Patent Document

CROSS-REFERENCES TO RELATED APPLICATIONS 
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     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK 
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     This invention relates to automatic scrubbers commonly used for cleaning the large floor area of modern markets and stores. More particularly, a vacuum pre-sweeping system for an automatic floor scrubber is disclosed which can easily be attached to extant scrubbers and utilized for vacuuming and sweeping to eliminate dry mopping in advance of scrubbing. A suspension system is disclosed which allows for up-and-down excursion of the vacuum sweeper system as well as movement of the system to an upward position when vacuuming and sweeping is not required. 
     BACKGROUND OF THE INVENTION 
     Modern supermarkets and stores contain large polished opened flooring in ranges from 40,000 square feet to 120,000 square feet and above. Typically, these floors are tile covered and polished or burnished with a finish that shines and gives the store a safe, clean appearance. 
     To maintain such floors, a four-step process is required by the prior art. First, the floor is typically dry dust mopped to clear the floor of large debris and dust. Second, the floor is scrubbed, usually with an automatic scrubber. The automatic scrubber dispenses detergent onto the floor, scrubs, and thereafter squeegees and vacuums the detergent from the floor. After the scrubbing step, the floor is polished or burnished with a buffer. Finally, after the polishing or burnishing, the floor is again dust mopped to pick up fine debris left in the wake of the polishing or burnishing operation. 
     Each of these discrete steps consumes time and labor. For example, utilizing machinery having a 27-inch-wide path, dry mopping can consume five minutes per thousand square feet of floor per employee. Likewise, scrubbing can consume seven minutes per thousand square feet of floor per employee. Similarly, polishing or burnishing can consume seven minutes per thousand square feet of floor per employee. Finally, the final mopping after burnishing or polishing can consume five minutes per thousand square feet per employee. Thus, 1000 square feet of floor can require up to 24 minutes per thousand square feet of employee time during regular scrubbing and polishing cycles. 
     It is to be noted that the above description of labor does not include so-called “double scrub” and “strip” cycles. In these latter cycles, the scrubber first dispenses detergent, scrubs with the detergent, and then leaves the detergent to dwell on the floor for a specific period of time. Thereafter, scrubbing is repeated with the detergent being gathered and recovered by the scrubber. Between the respective scrubbings, dry mopping is not utilized. 
     In Fields U.S. Pat. No. 5,388,305 issued Feb. 14, 1995, I have combined the polishing and burnishing cycle with the second dry mopping cycle. Simply stated, I disclose a polishing and vacuuming apparatus having a revolving head surrounded by a skirt which biases to and towards the floor. The skirt is provided with a series of serrated slits angularly inclined with respect to the rotating polishing and burnishing brush. The slits draw air from the exterior of the burnishing apparatus through the skirt into the interior of the burnishing apparatus at the skirt. Thereafter, by providing the combination of a deflector and a vacuum apparatus, I gather to a micro filter vacuum bag the dust and debris generated by the polishing and burnishing operation. This improvement to the polishing and burnishing operation has experienced commercial success and eliminated approximately five minutes of labor per thousand square feet of floor maintained assuming 27-inch-wide polishing equipment is used. 
     To date, there has been no equivalent improvement to the wet scrubbing operation. 
     Automated floor sweepers are known. In one such sweeper, counter-rotating conical brushes are used on the sweeper ends. These brushes each rotate about vertical axes at opposite sides of the sweeper. Sweeping of the counter-rotating brushes occurs at a central ramp which typically is maintained a small constant distance above the floor. In some cases, a large cylindrical brush rotating about a horizontal axis in front of the debris ramp cooperates with the counter-rotating conical brushes to sweep large debris up the ramp and into a collector. No vacuuming provision is made for the collection of dust. 
     Unfortunately, it is my experience that such sweepers are inadequate when utilized immediately before a scrubbing operation. Specifically, they are successful in collecting the large debris only and constitute a separate operation adding additional labor. They also lack the ability to collect fine particles and dust. Uncollected fine particles and dust give a “mud like” appearance to the floor in the wake of the wet scrubbing apparatus and constitute a serious degradation to the floor maintenance cycle. As a consequence, conventional dry mopping is almost always used before a floor scrubbing operation. 
