Patent Publication Number: US-6655870-B1

Title: Narrow gauge road paving apparatus

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to concrete paving and paving repair machines and, in particular, to a narrow gauge road repair apparatus. 
     Concrete road paving machines are well known. Concrete roads are typically paved utilizing fixed form paving methods or slipform paving methods. Fixed form paving methods are typically manual in nature and utilize wood or concrete forms to help the concrete achieve its desired shape. Slipform paving methods, utilizing slipform paving machines, are preferred. Slipform paving machines do not require a wood or concrete form for the concrete and are commonly self-propelled. A typical slipform road paving apparatus includes a frame, a means of self-propulsion, an auger for extruding the concrete mixture, a roller for smoothing the concrete mixture after extrusion, and a vibrating apparatus or tamper to help consolidate the concrete and ease the progress of paving by making the concrete more fluid. 
     A common practice for paving roads is to utilize these prior art fixed form paving methods or slipform paving machines to lay parallel lanes of concrete paving material typically corresponding in width to traffic lanes. The parallel lanes are connected at a longitudinal joint known in the art as the centerline, which is then treated with a sealant. A common problem is that the centerline often cracks and requires repair much earlier than the remainder of the road because the centerline is the weakest link in the road and allows for the introduction of moisture and incompressible materials regardless of the type of sealant used. Cracks requiring repair also occur along longitudinal expansion saw cuts for the same reasons outlined above. 
     To address these problems and in an effort to keep road repair costs low, many transportation agencies responsible for road repair are choosing to repair just the damaged pavement surrounding the centerline, rather than the more expensive and time-consuming choice of replacing the entire roadway. A damaged portion of each parallel lane adjacent the centerline is removed and replaced with new concrete. Typical slipform road paving machines are not suited for this type of repair because the width of the paving section is generally two feet, much less than that of prior art machines designed to pave a whole roadway or an entire lane. As a result, the repairs must be done manually, which is both expensive and time-consuming. When repaired manually, only approximately 300 feet of roadway can be repaired per day. 
     It is desirable, therefore, to provide a road repair apparatus for paving narrow gauge sections of a road and, in particular, to provide a road repair apparatus for use in centerline longitudinal joint removal and replacement operations. 
     SUMMARY OF THE INVENTION 
     The present invention concerns an apparatus for paving a narrow gauge trench in a concrete roadway. Preferably, the paving apparatus is utilized in centerline longitudinal joint removal and replacement operations. The paving apparatus according to the present invention includes an elongated frame having opposed ends. The frame includes a generally horizontal lower portion having a front wall and a rear wall extending upwardly therefrom, forming an open upper end and having a generally V-shaped cross section. A hopper is attached to the open upper end at one of the opposing ends of the frame. A concrete dispensing aperture extends through the lower portion of the frame at the other opposing end of the frame. An auger is disposed in and extends along the length of the a frame. The auger is rotatably attached to the opposing ends of the frame. A generally V-shaped strike-off member that is shaped to the width of the narrow gauge trench is attached to and extends downwardly from a lower portion of the frame adjacent the dispensing aperture. A roller is attached to and extends downwardly from a lower portion of the frame adjacent the strike-off member and extends rearwardly from the strike-off member. Preferably, the frame is adapted to be attached to a backhoe, tractor, or other type of vehicle having a power take-off that is operable to supply pressurized hydraulic fluid to a hydraulic system on the apparatus. The hydraulic system is the prime mover for the auger, and also controls the operation and orientation of the strike-off member and the roller through various pumps, valves, and rams. 
     In operation, the apparatus is attached to the vehicle, the hydraulic system is pressurized and a concrete mixture is introduced into the hopper at one end of the frame. The concrete mixture is moved toward the other end of the frame by the auger. The auger also maintains the proper mixture and keeps the concrete mixture flowing. The operator of the vehicle maneuvers the strike-off member adjacent the previously prepared trench and orients the dispensing aperture, the strike-off member, and the roller to a desired location. The concrete mixture exits the frame and is poured into the trench through the dispensing aperture. As the operator moves the vehicle forward along the longitudinal axis of the trench, the strike-off member directs the concrete mixture into the trench and moves any excess concrete further along the trench and the roller smoothes the poured concrete mixture in the trench when it passes over the poured concrete. The operator of the vehicle can advantageously change the orientation of the dispensing aperture, the strike-off member, and the roller as well as the operation of the auger and the roller during operation of the apparatus depending on the requirements of the paving. The operator of the apparatus controls the forward speed of the vehicle, the orientation of the strike-off member and the roller as well as the operation of the auger in order to fill the trench with the proper amount and location of the concrete mixture. 
