1. Technical Field
The present invention relates generally to paving material, and more particularly, to a pavement ramp edge maker, paving machine and related method.
2. Related Art
Typically, screed pavers include a self-propelled paving machine having a hopper for receiving paving material, e.g., asphalt, from a truck so that the truck progressively dumps its load of paving material into the hopper. A conveyor system on the paving machine transfers paving material from the hopper rearwardly for discharge onto the roadbed in front of transversely arranged screw augers, which spread the material laterally in front of a main screed. This main screed functions to compress and level the paving material to give a smooth finished road surface. The height and attack angle of the main screed may be varied to control the depth and surface of the pavement mat. The main screed may also include screed extenders to allow for a wider pavement mat to be laid. Subsequently, the paving material is compacted in position by, for example, a rolling machine or tamping machine.
A safety problem generated by basic paving machines are drop off edges that are left at a side or an end of a mat of paving material. Drop off edges are a safety problem because vehicles may catch a side of a tire on them, causing the vehicle to lose control. Drop off edges may range in size from a half inch to more than 2 inches, and may exist prior to and after compaction. Drop off edges can be found in highways, secondary roadways, parking areas, driveways, drainage sections, and a variety of other locations. The inherent safety issues generated by drop off edges have been identified in a report by the American Automobile Association's (AAA) Foundation for Traffic Safety that was prepared by the Transportation Center at the University of Tennessee entitled, “The Elimination or Mitigation of Hazards Associated with Pavement Edge Dropoffs During Roadway Resurfacing.” In addition, evidence of the road edge drop-off safety problem is provided by the large number of lawsuits filed against cities, counties and states as reported in the Road Injury Prevention & Litigation Journal.
Drop off edges may be generated during paving during in, among others areas, two notable situations. First, drop off edges are frequently generated when paving multiple active traffic lanes, where it is oftentimes impossible to pave two or more lanes in a short time span. The inability to pave two or more lanes quickly may be due to a variety of reasons, e.g., traffic, equipment shortages, etc. In this case, a drop off edge is often times left between a first active traffic lane over which a new pavement mat has been laid and a second active traffic lane upon which new pavement has yet to be laid. One approach for solving this type drop off edge is disclosed in U.S. Pat. Nos. 6,238,134, 6,238,136, 6,270,284 and 6,283,672. In each of these devices, a pavement edger is fixedly mounted to a main screed or screed extension of the paving machine, and moves as an integral unit with the main screed. The pavement edger generates a stepped tapered ramp having a highly compacted step and a highly compacted upper portion of the tapered ramp. The ramp eases a vehicle's transition over the drop off edge and solves a number of paving problems relative to laying the next lane's mat.
Second, referring to
In a worst-case scenario, this type drop off edge 10 is not corrected and the current non-repaved area 14 is left as is. One approach to diminish this type drop off edge, however, has been to spread gravel 20 from a top edge 22 of the new pavement mat 16 to the non-repaved area surface 18. Unfortunately, this approach does not provide a permanent solution since the gravel eventually loosens and is thrown off the road. Further, this approach is fairly expensive since it requires additional passes over the area.
Ideally, a remedy for roadside drop off edge 10 should be provided during paving because each re-visitation to a site costs time and money. One approach used during paving has been to provide a strike off on an end of the paving machine screed to form a ramp. A strike off is a vertical plate attached to the screed or an opening in the screed that scrapes a ramp into the paving material passing thereunder. Unfortunately, a strike off does not adequately solve this type drop off edge because it provides hardly any compaction, which permits the ramp to be readily torn apart. In addition, a strike off tends to tear the edge of the mat causing a non-straight and disfigured pavement edge. Tearing of the edge of the mat also reduces the integrity of the mat, which decreases the life of the pavement.
The pavement edger described in the above-identified patents is impracticable relative to a drop off edge 10 adjacent a non-repaved area 14 for a number of reasons. First, the pavement edger is coupled to a main screed or screed extension of a paving machine. As a result, the pavement edger is incapable of following undulations that are common in non-repaved traffic areas. Second, the ramp generated includes vertical edges for mating with subsequent pavement mats. This ramp, although significantly better than an inclined drop off edge 10, is not designed to be a permanent remedy to drop off edge 10.
In view of the foregoing, there is a need in the art for a pavement edge maker that addresses the problems with the related art.
