Abstract:
Disclosed are improvements to a high speed power buffer assembly provided with a dust evacuation system. The assembly includes a hood depending from the chassis to encircle the high speed rotating buffer pad, a peripheral skirt depended from the chassis, a dust collection aperture adjacent the buffer penetrating the hood for the outlet of dust to the exterior of the hood, a curved dust collector chute, aligned and in communication with the dust collection aperture, and a dust collection bag, communicated with the dust collector output. The skirt has inclined grooves to co-act with the buffer pad to entrain air from the outside of the skirt to the inside. Given the arrangement of the foregoing features, the dust evacuation system can operate without the use of a vacuum pump.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation application of, and claims benefit of and priority to, U.S. patent application Ser. No. 13/927,997, filed Jun. 26, 2013, the disclosure of which is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to high speed buffer assemblies utilized for large polished floor surfaces, such as those found in super markets and other retail establishments. 
         [0003]    Large polished floor surfaces are the standard for the modern retail environment. For both appearance and cleanliness, these surfaces are waxed and buffed. In the modern store environment, relatively large (from one-half to three feet in diameter), high speed buffer assemblies are utilized. 
         [0004]    The standard construction of these buffer assemblies is relatively straightforward. They usually include a chassis mounted over a set of wheels, the chassis carrying a motor for driving a disc shaped buffer pad. The buffer pads depend from the chassis for polishing the floor. A hood is mounted to the chassis and depends over the high speed rotating buffer pad when polishing a surface. This hood encircles the buffer pad and serves to prevent the rotating buffer pad from coming in contact with anything above or to the side of the buffer pad. Use of these buffer assemblies, where the floors are first swept and/or mopped, and thereafter waxed and buffed, results in a clean and inviting floor in a store or room. 
         [0005]    Unfortunately, such buffing is far from dust free. The large buffing pads, rotating in the order of 2,000 revolutions per minute, dislodge dust from the polishing surface during operation. If not contained, this dust is expelled out from under the hood edges at the sides of the rotating buffer pad where it escapes the hood. Such dust dislodgment and escape is especially aggravated when the buffing pad, during polishing, comes in contact with irregularities in the surface being polished, such as a seam in the flooring. 
         [0006]    Further, the dust that dislodges and escapes is particularly unpleasent. Typically, it is of extremely small particle size—slightly larger than one micron—and when escping is centrifugally thrown outward of the buffer during the high speed buffing operation. 
         [0007]    Left uncontained, this dust dislodgment and escape represents a serious problem. Dust from buffing which is thrown outward at high speed, billows upwardly from the buffing site, and settles everywhere, including high surfaces that are relatively removed from the floor surface being polished. Further, and while the dust is airborne, it is often near the nose and mouth of workers operating the buffer apparatus. Consequently, it can constitutes a health hazard due to the possibility of inhalation. 
         [0008]    Attempts to solve this problem have included depending skirts to confine dust flow to within the hood suspended over and around the rotating buffer. While these skirts enhance confinement of the dust, they still allow some dust to escape from the buffer assembly. Many buffer assemblies combine the buffer pad with a vacuum dust evacuator. Such evacuators either rely on air entrained by the rotating buffer and have independently powered vacuum apparatus to capture the dust by venting air from under the protective hood to collection bags. 
         [0009]    Further, the vacuum only systems which merely communicate to the hood are not able to draw sufficient vacuum; the rotating air entrained by the high speed rotating buffer simply bypasses the vacuum inlet given its configuration. In the past, attempts to allow the rotating buffer to supply the total dust evacuation action were insufficient; dust was still broadcast at the periphery of the buffing pad, out from under the hood or skirt. The present invention improves upon the systems of the past and is able to supply the total dust evacuation action by the rotating buffer given the configuration of the features disclosed herein. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    A high speed power buffer assembly is provided with a dust evacuation system. The assembly has a chassis for movement along a directed path over a surface to be polished, a motor mounted to the chassis, and a high speed polishing buffer pad depending from said chassis the buffer pad being driven by the motor in rotating contact with the floor along a preselected direction of rotation. The dust evacuation system includes a hood depending from the chassis to encircle the high speed rotating buffer pad, a peripheral skirt depended from the chassis immediate the periphery of the hood, a dust collection aperture adjacent the buffer pad penetrating the hood for the outlet of dust from inside said hood to the exterior of the hood, the aperture having an inlet on the inside of the hood and an outlet on the outside of the hood, a dust collector output, aligned and in communication with the dust collection aperture output on the outside of the hood, and a dust collection bag, communicated with the dust collector output. The skirt, at the extremity adjacent the surface to be polished has grooves inclined with respect to the radial direction of rotation of the buffer pad to slant from outside of the skirt to the inside of the skirt in the direction of buffer disc rotation to co-act with the buffer pad when rotating to entrain air from the outside of the skirt to the inside of the skirt. The dust collection aperture inlet is defined by a first end, a second end, a first side and a second side, where the first end is wider than the second end. Given the arrangement of the foregoing features the dust evacuation system can operate without the use of a vacuum pump. 
