Pavement marker, kit and method

Abstract

A kit containing thermoplastic pavement markers for convenience in transportation and application at a jobsite. The pavement markers have light colored projections on the upper surface to deflect water and reflect light for ease in viewing during rain, darkness and other adverse conditions. The method describes the application of the pavement markers on a road or other substrate for strong adhesion to asphalt and concrete.

Description

FIELD OF THE INVENTION

The invention herein pertains to pavement markers and particularly pertains to pavement markers formed of thermoplastic materials with reflective properties which are packaged in kits for application on substrates such as roads, parking lots, walkways and the like for direction, visibility and safety purposes.

DESCRIPTION OF THE PRIOR ART AND OBJECTIVES OF THE INVENTION

In recent years state highway and transportation departments, businesses, municipalities and others have sought methods of improving the visibility and safety of drivers during dark, wet and other unfavorable weather conditions to prevent accidents and injuries resulting therefrom. As assistance to drivers of vehicles during dark and wet road conditions, it is common to mark the roads and streets with reflective thermoplastic tear drop like shapes on the edges of a roadway using special ridden or walk behind machinery whereby a light colored semi-liquid (Awet@) thermoplastic material is directly applied to asphalt or concrete surfaces. It is also standard practice to treat and seal the cracks and fissures in concrete prior to applying a plastic topping. Nevertheless, conventional machinery which applies Awet reflective@ thermoplastic materials are expensive to purchase, operate and maintain. Such machinery as sold by Hofmann GMBH of Rellingen, Germany and others. Experienced personnel must operate the machinery which again adds to the cost of the marking. Required, regular maintenance of such machinery whether of the ridden or walk behind type is expensive and small municipalities and departments often do not have the funds available for such expenses. In addition, contractors applying Awet reflective@ markings at shopping centers, parking lots and the like do not want to make a large investment in specialized machinery that is infrequently used.

Other road markings in the past have included relatively thin, reflective tapes made of polymeric material, pigments and glass beads, as sold by 3M Company of Minneapolis, Minn. under the trademark: STAMARK™. The reflective tapes have limited durability and as force is applied over time through Awear and tear@ such as vehicles passing over, braking or turning, the Abond@ of the marking can fail and eventually come up entirely from the substrate.

Thus with the disadvantages of conventional road and street marking methods for wet reflective thermoplastic pavement markings, the present invention was conceived and one of its objectives is to provide a kit containing a plurality of pavement markers which can be easily opened and the pavement markers applied to a substrate with standard tools and equipment by relatively unskilled workers.

It is another objective of the present invention to provide a thermoplastic pavement marker which includes a flat planar base having a series of reflective tear drop projections on the top surface thereof.

It is still another objective of the present invention to provide a thermoplastic pavement marker having quick (storm water) draining tear drop projections which are light in color and highly reflective.

It is yet another objective of the present invention to provide an efficient method for applying the thermoplastic pavement markers from the kit in a quick and efficient manner.

It is still a further objective of the present invention to provide a thermoplastic pavement marker having quick draining reflective tear drop or other shaped projections such as in a Asplatter pattern@ which can be manufactured in a variety of sizes.

Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.

SUMMARY OF THE INVENTION

The aforesaid and other objectives are realized by providing a kit containing a plurality of preformed thermoplastic pavement markers for easy application on a road, street or other location. The pavement markers preferably include three (3) dimensional tear drop shaped reflective projections along the top surface of a planar base having a lower softening point then the projections. The pavement markers are first removed from the kit, positioned on a substrate, heated along the top surface with a standard propane blow torch such as a Flint 2000EX heat gun, manufactured by Flint Trading, Inc. of Thomasville, N.C. The heated, softened thermoplastic pavement marker is then by gravitational forces as it cools and hardens adhered to, for example the edge of an asphalt roadway which has been previously swept clean to remove any dirt and debris for strong adherency. The tear drop projections preferably have a light colored or white surface and are embedded with reflective shards such as small glass particles or beads to quickly shed water and remain highly visible when struck by vehicle lights in heavy rain storms, darkness and other adverse conditions. The pavement markers are applied individually or end-to-end as needed to mark a section of a road, highway, parking lot, walkway or other substrate as desired. Relatively unskilled personnel can apply the markers and create a pattern without expensive, specialized machinery or special training. On concrete surfaces the preferred application method utilizes a standard concrete sealer that is first applied to the concrete to close any cracks or fissures to ensure proper bonding of the heated thermoplastic pavement marker.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a top plan view of the pavement marker as described herein;

