SCREED ASSEMBLY FOR ROAD PAVING MACHINES, AND A METHOD FOR REPAVING ROAD SURFACES

Abstract

A new and improved method and apparatus for use in conjunction with the free floating paving screed used for road paving is disclosed. The method of forming a bituminous mixture into a smooth flat paved mat comprising some areas with a given nominal mat density and some selected areas with a predeterminedly higher mat density is described wherein problems posed by a reduced compaction ratio occurring subsequently to paving the mat where the roller drum bridges over recesses in the subbase are addressed. The modified paving screed described employs a new adjustable screed plate that allows localized areas of increased angle of attack and a device to increased material entry density in localized areas in front of a screed plate leading edge. Either method is used to create an increase in mat density in the desired area. The method and apparatus teach that by pairing differences in compaction ratio that inherently occur due to subbase irregularities with correspondingly predetermined and different mat densities in the paved mat, a good consistent final density can be achieved notwithstanding the limitations of the compaction rolling. A forward looking vision system is described that identifies subbase recesses, a digital controller quantifies the density increase required, and a GPS system maps locations where the mat density increases are to be applied.

Claims

1. A new and improved screed assembly for a road paving machine used for repaving a road surface with new paving material, comprising: a plurality of screed segments disposed adjacent to each other in a horizontally extending array, wherein each one of said plurality of screed segments is individually and independently movable within a vertical plane such that a lower, front edge portion of a particular screed segment can be vertically adjusted so as to alter its angle of attack and thereby predetermine the amount of new paving material which can pass under said lower, front edge portion of said particular screed segment in order to vary the amount of new paving material passing under said lower, front edge portion of said particular screed segment whereby the density of the new paving material comprising the newly paved road surface will substantially be constant regardless of ruts, tracks, depressions, or potholes present within the road surface being repaved.

2. The new and improved screed assembly as set forth in claim 1, wherein: said plurality of screed segments are pivotally mounted upon said screed assembly so as to achieve a predetermined angle of attack.

3. The new and improved screed assembly as set forth in claim 2, wherein: said plurality of screed segments are pivotally mounted at lower, read end portions upon said screed assembly so as to achieve said predetermined angle of attack.

4. The new and improved screed assembly as set forth in claim 1, wherein: each one of said plurality of screed segments has the configuration which is substantially that of a rectangular parallelepiped.

5. The new and improved screed assembly as set forth in claim 4, wherein: each one of said plurality of screed segments, having said configuration which is substantially that of a rectangular parallelepiped, is approximately six inches (6″) wide.

6. The new and improved screed assembly as set forth in claim 1, further comprising: a plurality of actuators operatively connected to each one of said plurality of screed segments for pivotally moving individual ones of said plurality of screed segments so as to achieve a predetermined angle of attack.

7. The new and improved screed assembly as set forth in claim 6, wherein: said plurality of actuators comprise pneumatic actuators.

8. The new and improved screed assembly as set forth in claim 6, wherein: said plurality of actuators comprise hydraulic piston-cylinder assemblies.

9. The new and improved screed assembly as set forth in claim 1, further comprising: a vision system for visually detecting the presence of ruts, tracks, depressions, or potholes within the road surface ahead of the screed assembly such that individual ones of said plurality of screed segments can have its angle of attack adjusted in order to predetermine the amount of new paving material which can pass under said lower, front edge portions of said individual ones of said plurality of screed segments which have had their angles of attack adjusted in order to vary the amount of new paving material passing under said lower, front edge portions of said adjusted screed segments whereby the density of the new paving material comprising the newly paved road surface will substantially be constant regardless of ruts, tracks, depressions, or potholes present within the road surface being repaved.

10. The new and improved screed assembly as set forth in claim 9, wherein said vision system comprises: a camera and a GPS system for detecting the presence and location of depressions, ruts, tracks, or potholes within the road surface being repaved; a digital processor for using data from said gamer and GPS system for digitally mapping the dimensions and locations of the depressions, ruts, tracks, or potholes within the road surface being repaved; a programmable logic controller (PLC) for outputting signals to control said individual ones of said plurality of screed segments; and a plurality of solenoid-controlled valve for controlling fluid to actuators operatively connected to said individual ones of said plurality of screed segments in order to actuate said individual ones of said plurality of screed segments such that said individual ones of said plurality of screed segments will achieve their desired movements and angles of attack.

