Abstract:
A track scraper for removing rubber from a racetrack is provided. The scraper comprises rotating blades that are moved along the surface of the track and that skim off portions of rubber that has been deposited on the track by race cars. The scraper is installed on and powered by a standard garden tractor.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of and claims priority to U.S. Non-provisional patent application Ser. No. 12/466,700, filed on May 15, 2009, the entire content of which are incorporated by reference. This application is related to U.S. Provisional Application Ser. No. 61/053,479 filed on May 15, 2008, the entire contents of which are herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the field of tractor-based, rotary-driven power equipment, and more particular relates to a device for scraping rubber from pavement. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Tires burning out on race tracks deposit rubber on the track. Over time, the rubber may build up into a layer that affects the performance of the tires on the track. 
     The present invention provides a track scraper with rotating blades that scrape rubber from the surface of the track. The track scraper is installed on and powered by a standard tractor. In one embodiment, the track scraper comprises three scraping blades, each of which is rotated by a gearbox. In operation, the track scraper is lowered until its rotating blades contact the track, and then the scraper is moved along the surface of the track to remove rubber from the track. The blades are positioned for maximum coverage of the track area. 
     For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a front perspective view of an embodiment of an exemplary track scraper in accordance with the present disclosure. 
         FIG. 2  is a front plan view of the exemplary track scraper illustrated in  FIG. 1 . 
         FIG. 3  is a top plan view of the exemplary track scraper illustrated in  FIG. 1 . 
         FIG. 4  is an exploded view of an exemplary hub disc spring assembly of the track scraper of  FIG. 1  in accordance with the present disclosure. 
         FIG. 5  is a bottom plan view of a blade support showing the plurality of scraping blades. 
         FIG. 6  is a bottom perspective view of the blade support of  FIG. 5 . 
         FIG. 7  is a front plan view of a mounting bracket. 
         FIG. 8  is an end view of the mounting bracket of  FIG. 7 . 
         FIG. 9  is a front plan view of a scraping blade according to an embodiment of the present disclosure. 
         FIG. 10  is an end view of the scraping blade of  FIG. 9 . 
         FIG. 11  is a front perspective view of an alternative embodiment of a track scraper according to the present disclosure. 
         FIG. 12  is a top plan view of the track scraper of  FIG. 11 . 
         FIG. 13  is a front plan view of the track scraper of  FIG. 11 . 
         FIG. 14  is a top perspective view of an embodiment of a blade assembly used on the track scraper of  FIG. 11 . 
         FIG. 15  is a top plan view of the blade assembly of  FIG. 14 . 
         FIG. 16  is a front plan view of the blade assembly of  FIG. 14 . 
         FIG. 17  is a bottom plan view of the blade assembly of  FIG. 14 . 
         FIG. 18  is a bottom perspective view of the blade assembly of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a front perspective view of a track scraper  100  according to one embodiment of the present disclosure. The scraper  100  comprises three (3) rotating blade supports  22 , each blade support  22  comprising a plurality of blades  69 . The blades  69  contact the surface of a race track (not shown) when the track scraper  100  is in use and the blade supports  22  rotate to scrape rubber (not shown) from the track. In this embodiment, the blade supports  22  comprise slightly concave generally circular discs. Each blade support  22  rotates around a central axis (not shown), and is connected to a hub disc spring assembly  9  (only one of which is shown in  FIG. 1 ) as shown. The hub disc spring assemblies  9  retain the blade supports  22  and connect to a divider gearbox  2  and two right angle gearboxes  3   a  and  3   b.    
     The three (3) gearboxes  2 ,  3   a , and  3   b  comprise gears (not shown) for turning the blade supports  22 . The gearboxes  2 ,  3   a , and  3   b  are bolted to a deck  21  with a plurality of bolts  5 . Two yoke-cross joint assemblies  4  rotatably connect the two right angle gearboxes  3   a  and  3   b  to the divider gearbox  2 . The yoke-cross joint assemblies  4  comprise any of a number of flexible mechanical connections known by persons with skill in the art to transmit rotary motion from one shaft to another. 
     The divider gearbox  2  is connected to a planetary gearbox  77  in the illustrated embodiment. The gearboxes  2 ,  3   a ,  3   b , and  77  and the yoke-cross joint assemblies  4  are commercially-available parts. 
