Abstract:
A placer/spreader for distributing already mixed concrete from an access road to a subgrade path to be paved includes a frame having at least two side bolsters standing parallel to the subgrade path and at least two cross beams spanning the subgrade path for forming a conveyor supporting structure. A roll in/roll out conveyor having a receiving end for receiving already mixed concrete from an access road and a discharge end for discharging already mixed concrete to the subgrade path, this conveyor being hinged to enable conformation to differing access road elevations. One of the two side bolsters defines forward and rear transport attachment points with a spatial interval between the transport attachment points. This spatial interval permits the roll in/roll out conveyor to be supported between forward and rear attachment points.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]     NOT APPLICABLE  
       STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     NOT APPLICABLE  
       REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK.  
       [0003]     NOT APPLICABLE  
       BACKGROUND OF THE INVENTION  
       [0004]     This invention relates to a placer/spreader for receiving mixed concrete or base materials and distributing these materials in windrows on subgrade in the path of a slipform paver. More particularly, a placer/spreader spanning a road subgrade is provided with a roll in/roll out conveyor for receiving concrete or base material from an access road along side the road subgrade and thereafter distributing the concrete onto the road subgrade for slipforming by a following paver. The placer/spreader includes a power unit offset from the roll in/roll out conveyor, and beam reinforced with the conveyor track for strengthening the placer/spreader frame and supporting crawler tracks. With the roll in/roll out conveyor telescoped within and underneath the frame, the placer/spreader frame folds into a compact simplified transport disposition for shipping on a single trailer between job sites with reduced set up time and overhead.  
         [0005]     Slipform pavers are commonly utilized for paving reinforced and non-reinforced concrete roadways and airfield pavements. It is common practice for the concrete delivery trucks to back up on the subgrade and dump the contents of the truck on the subgrade in the path of a slipform paver and thereafter slipform the placed concrete into the final profile of the specified concrete slab section. However, in some cases it is not possible for the trucks to drive on the subgrade of the roadway in the path of the slipform paver and a separate access road must be employed along side the road.  
         [0006]     The placer/spreader here disclosed has utility where an access road is required. Access roads are required along the road subgrade when the subgrade in front of the slipform paver is not suitable for driving and dumping (such as when the subgrade is extremely porous for example where superior drainage under the placed pavement is desired) or too soft thus not supportive enough for the delivery trucks. It also has utility to receive and distribute concrete over the top of pre-placed dowel basket assemblies or chaired continuous reinforcing bar reinforcement secured to the subgrade that would otherwise block the path of the concrete delivery trucks.  
         [0007]     Placer/spreaders of the prior art typically utilize a side delivery conveyor for receiving from concrete delivery trucks traveling along the access road (along side the road subgrade) and then distributing freshly mixed concrete in front of the slipform paver on the subgrade to be paved. These side receiving conveyors of are of two types; hinged conveyors and so-called “roll in/roll out” conveyors.  
         [0008]     Hinged conveyors extend to the side of the placer/spreader at the access road for receiving already mixed concrete from a delivery truck and transporting and distributing that concrete onto the subgrade in the path of the slipform paver. These hinged conveyors are relatively inexpensive and well understood in their operation. Such hinged conveyors do have disadvantages and advantages over roll-in/roll-out conveyor.  
         [0009]     First, such hinged conveyors typically hinge down onto and up out of an access roadway at the side of the road surface to be paved each time a delivery truck must pass. Typically there is not sufficient room on the access road for trucks to drive around the hinge conveyor in the down position. The access road is only wide enough for one truck to pass. Before such hinging up movement can occur, the conveyors have to be emptied of concrete. Only when the conveyors are emptied of concrete can hinging occur. Thus a precisely timed sequence of truck dumping and conveyor loading, belt emptying, and finally belt hinging up (to allow the next truck to pass) and coordinated delivery truck movement must occur. This precise coordinated movement is not always possible at construction sites, especially were soft road conditions make movement of both the placer/spreader and delivery trucks unpredictable.  