FIG. 2 shows a side elevational view of the pavement marker as seen in FIG. 1;

FIG. 3 depicts a bottom plan view of the pavement marker as shown in FIG. 1;

FIG. 4 demonstrates a front end elevational view of the pavement marker as shown in FIG. 2;

FIG. 5 pictures a rear end elevational view of the pavement marker as shown in FIG. 2;

FIG. 6 illustrates a kit comprising a box shown open with the pavement markers exploded therefrom;

FIG. 7 features a typical fragmented two lane road with the pavement markers partially applied along one edge;

FIG. 8 shows an enlarged view of one pavement marker in a side elevational view on the road as seen in FIG. 7;

FIG. 9 illustrates schematically various steps in the application of the pavement markers along one edge of a two lane road shown fragmented;

FIG. 10 shows in top view another embodiment of the invention with projections having a random splatter pattern; and

FIG. 11 depicts the pavement marker of FIG. 10 in a side elevational view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND OPERATION OF THE INVENTION

For a better understanding of the invention and its operation, turning now to the drawings, FIGS. 1-9 show preferred pavement marker 10 in various views. Pavement marker 10 is formed from a conventional thermoplastic material as used for other standard pavement markers and has an overall thickness of approximately 0.10 inches (0.254 cm) to approximately 0.25 inches (0.635 cm), a length of three (3) feet (91.4 cm) and a width of twelve (12) inches (30.5 cm) although various sizes can be made to accommodate specific applications. Pavement marker 10 can be made for example two (2) feet (61 cm) to three (3) feet (91.4 cm) in length and four to twenty-four (4-24) inches (10-61 cm) in width. Pavement marker 10 can also be made in roll form with a typical length of thirty (30) feet (9.15 m). The thickness of 0.10 inches (0.254 cm) to 0.25 inches (0.635 cm) can also vary as required with the exact size dependent on the particular needs of the user.

As shown in FIG. 1, pavement marker 10 includes a series of three (3) dimensional tear drop projections 11 which are arranged staggered in four (4) columns and four (4) rows on the top surface of base 12 to provide spacing therebetween. The exact number of columns and rows will depend on the overall dimensions of the particular marker size selected to allow efficient drainage of water therefrom during storms. Projections 11 have a flat top surface and are formed of a color equivalent to or lighter than base 12, preferably white or yellow and may contain or be formed with a layer of glass beads 13 therein to improve retroreflective properties such as by standard molding techniques.

Base 12 has a flat, smooth bottom surface 14 as shown in FIG. 3 and is of an equivalent color to projections 11. Rain or other water quickly drains from tear drop projections 11 due to their raised posture and the spacing therebetween as seen in FIGS. 1 and 7 and allows drivers and others easy visibility of pavement markers 10 such as when headlights strike glass beads 13 of projections 11 at night, during adverse weather conditions or during other periods of low visibility. It is preferable that projections 11 be thicker than base 12 and have a higher softening point. Projection 11 is preferably 1.5 to 2 times thicker than base 12, it being understood that the thickness or ratio can vary.

Projections 11 are preferably integrally formed during molding with base 12 using conventional procedures. Pavement markers 10 are then cut to a specific size and packed for example, in cardboard boxes such as cardboard box 16 shown in FIG. 6. Four (4) such pavement markers 10 will be packaged in each box 16 to form kit 20 for ease in handling, transportation, storage and use, although other sizes and numbers of markers can also be packaged in kit form as desired.