     The planetary gearbox  77  reduces the rotation of the gears (not shown) in the gearboxes  2 ,  3   a , and  3   b . For example, in one embodiment, the rotation of the blade supports  22  is desired to be generally 150 RPMs, and the commercially-available gearboxes  2 ,  3   a , and  3   b  spin at generally 800 RPMs under normal operation. The planetary gearbox  77  reduces the rotation of the gears in the gearboxes  2 ,  3   a , and  3   b  to 150 RPMs. In other embodiments, the planetary gearbox  77  is not used. 
     The planetary gearbox  77  comprises a front shaft  25  rotatably connected to a power take-off (PTO) (not shown) of a tractor (not shown). As is known by persons of skill in the art, a power take-off is a splined driveshaft on a tractor or truck that is used to provide power to an attachment or separate machines. The power take-off provides rotation to the front shaft  25  of the planetary gearbox  77 , which in turn imparts rotation to the divider gearbox  2 , which imparts rotation to the right angle gearboxes  3   a  and  3   b  and to the front hub disc spring assembly  8 , which in turn rotates the blade supports  22 . The rotation of the blades  69  is in generally the same plane as the plane of the surface being scraped (not shown). 
     A deck weldment  1  comprises a frame  20  and the deck  21 . The frame  20  is comprised of generally rectangular metal strips bent and/or welded into a shape resembling a triangle with cropped corners. The deck  21  is a generally thin metal plate tack-welded or otherwise securely affixed to the frame  20 . The deck  21  comprises three (3) openings (not shown) for receiving the hub disc spring assemblies  9  and additional openings (not shown) to receive the plurality of bolts  5 . 
     A lift frame  26  affixed to the deck  21  supports the scraper  100  for lifting by a tractor (not shown). In the illustrated embodiment, the lift frame  26  comprises two (2) generally horizontal supports  27  that are welded or otherwise affixed to the deck  21  and/or frame  20 . The lift frame  26  further comprises two (2) front supports  28  that are affixed to the horizontal supports  27  near the front ends  30  of the horizontal supports  27 . The front supports  28  extend generally upward and provide openings (not shown) for receiving lift pins  15  which are connectable to the tractor (not shown). At their upper ends  29 , the front supports  28  extend inwardly toward each other, and are maintained in a fixed spaced apart position by a lift arm spacer  13 . Two (2) brace arms  11  are affixed between the upper ends  29  of the front supports  28  and the rear ends of the horizontal supports  27 . 
     The scraper  100  may be installed on a tractor (not shown) by a three point hitch (not shown) that is known in the art. The three point hitch connects to the scraper  100  via the lift pins  15 , which connect to the lift arms (not shown) of the three point hitch, and via a pin (not shown) that passes through openings  38  in a swivel linkage  76  that is rotatably fastened between the upper ends  29  of the front supports  28  and connects to a top link (not shown) of the three point hitch. 
     The scraper  100  may also be installed on the tractor via a quick hitch (not shown) that is known in the art. The quick hitch may comprise three hooks that connect to the lift pins  15  and the lift arm spacer  13 . 
       FIG. 2  is a front view of the track scraper  100  illustrated in  FIG. 1 . As shown in the figure, blade supports  22   a ,  22   b , and  22   c  are positioned such that the blades  69  cover the entire width “W” of the area between the outermost edge  33  of a rightmost blade  69   a  on a right side of the track scraper  100  and the outermost edge  34  of a leftmost blade  69   b  on a left side of the track scraper  100 . 
     Note that the blade supports  22   a ,  22   b , and  22   c , have convex top surfaces as illustrated. However, the blades  69  are aligned in the same plane, i.e., a generally flat plane. This is because the blades  69  are affixed to a flat plate (not shown) that is recessed within the blade supports  22   a ,  22   b , and  22   c . Also note that the blades  69  are designed to scrape, but not extend into, a track surface  68 . 
       FIG. 3  is a top view of the embodiment of the track scraper  100  illustrated in  FIG. 1 . The deck  21  is in the general shape of a triangle with cropped corners, with the three blade supports  22   a ,  22   b , and  22   c  each disposed each near a corner as illustrated. Blade support  22   a  is disposed near the front of the deck  21 , and blade supports  22   b  and  22   c  and disposed near the left and right corners respectively. The blade supports  22   a ,  22   b , and  22   c  are positioned for maximum coverage of track area when the scraper  100  is moved across the track in the direction shown by direction indication arrow  32 . 
