Patent Publication Number: US-2021172124-A1

Title: Versatile Light Rail Bed Paver

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This utility conversion application is based upon and claims priority from prior U.S. Provisional Application entitled “Versatile Light Rail Bed Paver,” Ser. No. 62/946,140, Filed Dec. 10, 2019, by inventor Edward Andrew Waldon (American Citizen), which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates generally to mechanized pavers for compacting and densifying raw or wet concrete when forming supportive decks. More particularly, the present invention relates to concrete pavers for shaping and finishing rail trackbeds characterized by multiple, parallel, plinth strips separated from and/or bordering multiple, parallel, channel floors. 
     II. Description of the Prior Art 
     Modern “light-rail” train systems offer numerous well-known transportation advantages and efficiencies to urban environments. Light rail systems provide a form of tramway or urban rail transit, using rolling stock. They operate at a higher capacity than most historical tramways, and are often formed on an exclusive right-of-way in potentially congested commuting areas. In use, either individual tramcars or multiple units are coupled to form a train that is of lower capacity and lower speed than a conventional, heavy-rail passenger train or metro system. A few light rail networks tend to have characteristics closer to rapid transit; some of these heavier, rapid transit-like systems are referred to as light metros. Other light rail networks are tram-like in nature and partially operate on streets. 
     Light-rail systems of course include elongated stretches of rails, which are placed over suitable supporting trackbeds constructed along dedicated pathways. A typical trackbed comprises lower layers of ballast and sub-ballast prepared over a subgrade. A properly constructed trackbed can significantly improve the ride quality experienced by passengers. The trackbed&#39;s uppermost, exposed outer deck usually comprises concrete, which may be laid down and shaped by concrete finishing and placement machines known in the art. Suitable raised concrete projections, comprising slightly elevated blocks or slabs known as plinths, can be formed for supporting steel rail tracks and their mounting hardware, which are secured to the trackbed as the construction process progresses. 
     It is well recognized in the art that wet or plastic concrete must be processed or finished soon after pouring and before significant hardening to achieve desirable characteristics. Wet concrete is normally discharged from above and poured between spaced-apart forms that may border and traverse regions to be paved, such as bridge decks and the like. Usually wet concrete is poured immediately in front of a concrete finishing machine that may be supported by spaced-apart concrete forms that function as supporting guide rails for the machinery. For best results, it preferred to vigorously vibrate green concrete during pouring to facilitate desirable concrete consolidation. A variety of finishing devices such as strike-offs, screeds, vibrating screeds, roller screeds or pavers, and bridge deck pavers are known in the concrete arts. Various propulsion means may be employed for machine displacement over supports for travel along the deck length. 
     The concrete deck forming the top of the trackbed can be formed, but not without difficulty, with various bridge deck and concrete placement apparatus. The concrete deck may comprise at least a pair of parallel, spaced apart, plinth strips for supporting pedestal-like plinth structures that are subsequently formed atop the concrete structure. Completed plinth&#39;s are formed with elevated, box-like support forms that surround rebar stirrups emanating from the previously established plinth pathways. Smoothed channels usually comprising a squarish or rectangular profile are preferably formed between the plinths. These channels may be shaped or interiorly contoured for a variety of reasons, such as supporting drainage scuppers at the reduced elevation centers of one or more of the channel floors. Once the plinths are finished, the bordering channel floors form the bottom of troughs that extend along and adjacent to the plinths. 
     Plinth strip rebar stirrups provide an attachment means for the subsequently attached rail mounting hardware and the various rails themselves. After the concrete hardens, the various rail supporting hardware items, including fasteners, support plates, dampening layers and the like are fastened atop the plinths and interconnected with rebar prior to installation of the train rails. 
     Automated concrete finishing and forming machines for quickly and efficiently laying down significant lengths of trackbed concrete, with a proper arrangement of plinth and channel structures, are thus desirable. However, known concrete finishing machines of conventional construction are not particularly adept at the latter function. 