         [0010]     Where precise delivery truck and/or placer/spreader movement does not occur, collisions between the receiving end of the conveyor and delivery truck frequently occur. This often time results in structural damage to the conveyor, intermittent concrete delivery, and ultimately less than optimum slipform paver movement. Conveyor damage can be catastrophic bringing the entire road building process to a halt. Further, these collisions, intermittent delivery, and intermittent paver movement can cause uneven pavement surfaces with resultant contract penalties for placement of other than level (smooth) pavement surfaces. As modern road construction contracts provide premium or bonus payment for smooth roadways and deduction from full payment for uneven pavement surfaces, smooth/level pavement surfaces can significantly impact the road contractor financial results on the project.  
         [0011]     Furthermore, the time lost in running the conveyor empty prior to hinging up the conveyor reduces the productive ability of the placer/spreader by reducing the number of loads per hour that the placer/spreader can handle. This reduced productivity may require a second placer/spreader to be used in conjunction with the slipform paver in order for the paving spread to be able to absorb the full output of a high production concrete plant.  
         [0012]     Many times access road elevations can vary widely when the access road surface is soft. This can cause problems where the receiving end of the conveyor is too high for the truck to dump into. This leads to delay in the dumping of the truck and adversely affects production.  
         [0013]     It is known in the prior art that one advantage of the hinging conveying is that the angle of the receiving end of the conveyor can be varied hydraulically on the fly to match the slope or uneven elevation of the access road. The disadvantage of the prior art roll-in/roll-out conveyor is that it had no ability to adjust the angle of the receiving belt to match the slope or uneven elevation of the access road on the fly. The inability of the conveyor to adjust easily for varying access road slopes and elevations also contributes to lost production.  
         [0014]     The roll in/roll out conveyor of the prior art has a concrete receiving end and a slightly elevated concrete discharge end. The concrete receiving end typically telescopes out into and is supported in a cantilever fashion overlying the access road. This requires the access road to be well graded, compacted and level. Already mixed concrete is unloaded onto the cantilevered concrete receiving end of the conveyor. The roll in/roll out conveyor then undertakes two discrete movements.  
         [0015]     A first movement is the conventional operation of the conveyor transporting the received concrete from the receiving end of the conveyor to the discharge end of the conveyor. Dependent upon the location of the discharge end of the conveyor, concrete is distributed onto the subgrade to be paved.  
         [0016]     A second movement is the so-called telescoping movement of the conveyor. Typically, while the conveyor is running in conventional conveying movement (with concrete still on the belt), the entire conveyor telescopes relative to a supporting U-frame so that its discharge end traverses the subgrade to be paved (e.g. “roll-in”). In such traversing of the subgrade, concrete is still being unloaded off the belt and distributed as the discharge end traverses the subgrades to be paved. As much as a third of a truckload of concrete can still be present on the running belt when the belt is being rolled in.  
         [0017]     Additionally, and as a consequence of the second movement, the discharge end of the conveyor distributes the remaining concrete on the belt across the subgrade during its traversing movement. Prior to the transverse movement of the conveyor, concrete can accumulate in the traversing path of the telescoping conveyor overlying the subgrade. The conveyor discharge end when equipped with a strike-off plate can collide with and strike off the upper portion of the accumulated concrete pile, further distributing concrete on the subgrade to be placed. This allows the entire truckload of concrete to be discharged without delay.  
         [0018]     In contrast to this, a hinge-up conveyor design must receive the entire truckload of concrete before the placer/spreader can move ahead. With large truckloads of concrete, many times the concrete pile under the discharge end of the conveyor gets so high that it prevents remaining concrete on the conveyor from being discharged. The concrete backs up on the conveyor. The only way to resolve this situation is the placer/spreader and dumping truck must move ahead to make room under the discharge end of the conveyor so the conveyor can empty. Only when the conveyor is empty can the conveyor-receiving end hinge up to allow the next delivery truck to pass.  
