Abstract:
An apparatus for abrading a surface is provided. The apparatus includes: a framework with a motor housed therein; a chassis housing a drivetrain, the drivetrain including a drive pulley operative connected to the motor, a plurality of tool assembly pulleys, a belt operatively connecting the drive pulley and the plurality of tool assembly pulleys; a plurality of tool assemblies operatively connected to the drive pulley and the plurality of tool assembly pulleys, each tool assembly including: a tool holder, a tool plate comprising a tool segment with an abrading surface, wherein the tool holder and tool plate are detachably connected by a plurality of equidistantly spaced pins, wherein the number of pins is a multiple of three.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 14/373,514 (published as US 2015/0328739) filed 21 Jul. 2014, which is a national phase application of PCT international application number PCT/CA2013/000049 (published as WO/2013/106917) filed 21 Jan. 2013, which claims priority to U.S. provisional patent application No. 61/588,635 filed 12 Jan. 2012, all of which are incorporated by reference in the entirety herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to construction tools. In particular, the present invention relates to an apparatus for resurfacing through abrasion. 
       BACKGROUND 
       [0003]    It is common for home and business owners, developers, and renovators to wish to renew a horizontal surface such as a floor, deck, patio or other indoor or outdoor surface. One means of performing such renewal is to abrade the upper surface of the existing material to provide a newly revealed, cleaner surface, or to prepare the surface for installation thereon of another surface material. 
         [0004]    Various abrading apparatus for performing surface abrasion are well known in the prior art. Such prior art apparatus, however, have several drawbacks. Some are limited in the type of power supply they may employ. Others leave undesirable tooling marks in the surface, or fail to abrade the surface sufficiently close to adjoining walls. Still others may overheat and require frequent cooling periods, or may be difficult to service. Others are larger and heavier and making mobility between floors of a building difficult or even impossible. 
         [0005]    There is a general desire for apparatus that overcomes one or more of the above-discussed drawbacks. 
         [0006]    The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
       SUMMARY 
       [0007]    The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
         [0008]    One aspect of the invention provides an apparatus for abrading a surface comprising: a framework with a motor housed therein; a chassis housing a drivetrain, the drivetrain comprising: a drive pulley operative connected to the motor; a plurality of tool assembly pulleys; a belt operatively connecting the drive pulley and the plurality of tool assembly pulleys; a plurality of tool assemblies operatively connected to the drive pulley and the plurality of tool assembly pulleys, each tool assembly comprising: a tool holder; a tool plate comprising a tool segment with an abrading surface; wherein the tool holder and tool plate are detachably connected by a plurality of equidistantly spaced pins, wherein the number of pins is a multiple of three. 
         [0009]    The belt may operatively connect the drive pulley and the plurality of tool assembly pulleys, and the plurality of tool assembly pulleys are configured in an array, whereby lateral or longitudinal displacement of the chassis across the surface to be abraded results in a path of any one tool assembly rotating in one direction to be at least partially overlapped by a path of at least one other tool assembly rotating in the opposite direction. Or, the belt may operatively connect the drive pulley and the plurality of tool assembly pulleys, and the plurality of tool assembly pulleys are configured in an array, whereby lateral or longitudinal displacement of the chassis across the surface to be abraded results in a path of a first tool assembly rotating in one direction to be subsequently fully overlapped by a path a second tool assembly rotating in the opposite direction, resulting in a complete cross cut, as well as being subsequently at least partially overlapped by a path of a third tool assembly. 
         [0010]    The apparatus may comprise one drive pulley and five tool assembly pulleys, wherein the array comprises six tool assemblies. 
         [0011]    The framework may comprise a laterally extending post on each side, each post configured to receive a weight thereon. 
         [0012]    The chassis may comprise an upper chassis plate and a lower chassis plate, and the lower chassis plate may comprise a recess for housing the drive pulley, the plurality of tool assembly pulleys and the belt. 
         [0013]    The upper chassis may comprise an opening, wherein an input shaft extending through the opening operatively connects the motor to the drive pulley. 
         [0014]    The input shaft and the drive pulley may be operatively connected by a detachable jaw coupling. 
         [0015]    The apparatus may comprise a handle connected to the framework, the handle comprising a plurality of articulation points, wherein the handle is configurable in an extended position and a stowed position, wherein in the stowed position the handle is folded within a footprint of the apparatus. 