         [0011]    The peripheral skirt depends from a hood overlying the high speed rotating buffer pad. This skirt, at the extremity adjacent the surface to be polished, is supplied with angularly inclined grooves sloped away from the radial disposition with respect to the buffer pad. These angularly inclined grooves slope from the outside of the skirt to the inside of the skirt in the direction of buffer pad rotation at the buffer pad periphery and are maintained by the telescoping skirt immediately adjacent the surface being polished. Entrained air is drawn at the surface being polished in the direction of buffer disc rotation from the outside of the skirt to the inside of the skirt through the slanting louvers establishing a buffer dust confining boundary at the depending peripheral skirt immediately adjacent the floor. In some embodiments, a skirt lip seal attaches to the skirt at its bottom where the skirt would otherwise be directly adjacent to the surface being polished. The skirt lip seal further aids in establishing the buffer dust confining boundary preventing entrained air from escaping the skirt and hood, to the outside, and maximizing the amount of entrained air retained within the skirt and hood. 
         [0012]    Overlying the buffer pad, the hood defines an internal cavity which encircles the rotating buffer. The hood has a collection aperture, which during operation, channels the entrained air within the hood and skirt to outside the hood to a chute. The collection aperture is located in and penetrates the side wall of hood. The aperture shape is defined by four sides, a first end, second end, and two sides. The first end is wider than the second end. The first end is located first in the rotational direction with respect to the second end and the two sides connect the first and second ends. This results in the aperture tapering in the rotational direction. This tapering aids in channeling and accelerating the entrained air out of the hood through the aperture to the outside of the hood where it is further directed to chute discuss in further detail below. 
         [0013]    In some embodiments, a deflector is utilized on the second end of the aperture. Additionally, sidewalls, arising from each of the two sides, extend into the hood cavity. The deflector and sidewalls further aid in collecting and channeling the entrained air through the aperture. 
         [0014]    At the exterior of the hood and aligned with the aperture, a chute is provided. This chute, at the end which aligns with the aperture, has an inlet geometry which matches the aperture. The chute tapers as it protrudes away from the hood. Its shape, at the end opposite the aperture, the chute outlet, is configured to mate with a hose connected to a collection bag or a vacuum pump. 
         [0015]    A dust collector vacuum can communicate with the dust collection chute and thereby, with the aperture on the outside of the hood, drawing suction through the dust collection aperture. The vacuum outputs, under positive pressure, to a paper micro filter bag having the capability of collecting particles in the order of one micron. 
         [0016]    In operation, air at the skirt is provided with a positive boundary which inhibits scattering dust or debris particles as the buffer passes over a floor surface being polished. This boundary is enhanced by the inclusion of the skirt lip seal. Dust contaminated air, under the hood and skirt, is entrained and rotates under the protective hood. The air encountering such rotation enters into the hood cavity, encountering the deflector and sidewalls of the aperture, when it is then channeled through the aperture under positive pressure out to the dust collector chute. The air dust combination then travels to the communicated collection bag or dust vacuum. This dust contaminated air is discharged under positive pressure through to the dust collecting micro filter air bag for substantial and improved dust free operation of the buffer assembly. 
         [0017]    Thus, the skirt with the angled cuts allow air to flow in an inward direction to the underside of the hood body. This establishes a dust containment boundary between the surface being polished on the inside of the hood and remainder of the floor surface on the exterior of the hood. The skirt lip seal improves the efficacy of this boundary resulting in superior dust contamination collection. 
         [0018]    During operation the buffer pad turning at high speed inside the hood and depending skirt, causes this inward flow of air to flow around under the protective hood toward the aperture. 
