Abstract:
An apparatus and method for repairing failed metal pipe inverts includes an apparatus for distributing concrete that is positioned at one entrance of the metal pipe invert. The apparatus includes a frame having a forward end and a rearward end. A trough is connected to the forward end, and a support arm is connected to said rearward end. One end of a chute traverses the trough, while the other is supported by the support arm. A scraper is to the chute to spread concrete distributed from the trough into the pipe invert. The concrete is poured into the chute and distributed into the trough. The apparatus is pulled through the metal pipe invert to distribute concrete from an opening in the trough onto the metal pipe invert. The scraper engages the concrete to selectively spread the concrete on the metal pipe invert and repair the invert.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims priority from U.S. Provisional Application Ser. No. 61/050,851, filed on May 6, 2008, said application being relied upon and incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Metal culverts have been used in building roads for a long time because metal pipe is lighter than concrete pipe and road crews needed special equipment to set heavier concrete pipes in road cuts. Metal pipes started as galvanized plates, which were bolted or riveted together. They later became rolled pipes which were fabricated at a plant and then installed in twenty-foot lengths to be jointed with a band to other twenty-foot segments to form a long culvert. 
     Metal pipe inverts will experience failure over time, which has been blamed on rust or corrosive soil conditions. Further analysis indicates that the failure is caused by continuous movement of sediment through the drain via drain water, effectively “sand blasting” or eroding the bottom of the pipe. Once protective elements have eroded portions of the pipe, then the pipe will rust. 
     Removing the metal pipes having failed inverts is an extraordinarily expensive and time consuming job. In particular, the soil must be removed to expose the pipe experiencing failure. The excavated hole must be wide enough to prevent further soil collapse. The bed must then be reworked, such as with crushed stone. The bed must be on an even stable grade to prevent pipe separation at the joints, and the replaced material must be compacted. Once that step is complete, base and pavement layers must then be replaced. 
     SUMMARY OF THE INVENTION 
     An apparatus and method for repairing failed metal pipe inverts is described herein. The apparatus includes a frame having a forward end and a rearward end. A trough is connected to the forward end, and a support arm is connected to said rearward end. One end of a chute traverses the trough, while the other is supported by the support arm. A scraper is to the chute to spread concrete distributed from the trough into the pipe invert. 
     In operation, the apparatus for distributing concrete that is positioned at one entrance of the metal pipe invert. The concrete is poured into the chute and distributed into the trough. The apparatus is pulled through the metal pipe invert to distribute concrete from an opening in the trough onto the metal pipe invert. The scraper engages the concrete to selectively spread the concrete on the metal pipe invert and repair the invert. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an apparatus for laying concrete on metal pipe inverts; 
         FIGS. 2 and 3  are side elevational view of the apparatus engaging a metal pipe invert; 
         FIG. 4  is a side sectional view of the metal pipe invert illustrated in  FIG. 3 ; 
         FIG. 5   a  is a cross-sectional view of the metal pipe invert; 
         FIG. 5   b  is a cross-sectional view of the metal pipe invert treated with the apparatus; 
         FIG. 6  is a top plan view of the apparatus; 
         FIG. 7  is an elevational view of the forward end of the apparatus; 
         FIG. 8  is an elevational view of the rear end of the apparatus; and 
         FIGS. 9 and 10  is a perspective view of the apparatus engaging a metal pipe invert. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now in detail to  FIGS. 1-10 , an apparatus  10  to lay concrete  6  on metal pipe inverts  8  is illustrated. The apparatus  10  includes a base frame  14 , which in the illustrated embodiment includes a pair of spaced apart runners  16  that are connected to each other via one or more support arms  18 . Each runner  16  has a forward end  16   f  and a rearward end  16   r , with the support arms  18  connecting the runners  16  at the rearward end  16   r . As shown in the embodiment illustrated, the support arms  18  form an A-frame between the runners  16 , although it is foreseen that the support arms  18  may be designed according to any known shape useful for the present application. 