A pavement ramp edge maker, paving machine and related method are provided for generating a pavement edge ramp that is equal to or less than approximately 45° relative to a surface upon which the ramp is formed. The ramp reduces safety problems relative to drop off edges adjacent a non-repaved area, and increases the life of the pavement by providing a compacted edge. The edge maker generates a ramp that is partially compacted. When the pavement mat is compacted, the resulting ramp has an angle that is equal to or less than approximately 45° relative to a surface upon which the ramp is formed. In an alternative embodiment of the invention, a coupling device for a compaction member of the edge maker includes a spring bias and vertical adjustment system for mounting the compaction member to a fixed structure of the paving machine, but allowing vertical movement.
A first aspect of the invention is directed to a pavement ramp edge maker comprising: a compaction member have a compaction surface for partially compacting paving material received thereby into a ramp; and a coupling device for coupling the compaction member to a paving machine, wherein the compaction surface is set at an edge angle such that a final angle of the ramp after compaction is less than or equal to approximately 45° relative to a surface upon which the ramp is formed.
A second aspect of the invention is directed to a paving machine comprising: a screed for distributing paving material during paving; a vertically self-adjusting end gate coupled to the screed; and a pavement ramp edge maker including: a compaction member including a compaction surface for partially compacting paving material received thereby to form a ramp; and a coupling device for coupling the compaction member to the paving machine, wherein the compaction surface is set at an edge angle such that a final angle of paving material after compaction is less than or equal to approximately 45° relative to a surface upon which the ramp is formed.
The foregoing and other features of the invention will be apparent from the following more particular description of embodiments of the invention.
The embodiments of this invention will be described in detail, with reference to the following figures, wherein like designations denote like elements, and wherein:
A pavement ramp edge maker, paving machine and related method are provided for generating a pavement edge ramp that is equal to or less than approximately 45 degrees relative to a surface upon which the ramp is formed. For definition purposes herein, a “mat” or “pavement mat” is considered a layer of paving material. “Paving material” is any material used for paving roadways, such as bituminous material like asphalt.
Referring to
Turning to
Paving machine 150 also includes a vertically self-adjustable end gate 170 (hereinafter “end gate”) at each end of screed 158, as is commonly known in the art. Each end gate 170 may include a vertically adjustable sled 172, as is conventional, to support end gate 170 as it traverses surface 118. Each end gate 170 follows the contours of surface 118, and may be biased downwardly by a biasing mechanism 174, such as a spring loaded or hydraulically powered, suspension to maintain contact with surface 118.
Referring to
Coupling device 182 includes a mounting post 200 coupled to compaction member 176, and a mounting clamp 202 for coupling the mounting post to end gate 170. In one embodiment, mounting post 200 is provided as a W-shaped member, and mounting clamp 202 is a U-shaped channel. Mounting clamp 202 is capable of receiving one of a first post section 206 and a second post section 208 of mounting post 200, and a top edge 204 of end gate 170. Mounting clamp 202 receives a number of threaded fasteners 210A, 210B that can be tightened to hold mounting post 200 (first post section 206 as shown) against end gate 170.
Coupling device 182 may also include a vertical adjuster 212 for adjusting the vertical position of compaction member 176 relative to end gate 170. Vertical adjustment of compaction member 176 relative to end gate 170 is advantageous to accommodate varying sizes of paving material aggregate and prevent tearing paving material mat 116 (
In order to vertically adjust compaction member 176, a user loosens threaded fastener 210B and turns engagement member 224, which turns adjustment member 214. As adjustment member 214 turns, the vertical position of compaction member 176 relative to end gate 170 changes because of adjustment member's 214 threaded connection at brace member 194. Once in a desired position, a user re-tightens threaded fastener 210B to couple mounting post 200 to end gate 170. While the adjustment range may vary to accommodate all varieties of paving material, in one embodiment, compaction surface 180 is set to be slightly (less than 0.5-inch) above a bottom edge 226 of end gate 170 and has an adjustment range between approximately 12 mm and approximately 24 mm.
It should be recognized that a variety of other mechanisms for mounting compaction member 176 to end gate 170 and for vertically adjusting compaction member 176 are possible, and are considered within the scope of the invention. Other possibilities for vertical adjustment include, for example, a pin and a plurality of holes, a slot and positioning bolt, etc. In addition, alterations of the described embodiment are also possible and considered within the scope of the invention.