         [0019]    The improved aperture, including the deflectors on its end and two sides, catches the air and entrained dust and directs it out of the hood into the chute and into the collection bag or vacuum. Such redirection occurs under a positive pressure produced by the rotating buffer pad directing air through the aperture and then the chute. 
         [0020]    A connected commercially available collection bag is utilized having the ability to trap particles down to a dimension of one micron. This bag effectively collects the dust and keeps it in the bag, not allowing particles larger than one micron from flowing back into the air adjacent the buffing site. 
         [0021]    For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the embodiments of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    Other objects, features and advantages of this invention will be more apparent after referring to the following description and attached drawings in which: 
           [0023]      FIG. 1  is a perspective view of the high speed buffer of this invention; 
           [0024]      FIG. 2  is an inverted view of the buffer hood illustrating the hood shape and showing the aperture and deflectors; 
           [0025]      FIG. 3  is a top view of the buffer hood illustrating the hood shape and showing the aperture outlet and exterior curved chute; 
           [0026]      FIG. 4  is an inverted view of a portion of the hood assembled into the chassis without the skirt showing the aperture and chute details; 
           [0027]      FIG. 5  is an inverted view of the hood assembled into the chassis without the skirt as seen from the rear of the high speed buffer; 
           [0028]      FIG. 6  is a perspective view of the hood component assembled into the chassis. 
           [0029]      FIG. 7  is a view of the underside of the chassis showing the assembly of the hood component into the chassis and showing the aperture chute; 
           [0030]      FIG. 8  is a side perspective view of the hood component assembled into the chassis with the skirt and skirt seal; and, 
           [0031]      FIG. 9  is a front perspective view of the hood component assembled into the chassis with the skirt and skirt seal. 
           [0032]      FIG. 10  is an inverted view of the hood assembled into the chassis showing the buffer pad. 
           [0033]      FIG. 11  is an inverted view of the hood and skirt assembled into the chassis showing a partial buffer pad and the direction of circulation of the buffer pad as well as the airflow travel and evacuation of airflow from under the hood. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    Vacuum buffer assemblies of the prior art include a chassis connected to a hood over a rotating buffer pad and a skirt depending from said hood, where the skirt has louvers at intervals circumventing the skirt at the side of the skirt which interfaces with the surface to be polished. These particular prior art buffers were problematic in that dust was not fully contained and vacuum pumps were required to draw the dust captured under the hood out to a collection bag. Other Vacuum buffers of the prior art, utilized slanted louvers relative to the direction of the rotation of the buffer pad, to draw air in through the louvers and entrain an air and dust combination under the hood and then out through an aperture to a collection bag. These prior art vacuum buffers operate to entrain combined air and dust under the hood and direct it through an aperture and chute under positive pressure to a collection vacuum eliminating the requirement for a vacuum pump to pull the dust out from under the hood. These prior art buffers however exhibited vacuum loss and dust leakage given their configuration. One such prior art vacuum buffer is disclosed in U.S. Pat. No. 5,388,305, the full disclosure of which is hereby incorporated herein by reference. 
         [0035]    This disclosure is directed toward various improvements to the vacuum buffer assembly of the &#39;305 patent. These improvements include: improved sealing of air and dust inside the vacuum hood and skirt by way of a skirt lip seal, enhanced egress of the air and dust combination from the vacuum buffer hood area to the collection bag by way of an improved chute geometry, enhanced operation of the vacuum buffer given the combination of the skirt lip seal and the geometry of the hood including elimination of skirt mounting slots that allowed for dust leakage and would easily bind when damaged, and the improved collection aperture and curved chute enabling the vacuum buffer to collect and remove the dust and air combination without the necessity for running an external vacuum pump for ordinary buffing operations. Coincidently, the present invention can also use a vacuum pump in heavier buffing modes but still benefits from the enhanced sealing and egress of the air dust combination from within the hood. As compared to the &#39;305 vacuum buffer, this arrangement significantly enhances flow conditions under the hood and further minimizes egress of the dust and air combination from the machine at and around the hood  40 . 
         [0036]    Referring to  FIG. 1 , the high-speed buffer assembly  2  according to the embodiments of the invention is illustrated. It includes a chassis  4  mounted on wheels  16  for transport over a floor to be polished. The chassis  4  extends from over the wheels to over a high speed buffer pad  20 . Powered motor  6  drives the buffer pad  20 . Buffer pad  20  rotates and polishes the floor under hood  40 , which is under the chassis  4 . Simultaneously, motor  6 , in certain modes, may power vacuum apparatus  10  which can exhaust accumulated dust from buffing to paper bag filter  14 . Skirt  30  depends from the portion of the chassis  4 , which extends over the buffer  20 . 