         [0016]    In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
           [0018]    In drawings which illustrate by way of example only specific embodiments of the invention: 
           [0019]      FIG. 1  is a perspective view of a surface abrasion apparatus according to an embodiment of the invention; 
           [0020]      FIG. 2  is a bottom plan view of the apparatus of  FIG. 1 , showing the configuration of the tool plate array (with tool segments removed); 
           [0021]      FIG. 3  is a perspective view of the chassis of the apparatus of  FIG. 1 , showing the upper chassis plate and lower chassis plate separated; 
           [0022]      FIG. 3A  is a bottom plan view of a surface abrasion apparatus according to another embodiment of the invention, showing the configuration of the tool plate array; 
           [0023]      FIG. 3B  is a perspective partially exploded view of the chassis of the apparatus of  FIG. 3A ; 
           [0024]      FIG. 4  shows components of the apparatus of  FIG. 1 : a bottom plan view of a tool plate (with tool segments removed); a side plan view of a tool assembly; and a perspective view of a tool plate with one tool segments attached and one tool segment detached; 
           [0025]      FIG. 5  shows components of the apparatus of  FIG. 1 : a bottom perspective view of a tool holder; a tool plate having a hook and loop fastener backing; and a tool plate with associated fastening magnets; 
           [0026]      FIG. 5A  is a perspective partially exploded view of the tool assembly of the apparatus of  FIG. 3A ; 
           [0027]      FIG. 6  depicts a vacuum opening and vacuum pipe insertable therein of the apparatus of  FIG. 1 ; 
           [0028]      FIG. 7  shows a front perspective view of the apparatus of  FIG. 1  with two attached weight plates and one detached weight plate; 
           [0029]      FIG. 8  shows the hand grips and control panel of the apparatus of  FIG. 1 ; 
           [0030]      FIG. 9  is a side view of the apparatus of  FIG. 1 , showing the handle in an extended position; 
           [0031]      FIG. 10  is a side view of the apparatus of  FIG. 1 , showing the handle in a stowed position; and 
           [0032]      FIG. 11  is a rear view of the apparatus of  FIG. 1 , showing the variable frequency drive attached to the motor. 
       
    
    
     DESCRIPTION 
       [0033]    Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
         [0034]    According to aspects of the present invention, there is provided an apparatus for abrading a surface. 
         [0035]    As may be seen in  FIGS. 1 to 11 , a surface abrasion apparatus  1  according to some embodiments of the invention. Apparatus  1  includes a chassis  2  having a motor  4  attached thereon. A variable frequency drive  5  is connected to motor  4 , and a framework  6  houses motor  4 . A pair of wheels  8  is connected to framework  6  to permit rolling transport of apparatus  1 . An elongated handle  10  extends upwardly from chassis  2 . A pair of opposing weight posts  12 ,  14  extends horizontally from opposing sides of framework  6 . A third weight post  16  extends vertically from the top of framework  6 . 
         [0036]    Chassis  2  comprises upper and lower chassis plates  18 ,  20  having paired openings  22  for insertion of tool plates  24 , input shaft  26  for driving a drive pulley  41 , and tool assembly pulleys  28  driven by a belt  40 . Preferably, an even number of tool assemblies  42  are disposed within an array of an equal number of openings  22  in chassis  2 . In some embodiments input shaft  26  may be substituted with a gear that drives drive pulley  41 . Idler pulleys  32  occupy two additional openings  34  in chassis  2 . Finally, a pair of vacuum ports  36  is disposed on opposing sides of chassis  2 . 
         [0037]    As best illustrated in  FIG. 3B , the drive components within chassis  2  (namely tool assembly pulleys  28 , idler pulleys  32 , belt  40 , drive pulley  41  and bearing (not shown) are disposed in a continuous recess  68  in lower chassis plate  20 . Upper chassis plate  18  may be attached to lower chassis plate  20  with fasteners  70 . Drive pulley  41  of the drive components detachably engages with input shaft  26  via a jaw coupling. Locating all of the drive components in lower chassis plate  20  and providing a jaw coupling between input shaft  26  and drive pulley  41  facilitates quick access for maintenance such as replacement of belt  40 , as well as disassembling machine  1  into three pieces for ease in transportation by a single person (instead of two people). 
         [0038]    Chassis  2  may be of a monocoque design to dissipate heat. Chassis  2  may be constructed of aluminum to further improve heat dissipation. Improved heat dissipation improves the longevity of the enclosed drive components by pulling away undesirable heat therefrom. 