     The apparatus  10  further includes a trough or receptacle  12  that is mounted between both runners  16  of the frame  14  toward the forward end  16   f  of the runners  16 . The trough  12  includes a forward wall  12   f , a rearward wall  12   r , two side walls  12   s , and a floor  13  connected with the lower most edges of the walls  12   f ,  12   r  and  12   s . It is foreseen that various configurations of the trough  12  beyond the box-shape illustrated in the attached drawings could be implemented by one having ordinary skill in the art to achieve the desired distribution of concrete  6  described herein. 
     The apparatus  10  additionally includes a chute  20 , duct or other conduit having a distal end  20   d  and a proximal end  20   p . In the embodiment illustrated, the chute  20  has a hollow cylindrical shape, with the proximal end  20   p  intersecting or connecting with the rearward wall  12   r  of the trough  12 . The distal end  20   d  of the chute  20  is supported by the support arms  18  mounted on the runners  16 . 
     A recession  22  is defined in the distal end  20   d  of the chute  20  to receive cement  6  from a concrete mixer or other source  21  (see  FIG. 2 ). Furthermore, the distal end  20   d  of the chute  20  is elevated by the support arms  18  above the proximal end  20   p  so that cement may be dispense into the chute  20  through the recession  22  and directed by gravity into the trough  12 . The trough  12  includes an opening  11  traversing or proximate the floor  13  of the trough  12 . The opening  11  may extend from runner  20  to runner  20 , or it may have a varying shape. In addition, a supplemental plate (not shown) may be incorporated to vary the size of the opening  11 . Similarly, the floor  13  adjacent the opening  11  may be positioned at an angle to assist the flow of concrete  6  on to the invert  8 . In any case, the opening  11  is designed to allow the concrete  6  to pass through the floor  13  to the surface below the apparatus  10 , which in operation is the metal pipe  8 . 
     A pair of cable connectors  24  are attached to the forward wall  12   f  of the trough  12 , and they may also be connected to the rearward end of the apparatus  10 , such as on the support arms  18 . A cable, chain, rope or similar embodiment may be linked to the connectors  24  to assist the user in moving the apparatus  10  back and forth in a substantially horizontal direction. In addition, a lift connector  26  is affixed to the chute  18 , such that the apparatus  10  is able to be lifted and positioned using this connector  26 . 
     The apparatus  10  additionally includes at least one scraping apparatus for controlling the dispersion of the concrete  6  in the metal invert. A first scraping apparatus  30   a  is attached to the distal end  20   d  of the chute  18 . The first scraping apparatus  30   a  includes a pair of connectors, such as L-shaped arms  32 , that are securely connected to opposite sides of the chute  18 , such as by welding. A connecting aperture  34  extends through both L-shaped arms  32 , and through the use of a pin  35 , a support sleeve  36  is connected to the respective L-shaped arm  32 . 
     The scraping assembly  30   a  additionally includes a primary flexible scraper flange or wings  38  that is connected to the support members  36 . In the embodiment shown in the figures, the scraper flange  38  has somewhat of a semi-circular or semi-ellipse shape, with the width of the primary scraper  38  being greater than the width of the trough  12 . That is, the primary scraper  38  has a contoured side edge and a substantially flat bottom edge. In this embodiment, the scraper  38  is sandwiched between two metal plates  40  that are connected with a support member  37 . The scraper  38  is made of a flexible material (such as rubber) so that it will be able to bend when in contact with the metal pipe  8 . The support member  37  will traverse or engage the support sleeve  36  so that the position of the support member  37  may be adjusted with respect to the sleeve  36  to determine the position of the scraper  38  with respect to the runners  16  and the metal invert  8 . 
     In addition, a pivot bar or rod  39  may be mounted to the distal end  20   d  of the chute  20  to provide a supplemental means for adjusting the first scraping apparatus  30   a . That is, the first scraping apparatus  30   a  may be pivotally connected to the rod  39  so that the first scraping apparatus  30   a  may pivot between a lowered position (see  FIG. 1 ) and a raised position (see  FIG. 9 ). In the lowered position, the first scraping apparatus  30   a  will engage the concrete  6  distributed in the invert  8 , whereas in the raised position, the first scraping apparatus  30   a  will simply be displaced from the surface of the concrete  6 . 
