle  872  located on the front end of the wheel carriage  865  for supporting the frame  822 . An inverted u-shaped raised cam follower  890  is formed on the upper side of the axle  872  and rides along the bottom side of a slide block  866 . The slide block  866  is slidably mounted to the brush motor cover  847  by screws  874  extending through respective washers  876  and then into a pair of elongated longitudinal slots  878 . The washers  876  are secured to the screws, by for example, welding them thereto. The washers  876  radially extend beyond opposite longitudinal ends of the slots  878  to secure the slide block  866  to the motor cover  847 . Thus, the slide block  866  slides along the longitudinal axis of the slots  878 , yet is secured to the base assembly  814 . 
   A compression spring  880  is connected between the screw  874  closer to the right pedal  818 R and portion of the slide block  866  underneath the slot  878  further away from the right pedal  818 R. A ramp portion  867  is integrally formed on the bottom side of the slide block  866  and extends downwardly. An upwardly extending arm  882  is integrally molded on the left end of the slide block. The arm  882  is angled outwardly and is positioned under and inwardly extending projection  886  of the right pedal  818 R. The arm  882  includes a roller  884  rotatably connected to it at the upper end of the arm  882 . The projection  886  has a beveled edge  888  ( FIG. 34A ) formed on its bottom right corner. 
   When the nozzle assembly  820  is in the raised position, the ramp portion  867  abuts against the cam follower  890 , thereby raising the frame  822  ( FIG. 34A ) and hence nozzle assembly  820  ( FIG. 34A ) with respect to the wheel carriage  866  and floor. Upon depression of the right pedal  818 R, the beveled edge  888  ( FIG. 34A ) of the projection  886  cams against the roller  884  which causes the slide block  866  to move inwardly until the cam follower  890  moves away from the ramp portion  867 , thereby lowering the frame  822  ( FIG. 34A ) and nozzle assembly  820 . Upon depression of the pedal  818 R again, the projection  886  moves upwardly away from the arm  884 . This action allows the spring  880  to urge the slide block  866  to slide outwardly such that the cam follower  890  cams against the ramp portion  867 , thereby raising the frame  822  ( FIG. 34A ) and nozzle assembly  820  from the floor. Additionally, a raised stop member  885  ( FIG. 34A ) of the slide block  866  abuts against the distributor thereby raising the brush assembly  816  and preventing it from lowering. 
   Turning to  FIGS. 37A and 37B , the pedals  818 R,  818 L contain a push-push mechanism, which allows the right pedal  818 R to raise or lower the nozzle assembly ( FIG. 34A ) upon depression, and allows the left pedal  818 L to raise or lower the brush block assembly  816  ( FIG. 34A ) upon depression. Both the pedals and their push-push mechanisms are generally similar in design and function so only the left pedal  818 L and its push-push mechanism will be herein described. Thus, the elements described below for the left pedal  818 L and its push-push mechanism are also used for the right pedal  818 R and its push-push mechanism. The push-push type mechanism acts upon each of the pedals  818 R,  818 L to lock and unlock it when it is pushed. 
   In particular, a coiled spring  862  attached to the underside of the pedal  818 L depends downwardly and abuts a bottom ledge  898  of the frame  822 . A rotor  892  having first and second notches  894 ,  896  is rotatably connected to the portion of the side of the base assembly  916  between the channels  858 . When the pedal  818 L is depressed, an upper rib  900  on the pedal  818 L engages the first notch  894  to rotate the rotor  892 . The rotor  892  is rotated until a second notch  896  engages a bottom rib  902 . When the pedal  818 L is released, the coiled compression spring  862  moves the pedal  818 L up slightly so that the bottom rib  902  rotates the rotor  892  so that the upper rib  900  is aligned with the outer side of the rotor  892  between the notches  894 ,  896 . In this position as depicted in  37 B, the engagement of the bottom rib  902  with the second notch  894  prevents further rotation of the rotor  892  and thus locks the pedal  818 L. Depressing the pedal  818 L again moves the bottom rib  902  out of the way of the second notch  170  and causes the upper rib  900  to engage the outer side  904  of the rotor  892  rotating it such that the second notch  896  rotates past the bottom rib  902 . At this position, there is no interference to prevent the pedal  818 L from moving back to its original position. 
