Abstract:
A mounting assembly for rotatably mounting a surface processing tool holder on at least one motor driven rotatable arm of a surface processing apparatus, such that the tool can spin freely as the arm is driven by the motor, includes an elongate shank having a smooth surfaced, cylindrical portion intermediate its ends adapted for positioning within an aperture in the tool holder with one threaded end portion projecting through the aperture for attachment to an elongate mounting bar adapted for attachment to the arm. A bearing supported by the tool body and surrounding the smooth surfaced portion of the shank is rotatable relative to the shank. The mounting bar includes a threaded aperture for receiving the threaded end portion of the shank and the threaded aperture includes a counterbore for receiving the end portion of the smooth surfaced shank portion which is adjacent the threaded end portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a non-provisional application based upon U.S. provisional applications Ser. No. 60/961,862, filed Jul. 25, 2007, now pending, and Ser. No. 61/065,954, filed Feb. 16, 2008, now pending. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to surface processing machines for mounting surface processing tools and, more particularly, to mounting means for rotatably mounting circular brushes on the arms of motor driven spider arm assemblies of such machines. 
     BACKGROUND OF THE INVENTION 
     Typically, when large area concrete floors are installed, they may be surface finished, e.g., texturized, cleaned, prepared for subsequent application of a penetrating sealer or other substance, using a surface processing machine, such as conventional walk behind floor polishing-type machines  20  comprising a gas or electric engine  22 , a handle  24  for machine control and steering and a circular rotating brush  26  driven by engine  22 , as shown in  FIG. 1 . Such machines have a typical finished area per revolution of less than 20 square feet. When it is appreciated that large warehouse floors may be hundreds of thousands of square feet, it can be seen that performing a finishing operation on large area floors using walk behind type brush machines will either take a very long time or require many operators and machines. 
     It is known that during the installation of concrete floors, the troweling and finishing operation is performed on the wet concrete using either walk-behind or ride-on power trowels. Inasmuch as at least one type of power trowel machine is generally already on site during the installation of concrete floors, the present invention seeks to use the on-site availability of these machines for surface finishing purposes. In addition, generally, concrete contractors do not have floor polishing machines on site and typically do not own such machines. Therefore, where conventional floor polishing machines are used to surface finish concrete surfaces, concrete contractors have to invest in and own or lease separate, expensive pieces of equipment. 
     In one of its forms, the present invention takes advantage of the larger finished area attainable with ride-on power trowel machines by converting these power trowel machines to surface finishing machines suitable for tasks other than troweling. Ride-on power trowel machines typically range in size from approximately 6 feet to slightly more than 10 feet in width and produce a troweled area of up to 40 square feet. The largest units weigh more than a ton and can finish about 30,000 square feet per day. Ride on trowels, such as the trowel machine illustrated in  FIG. 2 , can be configured with two or more rotors, each having a plurality of radially oriented, spaced-apart arms and a trowel blade mounted on each arm. The blades on adjacent rotors may be overlapping or non-overlapping. A typical four arm spider assembly suitable for use with either a ride-on or walk-behind power trowel is illustrated in  FIG. 3 . The assembly includes four radially extending arms emanating from a central hub, which receives a drive shaft. A trowel blade is mounted directly via bolts or indirectly via a mounting bar on each of the arms. Concrete surface processing machines having spider assemblies for non-rotatably mounting trowel blades, and the manner of attachment of the trowel blades to the spider arms are discussed in detail in U.S. Pat. No. 7,059,801—Snyder et al, the disclosure of which is incorporated herein by reference. Another means for rotatably mounting surface processing tools to spider arms is disclosed in U.S. Pat. No. 4,319,434—Brecha. 