         [0019]     Because of these distribution characteristics, roll in/roll out conveyors have superior concrete distribution characteristics over hinged conveyors and are more highly productive. Furthermore because of the inherent weakness of a hinge conveyor to side loads (namely a truck colliding with it) the roll in/roll out conveyor design is superior and more robust in construction. Because the hinged conveyor must be able to hinge more than 90 degrees, it is almost impossible to build a hinge with sufficient strength and structurally integrity to withstand being damaged when a truck hits it. The more robust construction possible with a the receiving end of a roll in/roll out conveyor makes it capable of colliding with and even pushing delivery trucks where a hinged conveyor is not. This is important from a standpoint of minimizing potential down time and increasing the productive capability of the roll in/roll out conveyor or a hinged conveyor.  
         [0020]     In the prior art, the roll in/roll out conveyor is typically supported on a separate support frame (conveyor module). This modular support frame includes paired bolsters aligned parallel to the subgrade to be paved on either side of the subgrade to be paved. Paired crossbeams span the subgrade between the bolsters and tie the two bolsters together. The conveyor and its overlying support frame (as a module) is inserted between bolster supported jacking columns with supporting crawler tracks in front and a traditional paver like tractor with power plant at the rear of the conveyor module. The diesel/hydraulic power unit is centered and on top of the tractor frame for the powering all the placer/spreader requirements including the roll in/roll out conveyor. This tractor unit also includes the removable set of rear jacking columns and supporting crawler tracks.  
         [0021]     Unfortunately, roll in/roll out conveyors as presently used and implemented on such support frames and tractor frames with power unit have had several disadvantages.  
         [0022]     First, such roll in/roll out conveyors and their supporting structures require heavy-duty construction. When loaded with already mixed concrete their weight increases considerably. Typically, when the conveyor is rolled in the conveyor can be holding up to four yards of concrete, each yard of concrete weighing approximately 3000 pounds. Thus the supported roll in/roll out conveyors are a heavy dynamic load, placing high loading on their supporting frames.  
         [0023]     These heavy roll in/roll out conveyors are typically provided with two support points. A first support point is adjacent the access road. This support point adjacent the access road enables the extended conveyor to cantilever out into the access road for receiving ready mix concrete. The second support point is on a rail spanning the width of the subgrade over the roll in/roll out conveyor. When the conveyor telescopes in, severe loading is placed on the support frame through the second support points on the spanning a rail. From the spanning rail, the loading is distributed to the placer/spreader frame.  
         [0024]     Second, such placer/spreader frames are utilized to support a hydraulic power plant for powering the entire placer/spreader including the roll in/roll out conveyor. Adding the weight of the roll in/roll out conveyors to the same frame supporting the power plant has thus far necessitated the use of two frames. Specifically, the tractor frame is utilized to support a ground-level concrete spreader (such as an auger spreader) and the hydraulic power unit. A second dedicated conveyor-supporting frame is utilized for the support of the loaded telescoping roll in/roll out conveyor.  
         [0025]     In the mid-1960s, CMI Corporation (originally Construction Machinery Inc.) of Oklahoma City, Okla. manufactured a placer/spreader known as the PST  400  having the above construction with a roll in/roll out conveyor belt. Since then, another manufacturer copied this machine in its entirety. The machine included a main tractor frame with two side bolsters supporting an underlying concrete spreader auger with strike-off and an attached overlying power unit. The main tractor frame had an attaching rear bolster. Attached to the front of the main tractor frame was a conveyor supporting frame (conveyor module) which had an underlying roll in, roll out conveyor and an attaching front bolster. The entire assembly was supported on four jacking columns with crawler tracks.  
         [0026]     This machine had superior function and productivity but was bulky, requiring multiple loads to be transported between job sites.  
         [0027]     Specifically, three discrete loads are required to transport it. Further, both assembly and disassembly of the unit requires a crane assist. Regarding the loads, a first load includes the main tractor frame with power unit and underlying spreader auger assembly. A second load includes the conveyor-supporting frame with underlying roll in, roll out conveyor. A third and final load included the disassembled front and rear bolsters each with jacking column and supporting crawler track. Disassembly and assembly of the placer/spreader was and is very time consuming taking days to set up and tear down.  