     Allen Engineering Corporation has previously developed concrete finishing machines that can use rigid, horizontally disposed, support frames, such as box frames or triangular truss frames. These can support various tool arrangements that hang down and contact wet concrete. Allen U.S. Pat. No. 4,249,327, for example, discloses a rigid, elongate triangular truss frame. 
     Besides well-known screed and strike-off elements, rollers are known. For example, a roller-tube finishing machine is seen in U.S. Pat. No. 4,314,773 issued Feb. 9, 1982 and owned by the present assignee. It discloses a form-riding, concrete placement and finishing machine comprising multiple roller tubes, that is positioned above an area into which wet concrete has been poured, for vibrating the concrete mass and finishing the concrete surface. 
     U.S. Pat. No. 4,702,640 issued Oct. 27, 1987, and also owned by Allen Engineering Corporation, discloses another rotating-tube type concrete finisher. 
     U.S. Pat. No. 5,562,361 issued to Allen Engineering Corporation Oct. 8, 1996 discloses a powered, form-riding, concrete finisher that uses a trio of rotating tubes to strike-off, screed and finish concrete. 
     U.S. Pat. No. 5,352,063, issued to Allen Engineering Corporation on Oct. 4, 1994 discloses a concrete finisher entitled “Polymer Concrete Paving Machine.” The latter machine comprises a self-propelled paver that distributes, consolidates, places and finishes polymer concrete to resurface roadbeds. A finishing assembly secured upon a supportive chassis includes a distribution assembly for applying concrete transversely across a surface, and a trailing finishing screed that densifies the concrete. The finishing screed comprises a rigid strike off that initially contacts uncompacted concrete laid by the distribution system. However, none of that machine&#39;s accessories or parts are configured or designed to shape rail trackbeds. 
     While the previously discussed finishers such as roller tube finishers are ideal for certain concrete structures, like bridge decks and floors of “big box” stores, etc., they are impractical for rail trackbed projects because of the alternating plinth&#39;s and voids needed in a rail trackbed deck. Numerous other concrete placement machines of diverse forms have been patented by the present assignee, but none are particularly relevant to the construction of concrete rail beds where plinth strips and intermediate channels are required. For example, there are numerous types of strike-offs in use, such as the designs seen in U.S. Pat. No. 5,476,342, owned by the same assignee as in this case. 
     However, applicant is unaware of any concrete forming machine designed for the specific application of treating and forming concrete trackbed decks, with their plinths and parallel channels. Providing concrete finishing apparatus especially configured for dealing with alternating plinth&#39;s and channels needed in a rail trackbed deck is the goal of this invention. 
     SUMMARY OF THE INVENTION 
     A concrete finishing and forming machine adapted especially for rail trackbed deck construction, accommodates the subsequent completion of various plinths and channels needed for light rail construction. 
     The highly versatile and adjustable machine is quickly adaptable to a wide variety of deck configurations and sizes, and may be adjusted at the job site to accommodate varying trackbed paths, inclinations, and angular pathways. The machine preferably comprises an elongated, horizontally extending box or truss frame disposed above the deck by preferably four, vertically upright, adjustable jack stands. In one configuration a jack stand is positioned at each machine corner. The jack stands are supported at their bottoms by wheeled bogies. Preferably the bogies rest upon upon suitable supports, such as travel rails, provided at opposite sides of the intended deck location prior to concrete treatment. Gross frame and machine displacements along the deck pathway are enabled by the hydraulically powered bogies so the machine can move over and along the trackbed as concrete is configured. 
     The jack-stands enable frame support vertically above the lower concrete workpiece at a user-selected height. The upper portions of the jack-stands are rigidly connected to supporting swing arms that extend from a rigid, vertically disposed pivot sleeve, that enables the jack stands to assume varying positions angularly swung out relative to the frame. The pivot sleeves are mounted to sleeve brackets that include rollers engaging tracks on the frame, enabling gross adjustments to the frame position by sliding the frame through desired displacements into a correct spacing relative to the jack-stands and thus the lower deck (i.e., the deck segments). 