     There have been attempts to combine the dry mopping, scrubbing, and polishing and burnishing operation. Machines making such combinations have at least three problems. First, where the machines are battery operated, conventional battery operation has difficulty in simultaneously powering the sweeping, scrubbing, and polishing apparatus. In order to enable these three steps to be simultaneously powered from the same battery pack, machines of reduced width are required. As of this disclosure, combined sweeping, scrubbing, and polishing and/or burnishing machines have a width which does not exceed 20 inches due to the energy required to run sweeping, scrubbing, and polishing and/or burnishing operations simultaneously. 
     Second, such machines are long with all three components in a straight line, one after the other. They do not operate efficiently on sharp turns such as those required to pass around the counter ends between aisles. A separate maneuver is required to align such machines for each pass down the floor aisles between the counters. Wasted time and energy results. 
     Third, polishing and burnishing directly after scrubbing requires additional time. Since such machines are series machines, they can proceed at a speed no greater than the efficiency of the slowest component. In this case, it is the slow polishing cycle immediately after wet scrubbing the floor. For example, and utilizing a 20-inch machine, polishing and burnishing immediately after scrubbing results in the polishing and burnishing operation occurring on a semi dry surface. This semi dry surface can require up to 15 minutes per thousand square feet per employee with such a machine. The efficiency originally sought in the combined pre-sweeping, scrubbing and polishing and/or burnishing is not realized. 
     BRIEF SUMMARY OF THE INVENTION 
     A vacuum sweeper is cantilevered to a hinged bracket mounted to the front of a conventional automatic floor scrubber. The sweeper includes a central vacuum head, an overlying central debris ramp, and two vertically rotating, conical brushes having their base ends in contact with the floor. The base end of the conical brushes sweep a path at the edge of the vacuum sweeper in excess of the width of the scrubber. This enables sweeping to the edges of floor-standing counters at their inset kick plates. The base end of each of the conical brushes rotates large debris to and toward the ramp overlying the vacuum entrance to sweep the large debris up the ramp and into a following drawer mounted hopper. The base end of each of the conical brushes rotates small debris, such as dust, into the vacuum head on the underside of the ramp. The vacuum head is mounted between the counter-rotating conical brushes and defines a small gap over the floor being swept and vacuumed on the order of ⅜ of an inch. The rear and sides of the vacuum head are enclosed by substantially airtight bristle walls which slide over the floor surface behind the gap. Immediately adjacent to the gap, paired rollers support the forward lip to maintain the small gap at the leading edge of the vacuum head. When a vacuum is pulled upon the vacuum head, the energy of the vacuum is confined to and concentrated at the gap at the leading edge of the vacuum head. This produces a concentration of vacuum energy at the gap for the removal of small debris, such as dust. The entire vacuum sweeper apparatus is mounted for vertical excursion relative to the cantilevered mount to the hinge bracket to enable up and down excursion of the sweeper and vacuum responsive to either scrubber motion or inevitable floor irregularities encountered during floor scrubbing. Where vacuuming is not required in advance of scrubbing, such as during double scrubbing or floor stripping cycles, provision is made to hinge the vacuum sweeper upwardly away from floor engagement. 