         [0028]     Moreover, the two discrete frames namely the conveyor support frame and tractor frame require re-sectionalization when a width change of the placer spreader is required say to change the width from a standard 24 ft. wide pavement to a 30 ft. wide pavement.  
         [0029]     It should be understood that spreader augers utilized by the prior art are less than optimum. Typically, and because of the limits of the auger flighting and the mass of the auger, a central support bearing is required to support the auger from the main tractor frame. The supported auger includes opposed auger flights terminated at the central bearing. Further, such augers have a diameter in the range of three feet in order to be large enough to spread concrete rapidly. Finally, and assuming that more concrete is placed on one side of the auger support bearing than on the other side of the auger support bearing, redistributing concrete across the central support bearing of the spreader auger is problematic at best. Furthermore, spreader augers are very costly to operate because of the auger flighting and bearings wears out rapidly when conveying abrasive concrete.  
         [0030]     During the research that lead the development of the following described placer/spreader, we encountered considerable resistance by our prospective customers to the use of roll in/roll out conveyor belts. This resistance was a direct result of the extraordinarily difficult and time-consuming set up, transport and width change costs of prior art machines utilizing roll in/roll out conveyors. Interestingly enough, even though they did not like the prior art placer/spreader customers often cited the advantages of the roll-in roll out conveyor. Specifically, we realized after our research that a placer/spreader utilizing a roll in/roll out conveyor (that had some limited ability to adjust the angle of the receiving end of the belt to adjust for sloped or uneven access roads) and that could be transported in a single load could have utility and value to our customers.  
         [0031]     The reader will realize that the above close analysis of failings of the prior art has been our work product, resulting from considerable research. It will be further understood that we have never seen the comments set forth above serially in the prior art together with the problems generated by such prior art. It is well known that the recognition of problems to be solved can constitute invention. Accordingly, we claim invention in recognizing the problems to be solved as well as setting forth the particular solutions to those problems.  
       BRIEF SUMMARY OF THE INVENTION  
       [0032]     A placer/spreader for distributing already mixed concrete from an access road to a subgrade path to be paved includes a frame having at least two side bolsters standing parallel to the subgrade path and at least two cross beams spanning the subgrade path for forming a conveyor supporting structure. A roll in/roll out conveyor having a receiving end for receiving already mixed concrete from an access road and a discharge end for discharging already mixed concrete to the subgrade path, this conveyor being hinged to enable conformation to differing access road elevations. One of the two side bolsters defines forward and rear transport attachment points with a spatial interval between the transport attachment points. This spatial interval permits the roll in/roll out conveyor to be supported between forward and rear attachment points. The other of the two side bolsters defining an attachment point for at least one transport. At least three transports are attached at the two side bolsters with the at least two transports attached to the forward and rear transport attachment points and the at least one transport attached to the other of the two side bolsters. A support mounted within the spatial interval between the transport attachment points provides for the cantilevered telescoping support of the roll in/roll out conveyor during telescoping movement adjacent the access road. A support rail for the traversing support of the discharge end of the roll in/roll out conveyor is included below the frame, so as to reinforce the frame against bending as well as provide a support for the traversing conveyor. A support attached at the discharge end of the roll in/roll out conveyor moves along the support rail for the traversing support of the discharge end of the roll in/roll out conveyor. Finally, there are means for moving the roll in/roll out conveyor in telescoping movement relative to the frame whereby the receiving end of the roll in/roll out conveyor is telescoped from and extends from the cantilevered support into the access road to receive already mixed concrete. Thus, the discharge end of the roll in/roll out conveyor discharges and/or distributes already mixed concrete across the subgrade path during the telescoping movement. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0033]      FIG. 1A  is a view of a prior art placer/spreader of the roll in/roll out variety illustrating the placement of concrete from an access roadway to a subgrade for the placement of a roadway or airfield pavement;  