11. The new and improved screed assembly as set forth in claim 1, wherein: more than one of said plurality of screed segments may be actuated simultaneously.

12. A new and improved road paving machine used for repaving a road surface with new paving material, and having a screed assembly mounted thereon, wherein said screed assembly comprises: a plurality of screed segments disposed adjacent to each other in a horizontally extending array, wherein each one of said plurality of screed segments is individually and independently movable within a vertical plane such that a lower, front edge portion of a particular screed segment can be vertically adjusted so as to alter its angle of attack and thereby predetermine the amount of new paving material which can pass under said lower, front edge portion of said particular screed segment in order to vary the amount of new paving material passing under said lower, front edge portion of said particular screed segment whereby the density of the new paving material comprising the newly paved road surface will substantially be constant regardless of ruts, tracks, depressions, or potholes present within the road surface being repaved.

13. The new and improved paving machine as set forth in claim 12, wherein: said plurality of screed segments are pivotally mounted upon said screed assembly so as to achieve a predetermined angle of attack.

14. The new and improved paving machine as set forth in claim 13, wherein: said plurality of screed segments are pivotally mounted at lower, read end portions upon said screed assembly so as to achieve said predetermined angle of attack.

15. The new and improved paving machine as set forth in claim 12, wherein: each one of said plurality of screed segments has the configuration which is substantially that of a rectangular parallelepiped.

16. The new and improved paving machine as set forth in claim 15, wherein: each one of said plurality of screed segments, having said configuration which is substantially that of a rectangular parallelepiped, is approximately six inches (6″) wide.

17. The new and improved paving machine as set forth in claim 12, further comprising: a plurality of actuators operatively connected to each one of said plurality of screed segments for pivotally moving individual ones of said plurality of screed segments so as to achieve a predetermined angle of attack.

18. The new and improved paving machine as set forth in claim 17, wherein: said plurality of actuators comprise pneumatic actuators.

19. The new and improved paving machine as set forth in claim 17, wherein: said plurality of actuators comprise hydraulic piston-cylinder assemblies.

20. The new and improved paving machine as set forth in claim 12, further comprising: a vision system for visually detecting the presence of ruts, tracks, depressions, or potholes within the road surface ahead of the screed assembly such that individual ones of said plurality of screed segments can have its angle of attack adjusted in order to predetermine the amount of new paving material which can pass under said lower, front edge portions of said individual ones of said plurality of screed segments which have had their angles of attack adjusted in order to vary the amount of new paving material passing under said lower, front edge portions of said adjusted screed segments whereby the density of the new paving material comprising the newly paved mat will be increased in the area of the ruts, tracks, depressions, or potholes present within the road surface being repaved.

21. The new and improved screed assembly as set forth in claim 20, wherein said vision system comprises: a camera and a GPS system for detecting the presence and location of depressions, ruts, tracks, or potholes within the road surface being repaved; a digital processor for using data from said gamer and GPS system for digitally mapping the dimensions and locations of the depressions, ruts, tracks, or potholes within the road surface being repaved; a programmable logic controller (PLC) for outputting signals to control said individual ones of said plurality of screed segments; and a plurality of solenoid-controlled valve for controlling fluid to actuators operatively connected to said individual ones of said plurality of screed segments in order to actuate said individual ones of said plurality of screed segments such that said individual ones of said plurality of screed segments will achieve their desired movements and angles of attack.

22. The new and improved screed assembly as set forth in claim 12, wherein: more than one of said plurality of screed segments may be actuated simultaneously.