     In operation of the track scraper  100  in one embodiment, blade support  22   c  rotates clockwise, as indicated by direction arrow  70  in  FIG. 2  and blade support  22   b  rotates counterclockwise, as indicated by direction arrow  71 . With both blade supports  22   b  and  22   c  rotating such that their front edges move outwardly in this fashion, rubber removed from the track will be pushed out of the path of the track scraper  100 . In other embodiments, all three blade supports  22   a ,  22   b , and  22   c  may rotate in the same direction. 
       FIG. 4  is an exploded view of a hub disc spring assembly  9 . The hub disc spring assembly  9  comprises a drive tube assembly  59 , which comprises a base  41 , a main drive tube  42 , and an upper shaft  57 . The drive tube assembly  59  receives the blade support  22 . In this regard, the blade support  22  is installed onto the drive tube assembly  59  via an opening  40  in the blade support  22  fitting over the main drive tube  42  and resting against the base  41 . As illustrated, the main drive tube  42  has a generally square cross section and fits inside the similarly-shaped opening  40 . Other shapes of openings/drive tubes may be used in other embodiments. 
     The blade support  22  is curved such that its top side  330  is convex, as was discussed above and as illustrated in  FIG. 2 . The opening  40  is generally square to receive the main drive tube  42 . Because the top side  330  is curved and the opening  40  is generally square, the blade support  22  has some clearance such that it can “rock” or move slightly even when restrained by the hub disc spring assembly  9 . This motion allowed by the blade design permits the blade supports  22  in the track scraper  100  to individually adjust such that they follow the topology of the surface (not shown) being scraped. 
     A lower spring cap  43  may be installed on the main drive tube  42  such that it rests against the blade support  22 . The lower spring cap  43  has an opening  46  that mates with the main drive tube  42 . A disc spring  44  may also be installed on the main drive tube  42 , followed by an upper spring cap  45 . The upper spring cap  45  has an opening  47  that mates with the main drive tube  42 . The disc spring  44  may thus be “sandwiched” between the lower spring cap  43  and the upper spring cap  45 . A spacer tube  55  with opening  48  is a hollow tube shaped to mate with the main drive tube  42 . The spacer tube  55  is installed on top of the upper spring cap  45 . 
     A washer  49  with opening  50  is installed on top of the spacer tube  55  and rests against an upper lip  56  of the main drive tube  42 . The opening  50  of the washer  49  is sized and shaped to be received by the generally cylindrical upper shaft  57  of the main drive tube  42 . A clamp  51  fits over the upper shaft  57  and is tightened by bolt  52 , washer  54 , and nut  53 . The clamp  51  retains the components  22 ,  43 ,  44 ,  45 ,  55 , and  49  onto the drive tube assembly  59 . 
     The disc spring  44  is not utilized in some embodiments of the track scraper  100 , and in those embodiments the lower spring cap  43  and the upper spring cap  45  are also not present. 
     Although the illustrated embodiment discloses a track scraper  100  with three (3) blade supports  22 , more or fewer blade supports  22  could be employed without departing from the scope of the present disclosure. 
       FIG. 5  is a bottom plan view of a blade support  22  of  FIG. 1 , showing three (3) substantially similar blades  69   a ,  69   b , and  69   c . The blades  69   a ,  69   b , and  69   c  are each rigidly affixed via a plurality of fasteners  66  to a mounting bracket  67 . The mounting brackets  67  are rigidly affixed to a backing plate  235 , a generally flat plate that is rigidly affixed to the blade support, by welding in the illustrated embodiment. 
     The blade  69   a  comprises a scraping edge  64  that is serrated in the illustrated embodiment. The scraping edge  64  lies along a substantially straight line indicated by line  63   a . Importantly for this embodiment, the scraping edge  64  does not lie along any plane or a line emanating radially from a center  65  of the blade support  22 , e.g., the scraping edge  64  is not coextensive with a radius line indicated by “R.” Rather, the scraping edge  64  is angled outwardly at an angle “θ” with respect to the radius line R. Of course, the angle between other radius lines and the scraping edge  64  would be different—and the angle will even be zero at certain radiuses around the blade support  22 —but in no event would the scraping edge  64  be coextensive with a radius of the blade support  22 . 