     Preferably the frame supports an internally fitted, slidable carriage that can be displaced longitudinally relative to the frame. Carriage wheels engage frame tracks for displacement relative to the frame, enabling precise position adjustments. The carriage supports at least one downwardly extending, longitudinally displaceable paving head that, when immersed within wet concrete below and horizontally drawn along as the machine moves over its supports, strikes off elongated, smoothed channels resembling pathways upon the concrete. Elongated, spaced apart, unfinished plinth strips are concurrently formed between the smoothed channels. Preferably the paving heads are slidable relative to the carriage, and suspended by head wheels that engage the carriage for establishing yet another means for longitudinal position adjustments necessitated by the precision required for safe rail construction. 
     The rough plinth strips include projecting rebar stirrups that extend upwardly and outwardly from the strips. The stirrups penetrate subsequently formed, concrete plinth structures that directly support and receive the train rails and their rail mounting structure. Concrete forms properly positioned on the plinth strips shape the resulting plinths, after concrete fills the forms. Thus the stirrups end up immersed within the upright, concrete plinth structures that are subsequently formed atop the initially formed plinth strips after the instant machine completes its work. During its operation the preferred machine clears the plinth strip stirrups, and moves along over the deck without contacting the stirrups, while providing smoothed and properly contoured channels or pathways between the plinth strips. After construction these channel pathways occupy the bottom of troughs adjacent the plinths, forming floor bottoms or scuppers as desired. 
     Thus, it is a basic object of the present invention to provide a self-propelled concrete finishing machine for constructing light rail systems. 
     Another object is to efficiently lay down and finish concrete rail beds or trackbeds. 
     Another basic object is to provide a machine of the character described that smoothly establishes elongated, profiled channels between adjacent plinth regions. 
     It is also an object to provide a deck finishing machine of the character described that screeds and finishes concrete voids between plinth regions. 
     Another basic object of the present invention is to enable field adjustments to adapt the machine of the character described to rail trackbeds of different sizes and configurations. 
     Another important object of the present invention is to provide a concrete finishing machine of the character described that includes a control panel that can be switched between machine sides for moving different directions, obviating the necessity of hoisting and then rotating the entire machine for reversing the work direction. It is a feature of this machine that a plurality of quick-connect/disconnect hydraulic fittings enable quick reversing of the machine control position without hoisting and rotating. 
     A still further object of the invention is to provide a concrete finishing machine of the character described including a rigid, supporting truss assembly extending over the desired rail bed for supporting horizontally and vertically adjustable and spaced-apart paving heads that engage the lower concrete surface for deck finishing. 
     Another object is to provide a concrete finishing machine of the character described that can be adjusted to tilt the paving heads as desired to vary the configuration of the channels. 