   Thus, upon releasing the pedal  818 L, the coiled compression spring  862  moves the pedal  818 L upwardly. It should be apparent that upon depressing the pedal  818 L again to raise either the nozzle assembly  820  or brush block assembly  816 , the upper rib  900  now engages the second notch  896  and the first notch  894  engages the upper rib  900  but in all other aspects the raising and lowering operation will be similar, since the notches  894 ,  896  are similarly shaped. 
     FIGS. 38 ,  39 A and  39 B illustrate still another embodiment of a nozzle lifting mechanism and a brush lifting mechanism on a hard floor cleaning unit  906 . Turning to  FIG. 38 , the cleaning unit  906  comprises an upright handle assembly  908  pivotally connected to the rear portion of a base assembly  916  that moves and cleans along a surface. Wheels  922  are rotatably connected to the base assembly  916 . The handle assembly  908  includes a recovery tank  910  removably mounted in a complementary cavity. A latch  912  releasably locks the recovery tank  910  to the handle assembly  908 . A supply tank  914  is removably mounted to the handle assembly  908  and located rearwardly adjacent the recovery tank  910 . The base assembly  916  includes a nozzle assembly  918  connected to the frame  822  and fluidly connected to the recovery tank  910  via a central duct  924  attached thereto. A brush assembly  926  is secured to the base assembly  916  rearwardly adjacent the nozzle assembly  918 . The base assembly  916  further includes a hood or cover  919  covering it. As is commonly known, cleaning liquid from the supply tank  914  is distributed onto the floor and scrubbed thereon by the brush assembly  926 . A suitable suction source (not shown) draws the dirt and/or cleaning liquid from the floor through the nozzle assembly  918  and into the recovery tank  910 . 
   As depicted in  FIGS. 39A and 39B , a pair of right and left lever arms  928 ,  930  are attached to the nozzle assembly  918  and extend rearward. The right lever arm  928  is located outwardly adjacent the right side of the frame  920  and pivotally connected to the frame  920 . The left lever arm  930  is located inwardly adjacent the left side of the frame  920  and pivotally connected to frame  920 . The pivotal connections allow the nozzle assembly  918  to raise and lower. A right pedal  932 R is pivotally connected to an axle  934  journaled into the frame  920 . The right pedal  932 R has a top portion  936  that extends rearward and a bottom portion  938  that bears against the top surface of the rear portion  940  of the right lever arm  928 . Thus, when the top portion  936  of the pedal  932 R is depressed, the bottom portion  938  rotates and cams against the rear portion  940  of the right lever arm  928  causing it to pivot downwardly, thereby raising the nozzle assembly  918 . Referring to FIG.  39 B, a brush assembly  926  is secured to the frame  920  and is located rearwardly adjacent the nozzle assembly  918 . A pair of right and left lever arms  942 ,  944  is attached to the brush assembly  926  and extends rearward. 
   The right lever arm  942  is located inwardly adjacent the right side of the frame  920  and pivotally connected to the frame  920 . The left lever arm  944  is located outwardly adjacent the left side of the frame  920  and pivotally connected to it. The pivotal connections allow the brush assembly  926  to raise and lower. A left pedal  932 L is pivotally connected to the axle  934 . The left pedal  932 L has a top portion  946  that extends rearward and a bottom portion  948  that bears against the top surface of the rear portion  954  of the left lever arm  944 . Thus, when the top portion  946  of the left pedal  932 L is depressed, the bottom portion  948  rotates and cams against the rear portion  954  of the left lever arm  944  causing it to pivot downwardly, thereby raising the brush assembly  926 . The right side of the frame  920  includes an inwardly extending stop projection  950  that overlies the right lever arm  928  of the brush assembly  926  that limits the upward movement of the brush assembly  926 . 
   The present invention has been described by way of example using the illustrated embodiment. Upon reviewing the detailed description and the appended drawings, various modifications and variations of the preferred embodiment will become apparent to one of ordinary skill in the art. All such obvious modifications and variations are intended to be included in the scope of the present invention and of the claims appended hereto. 
   In view of the above, it is intended that the present invention not be limited by the preceding disclosure of a preferred embodiment, but rather be limited only by the appended claims.