     Continuing to view  FIG. 1 , the apparatus  10  may include a supplemental scraping apparatus  30   b  connected to opposite sides of the trough  12 . That is, the scraping apparatus  30   b  may be affixed to opposite sides of the rearward wall  12   r  of the trough  12 . The supplemental scraping apparatus  30   b  includes a secondary scraper flange or wing  42  that is connected to each side of the rearward wall  12   r  using a respective secondary plate  44  and bolt or screw  45 . The secondary scrapers  42  may be attached to the rearward wall  12   r  such that they extend outwardly from the trough  12  in opposite directions, with the secondary scrapers  42  engaging the side walls of the metal tube  8  as necessary. Because the scrapers  42  may be made of a somewhat flexible material (such as rubber), they will be able to bend as necessary for the apparatus  10  to traverse the metal invert  8 . Furthermore, a substantially horizontal slit  33  extends through each supplemental scraping apparatus  30   b , such that the position of the supplemental scraping apparatus  30   b  may be adjusted with respect to the pipe  8  as desired by simply loosening the screw or bolt  45  and adjusting the position of the secondary scraper flange  42  and secondary plate  44 . 
     Placing concrete  6  in the failed metal pipe inverts  8  is a much faster and less expensive process than conventional replacement of the metal pipe  8 . In operation, the concrete  6  from the mixer  21  is poured into the chute  20  through the recession  22 , and thereby distributed into trough  12 . The concrete  6  will temporarily be stored in the trough  12 , and the apparatus  10  will be pulled through the metal pipe  8 , with the forward end  16   f  initially leading the way through the pipe  8  the first time. The scrapers or wings  38  of the apparatus  10  will spread the concrete  6  as the apparatus  10  is pulled through the metal pipe  8 . The concrete  6  will fill up the holes below the invert  8  as well as the lower portion of the pipe invert  8  (see  FIG. 5   a ), and the concrete  6  will then be allowed to set. After the concrete  6  has set, the process will be repeated, and these steps will be followed until the complete bottom of the metal invert  8  is covered with concrete  6 , such as 3000 PSI pea gravel mix with fibermesh. 
     In order to fill all of the failed invert  8  at the desired distribution, the user may make multiple pulls of the apparatus  10  through the metal pipe  8 . That is, the rearward end  16   r  may be pulled back through the pipe  8 , and then the forward end  16   f  will be pulled through one again. The last pass is with adjusted scrapers or wings  38  so the concrete  6  can be smoothed and pulled up the walls of the metal pipe  8 . This gives a concrete bottom  6  for the water to run across during normal flow, and therefore the metal remains dry during this normal flow period. During rains or high water periods, the metal pipe  8  may fill up and carry the water load. After high flows recede, though, the water level will return to normal flow and the metal pipe  8  will dry. 
     The manpower needed for operation of the apparatus  10  will vary, but it is foreseen that it can be operated by two to three persons and take about one hour for typical operation in a standard pipe  8 , which would include passing the apparatus  10  down and back a pipe  8  of standard length (approximately 20 feet), with one additional pass all the way through the pipe  8 . During the first two pulls, the scrapers/wings  38  will be kept in an upright position. In the last pull through, the scrapers/wings  38  will be lowered and the user will simply pull the apparatus  10  all the way through the pipe  8 . 
     The apparatus  10  may operate with pipes  8  of having various lengths and widths. In addition to the standard sized pipes  8  noted above, it can be used with pipes  8  having various diameters (e.g, 54-72 inch diameters) and having lengths of 60 to 90 feet and longer according to the length of the pipe laid. These dimensions are simply examples, and it is noted that the diameters and lengths of the pipes  8  may vary with the apparatus  10  still being able to operate properly. Furthermore, the dimensions of the apparatus  10  disclosed above and in the drawings may vary as necessary for the corresponding pipe  8 . 
     While the invention has been shown and described in preferred forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein. For example, the footholds can be secured to the platform of the tree stand assembly. These and other changes can be made without departing from the spirit and scope of the invention as set forth in the following claims.