23. A method of using a modified free floating paving screed that can apply a paved mat of different material densities, to pave a road surface which has planar areas and depressions located therewithin, comprising the steps of: depositing roadway material onto the road surface to be repaved wherein a first predetermined material density of roadway material is deposited upon first areas of the road surface that do not have depressions located therewithin and wherein said areas are inherently accessible to effective compaction, and wherein a second predetermined material density of roadway material, greater than said first predetermined material density roadway material, is deposited upon second areas of the road surface that do have depressions located therewithin, wherein said areas inherently afford reduced accessibility to effective compaction compared to said first areas of the road surface that do not have depressions located therewithin; and moving at least one roller over the road surface so as to compress and compact the roadway material comprising the first and second predetermined mat densities of roadway material respectively located upon the first areas of the road surface that do not have depressions located therewithin and the second areas of the road surface that have depressions located therewithin, whereby the finalized compaction density of the roadway material, compressed and compacted onto the first and second areas of the road surface as a result of the roller moving over the first and second areas of the road surface will be uniform as a result of said second predetermined mat density of roadway material, which is greater than said first predetermined mat density of roadway material, said area of greater material density receiving a requisite increase in mass such that finalized compaction density is achieved irrespective of the inherent lesser effective compaction ratio that said area of road surface depression located therewithin will receive.

24. The method as set forth in claim 23 above, wherein: the topography of said first areas of the road surface are mostly planar, and the new road surface material applied thereon forms an additional depth of material above it and is substantially planar; the topography of said second area of the road surface consists of a recess and the material applied thereon both fills said recess and similarly forms an additional depth of new material above it; wherein the ability of a subsequent rolling operation to compact material of said first area and second area will be constrained by both the topography of the road and the dimensional characteristics of the roller drum such that the degree of compaction that can be applied will meet the requirements of the height of material and density of material over said first area, said degree of compaction being controlled by the first area, producing good final density therein; wherein the degree of compaction applied as controlled by the first area will be insufficient to produce good final density over said second area due to the increased total height of material when using said density of material applied thereon; and wherein laying a higher density mat over said second area only, the degree of compaction applied as controlled by the first area then becomes sufficient to achieve good final density in both the first and second areas of the new road surface.

25. The method as set forth in claim 23, wherein: the first and second predetermined densities of fresh roadway material are respectively deposited upon the first and second areas of the road surface by a screed assembly comprising a plurality of screed segments disposed adjacent to each other in a horizontally extending array, wherein each one of said plurality of screed segments is individually and independently movable within a vertical plane such that a lower, front edge portion of a particular screed segment can be vertically adjusted so as to alter its angle of attack and thereby predetermine the amount of fresh paving material which can pass under said lower, front edge portion of said particular screed segment in order to vary the amount of fresh paving material passing under said lower, front edge portion of said particular screed segment, whereby the density of the newly paved mat comprising the repaved road surface will be increased over the ruts, tracks, depressions, or potholes present within the road surface being repaved.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other features and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

[0021] FIG. 1 is a schematic side elevational view of a conventional, PRIOR ART asphalt supply truck and a paving machine to the rear end of which there is attached a screed assembly for paving a roadway or parking lot;

[0022] FIG. 2 is a schematic top plan of the conventional, PRIOR ART paver or paving machine as illustrated within FIG. 1 wherein it is seen the screed assembly comprises a centrally located main or primary screed assembly, a pair of auxiliary or side extension screed assemblies which extend transversely and outwardly from left and right sides of the main or primary screed assembly, and a plurality of horizontally oriented augers for distributing the asphalt material transversely;

[0023] FIG. 3 is an enlarged schematic view of the conventional PRIOR ART screed assembly as attached to a tow truck by means of a pair of tow arms, only one of which is shown, and illustrating various different components of the paving machine which can be utilized to alter the angle of attack of the screed assembly with respect to the underlying road surface or parking lot;

[0024] FIG. 4 is a schematic perspective view of the new and improved screed assembly as constructed in accordance with the principles and teachings of the present invention wherein it is seen that the new and improved screed assembly comprises a plurality of screed components or segments wherein each component or segment has the configuration which is substantially that of a rectangular parallelepiped, the plurality of screed components or segments are disposed adjacent to each other and extend in a serial manner within a horizontally extending array, and wherein each one of the screed components or segments is independently movable in a pivotal manner by means of a pivotal connection located along the rear edge portion of each screed component or segment such that the angle of attack of the lower, forward edge portion of each screed component or segment can be adjusted as required or desired in order to effectively move a predetermined amount of asphalt material beneath that particular one of the plurality of screed components or segments, it being additionally noted that the first or leftwardmost one of the plurality of screed components or segment has been actuated such that it effectively has a greater angle of attack than the remaining screed components or segments;