     These and other objects and advantages will appear or become apparent in the course of the following descriptive sections. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views: 
         FIG. 1  is a partially fragmentary, frontal isometric of my new trackbed paver machine, showing it in use disposed upon conventional pipe rail supports proximate a partially completed concrete trackbed deck to be formed and treated in accordance with the invention; 
         FIG. 2  is an enlarged, fragmentary, isometric view of a partially completed, concrete trackbed deck processed by the invention, showing the desired plinth strips and spaced apart channels critical to the invention, with portions thereof shown in section for clarity; 
         FIG. 3  is a partially fragmentary, front plan view of the trackbed deck finishing machine of  FIG. 1 ; 
         FIG. 4  is an enlarged, fragmentary isometric view of a preferred box frame segment showing the slidable carriage disposed within it; 
         FIG. 5  is an isometric view of a preferred box frame as it appears without the carriage; 
         FIG. 6  is a fragmentary, isometric view of the preferred carriage that is slidably disposed within the frame; 
         FIG. 6A  is an enlarged, isometric view derived from circled region “ 6 A” in  FIG. 6 ; 
         FIG. 7  is an enlarged, fragmentary plan view derived from circled region “ 7 ” of  FIG. 3 , showing preferred jack stand and paving head detail; 
         FIG. 8  is an enlarged, partially fragmentary sectional end view taken generally along line  8 - 8  in  FIG. 7  in the direction of the arrows; 
         FIG. 9  is a partially exploded, isometric assembly view showing the jack plate mounting system for fixedly securing the jack-stands directly to the frame, with portions thereof omitted for clarity; 
         FIG. 10  is a partially exploded, fragmentary isometric view of an optional swing-out mounting arrangement adapting a jack stand for radial movements towards or away from the frame; 
         FIG. 11  is a fragmentary top plan view illustrating jack-stand radial deflections, taken generally along line  11 - 11  of  FIG. 7 , and with moved positions illustrated in dashed lines; 
         FIG. 12  is a view similar to  FIG. 11  but showing another jack-stand on an opposite frame side in one of several possible radially advanced positions enabled by a swing-out assembly, and with moved positions illustrated in dashed lines; 
         FIG. 13  is an enlarged, partially exploded, fragmentary isometric view of a typical drive bogie that supports and displaces the preferred jack-stands; 
         FIG. 14  is an enlarged isometric view of a driven bogie chassis; 
         FIG. 15  is an enlarged isometric view of a preferred paving head; 
         FIG. 16  is an end view of a paving head, taken from a position generally to the left of  FIG. 15 ; 
         FIG. 17  is a fragmentary isometric view showing a typical paving head slidably mounted to the paver carriage; 
         FIG. 18  is an isometric view of the preferred power unit; and, 
         FIG. 19  is an isometric view of the preferred controller. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With primary reference now directed to  FIGS. 1-3  of the appended drawings, a trackbed deck paver constructed in accordance with the best mode of the invention known at this time has been generally designated by the reference numeral  50 . In  FIG. 2  of the drawings a partially completed trackbed deck that is formed and processed by the paver  50  after a concrete pour has been illustrated and designated generally by the reference numeral  52 . The trackbed route will have been previously laid out by the train designers and engineers. It will follow a predetermined course over an appropriate sub-grade  53  upon which the deck  52  will be completed. 
     As illustrated, deck  52  ( FIG. 2 ) is wide enough to support two pairs of tracks, for trains running in opposite but parallel directions. Conventional, previously established concrete forms (not shown) confine plastic concrete during the pouring process between deck ends  57  and  58 . Numerous pieces of conventional rebar  59  is disposed within the deck, which may be approximately thirty-six inches deep and thirty feet wide. Flat transition surfaces  60  and  61  respectively border deck ends  57  and  58 . Importantly, the deck paver  50  forms smoothed channels  62  and  64 ,  62 B and  64 B, and central smoothed channel  65 . These smoothed channel floors are formed by downwardly hanging paving heads  70 - 74  ( FIG. 1 ) that are adjustably suspended from at least one longitudinally displaceable carriage  80  (e.g.,  FIGS. 4, 6 ) discussed hereinafter. As detailed below each paving head  70 - 74  has a lower concrete forming tool that engages and forms concrete as the paver  50  moves along to provide the desired profile. For example, paving head  70  (e.g.,  FIGS. 7, 17 ) has a lower forming tool preferably comprising a transverse strike-off  82  that contacts the green concrete below to form channels or floors. Importantly, there are a plurality of plinth strips defined between adjacent channel floors. For example, plinth strip  90  ( FIG. 2 ) is located between parallel adjacent channels  62  and  64 . Plinth strip  91  ( FIG. 2 ) is parallel to and spaced apart from plinth strip  90 , and is located between parallel adjacent channels  64  and  65 . The plinth strips  94  and  95  for the other trackbed (i.e., at the right of  FIG. 2 ) are similarly positioned. It is to be noted that the plinth strips support multiple, upwardly projecting rebar loops  99  arranged in parallel rows on each side of each plinth strip. After processing of the deck  52  with paver  50 , a conventional concrete form (not shown) will be placed over the plinth strips covering the rebar loops  99 , and filled with concrete. Once hardened the resultant plinths may support the railroad train tracks and their mounting assemblies (not shown). 
