Abstract:
A pipe arching apparatus, comprising an internal means for flattening and elongating the lower circumference of a pipe, while said pipe is positioned upon the ground. The apparatus is retractably compactible to be towably transportable and will arch pipes of larger size and longer lengths than traditional pipe arching equipment. 
     It is powered by an internal combustion engine, has hydraulically extendible radius forms for forcibly reshaping the inside of a pipe, and is steerably drivable into and out of a pipe.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of provisional patent application No. 60/085,777 Filed May 18, 1998. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     REFERENCE TO MICROFICHE APPENDIX 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to pipe arching apparatus, and more particularly to a pipe arching apparatus that flattens and elongates the lower circumference of a pipe positioned directly upon the ground. 
     Arched pipe is used for highway drainage systems and various other construction projects where diversion of water flow or drainage of runoff is required. Full round pipe is suitable for most applications. However, sometimes it is beneficial to use a round pipe that has been forcibly widened at the bottom to increase the water flow area. 
     Prior pipe arches have been formed in the factory, either by an external pipe arching apparatus or by an internal pipe arching apparatus. To affect external pipe arching, force is applied directly to the external surface of the pipe to compress it until a desired shape is obtained. Although pipe arched by an external pipe arching apparatus is suitable for some applications, the act of forcibly reshaping the outer circumference could structurally weaken the pipe. A more uniform arch can be obtained by using an internal pipe arching apparatus. 
     A typical internal pipe arching apparatus utilizes a horizontal beam, with longitudinally extending radius forms mounted on opposite sides of the beam. The beam is about 25 feet long. The radius forms are extendible in opposite directions in a horizontal plane to forcibly reform the internal side walls of a pipe section that is suspended on the beam. As the side walls of the pipe are stretched to flatten the bottom of the pipe, some stretching and flattening of the upper pipe circumference also occurs which could structurally weaken the pipe. 
     A recent attempt was made to produce a pipe arching apparatus that could be used at the job site. The apparatus featured the typical horizontal beam arrangement, with a forklift truck at one end and a wheel support arrangement at the other. This apparatus could not be readily transported to the job site due to size and weight considerations. Additionally, it could not be self propelled to the job site unless the job site was within a very short distance. Even if it were practical to get this apparatus to the job site, it would only be able to arch a pipe of a size it could lift into arching position. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention comprises an apparatus for arching pipe that forcibly flattens and elongates the internal lower circumference of a pipe that is positioned upon the ground. The machine includes a set of wheels at the front and rear of a horizontal beam arrangement, to create a structure that is substantially similar in size and shape to existing trucking industry trailer designs. The beam is about 15 feet long between the wheels. Extendible radius forms are mounted on opposite sides of the beam. The radius forms are extendible in opposite directions, vertically and horizontally, allowing forming in the lower circumference prior to forcibly reforming the internal side walls of the pipe. The machine can be repositioned within the pipe and the steps of flattening and elongating the lower circumference can be repeated as many times as necessary to arch the entire pipe length. 
     It is the principal object of the present invention to provide an apparatus for arching pipes that is readily transportable and is not limited by the same size and length considerations of traditional pipe arching equipment. 
     This and other advantages of the present invention will become apparent from following the detailed description taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a perspective view of the pipe arching apparatus shown in a fully extended position just after exiting a piece of arched pipe. 
     FIG. 2 is a perspective view of the pipe arching machine shown in a partially extended position just before entering a piece of round pipe. 
     FIG. 3 is a perspective view of the pipe arching machine shown in a completely retracted position to be towably transportable. 
     FIG. 4 is a top view of the pipe arching machine as shown partially extended. 
     FIG. 5 is a front view of the pipe arching machine as shown partially extended. 
     FIG. 6 is a side view of the pipe arching machine as shown partially extended. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now in detail to the drawings, the present invention, a pipe arching apparatus as shown in FIGS. 2 and 4, includes a plurality of radius forms  70 , pivotably attached with pivot pins  29 , to an elongated weldment beam structure  80 . The beam structure  80  is connected with pivot pin  55 , to a wheel carriage  30  at one end, and pivotably connected with pivot pin  64 , to wheel carriage  50  at the other end. An operator platform  40 , with controls  61  is mounted to the surface of wheel carriage  50 , with a hydraulic rack and pinion  63  connected at pin  64  to make wheel carriage  50  steerable. Means for producing rotational energy  60 , is mounted to the surface of wheel carriage  30 , and includes; an internal combustion engine with transmission  51 , rotationally coupled to a gearbox  52 , which is rotationally coupled to a hydraulic power supply  53  including a hydraulic motor  54  to provide means for controllably coupling said rotational energy to wheel carriage  30 . 