The preferred method of applying pavement markers 10 is described with reference to FIGS. 7, 8 and 9. Here, workmen receive a selected kit such as preferred kit 20 at a jobsite such as at road 30 seen in FIG. 7. Road 30 has two (2) traffic lanes and is formed of asphalt and includes top surface 32 having typical centerline 31. Kit 20 is opened and one pavement marker 10 is removed and positioned on top surface 32. A typical propane torch such as torch 40 shown in FIG. 9 is activated (lit) and pavement marker 10 is heated till soft and pliable. Projections 11 when formed of a higher softening point thermoplastic than base 12 tend not to distort during heating and application to the road surface or other substrate. Once softened, pavement marker 10 is then adhered by gravity forces to the pre-cleaned and swept substrate such as top surface 32 (FIG. 9), as shown for example along the edge to allow drivers to easily determine the edge of road 30 clearly in dark and/or wet conditions. Additional pavement markers 10 are applied in the same manner in abutting relation as shown in FIG. 7 to form a marking along the entire road edge length as required.

Should road 30 consist of a concrete substrate, then standard concrete sealer 33 as shown in FIG. 9 is first brushed or otherwise applied with brush 34 to the intended area for placement of marker 10. Sealer 33 may be any of a series of conventional polymeric sealers which will fill and close the cracks and fissures in the concrete substrate. Once the sealer has dried or cured pavement marker 10 is positioned and heated as hereinbefore described to soften base 12 and marker 10 is adhered by gravitational forces atop the sealed concrete substrate. Additional markers 10 are likewise applied for the specified length required.

While FIGS. 7, 8 and 9 demonstrate the application of pavement markers 10 only along one edge of a conventional two (2) lane road 30, both edges and center line 31 would normally be identically marked. Other uses and applications are likewise anticipated such as transverse stop lines, turn arrows, word messages, etc. The markings can also be used on parking lots, walkways and the like as desired.

In an alternate embodiment seen in FIGS. 10 and 11 pavement marker 40 is shown having projections 41 with a Arandom@ appearance. Projections 41 are about two (2) times the height of base 42 and also contain reflective glass beads 13 as earlier described for pavement marker 10. Projections 41 are likewise formed of a thermoplastic material having a softening point higher than the softening point of base 42 for convenience in adhering pavement marker 40 to a substrate.

The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims.

Claims

1. A pavement marker comprising: a planar base, a plurality of projections, said projections adhered to said planar base.

2. The pavement marker of claim 1 wherein said projections are tear drop shaped.

3. The pavement marker of claim 1 wherein said planar base comprises a thermoplastic material.

4. The pavement marker of claim 1 wherein said planar base and said projections are integrally formed.

5. The pavement marker of claim 1 wherein said planar base has a smooth flat bottom surface.

6. The pavement marker of claim 1 wherein said projections extend above the top of said planar base.

7. The pavement marker of claim 1 wherein said projections are retroreflective.

8. The pavement marker of claim 1 wherein said base has a lower softening point than said projections.

9. A method of applying a pavement marker to a substrate comprising the steps of:

a) selecting a pavement marker having a base with a plurality of tear drop projections thereon;

b) heating the pavement marker to soften the base; and

c) adhering the pavement marker to the substrate.

10. The method of claim 9 wherein heating the pavement marker comprises the step of heating the pavement marker with a heat torch.

11. The method of claim 9 wherein adhering the pavement marker comprises the step of adhering the pavement marker by gravitational forces.

12. The method of claim 9 further comprising the step of sealing the substrate with a coating before adhering the pavement marker.

13. The method of claim 9 wherein adhering the pavement marker comprises the step of adhering the pavement marker to an asphalt substrate.

14. The method of claim 9 wherein adhering the pavement marker comprises the step of adhering the pavement marker to a concrete substrate.

15. A kit comprising a container, a plurality of polymeric pavement markers, said pavement markers each comprising a base, a plurality of projections, said projections affixed to said base, said pavement markers positioned within said container.

16. The kit of claim 15 wherein said container comprises a box.

17. The kit of claim 15 wherein said projections are retroreflective.

18. The kit of claim 15 wherein said projections are tear drop shaped.