[0025] FIG. 5 is a schematic, cross-sectional view of the new and improved screed assembly as disclosed within FIG. 4 showing the disposition of any one of the screed components or segments of the screed assembly when the particular one of the screed components or segments is disposed at an angle of attack, of for example, 2° with respect to the underlying road surface or parking lot;

[0026] FIG. 6 is a schematic, cross-sectional view of the new and improved screed assembly as disclosed within FIG. 4 showing the disposition of any one of the screed components or segments of the screed assembly when the particular one of the screed components or segments is disposed at an angle of attack, of for example, 8° with respect to the underlying road surface or parking lot;

[0027] FIG. 7 is a schematic cross-sectional view of the new and improved screed assembly as disclosed within FIGS. 5 and 6 wherein the plurality of adjacent screed components or segments, mounted upon the screed assembly has a plurality of pneumatic actuators operatively associated with each one of the screed components or segments comprising both the main screed assembly and the auxiliary or side extension screed assemblies;

[0028] FIG. 8 is a schematic cross-sectional view of the new and improved screed assembly as disclosed within FIGS. 5 and 6 wherein the plurality of adjacent screed components or segments, mounted upon the screed assembly has a plurality of hydraulic piston-cylinder actuators operatively associated with each one of the screed components or segments comprising both the main screed assembly and the auxiliary or side extension screed assemblies;

[0029] FIG. 8a is a schematic view of the encircled region 8a as noted within FIG. 8 wherein the hydraulic piston-cylinder actuators are disposed at their retracted positions such that the lower front edge portions of the screed components or segments are disposed at a relatively large angle of attack;

[0030] FIG. 9 is a schematic view similar to that of FIG. 8 showing, however, a second embodiment of the screed assembly constructed in accordance with the principles and teachings of the present invention and wherein a plurality of vertically oriented augers are respectively operatively associated with each one of the screed components or segments of both the main screed assembly and one of the extension screed assemblies so as to enhance the density of the asphalt material just prior to the asphalt material being passed beneath the plurality of screed components or segments and fixedly laid down upon the roadway or parking lot being repaved;

[0031] FIG. 10 is a schematic front elevational view of the second embodiment of the screed assembly as shown in FIG. 9 wherein the plurality of vertically oriented augers are respectively disposed in front of the plurality of screed components or segments of the main screed assembly so as to enhance the density of the asphalt material just prior to the asphalt material being passed beneath the plurality of screed component or segments and fixedly laid down upon the roadway or parking lot being repaved; and

[0032] FIG. 11 is a schematic block diagram of a control system which illustrates how the forward-looking vision system of the new and improved screed assembly of the present invention is utilized to detect the presence and location of ruts, depressions, tracks, or potholes within the roadway or parking lot, and how to accordingly accurately actuate one or more of the screed components or segments in order to alter the angle of attack of the front lower edge portion of the one or more of the screed components or segments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0033] Referring now to the drawings, and more particularly to FIGS. 1-3, a typical or conventional PRIOR ART paver or paving machine is disclosed and is seen to comprise a tractor and a screed assembly wherein the paver is disclosed and is generally indicated by the reference character 100, while the tractor is disclosed at 102 and the screed assembly is disclosed at 104. A driver 106 is seated within a cab 107 of the tractor 102 so as to drive the tractor 102 in a direction of travel DOT, and a pair of tow bars 108, only one of which is visible, are disposed upon opposite sides of the tractor and are connected to the screed assembly 104 so as to tow the screed assembly 104 behind the tractor 102 as the tractor moves along the roadway, road surface, parking, or the like 110 such that the screed assembly 104 can lay down a new, fresh surface of pavement 112. In order to accomplish this, a truck 114, carrying a supply of fresh asphalt, moves ahead of the tractor 102 and delivers a supply of fresh asphalt 116 onto a pair of endless conveyors 118 which are located beneath the cab 107 of the tractor 102, wherein the upper run of the endless conveyors 118 conveys the asphalt material in the aft direction toward a pair of augers 120,120 which extend laterally outwardly in opposite directions from the centerline of the paver 100 as can best be seen in FIG. 2. The augers 120,120 move the freshly supplied asphalt material 116 laterally outwardly, as schematically illustrated by the arrows LO, LO, so that the asphalt material 116 is effectively deposited in a pile 122 in front of the screed assembly 104 whereby the screed assembly 104, which conventionally comprises a solid screed block, will lay down a new, fresh pavement of asphalt material which will have a predetermined thickness dimension depending upon the angle of attack of the lower forward edge portion of the screed assembly 104.