     With joint reference now directed to  FIGS. 4-6 , the machine frame  54  can comprise one or more elongated box frame segments  54 B that can be coupled together to form a frame of a desired length. The composite frame  54  ( FIG. 1 ) internally receives and suspends the carriage  80  ( FIG. 6 ) for limited slidable movements. The frame  54  is generally rectilinear in appearance, in the form of a parallelepiped. It has a pair of spaced apart sides formed by pairs of upper side rails  120  and  120 B and lower side rails  122  and  122 B ( FIG. 4 ). The frame side rails are maintained in vertically spaced apart, parallel relation by multiple vertical frame braces  126  and angled frame braces  128 . Pairs of spaced apart end struts  130 ,  133  extending between upper side rails  120 ,  120 B and lower side rails  122  and  122 B form the rigid ends of the frame  54 . Importantly, the bottom side rails  122 ,  122 B support parallel, elongated carriage tracks  135 , and  136  ( FIG. 5 ) that are secured by a plurality of rigid, spaced apart bracket supports  137 . Elongated wheel guards  138 ,  139  ( FIGS. 4, 5 ) laterally restrain the carriage support wheels discussed below as they ride upon tracks  135  and  136 . 
     Multiple frame segments  54 B of varying lengths can be coupled together longitudinally to form the frame  54  of varying frame lengths. To this effect, it is to be noted that the bottom of each frame segment  54 B ( FIG. 5 ) has a female coupling  142  at the right end at the left bottom corner and another similar female coupling at the other end, at the right bottom corner. There are complimentary male couplings  144  at the right end at the right bottom corner, and at the left end at the left bottom corner. These male and female couplings enable adjacent frame segments to mate. There are also pairs of upper mounting flanges  146  and  147  ( FIG. 5 ) for locking frame segment ends together at their tops. 
     The elongated carriage  80  is slidably suspended from frame segment tracks  135 ,  136  discussed earlier. The carriage comprises a pair of spaced apart, rigid side bars  150  and  152  ( FIG. 6 ) secured in parallel relation by end braces  154  and intermediate cross braces  155 ,  156 . There are three pairs of wheel assemblies  160  for suspending the carriage  80  within the frame  54  (i.e., segments  54 B). Each wheel assembly  160  comprises a pair of upper suspension wheels  162 ,  163  that ride upon carriage tracks  135  and  136  within the frame  54  and the longitudinally aligned frame segments  54 B. Wheels  162 ,  163  are mounted for rotation upon bracket assembly  165 , that comprises a rigid, T-shaped trolley mount  166  whose bottom portion  167  rotatably secures confinement wheels  168  and side support roller  169 . Tubular gudgeons  161  ( FIGS. 6, 6A ) are secured to and project away from trolley mounts  166  ( FIG. 6A ). Gudgeons  161  secure the secure the bracket assembly  165  to the carriage when slidably engaging the pintles  164  that are welded to the carriage side rails  150 ,  152 . Suitable retainers such as pins  171  secure the pintle-to-gudgeon connection. The lower confinement wheels  168  abut against the underside of the tracks  135 ,  136  to resist misalignment. 
     The paver  50  has a plurality of upright, adjustable jack stands  200  described in detail below for support and locomotion. There preferably are four jack stands, one at each corner of the paver  50  ( FIGS. 1, 3 ). The jack stands  200  comprise lower, wheeled bogies for support. The drive bogies  204  ( FIG. 13 ) effect locomotion and the non-driven bogies  203  ( FIG. 14 ) merely provide support; both ride along and upon the conventional forms (i.e., pipe rails)  207  provided on each side of the deck prior to the concrete pour. Each jack stand  200  is secured to the paver frame  54  (i.e., an adjacent frame segment such as  54 B) with a rigid jack plate  206  ( FIGS. 9 and 10 ).  FIG. 9  shows the arrangement wherein a jack-stand  200  is fixedly mounted directly to the paver frame  54  with the jack plate  206 . In  FIG. 10  it is seen a jack-plate  206  may be associated with an optional swing-out assembly  208  that includes a pivot adaptor  210  for enabling radial displacements of a jack stand  200  from the paver frame. In the fixed or direct mounting arrangement of  FIG. 9  there is no swing out assembly  208  or pivot adaptor  210 . 