         [0034]      FIG. 1B  is a view of the prior art placer/spreader of  FIG. 1A  with the placer/spreader dismantled for transport between job sites, here illustrating the necessity for movement in three discrete loaded segments with the crane required for such dismantling shown adjacent the loaded bolsters;  
         [0035]      FIG. 2  is a perspective view of a roadway and/or airfield pavement under construction showing a subgrade path traversed by the placer/spreader of this invention with a roll in/roll out conveyor extending across a nearby access road bounding the subgrade path and a slipformed paver partially shown slipforming already mixed concrete placed in windrows and spreading by the placer/spreader in front of the advancing paver;  
         [0036]      FIG. 3A  is a view of the placer/spreader spanning a minimum paving width illustrating movement of the roll in/roll out conveyor;  
         [0037]      FIG. 3B  is a view of the placer/spreader spanning a maximum paving width illustrating movement of the roll in/roll out conveyor;  
         [0038]      FIG. 4  is a top plan view of the placer/spreader shown with a strike off bar and spreader plow attachment disposed in configuration for placing and spreading the already mixed concrete along a subgrade path to be paved;  
         [0039]      FIG. 5  is a top plan view of the placer/spreader shown in  FIG. 3A  supported on an underlying trailer with crawler tracks pivoted to enable loading/hauling and the roll in/roll out conveyor retracted into and underneath the main tractor frame;  
         [0040]      FIGS. 6A, 6B  and  6 C are side elevation sections of the placer/spreader taken at the access road illustrating the cantilevered support of the roll in/roll out conveyor where the access road changes with respect to grade illustrating the placement of a hinge on the roll in/roll out conveyor and its adjustment to receive concrete;  
         [0041]      FIGS. 7A and 7B  are a series taken at the cross beams illustrating expansion of the cross beams by both the insertion of a combination rail segments and conventional bolt in beam segments with the view of  FIG. 7A  illustrating a straight beam and the view of  FIG. 7B  illustrating a beam having an adjustable profile for the placement of a berm in the placed concrete. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0042]     Referring to  FIG. 1A , the apparatus of the closest prior art is illustrated deployed for paving. Placer/spreader  10  is illustrated with frame F 1  containing telescoping conveyor belt B. Frame F 2  supports machinery module M, opposed augers A 1  and A 2 , and central auger bearing R. As has been emphasized, the opposed augers are heavy, require relatively high power requirements for operation, and have difficulty in spreading concrete across their bearing R. The illustrated placer/spreader  10  is followed by a paver P for the forming of the placed concrete. Four crawlers  11  with attached columns  12  propel placer/spreader  10 .  
         [0043]     In operational order, the belt places the concrete, the augers spread the concrete, and finally the paver P forms the concrete into the road profile. Thus the progress of the placer/spreader  10  is from the left to the right of  FIG. 1A .  
         [0044]     Concrete is typically mixed at a batch plant (not shown) and transported in dump trucks D 1  and D 2 . In the view here shown, truck D 1  is shown after having delivered a load of concrete; truck D 2  is shown ready to position itself after roll in/roll out conveyer telescopes inward.  
         [0045]     Referring to  FIG. 1B , the apparatus of the closest prior art is illustrated being transported between jobsites. Frame F 2  is on flatbed truck T 1  and frame F 1  on flatbed truck T 2  with crane C shown placing the final crawler  11  and jacking column  12  on flatbed truck T 3 . The reader will understand that while the schematic of  FIG. 1B  would make such disassembly appear trivial, the actual practice is quite different; much time and effort is required for the disassembly and assembly. This will be understood by reference to the following drawings, which drawings have been reproduced from actual construction drawings for the equipment here illustrated. Accordingly, it is a main purpose of the present disclosure to simplify this process of transport between jobsites.  