     The blades  69   b  and  69   c  are substantially similar to blade  69   a . Further, the blades  69   b  and  69   c  are disposed equidistantly from each other, such that their scraping edges  64  are coextensive with the sides of an equilateral triangle. In this regard, the scraping edge  64  of blade  69   b  lies along a substantially straight line indicated by line  63   b  and the scraping edge  64  of blade  69   c  lies along a substantially straight line indicated by line  63   c . The lines  63   a ,  63   b , and  63   c  form an equilateral triangle in this embodiment. In other embodiments, the blades  69   a ,  69   b , and  69   b  may be further angled outwardly such that the blades are not coextensive with the sides of an equilateral triangle. Further, in other embodiments, more than three (3) scraping blades  69  may be employed. 
       FIG. 6  is a bottom perspective view of the blade support  22  of  FIG. 1 . The mounting brackets  67  are rigidly affixed to the backing plate  235 , by welding in the illustrated embodiment. The mounting bracket  67  is a generally thin angled bracket comprising a base portion  241  which is affixed to the backing plate  235 . The base portion  241  is affixed to the backing plate  235  by welding in one embodiment, though may be secured by other means. The base portion  241  is generally flat, as is the surface of the backing plate  235 . 
     The mounting bracket  67  further comprises a blade mount portion  242 . The blade mount portion  242  receives the scraping blade  69  and extends downwardly from the base portion  241  at an angle “A” ( FIG. 8 ) as further discussed herein with respect to  FIG. 8 . The blade mount portion  242  comprises a plurality of openings (not shown) for receiving the fasteners  66 . 
     Each mounting bracket  67  further comprises a gusset  236 , which is a thin flat rectangular plate welded to and extending between the base portion  241  and the blade mount portion  242  of the mounting bracket  67 . The gusset  236  supports the mounting bracket  67  and helps to maintain the angle A ( FIG. 8 ). The gusset  236  is generally affixed to the base portion  241  and the blade mount portion  242  via welding. 
       FIG. 7  is a front plan view of the mounting bracket  67  of  FIG. 6  before the mounting bracket  67  is bent into its final shape, as further discussed herein. The mounting bracket  67  is a generally rectangular plate comprising side edges  245 , a blade mounting edge  246  adjacent to the blade  69  ( FIG. 6 ), and a fixed edge  247  that is welded to the backing plate  235 . 
     Openings  244  pass through the bracket  67  and receive fasteners  66  ( FIG. 6 ) for releasably affixing the blade  69  ( FIG. 6 ) to the bracket  37 . In the illustrated embodiment, the bracket  67  comprises two (2) openings  244 , but more or fewer openings  244  may be used in other embodiments. A bend line  248  defines a line generally parallel to the edges  246  and  247  about which the bracket  67  is bent, as further discussed with respect to  FIG. 8 . 
       FIG. 8  is a side plan view of the bracket  67  bent at bend line  248  into its final form. The bracket  67  comprises the base portion  241  and the blade mount portion  242 . The blade mount portion  242  is disposed at an angle “A” to the base portion  241 . In the illustrated embodiment, the angle A is generally 45 degrees, though may be different in other embodiment. The purpose of the angle A is to extend the blade  66  ( FIG. 6 ) downwardly and away from the backing plate  235 . 
       FIG. 9  is a front plan view of the blade  69  of  FIG. 6 . The blade  69  is fabricated from a sheet of metal, such as ½ inch thick steel, in one embodiment. The blade  69  is generally rectangular with a scraping edge  64  for scraping rubber. The blade  69  comprises openings  253  aligned with the openings  244  ( FIG. 7 ) on the mounting bracket  67  ( FIG. 7 ) for receiving fasteners  66  ( FIG. 6 ) which removably affix the blade  69  to the bracket  67 . The scraping edge  64  is serrated in the illustrated embodiment. 
       FIG. 10  is an end view of the blade  69  of  FIG. 9 . The scraping edge  64  is tapered as shown. The openings  253  are countersunk so that the heads (not shown) of the fasteners  66  ( FIG. 6 ) can be recessed. 
       FIG. 11  is a front perspective view of another track scraper  200  in accordance with an embodiment of the present disclosure. In this embodiment, the track scraper  200  comprises three rotating blade assemblies  122 . The blade assemblies  122  comprise a blade support  123  (only one of which is visible in  FIG. 11 ) to which a plurality of angle mounts  124  is affixed. The angle mounts  124  receive a plurality of scraping blades  125  which contact the surface (not shown) to scrape rubber (not shown) from the track. 