     As can be seen, I disclose a vacuum sweeper process and apparatus for use immediately before scrubbing. By combining vacuum sweeping with the scrubbing apparatus and process, I effectively eliminate the dust mopping step prior to scrubbing to achieve a superior time-saving result by combining the vacuum pre-sweeping with the scrubbing. Additionally, by isolating vacuum sweeping and scrubbing to one apparatus, and maintaining polishing and burnishing with fine particle vacuum gathering to a second apparatus, I affect an overall 40 percent saving in the conventional four step floor maintenance cycle. Each apparatus processes approximately 1000 square feet of floor area every seven minutes utilizing an apparatus having a 27 inch width. Thus, utilizing the floor cleaning apparatus of my Fields U.S. Pat. No. 5,388,305 issued Feb. 14, 1995 and the disclosed apparatus herein, I can reduce what was a 24 minutes cycle per thousand square feet per employee to a 14 minutes cycle per thousand square feet per employee for an overall labor saving in the order of 40 percent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a conventional floor scrubber having the vacuum sweeper of this disclosure mounted and hinged at the forward end of the scrubber for sweeping and vacuuming the floor in the path of the scrubber; 
         FIG. 2  is a top plan view of the vacuum sweeper illustrating the counter-rotating conical brushes at either side of the central vacuum head, the central vacuum head, the overlying large debris ramp, and the attached vacuum apparatus for receiving fine debris from the vacuum; 
         FIG. 3  is a bottom plan view of the vacuum sweeper illustrating the conical base of the counter-rotating brushes, the bottom of this central vacuum head, the wheels for supporting the leading edge of the central vacuum head overlying the floor to define a measured gap with respect to the floor for concentrating vacuum intake through the gap, and the peripheral surrounding bristle wall for forming the support point of the central vacuum head relative to the floor; and, 
         FIG. 4  is a schematic side elevation section taken along lines  4 — 4  of  FIG. 3  illustrating gathering of large debris to the overlying debris ramp and vacuuming of small debris to the central vacuum head. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , automatic scrubber  1  is shown having vacuum sweeper  2  mounted at the forward end of scrubber  1 . The normal direction of scrubber movement proceeds from the left of  FIG. 1  to the right of  FIG. 1  so that vacuum sweeper  2  sweeps the floor in advance of scrubber  1 . 
     Automatic scrubber  1  is typical of scrubbers common to the marketplace. It includes a foreword rotating scrubbing brush  11  which is suspended from the main scrubber body. A medial propelling wheel  12  drives and supports automatic scrubber  1  as it is propelled along the floor. Rear supporting casters  14  in effect pivot automatic scrubber  1  about the medial propelling wheel  12 . Finally, there is a detergent removing squeegee  15  suspended at the rear of the scrubber  1 . Automatic scrubber  1  dispenses detergent, scrubs the floor utilizing the detergent, and recovers the used detergent by squeeging and vacuuming the detergent from the floor. 
     It will be understood that scrubbing brush  11  must be shielded. Specifically, if left unobstructed as viewed in  FIG. 1 , considerable splatter of dispensed detergent would occur from the floor scrubbing operation. It is common to provide a shielding skirt around the periphery of the scrubber—especially in the vicinity of scrubbing brush(s)  11  to prevent such splatter. Further, such a skirt is virtually required between the pre-sweeping vacuuming attachment here disclosed and the scrubbing brush  11 . As all such automatic scrubbers are supplied with these skirts, they will not be shown here in the interests of letting the reader understand the suspension and operation of the automatic scrubber here disclosed. 
     In the case of the vacuum sweeper  2 , I prefer to place a squeegee  15   a  between vacuum sweeper  2  and scrubber  1 . This assures that vacuum sweeping occurs in a dry environment. 
     Ignoring for the moment the operation of vacuum sweeper  2 , the conventional operation of automatic scrubber  1  is easy to understand. Automatic scrubber  1  is propelled from left to right in  FIG. 1 . Detergent tank  16  supplies detergent at rotating scrubbing brush  11 . Scrubbing brush effects scrubbing of the floor. The scrubber is propelled so that detergent removing squeegee  15  squeegees and vacuums detergent and scrubbed debris to detergent recovery tank  17 . Automatic scrubber  1  here shown is operated by an operator from operator station  18 , who walks behind the scrubber and guides it. 
     Automatic scrubber  1  will be understood to be exemplary of commercial scrubbers that are now extant. From the description given thus far, two important points can be made about automatic scrubber  1  and the mounting of vacuum sweeper  2  at the forward end of the scrubber. First, the scrubber will inevitably pass over floor irregularities. Such irregularities will cause the front portion of the scrubber  1 , especially at a mounted vacuum sweeper  2  to move up and down. Second, automatic scrubber  1  will tend to pivot on medial propelling wheel  12 . In such pivoting, vacuum sweeper  2  will again tend to move up and down. As will be hereinafter set forth, vacuum sweeper  2  is mounted to the front of automatic scrubber  1  so that such up-and-down movement can be accommodated without lifting the vacuum sweeper  2  from the floor. Preferably, vacuum sweeper  2  is biased to and towards the floor to maintain a firm sweeping and vacuuming contact with the floor. 