     Converting walk-behind or ride-on troweling machines to surface finishing machines involves providing mounting means which allows the rapid, on-site substitution of finishing tools, such as circular brushes, on the spider arms in place of the trowel blades which were used during the installation of the concrete floor. The mounting means of the present invention has the advantage that it can mount surface processing tools, such as scrubbing, brushing, buffing, grinding and polishing tools, on the spider arms using readily available hand tools in a very short period of time without need for heavy or expensive equipment. The surface finishing tools are mounted to each of the spider arms, desirably using a mounting bar, in such a way that, as the spider arms rotate about the hub, each of the surface polishing tools, e.g., circular brushes, on each arm is free to spin about a mounting axis perpendicular to the spider arms and parallel to the axis of rotation of the spider arms. By allowing circular brushes to rotate freely about the axis, the brushes will wear more uniformly than if they were rigidly mounted to the arms. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a walk behind floor polishing type machine. 
         FIG. 2  is a perspective view of a ride-on power trowel. 
         FIG. 3  is a top perspective view of a four arm rotor assembly mounting four trowel blades and suitable for use with ride-on surface processing machines of the present invention. 
         FIG. 4  is a bottom perspective view of a circular brush assembly showing a portion of the mounting means of a first embodiment of the present invention installed thereon. 
         FIG. 5  is a top perspective view of a circular brush assembly showing a portion of the mounting means of a first embodiment of the present invention installed thereon. 
         FIG. 6  is a top plan view of a circular brush assembly showing a portion of the mounting means of a first embodiment of the present invention installed thereon. 
         FIG. 7  is a partial sectional view taken along line A-A in  FIG. 6 . 
         FIG. 8  is a bottom perspective view of a circular brush assembly showing a portion of the mounting means of a second embodiment of the present invention installed thereon. 
         FIG. 9  is a top perspective view of a circular brush assembly showing a portion of the mounting means of a second embodiment of the present invention installed thereon. 
         FIG. 10  is another top perspective view of a circular brush assembly showing the components of the mounting means of a second embodiment of the present invention. 
         FIG. 11  is a partial sectional view taken along line B-B in  FIG. 9 . 
     
    
    
     SUMMARY OF THE INVENTION 
     It is, therefore, a primary object of the present invention to provide a mounting adapter for surface processing tools which allows their use on conventional power trowel machines having spider assembly arms. 
     It is another object of the present invention to provide a mounting adapter which allows advantage to be taken of the presence at a concrete floor construction site of high square footage capacity power trowel machines for surface processing purposes. 
     It is still another object of the present invention to provide a mounting adapter which allows the rapid, on-site substitution of surface processing tools on spider arms in place of the trowel blades used during concrete floor installation. 
     It is yet another object of the present invention to provide a mounting adapter for surface processing tools on spider assemblies which allows the surface processing tools to spin freely about their axes while the spider arms are rotatably driven in order to encourage more uniform wear of the tools and a longer useful life. 
     It is another object of the present invention to provide a mounting adapter which greatly increases the strength of the attachment between the mounting shank and the mounting bar and between the mounting bar and the spider arm. 
     The foregoing and other objects are achieved in accordance with the present invention by providing a mounting assembly for rotatably mounting a tool holding means comprising a tool holder body having first and second surfaces, a surface processing tool mounted on said first surface and an aperture extending through said second surface, on at least one motor driven rotatable arm of a surface processing apparatus, on an axis substantially parallel to the axis of rotation of said motor driven arm, whereby said surface processing tool can spin freely about its axis as said arm is rotatably driven by said motor, said mounting assembly comprising:
         elongate shank means including an elongate smooth surfaced, generally cylindrical shank portion intermediate the ends of said shank means, said shank means adapted for positioning within said aperture with one end projecting through said second surface of said tool holder body;   bearing means supported by said second surface of said tool body and surrounding said smooth surfaced portion of said shank means;   elongate mounting means adapted for attachment to said arm, said one end of said elongate shank means including means for non-rotatable attachment to said mounting means;   said bearing means being rotatable relative to said shank means for rotatably mounting said surface processing tool, whereby said surface processing tool can spin freely about its axis.       