     Each blade assembly  122  rotates around a central axis (not shown), and is connected to a hub assembly  108  (only one of which is shown in  FIG. 11 ) as shown. The hub assemblies  108  retain the blade assemblies  122  and connect to a divider gearbox  102  and two right angle gearboxes  103   a  and  103   b . The hub assemblies  108  retain the blade assemblies  122  in a similar manner to that described above with respect to the hub spring disk assembly  9  of  FIG. 4 . 
     The three (3) gearboxes  102 ,  103   a , and  103   b  comprise gears (not shown) for turning the blade assemblies  122 . The gearboxes  102 ,  103   a , and  103   b  are bolted to a deck  121  with a plurality of bolts  105 . Two yoke-cross joint assemblies  104  rotatably connect the two right angle gearboxes  103   a  and  103   b  to the divider gearbox  102 . 
     The divider gearbox  102  is connected to a planetary gearbox  166  in one embodiment. The gearboxes  102 ,  103   a ,  103   b , and  166  and the yoke-cross joint assemblies  104  are commercially available parts. 
     A front shaft  225  extends from the planetary gearbox  166  and rotatably connects to a power take-off (PTO) (not shown) of the tractor (not shown). The tractor provides rotation to the front shaft  225 , which in turn imparts rotation to the gears (not shown) in the planetary gearbox  166 , which in turn rotates the gears (not shown) in the divider gearbox  102 , which in turn rotates the gears (not shown) in the right angle gearboxes  103   a  and  103   b.    
     The planetary gearbox  166  reduces the rotation of the gears (not shown) in the gearboxes  102 ,  103   a , and  103   b . For example, in one embodiment, the rotation of the blade assemblies  122  is desired to be generally 150 RPMs, and the commercially-available gearboxes  102 ,  103   a , and  103   b  spin at generally 800 RPMs under normal operation. The planetary gearbox  166  reduces the rotation of the gears in the gearboxes  102 ,  103   a , and  103   b  to 150 RPMs. In other embodiments, the planetary gearbox  166  is not used. 
     A deck  101  substantially similar to the deck weldment  1  discussed above with respect to  FIG. 1  supports the gearboxes  102 ,  103   a    103   b , and  166 . 
     A lift frame  126  supports the scraper  200  for lifting by a tractor (not shown). In the illustrated embodiment, the lift frame  126  comprises two (2) generally horizontal supports  127  that are welded or otherwise affixed to the deck  101 . The lift frame  126  further comprises two (2) front supports  128  that are affixed to the horizontal supports  127  near the front ends of the horizontal supports  127 . The front supports  128  extend generally upward and provide openings (not shown) for receiving lift pins  115  which are connectable to the tractor (not shown). At their upper ends  129 , the front supports  128  extend inwardly toward each other, and are maintained in a fixed spaced apart position by a lift arm spacer  113 . Two (2) brace anus  111  are affixed between the upper ends  129  of the front supports  128  and the horizontal supports  126 . 
     The scraper  100  may be installed on a tractor (not shown) by a three point hitch (not shown) that is known in the art. The three point hitch may connect to the scraper  100  via the lift pins  115 , which connect to the lift arms (not shown) of the three point hitch, and via a pin (not shown) that passes through openings  138  in the front supports  128  and connects to a top link (not shown) of the three point hitch. 
     The scraper  100  may also be installed on the tractor via a quick hitch (not shown) that is known in the art. The quick hitch may comprise three hooks (not shown) that connect to the lift pins  115  and the lift arm spacer  113 . 
       FIG. 12  is a top view of the embodiment of the track scraper  200  illustrated in  FIG. 11 . The deck  121  is in the general shape of a triangle with cropped corners, with the three blades  122   a ,  122   b , and  122   c  each disposed each near a corner as illustrated. Blade  122   a  is disposed near the front of the deck  121 , and blades  122   b  and  122   c  and disposed near the rear corners of the deck  121 . The blades  122   a ,  122   b , and  122   c  are positioned for maximum coverage of track area when the scraper  200  is moved across the track in the direction shown by direction indication arrow  132 . 
     In operation of the track scraper  200  in one embodiment, blade  122   c  rotates clockwise, as indicated by direction arrow  170  in  FIG. 12 , and blade  122   b  rotates counterclockwise, as indicated by direction arrow  171 . With both blades  122   b  and  122   c  rotating such that their front edges move outwardly in this fashion, rubber (not shown) removed from the track will be pushed out of the path of the track scraper  200 . In other embodiments, all three blades  122   a ,  122   b , and  122   c  may rotate in the same direction. 