     Referring to  FIG. 2 , vacuum sweeper  2  is illustrated in plan. Here, vacuum sweeper  2  includes paired counter-rotating conical brushes  21 . The reader will of course understand that while two such brushes are preferred, only one conical brush  21  is required for the practice of this invention. 
     Rotating conical brushes  21  have a vertical axis of brush rotation  22 . The brushes rotate from a shaft attached to the truncated apex of the conical brush  23 . The rotating conical brushes  21  extend downwardly to an expanded base of conical brush  24  which is in contact with the floor. Conical brushes  21  are mounted to vacuum sweeper body  25 . Brush motors  26  cause the conical brushes  21  to counter-rotate with respect to one another. In the view of  FIG. 2 , left brush  21  rotates counterclockwise while right brush  21  rotates clockwise. This rotation occurs while vacuum sweeper  2  attached to automatic scrubber  1  proceeds downwardly to and towards the floor to be swept and vacuumed as shown in  FIG. 2 . It will be noted that central vacuum head  4  is located between counter-rotating conical brushes  21 . The rotation of brushes  21  serves to sweep debris into this central vacuum head  4  for accumulation to collection container  29  by suction of vacuum apparatus  27 . 
     Continuing with the view of  FIG. 2 , vacuum sweeper body  25  supports vacuum apparatus  27 . Vacuum collection container  29  contains a micro filter bag  28  for accumulating the debris fines in advance of the vacuum sweeper  2 . The micro filter bag  28  is confined within the vacuum collection container  29 . 
     Referring to  FIG. 2 , vacuum sweeper mounting bracket  3  (See  FIG. 1 ) is shown mounted to the front end of automatic scrubber  1  at mounting bracket  31 . Hinge  32  is placed between vacuum sweeper body  25  and bracket  31 . This enables vacuum sweeper  2  to either be placed in confrontation to the floor or to be moved to a pivoted position up and away from the floor, preferably at 90 degrees with respect to the position of the vacuum sweeper  2  illustrated in  FIG. 1 . 
     Referring to  FIG. 4 , vacuum head  4  can be seen in detail. With respect to the floor, vacuum head  4  has a top central shell  44  covering the top of the vacuum head. This top central shell  44  is communicated at opening  45  to vacuum apparatus  27 . Thus, fine debris drawn centrally of central vacuum head  4  will end up in micro filter bag  28  of vacuum apparatus  27 . 
     Support of central vacuum head  4  relative to the floor occurs at peripheral wall  41 . Preferably, peripheral wall  41  is made from a soft, pliable floor contacting material. Here, the soft floor contacting material constitutes a continuous U-shaped bristle brush which forms the peripheral wall. This bristle brush has a thickness and density so that a conformable, substantially airtight barrier is formed as the brush slides over the flooring. Peripheral wall  41  surrounds central vacuum head  4  along the rear and at the sides. The peripheral wall  41  terminates at gap  46 . Finally, floor contacting members  43 , here shown as wheels, suspend central vacuum head  4  at a constant elevation relative to the floor in the vicinity of gap  46 . This defines a constant spatial gap, the function of which can be understood with respect to  FIG. 4 . 
     I provide a second gap  46  defined by vacuum head partition  47 . This divides vacuum head  4  into a rear suction chamber  44  which communicates directly to opening  45  to having micro filter bag  28  in vacuum apparatus  27 . The provision of second gap  46  assures concentration of the vacuum energy at the rear of vacuum head  4  to effect efficient removal of vacuumed fines with minimum supplied vacuum. 
     Referring to  FIG. 4 , a section of vacuum head  4  taken along lines  4 — 4  of  FIG. 3  is shown. Specifically, despite variations in the level of the floor, it will be seen that floor contacting members  43  support central vacuum head  4  with gap  46  supported at a constant distance from the floor surface. With this support, the suction of vacuum apparatus  27  is maximized in the gap  46  between the vacuum head  4  and the floor. This assures that debris fines will be gathered to the vacuum head  4 . As a practical matter I have found that any separation of vacuum head  4  from the floor surface destroys the effectiveness of the vacuuming that I desire. 