         [0037]    Skirt  30  is mounted to the chassis  4  by flexible tabs  90 . The skirt  30  is capable of moving towards and away from the floor as buffer pad  20  passes in polishing rotation over the floor. Skirt  30  contains louvers  32  at the bottom skirt edge  36 , which is the skirt edge nearest the polishing surface. The configuration of these louvers  32  with respect to the periphery of rotating buffer pad  20  enables dust confinement as will be discussed in greater detail below. In one embodiment the skirt  30  has a skirt lip seal  34  attached to the bottom skirt edge  36 . The lip skirt seal  34  is u-shaped in cross section and covers the lower skirt edge  36  circumferentially around all or substantially the entire skirt diameter, extending a distance up the face of the skirt  30  partially covering louvers  32 . This skirt lip seal  34  enhances the skirt&#39;s ability to confine dust inside the skirt  30  and hood  40 . In addition to providing a better seal, the lip seal skirt  34  restrains and protects the ends of the louvers so that the louvers don&#39;t break or flex. 
         [0038]    Skirt  30  constitutes a flexible strip fixed to the chassis  4  by tabs  90 . Fastening may occur by way of rivets, which affix the tabs  90  to the chassis  4  at one end  92  of the tabs  90  and to the skirt  30  at the other end  94  of the tabs  90 . In addition to rivets, alternative means for attaching the tabs  90  to the Skirt  30  may include such fastening means as velcro, tape, screws and other similar fasteners, among other things. This flexible strip allows for multi-directional movement and flexibility of the skirt as it floats over the polishing surface by way of skirt lip seal  34  allowing for rotational, as well as horizontal and vertical movement of the skirt  30  about the hood  40  preventing binding of the skirt itself or the skirt attachment means. These flexible strips eliminate problems with prior art buffers where a bolt and slot attachment was utilized only allowing for vertical movement of the skirt along the hood in the direction of the slot length. In such prior art buffers the bolts would bend when hitting objects during operation, binding skirt  30  and effectively preventing skirt  30  from self-adjusting with floor irregularities, thus causing vacuum loss and dust to escape from under skirt  30 . Additionally, the slots themselves allowed for vacuum and dust leakage from the hood  40  reducing efficiency of the apparatus. While  FIG. 9  shows five tabs  90 , more or less tabs may be used as necessary. 
         [0039]    Louvers  32  are placed at intervals around skirt  30  adjacent the floor. Preferably, the louvers  32  have intervals between them in the order of less than two inches. As illustrated louvers  32  slant relative to the direction of rotation of buffer pad  20  at an angle of 45° but angles ranging from 30° to 60° will suffice. This slant, in some embodiments, is such that it is not possible to obtain a line-of-sight view radially from the center of rotation of buffer pad  20  through the louvers  32  to the exterior of skirt  30 . Along with the rotation of the Buffer pad  20 , the slant of the louvers  32  create inward suction of air and dust at skirt  30 . 
         [0040]    The hood  40  is attached to the chassis  4  by way of a plurality of common bolt/nut type fasteners  44  which penetrate through the top surface of the hood  46  and the chassis itself In  FIG. 10 , hood  40  is illustrated inverted and buffer pad  20  is shown inside the interior cavity of the hood  40 . In  FIGS. 2-4  hood  40  is illustrated inverted and buffer pad  20  is not shown so that the interior cavity configuration of the hood  40  can be seen. As can be seen, a raised portion  68  can be seen in depending radial sidewalls of the hood  40 , which is the result of two differing diameters of the hood radial sidewalls. Screw mount  78  connects the buffer pad  20  to motor  6 , protrudes through an opening  80  in the center of the upper interior surface of the hood  40 . The top interior surface of the hood  40  as shown is generally flat and a set distance above the buffer pad  20  whereby the distance between the top side of buffer pad  20  and the top interior surface of hood  40  remains essentially constant. 
         [0041]    During buffing, rapidly rotating objects will entrain air adjacent their respective surfaces and thus the high speed buffer pad  20  entrains air and dust under the hood  40  and within the skirt  30 , causing air to rapidly rotate under protective hood  40  in the direction of buffer pad rotation  22 . 