     In accordance with one aspect of the invention, the elongate mounting means includes a threaded aperture for receiving the threaded end portion of the shank means within the threaded aperture and the threaded aperture includes a counterbore for receiving the end portion of the smooth surfaced portion which is adjacent the threaded end portion. 
     In accordance with another aspect of the invention, the bearing means includes first and second relatively rotatable, concentric hubs, the first hub being supported by the second surface of the tool holder body such that the bearing means is concentric with the aperture therein, the first hub has a first central bore, the second hub has a second central bore concentric with the first central bore and is mounted within the first central bore and the elongate shank means extends through the second central bore with the threaded end portion of the shank and the end portion of the smooth surfaced portion which is adjacent the threaded end portion projecting from the second central bore and received by the threaded and counterbored aperture in the mounting means. 
     In accordance with still another aspect of the invention, the bearing means comprises a hollow cylindrical, elongate sleeve having an outside diameter smaller than the diameter of the aperture in the tool holding means and a circular flange extending radially outwardly from the periphery of one end of the sleeve for maintaining the sleeve within the aperture and the elongate shank means extends through the sleeve with the threaded end portion of the shank and the end portion of the smooth surfaced portion which is adjacent the threaded end portion projecting from the sleeve and received by the threaded and counterbored aperture in the mounting means. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 2  there is shown a conventional ride-on power trowel  10  comprising an operator seating and control station  12 , an engine  14 , at least two downwardly projecting rotor or spider assemblies  16 , each assembly having a plurality of radially extending, spaced-apart arms and a trowel blade mounted on each arm for providing at least two sets of horizontal rotating blades encircled by a guard ring cage  18 . A typical four arm spider assembly  30 , suitable for use with either a ride-on or walk-behind power trowel, is illustrated in  FIG. 3 . The assembly includes four radially extending arms  32  emanating from a central hub  34 , which receives a drive shaft (not shown). A trowel blade  36  is mounted via bolts  38  on each trowel arm  32 . It will be appreciated that each rotor assembly may contain more or less than four arms for mounting trowel blades thereon, the number of arms being a matter of design choice. 
     It will also be appreciated that although the mounting means of the present invention will be described herein with reference to ride-on surface processing machines due to the unique advantage they offer in terms of square feet of concrete which can be finished per day, the mounting means can, of course, be used with walk-behind surface processing machines which also conventionally use downwardly projecting rotor or spider assemblies for mounting trowel blades. A typical walk-behind surface processing machine mounting trowel blades for finishing wet concrete is illustrated in FIG. 2 of the aforementioned U.S. Pat. No. 7,059,801. 
     The mounting means of the present invention will be described herein with reference to circular brushes; however, it will be appreciated that the mounting means can, of course, be used with other surface processing tools, such as scrubbers, buffers, grinders, polishers, and the like. Referring to  FIGS. 4-7  there is shown a circular brush assembly  50  including a circular bristle brush  52  in the form of a ring having a hollow center  54  mounted to or with the bristles extending from the underside  56   a  of a brush cover plate  56 , which has an upper surface  56   b  which may be flat or slightly convex. Cover plate  56  includes a central aperture  58  for receiving a mounting shank  60  therethrough. Shank  60  includes a head  62  at one end  64 , a smooth surfaced, generally cylindrical shank portion  66  extending from head  62  to a point intermediate the ends of the shank  60  and a threaded portion  68  extending from the end of the smooth shank portion  66  to the end  70  of the shank opposite the shank head  62 . A brush assembly  50  is mounted to one of the arms  32  of a spider assembly  30  by first mounting the brush assembly to a mounting means  72 , such as an elongate mounting bar, which itself is mounted to the arm  32  of the spider assembly  30 . Brush assembly  50  is mounted to mounting means  72  in a manner which allows brush assembly  50  to spin freely on its axis, as will be seen from the following description. 