         [0039]    In some embodiments, an even number of openings are spaced within chassis plates  18 ,  20  in an alignment which permits a desired overlap  38  between the abrasion area of adjacent tool plates  24 , as shown in  FIG. 2 . This layout is arranged such that there are rows of tooling plates  24  that overlap each other from side to side in a calculated ratio to provide a cutting path that has an even and level tool path profile. 
         [0040]    Referring to  FIG. 3 , rotation of each tool plate  24  is effected by driving rotation of input shaft  26  with motor  4  to rotate drive pulley  26  to run belt  40  interwoven among tool assembly pulleys  28 , thereby rotating tool assemblies  42 . 
         [0041]    As shown in  FIG. 3A , tool assemblies  42  are arrayed and counter-rotate with respect to an adjacent one of another such any lateral or longitudinal displacement of chassis  2  across a surface results in a path of one tool assembly  42  rotating in one direction to be at least partially overlapped by the path of at least one tool assembly  42  rotating in the other direction. For example, if chassis  2  were displaced in a leftward direction on the page (arrow  70 ), then the paths of tool assemblies  24 C and  24 E rotating counter-clockwise would also be at least partially overlapped by the path of tool assembly  24 D rotating clockwise. This six head configuration thus results in both a double cut (since more than one tool assembly  24  will go over a given point on the surface with each pass) and a cross cut (because of the counter-rotation arrangement discussed above) with each pass of apparatus  1 , eliminating undesirable track marks left on the surface by known apparatus. In some embodiments, tool assemblies are arrayed and counter-rotate with respect to an adjacent one of another such any lateral or longitudinal displacement of the chassis across a surface results in a path of one tool assembly rotating in one direction to be fully overlapped by the tool assembly following, which will be rotating in the opposite direction, resulting in a complete cross cut, as well as being at least partially overlapped by at least one other rotating tool assembly. 
         [0042]    With reference to  FIG. 4 , each tool assembly  42  comprises a tool holder  44  disposed on the lower side of chassis  2 , adapted to receive a tool plate  24 , and a plurality of tool segments  46  adapted to engage with tool plate  24 . Tool plate  24  includes an input shaft  26  which extends upwardly through a pulley  28  within chassis  2 . The positioning of the openings of the drive train system of apparatus  1  is designed to ensure that tool plates  24  extend fully to the outer edge of chassis  2  to permit abrasion immediately adjacent a vertical surface such as a wall. 
         [0043]    Referring to  FIG. 5 , various means of attachment of each tool plate  24  to a corresponding tool holder  44  are possible. These means may include the use of magnets  48  or hook and loop fasteners (not shown). Tool plates  24  may also comprise a recessed pocket to receive a specifically designed tool retained by a fastener such a screw. 
         [0044]    Referring to  FIG. 5A , tool assembly  42  shows tool plate  24  and corresponding tool holder  44  in further detail. Each tool plate  24  has three equidistant pins  64 A,  64 B,  64 C that engage corresponding equidistant bearings  66 A,  66 B,  66 C of tool holder  44 . In some embodiments the bearings may be on the tool plate and the pins on the tool holder. The inventor has determined that this “tripod” pin engagement of tool plate  24  to tool holder  44  permits for even and stable articulation of tool plate assembly  42  across uneven surfaces (compared to known too assemblies with pins in multiples of two, e.g. bipod or quadruped engagement) leading to a smoother finish of the surface and minimizing track marks. In other embodiments, for larger apparatus, the number of pins can be multiples of three, i.e., 6 pins (three groups of 2 pins), 9 pins (three groups of 3 pins), 12 pins (three groups of 4 pins), etc. so long as the tripod arrangement is maintained. 
         [0045]    As shown in  FIG. 6 , in addition, a pair of replaceable vacuum pipes  49  may be disposed within vacuum ports  36  on opposing sides of chassis  2  to permit vacuum removal of generated heat, along with debris abraded from the surface being worked upon. A further cooling aspect comprises the placement of framework  6  a spaced distance  50  from motor  4  to permit free flow of air around motor  4  as shown in  FIG. 7 . 
         [0046]    In order to controllingly increase the degree of abrasion of a surface, weights  52  may be added to apparatus  1 . As shown in  FIG. 7 , one or more weights  52  may be added to each of the top post  16  and/or side weight posts  12 ,  14  to achieve a desired total added weight. Horizontal weight posts  12 ,  14  and weights  52  added thereon can also be used to adjust the lateral weight balance of apparatus  1  and thus the abrading characteristics thereof to allow a user to define selected point pressure bias depending on the shape or profile of a surface needing abrading. For example, placement of weights  52  can be biased toward a particular lateral side to facilitate polishing “curled up” edges of surfaces, particularly near walls. Weight posts  12 ,  14 ,  16  are designed to accept non-proprietary weights thereby allowing the user to add, for example, common Olympic weight plates of varying sizes and weights. Most prior art devices require use of proprietary weights. The biased weight system described herein would only be of benefit for the invention described herein as it would have little to no effect on common planetary machines. 