     Referring further to  FIG. 4 , the function of large debris accumulator  5  can be understood. Large debris ramp  51  is shown immediately overlying vacuum head  4 . Large debris ramp  51  empties at the top to large debris bin  52 . Large debris bin  52  has a large debris bin opening  53 . The large debris bin  52  is drawer mounted to the underside or rear of vacuum sweeper body  25 . This arrangement enables the large debris bin to be selectively removed and emptied when filled. 
     It is easy to understand filling of the large debris bin  52  with respect to  FIG. 4 . Specifically, rotating conical brushes  21  advance and rotate all debris, large and small, to and towards central vacuum head  4  and overlying large debris ramp  51 . Debris fines, which seriously interfere with the scrubbing process, are accumulated by the vacuum apparatus  27  to the micro filter bag  28 . At the same time, larger debris particles are swept up large debris ramp  51  into large debris bin  52  by the rotation of the rotating conical brushes  21 . Large debris particles such as wrappers, paper scraps, small sticks, and other debris are rapidly accumulated within large debris bin  52 . It will be noticed that at least some of the bristles protruding at the expanded base of conical brush  24  partially climb large debris ramp  51  assuring propulsion of the large debris particles up the ramp and into the waiting bin. Other brushes may be used for this require propulsion. 
     Finally, with respect to  FIG. 4 , it will be remembered that automatic scrubber  1  in the vicinity of vacuum sweeper  2  undertakes considerable excursion with respect to the floor. This excursion arises because of variations in floor height as well as natural rocking of scrubber  1 . This being the case, vertical bias suspension  6  is provided between vacuum sweeper body  25  and vacuum sweeper head  4 . Specifically, a series of rods  61  gravitationally suspends vacuum sweeper head  4  with respect to vacuum sweeper mounting attached to vacuum sweeper body  25 . As either the floor height varies or automatic scrubber  1  rocks, vacuum sweeper head  4  will remain in the same firm contact with the floor. As a result, consistent sweeping and vacuuming will result. It is preferred to have coil springs  63  biasing vacuum sweeper body  25  to and toward the floor. 
     The reader will understand that the above preferred embodiment can vary within wide limits. For example only one rotating conical brush  21  is required. Further, although a vertical axis of brush rotation is preferred, axes other than vertical may be used as well. For example, cylindrical brushes could be used as well. Further, while we show a conical brush, other brush shapes could be used as well. We illustrate a vacuum sweeper body  25 ; this body could take any form including joining some or all of the operative parts of vacuum sweeper  2  together. It will be understood that the vacuum sweeper mounting bracket  3  will change form to accommodate any portion of automatic scrubber  1  and any particular model of automatic scrubber  1  to which mounting is required. Further, while hinge  32  is preferred, it is not required. For example, the vacuum sweeper  2  could merely be elevated on rods  61 . 
     I prefer a vacuum sweeper retainer  33  to retain vacuum sweeper  2  from the horizontal position where vacuuming and sweeping is not required, especially during certain portions of double scrubbing and the floor stripping. Sweeper retainer  33  can take many forms. Here it is illustrated as a strap. Alternately, it could either be a mechanical lever, cable, solenoid apparatus, electric actuator, or of many formats to move vacuum sweeper  2  relative to hinge  32  on vacuum sweeper mounting bracket  3 . 
     Likewise it will be understood that central vacuum head  4  will admit of change. While the construction utilizing the gap  46 , peripheral wall  41 , and floor contacting member  43  is preferred, other vacuum heads incorporated with rotating conical brushes  21  will suffice. For example, where high horsepower vacuuming devices are used, the care taken with respect to gap  46  can be compromised. Further, while I illustrate floor contacting members in the form of wheels, slides, guides, pads, and others supporting members could as well be used. 
     It will be understood that the large debris accumulator  5  is not a requirement of this invention. I concentrate on collecting the fine debris in order to prevent the phenomenon of “mud” in the wake of scrubber  1 . It will be understood that the entire scrubbing process could proceed without the specific collection of large debris by the vacuum sweeper  2 . 
     Other variations can occur to accommodate specific circumstance.

Technology Category: 1