[0034] As is also common with conventional pavers 100, a pair of extension screeds 124,124 are provided upon opposite sides of the main or primary screed assembly 104 such that greater widths of new roadway or parking lots can be paved as the tractor 102 and the screed assemblies 104,124 traverse a single pass along the roadway or parking lot. Typically, the main screed may be approximately six to eight feet (6-8′) wide while the extension screeds may be, for example, three to four feet (3.4′) wide such that the entire screed assembly may be approximately fourteen feet (14′) wide. If such extension screeds 124,124 are utilized, it is noted that a pair of auxiliary augers 126,126 are mounted upon opposite ends of the main augers 120,120 such that the auxiliary augers 126,126 are coaxially arranged with the main augers 120,120, are driven by the same motor drive utilized to drive the main augers 120,120, and are adapted to receive asphalt material from the main augers 120,120 and subsequently distribute the asphalt material in front of the pair of extension screeds 124,124. To complete the paver assembly 100, a pair of oppositely disposed end gates 128,128 are provided upon opposite sides of the screed assembly 104 so as to prevent asphalt material from moving beyond the lateral extents of the main or primary screed 104 or the lateral extents of the extension screeds 124,124 when the extension screed 124,124 are employed. The end gates 128,128 are mounted upon the extension screeds 124,124 so as to permit the extension gates 128,128 to move laterally outwardly as needed or laterally inwardly as needed, depending upon whether or not the extension screeds 124,124 are moved laterally outwardly or inwardly. As will become clearer from the description of the present invention presented later in this specification, the extension screeds 124,124 and the main or primary screed 104 are not coaxially aligned with respect to each other so that the main or primary screed 104 does not interfere with the movement of the extension screeds 124,124 inwardly and outwardly.

[0035] With reference now being made to FIG. 3, which is effectively an enlarged view of the paver 100 as disclosed within FIG. 1 so as to clearly show components of the paver 100 which can be utilized to alter the angle of attack of the lower forward edge portion of the screed assembly 104, it is to be noted that forward ends 130 the tow bars 108 are pivotally connected to the tractor 102 by means of pivotal connections 132, only one of which is shown, while the opposite rear ends of the tow bars 108 are fixedly connected to the screed assembly 104 by means of downwardly extending arms 134. In addition, it is also to be noted that the forward end 130 of each tow bar 108, within which the pivotal connection 132 is defined, is adapted to be connected to a suitable actuator, not shown, wherein the end 130 of each tow bar 108 can be moved vertically upwardly and downwardly as schematically illustrated by the up and down arrows U, D.

[0036] Accordingly, it can be appreciated that as the actuators, not shown, move the forward ends 130 of the tow bars 108 upwardly or downwardly, the fixed connections defined between the tow bars 108 and the screed assembly 104 can alter the angle of attack a of the lower forward edge portion of the screed assembly 104. Still yet further, a manual or hand crank 136 is rotatably mounted upon upon an upper end portion of an upstanding mounting plate 138 which has its lower end portion pivotally mounted to the screed assembly 104 by means of a pivotal connection 140, while the manual or hand crank 136 is mounted upon a first externally threaded screw rod 142 which is fixedly connected to one end of a turnbuckle or sleeve member 144 which is threadedly engaged upon a first end of a second externally threaded screw rod 146 while the second end of the second externally threaded screw rod 146 is fixedly connected to one of the tow bars 108. Accordingly, depending upon which direction the manual or hand crank 136 is rotated, it causes the sleeve member 144 to travel leftwardly or rightwardly upon the second externally threaded screw rod 146 thereby causing the upstanding mounting plate 138 to pivotally move around the pivotal connection 140 in order to similarly adjust the angle of attack a of the lower forward edge portion of the screed assembly 104. Considered from different perspectives, the upward and downward movement of the ends 130 of the tow bars 132 may be considered to impart adjustments to the angle of attack a of the screed assembly 104, in order to follow grade, often using automatic grade controls and the hand crank system while the hand crank system imparts adjustments to the angle of attack a of the screed assembly 104 in order to make the mat thickness adjustment.