     Referring now to FIGS. 1 and 5, Radius forms  70 , includes; form shoes  12 , attached with pivot pins  38  to outer elongated supports  22  which are connected with pivot pins  26  to inner elongated supports  23 . Outer supports  22  are actuated by hydraulic cylinders  24 , which are end clevis mounted to inner supports  23  and rod clevis mounted to outer supports  22 . Inner supports  23  are attached to beam structure  80  with pivot pins  29 , and are actuated by hydraulic cylinders  27  which are end clevis mounted to beam structure  80  and rod clevis mounted to inner supports  23 . 
     The elongated beam structure  80 , as most clearly shown in FIGS. 1,  5  and  6  includes; vertical articulation links  81  connected with pivot pins  33  at both ends of beam structure  80 . Pivot pins  82  connect links  81  with wheel carriage  50  at pivot pin  64  and with wheel carriage  30  at pivot pin  55 . Hydraulic cylinders  83  are end clevis mounted to beam structure  80  and rod clevis mounted to the vertical articulation links  81 . The articulation links  81  are provided to allow for vertical adjustment of beam structure  80 . Upper pipe form  17 , and side pipe forms  16  are pivotably connected at  19  to provide a hinged canopy structure. The underside of form  17  and upper surface of beam structure  80  are provided with pivot connectors  42  and pivot pins  43 , which are used to connect a series of pivot links  37  to form a scissor lift arrangement. A hydraulic cylinder  71  is end clevis mounted to the upper surface of beam structure  80  and rod clevis mounted to canopy pivot pin  41 . Cylinder  71  is used to raise and lower the scissor lift arrangement. Swing out arms  15  are pivotably connected to pipe forms  16  with pivot connectors  18  and pivot pins  36 . The opposite end of swing out arms  15  are interconnected to radius forms  70  with pivot pins  26 . As the scissor lift arrangement is raised the swing out arms  15  cause pipe forms  16  to swing up and out in relationship to beam structure  80 . 
     Referring now to FIGS. 1 and 2, the pipe arching apparatus  20 , is shown in front of a piece of pipe  10  before being reshaped into an arch shape in FIG.  2  and after being reshaped into an arch shape in FIG.  1 . The pipe arching apparatus  20  as shown in FIG. 2 is driven into a pipe  10  that is positioned upon the ground. At a point where the radius forms  70  are inside pipe  10 , the radius forms  70  are hydraulically extended down into contact with the lower circumference of pipe  10  to forcibly begin to flatten out the radius. The beam structure  80  may also be lowered at this time to bring the full weight of the pipe arching apparatus  20  into contact with the bottom of the pipe  10  if needed. The act of flattening the lower circumference of pipe  10 , results in the upper circumference being lowered proportionally. The radius forms  70  are then extended in opposite directions laterally into the pipe wall to forcibly elongate the lower circumference of pipe  10  until the desired arch shape is achieved. The steps of flattening and elongating the lower circumference may be repeated as necessary to achieve the desired arch shape and the pipe arching apparatus  20  can be progressively moved through a length of pipe  10  repeating these steps as many times as needed. The upper pipe form  17  and side pipe forms  16  help to avoid elongating the lower circumference beyond the desired arch shape. As the upper radius of pipe  10  comes into contact with pipe form  17  the arching process is completed. The upper circumference of the pipe retains a consistent radial form since the area that needs to be reformed is the only area that is reformed using the method of flattening and elongating the lower circumference of a pipe while the pipe is positioned upon the ground. 
     Referring now to FIG. 3 the pipe arching apparatus  20  is shown fully retracted. Side pipe forms  16  conceal radius forms  70  (not shown), upper form  17  conceals the scissor lift arrangement, and the complete arching apparatus  20  is now compact for transport. A tow hook  95  is provided to make the arching apparatus towably transportable. 
     Various changes and modifications may be made in carrying out the present invention without departing from the spirit and scope thereof. Insofar as these changes and modifications are within the purview of the appended claims, they are to be considered as part of the invention.