     The apparatus according to the present invention is advantageously lightweight, portable, and inexpensive because it is operable to be attached to many types of vehicles and is not self-propelled. The apparatus allows narrow gauge trenches to be quickly and inexpensively paved. Utilizing the apparatus according to the present invention, approximately 6000 feet of roadway can be repaired per day. The apparatus provides a lightweight and portable means for paving a narrow gauge trench in a concrete roadway. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which: 
     FIG. 1 is a view of a block diagram of a hydraulic system for use with an apparatus in accordance with the present invention; 
     FIG. 2 is a front perspective view of a narrow gauge road repair apparatus according to the present invention; 
     FIG. 3 is a top perspective view of the apparatus shown in FIG. 2; 
     FIG. 4 is a rear perspective view of the apparatus shown in FIG. 2; 
     FIG. 5 is another rear perspective view of the apparatus shown in FIG. 2; 
     FIG. 6 is a side perspective view of the apparatus shown in FIG. 2; and 
     FIG. 7 is another top perspective view of the apparatus shown in FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to all of the drawing figures, a narrow gauge road repair apparatus according to the present invention is indicated generally at  10 . The paving apparatus  10  includes an elongated frame  12  having a front wall  14  and a rear wall  16  extending upwardly from a lower wall  18 , forming a generally V-shaped cross-section that defines an upper opening  20 . The frame  12  includes a first end  22  and a second end  24  attached to opposite ends of the walls  14 ,  16  and  18  to form a receptacle. The rear wall  16  of the frame  12  includes a mounting member  26 , best seen in FIG. 6, attached thereto that is operable to be attached to a vehicle, indicated generally at  28 , such as a backhoe, tractor, or similar vehicle. 
     A hopper  30  is attached to the first end  22  of the frame  12 . The hopper  30  is operable to receive a wet concrete mixture (not shown) in an upper opening  31  thereof. A generally planar first cover member  32  is attached to respective upper surfaces of the front wall  14  and the rear wall  16  adjacent the hopper  30  and extends from the hopper  30  towards the second end  24  of the frame  12 . The first cover member  32  covers the upper opening  20  of the frame  12  to a point  34  intermediate the hopper  30  and a second cover member  36 , best seen in FIG. 7, attached to the frame in a similar manner. A hydraulic system, indicated generally at  38  and discussed in more detail below, is attached to an upper surface of the second cover member  36 . A first wheel assembly  40  is attached to a side surface of the first end  22  of the frame  12  below the hopper  30 . The first wheel assembly  40  includes a longitudinal member  42  having a front wheel  44  and a rear wheel  46  attached thereto. A second wheel assembly  48  is attached to a side surface of the second end  24  of the frame  12 . The second wheel assembly  48  includes a longitudinal member  50  having a front wheel  52  and a rear wheel  54  attached thereto. The rear wheel  54  of the second wheel assembly  48  extends outwardly at an angle beyond the second end  24  of the frame  12 , best seen in FIG.  4 . 