[0037] While it can therefore be readily appreciated that conventional screed assemblies 104 can be adjusted such that their lower forward edge portion will be disposed at different angles of attack a so as to effectively produce the desired mat thickness and float over the paving material passing there beneath and form a newly paved surface, wherein such paved surface or mat will exhibit one relative consistent density, it is also readily appreciated that conventional screed assemblies 104 cannot be adjusted at specific locations across the entire lateral width of the screed assemblies so as to in fact permit more or less asphalt material to pass beneath the specific regions or locations of the screed assembly 104 so as to provide, for example, an increased mat density over depressions within the roadway being repaved wherein, for the reasons fully discussed hereinbefore, good roller compaction is facilitated throughout the paved roadway or parking lot such that a uniform final density is achieved which is critically important to the structural integrity of the newly paved roadway or parking lot, whereby the newly paved roadway or parking lot will also exhibit enhanced durability thereby eliminating the need to repave the roadway or parking lot more often.

[0038] With reference therefore now being made to FIG. 4 of the drawings, there is disclosed a new and improved screed assembly as constructed in accordance with the principles and teachings of the present invention and as denoted by the reference character 204. It is to be noted that whenever the new and improved screed assembly 204 is discussed, or whenever the new and improved screed assembly 204 as mounted upon the tractor components of a paver corresponding to the paver disclosed within FIGS. 1-3, all components of the new and improved screed assembly 204, or the tractor components of the corresponding paver, which correspond to the various component parts of the convention paver 100 as disclosed within FIGS. 1-3, will be denoted by corresponding reference characters except that they will be within the 200 series. Therefore, with particular reference being made to FIG. 4, it is seen that, in accordance with the principles and teachings of the present invention, the new and improved screed assembly 204 comprises a plurality of screed components or segments 205 wherein each component or segment 205 has the configuration which is substantially that of a rectangular parallelepiped, that the plurality of screed components or segments 205 are disposed adjacent to each other and extend in a serial manner within a horizontally extending array, and that each one of the screed components or segments 205 is individually and independently movable in a pivotal manner by means of a pivotal connection 242 located along the rear edge portion of each screed component or segment 205, as can best be seen in FIGS. 7 and 8, such that the angle of attack a of the lower, forward edge portion of each screed component or segment 205 can be altered or adjusted as required or desired in order to create a larger entry area for the asphalt material beneath that particular one of the plurality of screed components or segments 205. Such an adjustment, as shown within FIGS. 5 and 6, can be, for example, between 2° and 8°.

[0039] Each one of the screed components or segments 205 may also have a width dimension of approximately six inches (6″), although the components or segments may be provided with different width dimensions as may be desired or required, and it is additionally noted, within FIG. 4, that the first or Ieftwardmost one of the plurality of screed components or segments 205 has been actuated such that it effectively has a greater angle of attack a than those of the remaining screed components or segments. It is also noted that in connection with the foregoing structural components, the screed components or segments of the screed extensions have been noted by the reference character 205-E. It is lastly noted with reference being made to FIGS. 7, 8, and 8a, that in order to achieve the pivotal movement of the individual screed components or segments 205,205E, each individual screed component or segment 205,205 is provided with a suitable actuator which, as disclosed within FIG. 7, comprises a pneumatic cylinder 245 connected to a rear or back wall surface portion of the component or segment 205, while in FIG. 8, the actuators may comprise hydraulically actuated piston-cylinder assemblies 246,246-E. In FIG. 8a, it is noted that the piston of the piston-cylinder assembly 246 has been retracted, thereby effectively pulling the particular screed component or segment 205 rearwardly, causing the screed component or segment to pivot around the pivotal connection 242 and thereby effectively increasing the angle of attack a of the lower forward edge portion of the screed component or segment 205.

