Multiple Comb Gates and Method of Applying Road Markings

Abstract

An apparatus and method for applying a snowplowable traffic stripe to a surface of a road comprising independent dual comb gates for permitting compounds to be released from a tractive box through a comb. The independent dual comb gates can be opened and closed independently at different intervals to form a successive elongated protuberances overlapping along the longitudinal direction.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a tractive box for use in manufacturing a traffic stripe applied to a road surface and method for using the same. In particular, the present invention relates to a tractive box with dual comb gates for producing a traffic stripe having a profile portion including a plurality of overlapping protuberances that are resistant to snowplows.

2. Prior Art

Road markings are generally made by using hot or cold traffic stripe paint, cold tape, or other materials such as epoxies or thermoplastics. Road markings generally come in two forms, long line stripes and transverse stripes. Long line stripes are typically four inches wide and include a solid line, an interrupted line, a pair of solid lines, or a solid line in combination with an interrupted line. The interrupted lines include a series of predetermined length traffic stripes separated by a series of predetermined length gaps. Interrupted lines are generally used with solid lines when center turn lanes (i.e., left-hand turn lanes in the United States) are applied, for example, to a three lane road. When two lines are used together, they are normally spaced four inches apart from each other. However, the spacing and dimensions of a traffic stripe can differ according to different country, state, and city regulations.

Driving a motor vehicle during dry, daylight hours is a relatively simple task requiring one merely to obey the traffic signals and keep the vehicle within the proper traffic lane as defined by the markings on the road. This relatively simple task becomes a particularly exasperating and often treacherous assignment when darkness and wet weather conditions prevail. Under these conditions, the usual night driving handicap of reduced visibility is augmented by the wet weather conditions, thereby making traditional flat reflective road markings virtually imperceptible.

Generally, when stripes are applied, reflective materials may be added on top of the traffic stripe to give it increased reflectivity at night. The reflective material often consists of glass beads applied on top of the traffic stripe after the stripe has been applied to the road surface.

Water does not drain from conventional road markings during wet weather conditions. As a result, when it is raining, a thin film of water will form on top of the traffic stripe and significantly reduce the reflectivity of the striping material and the glass beads used therein. If a thick film of water forms on top of the traffic stripe, such as encountered in a heavy storm, the water will totally obscure the markings from view, thereby making them less effective.

Because of the deterioration in traffic guidance conditions that occurs during dark and wet driving conditions, the incidence of traffic accidents increases and the usual smooth flow of traffic is impeded. Attempts have been made to reduce these dangers by providing individual raised reflectors on the road surface, by using large reflective elements in road markings that protrude above the water film, and by forming profiled road markings having thickened transverse portions projecting above the water film.

One of the most widely used marking systems in the United States is an individual raised reflector, such as that available under the trade name Stimsonite.™. 948 or that shown in U.S. Pat. No. 3,332,327. The reflector generally comprises an approximately four and one-half inch by two and one-half inch marker that is raised one-half inch from the road and has sloped side surfaces. A reflective panel is disposed on each of the sloped sides of the marker and the entire top surface is then covered with a plastic or glass coating. The markers are secured to the road using an epoxy glue or an adhesive, however, a problem with maintaining the markers on the road surface exists. In regions where heavy snow fall require the use of snowplows, these markers are often damaged by the leading blade of the snowplow. Furthermore, the cost for such individual markers and their installation is also a significant drawback.

In the last twenty years, numerous snowplow resistant road markers such as U.S Pat. Nos. 5,277,513, 4,577,922, 5,975,794 and 6,439,803 have surfaced. They are all individual markers that require either epoxy glue or direct insertion into the road asphalt. Each design has its own unique way of mitigating the destructive nature of a snowplow but the original disadvantage regarding individual installation and cost still remains.

As an alternative to reflective markers, large glass beads have also been used to provide a profiled road marking having a pebble-like finish. In this system, produced by R.S. Clare & Co. Limited under the trade name Aquaflex.™, large one to four millimeter glass beads and small crushed stones are spread on top of a binder coat layer and then coated with paint. Smaller conventional reflective beads are then dispersed over the painted line. Portions of the large glass beads are able to protrude above thin water films on the road surface thereby providing a reflective surface. However, using this type of large glass bead substantially increases costs, and since the larger beads are not universally accepted for road marking, approval on a state by state basis is required. Further, because of their size, the large glass beads do not adhere well to the road marking and have a tendency to be dislodged by traffic and snowplows.

A series of patents to Marcato (the Marcato Patents), including U.S. Pat. Nos. 5,511,896, 5,114,268, and 5,642,962, use an apparatus that applies a thermoplastic stripe to the road surface, and a layer of reflective material to the thermoplastic stripe. The apparatus also passes a rotatable wheel having a plurality of projections around its periphery over the thermoplastic stripe such that the stripe is deformed and spaced grooves are formed therein. This process is very expensive and requires the use of costly heated thermoplastics, not suitable in all conditions. Regions which require the use of snowplows will also find that the groves created by this method will not withstand constant snowplowing.

U.S. Pat. No. 7,070,358 entitled Comb Gate and Method of Use solves many of the deficiencies of the prior art listed above. It provides a cheap and easy alternative to applying road markings with contoured protuberances using comb gate that combs a cold hardening compound into desired protuberance shapes. However, due to the desire to spread out the distance of the protuberances to mitigate shadowing and offer more angles of reflection, the protuberances are once again venerable to a snowplow blade.