         [0042]    Utilizing this phenomenon, to collect the dust and air entrained within the hood, a dust collection aperture  50  is located in the depending radial sidewalls of the hood  40 . The aperture  50  has a first end  52  and a second end  54 , a first side  56  and a second side  58 . The first end  52  of the aperture  50  is wider than the second end  54  of the aperture  50 . The collection aperture  50  is located adjacent the buffer pad  20  extending through to the exterior of hood  40  through a downward depending radial wall of hood  40 . This configuration causes evacuating dust and air to accelerate as it exits the hood  40  through the aperture  50 , aiding in the vacuum affect created by the rotationally created entrained air within the skirt  30  and hood  40 . The configuration of louvers  32  in skirt  30  at the periphery of hood  40 , the raised portion  68  of hood  40  and a collection aperture  50  cooperate to maximally capture centrifugally thrust out dust particles as illustrated in  FIG. 11  and direct the air and dust out through the collection aperture  50 . 
         [0043]    A deflector  60  is located at the distal second end  54  of the aperture  50 . The deflector  60  extends inward from the hood  40 , and in the embodiment shown, the deflector is angled opposite the rotational direction of buffer pad  20  so as to maximize trapping and redirecting of air and dust being entrained by the buffer pad  20  and deflect the air dust combination through the aperture  50  to exit the hood  40 . A first sidewall  62  and second sidewall  64  further assist in redirecting airflow from the edges of the hood where the speed of the airflow is at a maximum, and similarly where maximum dust particles collect, into the converging aperture  50 , to a chute  70  and then toward the inlet of the discharge exhaust. 
         [0044]    As can be seen in  FIGS. 3 and 7 , at the exterior of the hood  40  and aligned with the aperture  50  which penetrates hood  40 , the chute  70  is connected with the exterior of hood  40 . This chute  70 , at the end  72  that aligns with the aperture  50 , has geometry that matches the aperture  50  geometry. The chute  70  converges as it protrudes away from the hood  40  to a shape, which can mate with a collection bag or vacuum hose or other connection at its outlet  76 . As shown here, the shape of the chute outlet  76  is cylindrical to mate with a round hose. The chute&#39;s second end is configured to communicate with a dust collection bag  14 . For compactness, in the embodiment described and shown, the chute  70  is located below the chassis  4  and between the wheels  16 . The chute  70  has a smooth curved bend  74 , which efficiently directs air through the chute outlet  76  upwardly where it connects with a hose. This curved bend  74  allows for minimal internal turbulence, and thus least vacuum and operational losses of the dust/air transportation through the chute  70 . Because the chute  70  extends from the hood  40  at the outlet of the collection aperture  50  in a direction generally horizontal to the floor, the bend  74 , efficiently redirects the dust and air traveling from hood  40 , outward then upward to a vacuum hose or the collection bag  14 . The chute  70  can also connect directly to a vacuum inlet. 
         [0045]    Given the combination of the louvers  32 , skirt lip seal  34 , the collection aperture  50  and the chute  70  geometry, use of a vacuum pump is not required for egress of dust through the collection aperture  50  and the skirt lip seal  34  is able to prevent escape of the dust from under skirt edge  36  without a vacuum pump. Under heavier buffing modes, a vacuum pump may be used to assist with egress of the dust and air combination from the hood  40  and through the collection aperture  50 . This vacuum assist when operated draws power from the motor shaft which drives the buffer pad  20  and can be run by various different powering means including propane, battery or off of electricity by way of an electrical cord, among others. 
         [0046]    When performing the heavy buffing operations heavy particles are created, such as when buffing cement as opposed to lighter operations which create lighter particles such as polishing wood and polymer floors and both the rotation of buffer pad  20  and the vacuum  10  cooperate to remove dust through dust collection aperture  50 , the dust is extremely fine-going down to a particle size in the range of 1 micron. As such, the vacuum  10  usually exhausts to a paper filter for screening out particles having a dimension greater than 1 micron. As a relatively high pressure is required for this type of filtering and buffering, the interaction of the air impelled by buffer pad  20  in coordination with vacuum pump  10  provides the greater vacuum suction typically necessary for this particularly type of buffing. 
         [0047]    As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. Many other embodiments are possible without deviating from the spirit and scope of the invention. These other embodiments are intended to be included within the scope of the present invention, which is set forth in the following claims.