       FIG. 13  is a front view of the track scraper  200  illustrated in  FIG. 11 . As shown in the figure, blades  122   a ,  122   b , and  122   c  are positioned such that the blades cover the entire width “W” of the area between the outermost edge  133  of blade  122   c  and the outermost edge  134  of blade  122   b.    
     The planetary gearbox  166  is supported by a front plate  167  that is affixed to the horizontal supports  127 . The front plate  167  comprises a generally circular opening  169  for receiving the gearbox  166 . The planetary gearbox  166  is affixed to the front plate  167  via a plurality of fasteners  168 . 
       FIG. 14  depicts a blade assembly  122  according to an embodiment of the present disclosure. In this embodiment, the blade assembly comprises the blade support  123  which supports the scraping blades  125  via the plurality of angle mounts  124 . The blade support  123  comprises a relatively flat disk with a central opening  231  for releasably receiving a drive tube assembly  159 . In one embodiment, the drive tube assembly  159  is substantially similar to the drive tube assembly  59  discussed above with respect to  FIG. 4 , and extends upwardly from the blade assembly  122 . The blade support  123  and drive tube assembly  159  may be fabricated from any suitably strong and rigid material, such as steel. 
     The angle mounts  124  comprise rigid elongated L-shaped mounts that are rigidly affixed to the blade support  123 . In one embodiment, the angle mounts  124  are affixed to the blade support  123  by welding a generally flat top side  233  of the angle mount  124  to the generally flat bottom side (not shown) of the blade support  123 . 
     The scraping blades  125  extend from and are affixed to the angle mounts  124 . The scraping blades  125  have an angled leading edge  211  that extends downwardly beneath a bottom edge  214  of the angle mount  124 . The leading edge  211  angles toward the direction of rotation of the blade assembly  122 , as indicated by directional arrow  210 . The blade assembly  122  rotates in the same general plane as the plane of the track surface (not shown). The scraping blades  125  further have a tapered tip  213  that rotatably contacts the track surface when the track scraper  200  is in use. The scraping blades  125  may be fabricated by any suitably strong and rigid material, such as hardened steel. 
     The scraping blades  125  are affixed to the angle mounts  124  via a plurality of fasteners  212 . The scraping blades  125  are removable from the angle mounts  124  by removing the fasteners  212 . The scraping blades  125  are thus replaceable when they are worn. 
     In the illustrated embodiment, the blade assembly  122  comprises forward-facing scraping blades  125  rigidly affixed to L-shaped angle mounts  124 , which angle mounts  124  are rigidly affixed to the blade support  123 . In other embodiments, different configurations of blades and supports may be used for the blade assembly  122 . 
       FIG. 15  is a top plan view of the embodiment of the blade assembly  122  of  FIG. 14 . The drive tube assembly  159  extends from the center of the blade support  123 . The blade support  123  is generally circular in this embodiment, but may be differently shaped in other embodiments. 
       FIG. 16  is a side plan view of the blade assembly  122  of  FIG. 14 . In this embodiment, the blade support  123  is a generally flat plate, as illustrated. In other embodiments, the blade support  123  is curved in a manner similar to the blade supports  22  of  FIG. 1 , to allow the blade assembly to better conform to a surface  272  being scraped, as discussed above in reference to  FIGS. 1 and 5 . In this regard, the blade support  123  is configured so that it may tilt or rock in the direction indicated by directional arrow  271  to conform to irregular surfaces. 
       FIG. 17  is a bottom plan view of an embodiment of the blade assembly  122  of  FIG. 14 . In this embodiment, there are six (6) angle mounts  124  with affixed scraping blades  125  extending radially and equidistantly from a central opening  232 . In other embodiments, different numbers of angle mounts  124  and scraping blades  125  may be used. 
       FIG. 18  is a bottom perspective view of the embodiment of the blade assembly  122  of  FIG. 14 . In this embodiment, each scraping blade  125  is affixed to its angle mount  124  via two standard fasteners  212  that are received by openings (not shown) on the scraping blade  125  and the angle mount  124 . In other embodiments, different configurations and numbers of fasteners may be use to rigidly and removably affix the scraping blade  125  to the angle mount  124 .