[0040] With reference now being made to FIGS. 9 and 10, there is disclosed a second embodiment of a screed assembly 304 which has been constructed in accordance with the principles and teachings of the present invention and wherein the second embodiment screed assembly likewise comprises a plurality of screed components or segments 305. It is to, be noted that whenever the new and improved screed assembly 304 is discussed, or whenever the new and improved screed assembly 304 as mounted upon the tractor components of a paver corresponding to the paver disclosed within FIGS. 1-3, all components of the new and improved screed assembly 304, or the tractor components of the corresponding paver, which correspond to the various component parts of the convention paver 100 as disclosed within FIGS. 1-3, will be denoted by corresponding reference characters except that they will be within the 300 series. With continued reference therefore being made to FIGS. 9 and 10, it is seen that in conjunction with each one of the screed components or segments 305,305-E of the main or primary screed assembly or one of the extension screed assembly, a plurality of vertically oriented augers 348 are disposed in front of each one of the screed components or segments 305 of, for example, the main or primary screed assembly 304 such that when one or more augers 348 are respectively actuated, the augers 348 will impart a downward compressive force upon the asphalt material passing beneath the plurality of screed components or segments 305 in the desired area so as to therefore serve to enhance the density of the asphalt material just prior to the asphalt material being passed beneath the plurality of screed components or segments 305 and fixedly laid down upon the roadway or parking lot being repaved by means of the screed components or segments 305. It is lastly noted that each auger 348 is adapted to be driven by means of a suitable motor 350 which may be, for example, a hydraulic motor.

[0041] With reference lastly being made to FIG. 11, there is illustrated a schematic block diagram of a control system which comprises a forward-looking vision system 451 to be utilized in conjunction with the new and improved screed assembly of the present invention so as to detect the presence and location of ruts, depressions, tracks, or potholes within the roadway or parking lot ahead of the paver whereby one or more of the screed components or segments will be actuated in order to alter the angle of attack of the front lower edge portion of the one or more of the screed components or segments 305 in order to facilitate an enlarged area in which asphalt material entering under the one or more of the screed components or segments 305 in order to produce an area of increased mat density over the depressions, ruts, tracks, or potholes within the roadway or parking lot, the control system being generally indicated by the reference character 400. More particularly, the vision system comprises at least one camera component 452 and one global positioning system (GPS) component or antenna 454 so as to be capable of visually detecting ruts, depressions, tracks, or potholes within those portions of the roadway or parking lot that are located in front of the paver or paving machine and which are to be repaved.

[0042] The data derived from the camera 452 and the global positioning system (GPS) 454 is then transmitted by transmission line 456 as signals to a digital processor 458 which effectively digitally maps the dimensions and locations of all of the depressions, ruts, tracks, and potholes within the roadway ahead or in front of the approaching paver or paving machine. Signals from the digital processor 458 are, in turn, transmitted as signals along a transmission line 460 to a programmable logic controller (PLC) 462 which, in turn, generates desired output signals, along transmission line 464, to a suitable bank or assembly of solenoid-controlled valves 466 which are operatively associated with each one of the various pneumatic or hydraulic actuators 245,245-E,246,246-E, as well as the vertically oriented augers 348,348-E, so as to achieve the respective operations of the various screed components or segments 205,205-E, 305,305E, as well as the vertically oriented augers 348,348-E, in order to achieve the proper deposition of the asphalt material onto the roadway or parking lot being repaved. More particularly, particular ones of the plurality of screed components or segments 205,205-E,305,305-E can be pivotally actuated for movement within their respective vertically oriented planes, by means of the pneumatic or hydraulic actuators 245,245-E,246,246-E, so as to alter the forward-facing angles of attack of the particular ones of the plurality of the screed components or segments 205,205-E,305,305-E and thereby permit an increase in mat density to be deposited at predetermined times and locations onto the underlying roadway or parking lot in order to allow achievement of good final density even though a lesser value of compaction ratio will occur over the depression, rut, track, or pothole during the rolling operation. As has been noted, each one of the screed segments or components 205,205-E,305,305-E can be individually and independently movable with respect to the other screed segments or components 205,205-E,305,305-E, however, by suitable actuation of the pneumatic or hydraulic actuators 245,245-E,246,246-E, as well as the augers 348,348-E in conjunction with the movable screed segments 205,205E,305,305E, or by themselves by means of the hydraulic motors 350,350-E, in response to signals from the vision system 451, more than one, or a plurality of the screed segments or components 205,205-E may be simultaneously actuated in response to the asphalt deposition needs as determined by means of the vision system 451.