         [0046]     Referring to  FIG. 2 , placer/spreader  10  is shown supported on and propelled by two crawlers  11  and two jacking columns  12  adjacent access road  20  and one crawler  11  (not shown) and two jacking columns  12  on the opposite side. Placer/spreader  10  proceeds in direction  22  placing and spreading concrete while slip form paver P follows, slip forming the placed concrete  15  into the profile of the desired road or runway  16 .  
         [0047]     Concrete is received at belt B when the belt is telescoped out from under frame F. The concrete once received on the belt undertakes two functions. First, belt B conveys the concrete to the discharge end of the belt within frame F. Second, as belt B telescopes into the frame, the discharge end of the belt moves across the paving path from the side adjacent access road  20  to the side away from the access road  20 . This moves the discharge end of the belt B and causes further distribution of the concrete. Considerable power is required for this movement. Accordingly, hydraulic cylinders with accumulators are being used as of the writing of this application.  
         [0048]     Even this placement of the concrete is not perfect. Accordingly, between the strike off bar  30  and frame F there is placed spreader plow  32  riding on frame F. Spreader plow  30  through side to side movement further distributes concrete evenly into the advancing path of paver P. Further, strike off bar  30  also trims concrete to the desired profile at placed concrete  15  for slip forming by paver P. It will be seen that spreader plow  32  and strike off bar  30  by trailing belt B assure essentially an even distribution of concrete  15 . Spreader plow  32  is powered by a hydraulically operated reel and cable unit; powering by a double acting hydraulic cylinder can occur as well. Spreader plow  32  typically operates from a rail  31  which permits side to side movement.  
         [0049]     Power for the unit is required, the preferred unit here shown being hydraulic. Accordingly, machinery module M is placed eccentrically on frame F away from access road  20  toward single crawler  11  with its paired jacking columns  12 . This placement will be understood to be cooperative with the underlying railway for supporting the telescoping belt B, especially when placer/spreader  10  is expanded in width.  
         [0050]     Referring to  FIG. 3A , placer/spreader is shown configured for minimum  20  foot width. Several important features can be noted.  
         [0051]     First, telescoping belt B can be seen is side elevation in two dispositions. A first disposition has loading end  42  over access road with discharge end  44  located approximately medially of frame F. Second, belt B is shown telescoped into frame F with discharge end  44  remote from access road  20 . It will be understood that belt B telescopes horizontally between the two positions, discharging concrete during the telescoping movement.  
         [0052]     Second, belt B has a belt strike off plate  46 . As belt B moves in telescoping movement relative to frame F, strike off plate  46  will itself serve to spread concrete when concrete accumulates to the level of strike off plate  46 .  
         [0053]     Third, belt B is supported adjacent access road  20  by cantilever support  48 . Further, belt B is supported within frame F by rails  49 . These rails  49  allow belt support  41  to traverse the underside of frame F. Further, it will be understood that rails  49  stiffen the section of frame F as it supports machinery module M.  
         [0054]     Fourth, it will be seen that belt B is provided with a medial hinge  40 . Hinge  40  flexes belt B through an angle not exceeding 15°. This point of hinging allows belt B to accommodate access roads  20  of varying elevation relative to the path of placer/spreader  10 .  
         [0055]     Referring to  FIG. 3B , frame F is shown expanded to maximum 40 foot width. Along with the expansion of frame F, rails  49  are likewise expanded. This the traverse of discharge end  44  with its strike off plate  46  is expanded. Further, the section of frame F reinforced by rails  49  is also increased. It is this duality of the section of frame F reinforced by the section of rails  49  that makes the expanded unit possible to support machinery module M and undertake the dynamic loading caused by the telescoping movement of belt B. In the expanded disposition, all functions illustrated remain the same. It will be understood that the expansion is accomplished by the insertion of frame and rail segments  47 . The configuration of these segments as actually used are illustrated in the drawings; the reader will be understood that this configuration can be varied as necessity requires.  