     A concrete dispensing aperture  65 , best seen in FIG. 5, extends through the lower wall  18  adjacent the second end  24  of the frame  12  below the hydraulic system  38 . An elongated auger  56  is disposed in the frame  12  and extends along the length of the frame  12  from the hopper  30  to the dispensing aperture  65 . The auger  56  is rotatably attached to the first end  22  and the second end  24  of the frame  12 , preferably by a ball bearing connection or the like. A generally V-shaped strike-off member  58  is hingedly attached to two members  60  extending downwardly and rearwardly from a lower surface of the front wall  14  of the frame  12  and is suspended by a chain  62  from a strike-off member control ram  64 , discussed in more detail below, which is attached by another chain  66  to an upper surface of the rear wall  16  of the frame  12 . The strike-off member  58  is sized to accommodate a narrow gauge trench (not shown) in a roadway (not shown). A roller frame  67  is hingedly attached to mounting projections  68  on a lower portion of the rear wall  16  adjacent the strike-off member  58  and includes longitudinal members  70  which extend downwardly to join with opposing ends of a transverse member  72 . Roller mounting plates  74  are attached to the outer surface of the transverse member  72  and rotatably receive opposed ends of a roller  76 , which extends rearwardly from the strike-off member  58 . The transverse member  72  is suspended by another chain  78  from the strike-off member control ram  64 . 
     The hydraulic system  38  includes an inlet connection  80  and an outlet connection  82  that supplies hydraulic fluid (not shown) from a pressurized hydraulic fluid supply  81 , best seen in FIG. 1, on the vehicle  28 , such as by a power take-off or the like, to a central header or manifold  84 . The manifold  84  supplies the hydraulic fluid to a plurality of inlet conduits  86  and receives the fluid from a plurality of outlet conduits  88  extending therefrom. The conduits  86  and  88  are connected to a plurality of electrically actuated valves  90 . The valves  90 , when actuated by a controller (not shown), supply hydraulic fluid to a hydraulic auger motor  92 , the strike-off member control ram  68 , and a hydraulic roller motor  94 . The hydraulic auger motor  92  rotates the auger  56  via a chain or belt (not shown). The strike-off member control ram  64  controls the vertical orientation of the strike-off member  58  and the roller  76 . The hydraulic roller motor  94  rotates the roller  76 . 
     Preferably, the dispensing aperture  65 , the strike-off member  58 , and the roller  76  are located to a side of the vehicle  28 , best seen in FIG. 4, so the paving apparatus  10  may be utilized and viewed from within the vehicle  28  during operation. Alternatively, the dispensing aperture  65 , the strike-off member  58 , and the roller  76  are located directly in front of the vehicle  28 , which straddles the trench. 
     In operation, the paving apparatus  10  is attached to the vehicle  28 , the hydraulic system  38  is pressurized and the wet concrete mixture is introduced into the hopper  30  at the first end  22  of the frame  12 . When the hydraulic system  38  is pressurized, the valves  90 , the hydraulic auger motor  92 , the strike-off member control ram  64 , and the hydraulic roller motor  94  are energized, enabling the operation of the strike-off member  58 , the roller  76 , and the auger  56 . The concrete mixture is fed from the hopper  30  into the interior of the frame  12  and is moved toward the second end  24  of the frame  12  by the auger  56 , which is actuated by the hydraulic auger motor  92 . The auger  56  also maintains the proper liquidity for the concrete mixture in order to keep the concrete mixture flowing. The operator of the vehicle (not shown) maneuvers the strike-off member  58  above and adjacent the previously prepared trench (not shown) in the roadway surface (not shown) and orients the dispensing aperture  65 , the strike-off member  58 , and the roller  76  to a desired location. The concrete mixture exits the frame  12  and is poured into the trench through the dispensing aperture  65 . The strike-off member  58  is preferably lowered by the strike-off member control ram  64  so that a lower surface of the strike-off member  58  is touching the roadway surface. As the operator moves the vehicle  28  forward along the longitudinal axis of the trench, the strike-off member  58  skims the roadway surface and directs the concrete mixture into the trench and moves any excess concrete further along the trench. The roller  76  is rotated by the roller motor  94  in a direction opposite the travel of the vehicle  28  in order to smooth the poured concrete mixture in the trench and to push the concrete mixture farther down the trench. The operator of the vehicle  28  can advantageously change the orientation of the strike-off member  58  and the roller  76  as well as the operation of the auger  56  and the roller  76  during operation of the paving apparatus  10  depending on the requirements of the paving by starting, stopping, or varying the hydraulic fluid flow to the valves  90 , the auger motor  92 , the strike-off member control ram  64 , and the roller motor  94 . 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.