Coupling device 182 allows easy and quick installation of edge maker 152, and also allows mounting of edge maker 152 on either one of end gates 170. In order to switch from the end gate 170 shown in
Referring to
Referring to
Edge maker 152, in one embodiment, can accommodate pavement lifts of 1 to 4 inches compacted (or 1.5 to 5.5 inches uncompacted height). Since edge maker 152 is coupled to vertically self-adjusting end gate 170, it can automatically compensate for height variations between new pavement mat 116 and surface 118. Further, edge maker 152 insures that a maximum deviation from straight-line edge of pavement mat 116 does not vary more than 1.5 inches per inch of depth change after compaction. Further, ramp 130 does not require any special rolling devices to achieve a density level adequate for an operating life equal to that of paving material mat 116.
Referring to
Compaction member 376 also includes a paving material directing member 390 and a pair of support members 392 for positioning compaction surface 380. Compaction member 376 may also include a brace member 394. Paving material directing member 390 directs paving material toward compaction surface 380, and prevents paving material from flowing behind compaction surface 380. Other structure may also be added to prevent paving material from flowing behind compaction surface 380 such as a cover (not shown). In an alternative embodiment, compaction surface 380 also includes a trailing compaction surface 400 (shown best in
Relative to coupling device 382, an alternative embodiment provides a spring bias and vertical adjustment system 408, as shown in
System 408 also includes a threaded rod 416 slidably coupled to mounting plate 410 and threadably coupled to compaction member 376, i.e., brace member 394 of compaction member 376, and a spring bias 414 for biasing compaction member 376 against upward movement. Spring bias 414 includes a spring 424 mounted about threaded rod 416 and between mounting plate 410, i.e., a mount 420 of mounting plate 410, and a bias adjustment member 426 that is threadably coupled to threaded rod 416. Threaded rod 416 includes an upper end 418 vertically slidable relative to mount 420, and an end cap 421 to prevent threaded rod 416 from exiting mount 420. A lower end 422 of threaded rod 416 is threadably received in brace member 394 such that turning of threaded rod 416 adjusts the vertical distance between compaction member 376 and mounting plate 410. Hence, the vertical position of compaction surface 376 can be adjusted relative to the fixed structure of paving machine 150 (
In another alternative embodiment, a support member 392A adjacent end gate 170 is extended beyond a lower surface of compaction surface 380 and includes a rounded leading edge 440 adapted to engage a surface being paved.
Where possible, the above-described alternative embodiments may be provided as part of the
While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.
For example, paving machine 150 (
This application is a continuation-in-part of application U.S. Ser. No. 10/426,143, filed Apr. 29, 2003 and now U.S. Pat. No. 6,923,594.
Number | Name | Date | Kind |
---|---|---|---|
2311286 | Tufts | Feb 1943 | A |
3108518 | O'Connor, Jr. | Oct 1963 | A |
3398663 | Matich | Aug 1968 | A |
3625121 | Blumer et al. | Dec 1971 | A |
4027990 | Merrill | Jun 1977 | A |
4068969 | Beach et al. | Jan 1978 | A |
4181449 | Lenker | Jan 1980 | A |
4818140 | Carlson | Apr 1989 | A |
5051026 | Sovik | Sep 1991 | A |
5088854 | Sovik | Feb 1992 | A |
5213442 | Sovik | May 1993 | A |
5336019 | Hollon et al. | Aug 1994 | A |
5344254 | Sartain | Sep 1994 | A |
5362176 | Sovik | Nov 1994 | A |
5924819 | Breidenbach | Jul 1999 | A |
5997270 | LaBonte | Dec 1999 | A |
6106192 | Hargis et al. | Aug 2000 | A |
6238134 | Sovik | May 2001 | B1 |
6238136 | Sovik et al. | May 2001 | B1 |
6270284 | Sovik | Aug 2001 | B1 |
6273636 | Johanpeter | Aug 2001 | B1 |
6283672 | Sovik | Sep 2001 | B1 |
6709195 | Piccoli et al. | Mar 2004 | B2 |
Number | Date | Country |
---|---|---|
990565 | Jun 1976 | CA |
2113358 | Sep 1972 | DE |
0 027 164 | Apr 1981 | EP |
1 560 469 | Feb 1980 | GB |
Number | Date | Country | |
---|---|---|---|
20040218978 A1 | Nov 2004 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10426143 | Apr 2003 | US |
Child | 10720915 | US |