         [0056]     Referring to  FIG. 4 , a plan view of placer/spreader  10  is illustrated. Frame F is illustrated with crawlers  11  and jacking columns  12  supporting frame F. Here, and distant from access road  20 , a single crawler  11  having two supporting jacking columns  12  is utilized. Adjacent access road  20 , paired crawlers  11  each with its own attached jacking column  12  is utilized. As will here after emphasized with respect to  FIG. 5 , these respective crawlers  11  and jacking columns  12  are attached to frame F by pivotal arms  51 . The pivotal arms allow convenient folding of crawlers  11  to a position adjacent frame F when transport of the placer/spreader between jobsites occurs.  
         [0057]     Continuing on with  FIG. 4 , strike off bar  30  is supported from frame F by attachment probes  60 . Additionally, it can be seen that spreader plow  32  traverses frame F on a cable and rail system  62 . It will be understood that any system that enables spreader plow  32  to traverse frame F is acceptable; for example cable and rail system  62  could just as well have a hydraulic system supplant their function.  
         [0058]     It is important to provide the operator with a platform having a vantage point over the operation. Accordingly, fold down platform  64  provides for operator support overly telescoping belt B, spreader plow  32  and strike off beam  30 .  
         [0059]     It will be seen that the two crawlers adjacent access road  20  that are supported on pivotal arms  51  have rotation relative to the pivotal arms  51 . This not only permits steering of placer/spreader  10  but additional is critical in assuring a compact disposition of the placer/spreader when it is shipped between jobsites.  
         [0060]     Referring to  FIG. 5 , placer/spreader  10  is shown configured for transport between jobsites. First, crawlers  11  and jacking columns  12  have been pivoted on arms  51  to be adjacent the sides of frame F. In this disposition, the entire assembly is slightly over 8 feet of width and easily fits on a 40 foot long single flatbed truck. Further, jacking columns  12  can raise frame F to an elevation where a flat bed truck is easily backed under the elevated frame F.  
         [0061]     Once frame F is supported on a flatbed truck, jacking columns  12  can be raised from ground support to support from the bed of the truck.  
         [0062]     Further, spreader plow  32  is pivoted upward. At the same time, strike off bar  30  is drawn into close juxtaposition relative to frame F. The entire placer/spreader  10  is capable of being hauled on a single trailer.  
         [0063]     Referring to  FIG. 6A , a side elevation of placer/spreader  10  is taken from access road  20 . Crawlers  11  and their respective jacking columns  11  are shown with reciprocating belt B supported at cantilever support  48 . As can be seen, the height of cantilever support  48  can be varied to produce correspondingly varied support of belt B.  
         [0064]     Referring to  FIG. 6B , belt B is shown elevated for receiving concrete from an access road having an elevation above the surface upon which concrete is placed by the placer/spreader  10 . Similarly, referring to  FIG. 6C , belt B is shown for receiving concrete from an access road having an elevation below the surface on to which concrete is placed.  
         [0065]     Referring to  FIG. 7A , strike off beam  30  is illustrated in its narrowest disposition. In this disposition, the beam is 20 feet of width and comprises a solid straight beam extending across the pavement path. Referring to  FIG. 7B , strike off beam  30  is provided with a central hinge member  60  having a lower hinge  62  and an upper hydraulic cylinder  64 . The width of the strike off beam  30  is here expanded to 22 feet. By expansion and contraction, cylinder  64  can apply an upwardly exposed berm centrally of the placed pavement. It will be understood that by the addition of various metal sections, beam width can be likewise expanded, for example to widths of 32 and 40 feet.  
         [0066]     In the preferred embodiment, we have illustrated crawlers. It will be understood that other devices will work as well. For example, rails and flanged wheels are sometimes used. Any transport scheme capable of preserving the level placement of concrete will suffice.  
         [0067]     The above specification is exemplary of the main points of novelty of this invention. Much standard detail has not be described. For example, the apparatus illustrates leveling gauges for leveling the roughly placed concrete relative to a guide wire system. This system is common to pavers used throughout the paving industry and will not be further explained here. to under 12 ft We normally leave out the specific dimensions. It should be enough that you “narrow.” Claim  16 .