     With joint primary reference directed now to  FIGS. 1 and 8-10 , a typical jack-stand  200  that is preferably employed by the invention is a telescoping device that may be varied in length to change paver elevation. Each jack-stand comprises a rigid cylinder  220  that coaxially receives an internal, extensible jack-stand foot  222  that is threadably controlled within cylinder  220  by a manually activated crank  223  driven by handle  225  (e.g.,  FIGS. 9, 10, 12 ). The foot  222  mounts a lower, rigid clevis  227  (e.g.,  FIG. 14 ) that is pinned to a wheeled drive bogie  204  ( FIG. 13 ) described in more detail below. In the fixed arrangement of  FIG. 9 , the jack-stand  200  is directly coupled to the jack plate  206 , with the cylinder  200  secured to the jack plate with a plurality of clamps  230  that unite each jack stand with a jack plate  206 . 
     The outermost side of a jack plate  206  is best seen in  FIG. 9 , and the outer side of a typical jack plate  206  is best seen in  FIG. 10 . Each jack plate  206  comprises a rigid, internal vertical strut  234  that extends between upper and lower, generally triangular tops  236  and bottoms  238  which are respectively reinforced by cross-braces  240  and  242 . The triangular tops  236  support spaced-apart roller wheels  247  and  248  ( FIG. 9 ) that roll along the support track  249  ( FIG. 12 ) on frame  54 . The triangular jack plate bottoms  238  ( FIG. 10 ) support spaced apart roller wheel pairs  250  and  252  contact suitable frame rails  251  ( FIG. 7 ). 
     In some cases it is helpful to be able to radially shift the position of the jack-stands  200  for clearance purposes, so the swing-out assembly  208  ( FIG. 10 ) including a pivot adaptor  210  is employed. The optional pivot adaptor  210  comprises a rigid tube  260  that can be secured to a jack plate  206  with a clamp  262 . The adaptor  210  comprises a rigid, box-like standoff  264  comprising rigid, parallel arms  265  and  266  connected to support stanchion  267  and reinforced by angled cross-piece  268 . The upper and lower clamps  269  and  270  secure the pivot adaptor  210  to a jack-stand  206  by mechanically engaging jack-stand cylinder portion  220  ( FIG. 10 ) . With clamp  262  ( FIG. 10 ) loosened, radial jack-stand movements illustrated in  FIGS. 11 and 12  are enabled. 
       FIGS. 13 and 14  illustrate a preferred jack stand bogie in detail. The various undriven bogies  203  and driven bogies  204  support the paver  50  above the deck  52  during operation and enable paver movement. Bogies  203 ,  204  ride along pipe rails  207  as explained earlier. Each bogie comprises a rigid chassis  300  ( FIG. 14 ) that comprises rigid, generally rectangular and spaced-apart side plates  302  and  304  that are reinforced by internal cross braces  306  and  307 . The chassis ends comprise angled end plates  310  and  312 . Drive wheels  314  and  316  are journaled by axles  318  and  320  respectively, that penetrate chassis side plates  302  and  304  and are rotatably secured by various pillow blocks  322  and  324 . A removable pin  330  ( FIG. 14 ) penetrating chassis side plates  302  and  304  secures the previously described jack stand clevis  227 . With the driven bogies  204  drive wheels  314  and  316  are splined to suitable drive sprockets  334 , ( FIG. 13 ) that are driven by chain  338  ( FIGS. 13, 14 ) that engages idle sprocket  336  and drive sprocket  337 . The drive sprocket and the drive wheels wheels are driven by hydraulic propulsion motor  340  connected to hydraulic lines  341  and  342 . A rigid motor support  346  extending between the chassis sides secures the motor  340 . A somewhat cubicle cover  343  shrouds the bogie. 