         [0047]    As depicted in  FIG. 8 , at the upper end of handle  10  of apparatus  1  there is provided a perpendicular crossbar having opposing hand grips, separated by a control panel  54 . Control panel  54  may include a forward motion switch  56 , a reverse motion switch  58 , and an emergency stop switch  60 . 
         [0048]    Referring now to  FIGS. 9 and 10 , to permit operation in a variety of circumstances, handle  10  of apparatus  1  is provided with a plurality of articulation points  62  along its length. In some embodiments, such as that illustrated, one articulation point  62  is located approximately midway along handle  10 , and another articulation point  62  is located adjacent chassis  2 . Adjustment of handle  10  at articulation points  62  permits easier manoeuvrability of apparatus  1 . Handle articulations in multiple locations allow apparatus  1  to be operated in tight quarters, backwards, and under height restricted areas. In addition, handle  10  may thereby be folded over framework  6  of apparatus  1  for compact storage and transport, such that handle  10  is folded within the footprint of apparatus  1 . 
         [0049]    Referring to  FIG. 11 , apparatus  1  is outfitted with a customized variable frequency drive (“VFD”)  5  that allows users to use either single or three-phase power sources and to employ variable speed control. VFD also permits current-limiting to suppress current surges and to limit current to a desired maximum as defined within the VFD&#39;s programmable parameters. 
         [0050]    In operation, the motor, typically electric, variably drives an input shaft in a forward direction, clockwise or counter-clockwise. The input shaft causes a drive pulley to rotate, thereby rotating the drive belt, which in turn rotates each of the tool assembly pulleys and their associated tool plates, to which tool segments are attached. A user moves the apparatus around the surface being abraded to achieve a smooth surface. The motor may also be operated in a reverse direction to effect rotation of the pulleys, belt and tool plates in the opposite direction. A pair of idler pulleys redirects the drive belt around adjacent pulleys. 
         [0051]    The apparatus includes a plurality of tool plates, each adapted to receive modified tool segments, which have an abrasive media bonded to their lower surface. The modified tool segments are held in place by the magnet of the tool plate in some embodiments. In some embodiments a recessed pocket may be provided to receive a proprietary tool segment fastened with a fastener such as a screw. In some embodiments, the tool plate may have a hook and loop fastener for attachment of abrasive media having a hook and loop fastener interface. The apparatus further includes a plurality of tool assembly pulleys, each pulley being adapted to rotate a corresponding tool plate; and a plurality of drive shafts in continuous contact with the pulleys via the drive belt such that the tool plates rotate in one direction (counter-rotating with respect to one another as described above) when the forward drive shaft is engaged, and in the opposite direction when the reverse drive shaft is engaged. 
         [0052]    A control interface for the apparatus allows for both forward and backward tool rotation which allows the user to re-dress tooling without having to remove the tooling from the apparatus. The symmetrical design of the drive train system permits operation in forward or reverse direction without incident or impact on apparatus service factor. 
         [0053]    The drive train system of the apparatus is designed to be easily assembled and serviced in the field by an individual with basic mechanical skills. Unlike prior art apparatus that need to be sent to a repair facility, this drive train can be fully disassembled and re-assembled in approximately 20 minutes with a simple tools and without the use of liquid silicone-type sealers, as the drive train has o-ring seals or precisely machined mating surfaces. The drive train system of the present apparatus is fully sealed and water tight to prevent ingress of foreign debris and other contaminants, including water. All drive shafts extending from the bottom of the apparatus have axis shaft seals mounted in seal plates with o-rings fastened to the base. This allows for the apparatus to be used in both wet and dry conditions. 
         [0054]    The vacuum system of the invention has removable vacuum interface pipes on the upper side of the apparatus chassis to allow use of inserts of different sizes for vacuum hoses of varying sizes. The vacuum system also incorporates twin flare type openings at the bottom of the drive train which provides a venturi effect to maximize particulate extraction. 
         [0055]    The tool plate driver allows for multiple tool plate options that can be easily installed and removed by a simple pull. The tool plate driver system also has the ability to accept various densities of rubber to further expand the apparatus abrading capability by offering varying degrees of articulation. 
         [0056]    While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.