     Initially a rotary bearing  80  is mounted, e.g., via bolts  74  and nuts  76 , on the upper surface  56   b  of brush cover plate  56  and positioned thereon such that bearing  80  is concentric with central aperture  58 . Bearing  80  may be any type of bearing, e.g., ball bearing, roller bearing, fluid bearing, magnetic bearing, etc., which will permit each of the brushes  52  on each arm  32  to spin freely about its mounting axis perpendicular to the arms. In a preferred embodiment, bearing  80  includes a stationary hub  82  having a central bore  83 , which is mounted to the brush cover plate upper surface  56   b , a rotating hub  84  having a central bore  85  mounted within the central bore  83  of stationary hub  82  and fluid bearing means  86  sealed within bearing  80  and between hubs  82 ,  84  to facilitate concentric rotation of the hubs about a common axis, which is the central axis  59  of central aperture  58 . A threaded, radially extending lubrication port (not shown) is desirably formed in stationary hub  82  to facilitate the injection of lubricant, when required. The lubrication port is closed by a grease port through which the lubricant may be injected. 
     With bearing  80  bolted in place on the upper surface  56   b , end  70  of mounting shank  60  is inserted into the central aperture  58  of cover plate  56  from the brush side of cover plate  56  and extends through central bore  85  of rotating hub  84  with threaded portion  68  and the upper end portion of smooth cylindrical shank portion  66  emerging from the central bore  85 . The diameter of shank head  62  approximates the diameter of central aperture  58  but is slightly smaller so that the portion of head  62  which remains within central aperture  58  when shank  60  is fully inserted within rotating hub  82  does not frictionally engage the side walls of central aperture  58  as brush assembly  50  spins on mounting shank  60 . Cylindrical shank portion  66  has a smaller diameter than shank head  62  to define an annular shoulder  63  therebetween which seats against the underside of rotating hub  84  when mounting shank  60  is fully inserted therewithin. Cylindrical shank portion  66  has a diameter which allows central aperture  58  of brush assembly  50  to rotate freely about shank head  62  with just enough play to allow bearing  80  to absorb forces encountered during use, such as brush  52  striking bumps on the floor or brush cover plate  56  impacting with walls, and the like. The threaded portion  68  projecting from rotating hub  84  is threaded into central threaded aperture  90  in mounting bar  72 , which includes a counterbore  90   a  to receive upper end portion  66   a  of smooth cylindrical shank portion  66 . In this manner, mounting shank  60  is firmly seated between the underside of rotating hub  84  and mounting bar  72 . By having end portion  66   a  extend into counterbore  90   a , the strength of the connection between mounting shank  60  and mounting bar  72  is greatly increased. 
     Shank  60  is so dimensioned that, when thus mounted, the smooth portion  66  of mounting shank  60  is rotationally closely adjacent the inner diameter of rotating hub  84  and the brush assembly  50  is securely mounted on mounting bar  72 , yet is free to spin on the axis provided by mounting shank  60 . A recessed aperture  88 , such as a hexagonal aperture, is formed in end  64  of mounting shank  60  to facilitate threading mounting bar  72  onto threaded portion  68  of shank  60 . 
     Additional apertures  92  are provided in mounting bar  72  for attaching the brush assembly  50  to the rotor arms of the power trowel using at least two bolts, which extend through the rotor arms and are received in apertures  92 . An advantage of the present mounting adapter is that, by virtue of mounting bar  72 , it permits the brush assembly  50  to be attached to the arms  32  of spider assembly  30  using multiple bolts to provide added strength and reduce wear at the area of greatest operational stress. In addition, inasmuch as the mounting adapter of the present invention will be used with spider assemblies of many different manufacturers, the mounting bar  72  serves as a readily interchangeable interface between the mounting adapter and the spider assembly and can be readily altered to suit the configuration and bolt hole locations of the spider assembly. It will be appreciated that the mounting means need not be a mounting bar, but can be any well known mounting means, such as a channel. 