[0043] It is to be particularly noted that when repaving a roadway, road surface, or parking lot, in those regions where there are no depressions, ruts, tracks, or potholes, a fresh amount of asphalt material is laid down with a depth of two and one half inches (2.5″) because after rolling the fresh asphalt by means of a conventional roller, the finalized depth of the roadway or road surface or parking lot will be two inches (2.0″), wherein the paved mat has been compacted form an initial height of 2.5″ down to 2.0″ and would have been compacted by a ratio of 0.25 inches per inch. However, if, for example, there is a pothole present within the roadway or road surface being repaved, and the pothole has a depth of, for example, one half inch (0.5″), then the amount of fresh asphalt material to be laid down atop the pothole will be three inches (3.0″) because one half inch (0.5″) of the fresh asphalt material will be used to fill the pothole, leaving a residual amount of two and one half inches (2.5″) above the pothole. If the roller bridges across the pothole, the 3.00″ will be compacted down to 2.5″ which equals a compaction ratio of 0.20 inches per inch. As can therefore be readily appreciated, as a result of the development of the new and improved screed assembly 204 of the present invention, individual ones of the plurality of screed components or segments 205 may be pivotally tilted rearward so as to effectively raise the lower front edge portion of the particular screed component or segment 205 which increases the angle of attack so as to permit a relatively larger amount of asphalt material to pass thereunder when such a relatively larger amount of asphalt material is needed to produce a mat of increased density over the depressions, ruts, tracks, or potholes within the roadway, road surface, or parking lot being repaved such that these areas which will inherently experience a lower value of compaction ratio will then achieve good final density after rolling.

[0044] Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

REFERENCE NUMBER KEY

[0045] 100—Conventional road paving machine or paver [0046] 102—Tractor of machine or paver 100 [0047] 104—Screed assembly of machine or paver 100 [0048] 106—Driver of machine or paver 100 [0049] 107—Cab of tractor 102 [0050] 108—Tow arms connecting the screed assembly to the tractor of paver 100 [0051] 110—Road surface to be repaved [0052] 112—Newly repaved road surface [0053] 114—Truck for supplying fresh asphalt material [0054] 116—Mass of asphalt material supplied to front of tractor 102 [0055] 118—Endless conveyor of tractor conveying asphalt material aft [0056] 120—Horizontally oriented augers for conveying asphalt material laterally [0057] 122—Pile of new asphalt discharged by conveyor 118 ahead of screed 104 [0058] 124—Side extension screeds [0059] 126—Side extension augers [0060] 128—End gates [0061] 130—Forward end of two arm 108 [0062] 132—Pivotal connection of tow arm 108 to tractor [0063] 134—Downwardly extending rear end of tow arm 108 [0064] 136—Hand crank assembly for adjusting angle of attack of screed assembly [0065] 138—Upstanding mounting plate connecting screed to hand crank assembly [0066] 140—Lower pivotal connection of mounting plate 138 [0067] 142—First screw-threaded rod [0068] 144—Turnbuckle [0069] 146—Second screw-threaded rod [0070] DOT—Direction of Travel [0071] U—Up arrow indicating upward adjustment of tow bar end 130 [0072] D—Down arrow indicating downward adjustment of tow bar end 130 [0073] α—Angle of attack [0074] 204—New screed assembly [0075] 205—Individual screed components or segments of screed assembly 204 [0076] 205-E—Individual screed component or segment of extension screed [0077] 242, 242-E—Lower pivotal connections of screed components or segments [0078] 245, 245-E—Pneumatic actuators for screed components or segments [0079] 246, 246-E—Hydraulic actuators for screed components or segments [0080] 348—Vertically oriented augers for use in conjunction with screed segments [0081] 350—Hydraulic motors for augers 348 [0082] 451—Vision system [0083] 452—Camera of vision system [0084] 454—GPS system of visual system [0085] 456—Signal transmission line from vision system to digital processor [0086] 458—Digital processor [0087] 460—Signal transmission line from digital processor to PLC [0088] 462—Programmable logic controller (PLC) [0089] 464—Signal transmission line from PLC to solenoid control valve assembly [0090] 466—Solenoid controlled valve assembly