     A typical paving head  70  discussed earlier is seen in detail in  FIGS. 15-17 . Each paving head is slidably coupled to the carriage  80  ( FIG. 17 ) which, as mentioned, is slidably received within the paver frame. The box-like paver heads may vary in width between twenty-four to ninety-six inches, depending on the application and its assigned dimensions. 
     Each generally cubicle paving head comprises four extensible, parallel corner struts  350 ,  351 ,  352  and  354  that extend from lower strike-offs  82  and side braces  356  and  357  upwardly to upper frame members  360 ,  361  and frame bars  362 - 365 . The corner struts all have upper extensions  370  that lead to box-like roller cages  380  ( FIG. 16 ) that surmount carriage side bars  150 ,  152  ( FIG. 17 ) for locomotion with upper internal rollers  382 , and lower captivation rollers  384  ( FIG. 16 ). 
     The paving heads are adjustable in length with a pair of spaced-apart, hand driven cranks. The roller cages  380  are secured to extensions  370  that have slots  371  ( FIGS. 15, 17 ) through which fasteners  372  extend into engagement with the paver corner stanchions, enabling adjustable mounting. The cross pieces  391  extending between opposite roller cages  380  ( FIGS. 15, 16 ) support threaded shafts  385  that can be rotated with cranks  386  and handles  387 . Shaft  385  is threadably coupled to lower paver head frame bars  364  and  365  to vertically adjust the paver head position, providing locking fasteners  372  are loose within slots  371  ( FIG. 15 ). Suitable vibrators  390  secured to the strike-offs  82  ( FIG. 15 ) are powered by lines  393  and  395  ( FIG. 16 ) to vibrate the strike-offs during operation. The vibrators are preferably pneumatic but hydraulic vibrators are acceptable. 
       FIG. 18  shows the preferred power unit  400  for the paver  50 . A rigid, generally cubicle subframe  402  adapted to be mounted to box-frame  54  provides a generally planar mounting surface  404  for mounting a standard internal combustion motor  406 , that comprises a gasoline motor of between fourteen to fifty horsepower. Tank  409  stores hydraulic fluid for the system and mechanically mounts a hydraulic fluid filter  405 . Internal combustion motor  406  powers a conventional hydraulic pump  408  that ultimately provides hydraulic fluid flow through hydraulic lines  341  and  342  ( FIG. 13 ) for powering the bogie drive motor  340  that moves the jack stands and ultimately the paver  50 . 
     Preferably the paver  50  is manually controlled by an operator (not shown) who may stand on the removable control unit  450  that can be fitted to either side of the frame  54 . The control unit  450  comprises an upright ladder section  451  comprising a bottom foot stool portion  452  and an upper handrail section  454 . Suitable hydraulic control circuitry  456  can be actuated by the operator with valves  458  and  459  to control paver speed. The hydraulic circuitry  456  routs fluid throughout the paver, and to its hydraulic components such as the drive motor  340 , via quick-connect/disconnect fittings known in the art that are collectively designated by the reference numeral  460 . The various snap-connections that engage these fittings  460  and be reconnected quickly by a workman from an opposite side of the paver  50  after the control unit  450  is mechanically moved to another side of the paver form convenience. Once the unit  450  is moved to an opposite side of the paver  50 , the downwardly turned flange  461  ( FIG. 19 ) on top of the control unit  450  may be quickly placed over a frame rail  120  or  120 B ( FIG. 4 ) for securing the ladder  451  and foot stool  452  during subsequent operation. 
     From the foregoing, it will be seen that this invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure. 
     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. 
     As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.