     Referring to  FIGS. 8-11  there is shown a second embodiment of the mounting adapter of the present invention. Features common to each of the embodiments are designated by the same reference numerals. Circular brush assembly  50  includes a circular bristle brush  52  in the form of a ring having a hollow center  54  mounted to or with the bristles extending from the underside  56   a  of a brush cover plate  56 , which may be flat or slightly convex. Cover plate  56  includes a central aperture  58  for receiving a mounting shank  60  therethrough. Shank  60  includes a head  62  at one end  64 , a smooth surfaced, generally cylindrical shank portion  66  extending from head  62  to a point intermediate the ends of the shank  60  and a threaded portion  68  extending from the end of the smooth shank portion  64  to the end  70  of the shank opposite the shank head  62 . A brush assembly  50  is mounted to one of the arms  32  of a spider assembly  30  by first mounting the brush assembly to a mounting means  72 , such as an elongate mounting bar, which itself is mounted to the arm  32  of the spider assembly  30 . Brush assembly  50  is mounted to mounting means  72  in a manner which allows brush assembly  50  to spin freely on its axis, as will be seen from the following description. 
     Initially a hollow cylindrical sleeve  100  is inserted through the central aperture  58  of cover plate  56  toward the hollow center  54  of brush assembly  50 . One end of sleeve  100  has a circular flange  102  extending radially outwardly from the sleeve periphery to define a collar which seats upon the top side  56   b  of brush cover plate  56 , to prevent the sleeve  100  from falling through aperture  58 , while the cylindrical length of sleeve  100  extends into central aperture  58  toward the hollow center  54  of brush assembly  50 . Mounting shank  60  is inserted into sleeve  100  from the brush side of cover plate  56  with shank head  62  overlying the end of sleeve  100  at the underside  56   a  of brush cover plate  56 . The threaded portion  68  and the upper end portion  66   a  of smooth cylindrical shank portion  66  emerge from the collared end of sleeve  100 . The threaded portion  68  projecting from sleeve  100  is threaded into central threaded aperture  90  in mounting bar  72 , which includes a counterbore  90   a  to receive upper end portion  66   a  of smooth cylindrical shank portion  66 . By having end portion  66   a  extend into the counterbore  90   a , the strength of the connection between mounting shank  60  and mounting bar  72  is greatly increased. 
     Shank  60  is so dimensioned that, when thus mounted, the smooth portion  66  of mounting shank  60  is rotationally closely adjacent the inner diameter of sleeve  100  and the brush assembly is securely mounted on mounting bar  72 , yet is free to spin on the axis provided by mounting shank  60 . Desirably, with the brush assembly  50  securely threaded into aperture  90  of mounting bar  72 , the length of the mounting shank between the underside of shank head  62  and the surface of mounting bar  72  adjacent the top side  56   b  of cover plate  56  is about 1/16 inch longer than the length of sleeve  100  to provide the free space S necessary for brush assembly  50  to be able to freely spin about mounting shank  60 . 
     As with the first embodiment, additional apertures  92  are provided in mounting bar  72  for attaching the brush assembly  50  to the rotor arms of the power trowel using at least two bolts, which extend through the rotor arms and are received in apertures  92 . An advantage of the present mounting adapter is that, by virtue of mounting bar  72 , it permits the brush assembly  50  be attached to the arms  32  of spider assembly  30  using multiple bolts to provide added strength and reduce wear at the area of greatest operational stress. In addition, inasmuch as the mounting adapter of the present invention will be used with spider assemblies of many different manufacturers, the mounting bar  72  serves as a readily interchangeable interface between the mounting adapter and the spider assembly and can be readily altered to suit the configuration and bolt hole locations of the spider assembly. It will be appreciated that the mounting means need not be a mounting bar, but can be any well known mounting means, such as a channel. 
     While the present invention has been described in terms of specific embodiments thereof, it will be understood that no limitations are intended to the details of construction or design other than as defined in the appended claims.