A strong need therefore exists for a durable and economical way to apply road markings that mitigate snowplow damage while retaining the advantages of being visible when wet, providing an audible signal to a driver when a vehicle passes there over, and have increasing reflective properties to improve visibility in adverse conditions.

SUMMARY OF THE INVENTION

The present invention provides for a modified tractive box for applying marking lines consisting of a cold-hardening compound to surfaces. The cold-hardening compounds are of type sold under the trade name DURASET™ and manufactured by ENNIS PAINT, of Salem, Oreg.

The tractive box is principally constructed of a composition well, with a forward wall, two side walls, a rear wall and a base. The tractive box is designed to be moved in a longitudinal direction and may be affixed to a vehicle or self propelled. In the preferred embodiment, the rearward facing rear wall has dual gates to independently open and close the tractive box proximate the surface to be marked and a die head or comb through which the compound is extruded.

The tractive box is filled with the compound to be applied and longitudinally moved along the surface to be marked. The marking compound is extruded or released through the base gate and a pair of independent dynamic comb gates positioned proximate to the surface to be marked. The pair of comb gates can open and close independently of each other allowing independent formation of protuberance markings.

In the preferred embodiment, the protuberance markings made are of 0.1 to 0.5 inches in thickness. For improved reflectivity the compound will often have glass or similar beads in the compound. To further improve reflectivity, additional beads may be applied to the surface of the compound prior to hardening.

A third base gate may be used independently to provide a base line marking in the form of traditional tractive box marking.

The die head or comb is placed such that the marking compound is formed into a series of longitudinal protuberances as the marking compound is extruded from the tractive box. The comb may be removable or adjusted to permit alternate comb tooth patterns to be selected.

Due to the dual gates system, the patterns of the resulting protuberance markings can be so that the protuberances will form an overlapping pattern along the longitudinal direction. The overlapping pattern substantially mitigates snowplow and traffic damage to the resulting road markings.

The resulting mark or traffic stripe produced is not only durable but also is also significantly spaced to reduce shadowing effects, provides an audible signal to a driver when a vehicle when passes there over, and provide improved visibility in wet conditions.

Accordingly, an object of the present invention is to provide a tractive mark and method of producing the same which offers resistance to snowplow damage. It is a further object of the present invention to increase visibility in wet conditions and present a high degree of absorbability with low cost and ease of application. It is a further object of the present invention to provide a mark and method of producing the same which utilizes existing common mark producing equipment without the need for purchasing expensive new equipment or costly retrofits.

BRIEF DESCRIPTION OF THE DRAWINGS

The above description and other objects, advantages, and features of the present invention will be more fully understood and appreciated by reference to the specification and accompanying drawings, wherein:

FIG. 1 is a perspective view of the preferred embodiment of a tractive box for applying a traffic stripe to a road in accordance with one embodiment of the present invention;

FIG. 2 is a side elevation view of the invention with all gates closed;

FIG. 3 is a side elevation view of the invention with the base gate open and the resulting stripe produced;

FIG. 4 is a side elevation view of the invention with the base gate and one comb gate open while one comb gate is closed and the resulting stripe produced;

FIG. 5 is a back view of the comb and dual comb gates when both comb gates are closed;

FIG. 6 is a back view of the comb and dual comb gates when the left gate is closed and right gate is open;

FIG. 7 is a back view of the comb and dual comb gates when the left gate is open and right gate is closed;

FIG. 8 is perspective view of overlapping protuberance form of a traffic stripe produced in accordance with the present invention;

FIG. 9 is a side view of the overlapping protuberance form of the traffic stripe produced in accordance with the present invention;

FIG. 10 is a top view of the overlapping protuberance form of the traffic stripe produced in accordance with the present invention; and

FIG. 11 is a front view of the overlapping protuberance form of the traffic stripe produced in accordance with the present invention.

DETAILED DISCUSSION OF THE PREFERRED EMBODIMENTS

Referring to the figures, like elements retain their indicators throughout the several views. FIG. 1 depicts a perspective view of the invention, an improved tractive box 100 for striping a roadway 50. The tractive box 100 comprising a pair of side walls 14, a rear wall 12, a front wall 16, and a base 18, all generally defining a composition well for holding a compound 22 to be deposited on a roadway 50.

Mounted to the rear wall 12 is a comb 20 that is preferably removable. Also mounted to the rear wall 12 proximate the base 18 is are dual comb gates 24a and 24b that are independently slideable relative to the rear wall 12. The dual comb gates 24a and 24b are disposed such that each may be slideably lifted so as to expose the comb 20 to the interior of the composition well and permit the compound 22 to flow through the comb 20. This slideable action may be accomplished though the attachment of an articulating means to the comb gate attachment points 64a and 64b. Such articulating means (not depicted) may be manual, electromechanical, hydraulic or pneumatic or any of a large number of known forms.

In the preferred embodiment, mounted to the base 18 is a base gate 25 which is slideable relative to the base 18. The base gate 25 is disposed such that is may be slideably retracted so as to expose the interior of the composition well and permit the compound 22 to flow onto a surface 50 to be striped or marked. This slideable action may be accomplished though the attachment of an articulating means to a base gate attachment point 65 (see FIG. 2-4). Such articulating means (not depicted) may be manual, electromechanical, hydraulic or pneumatic or any of a large number of known forms.

In the preferred embodiment, the side walls 14 extend down below the base 18 and the base gate 25 such that there is a defined a volume when the tractive box 100 is placed on a surface 50. The volume contains the flow of the compound 22 when released by the base gate 25, and the portion of the side walls 14 which extend beyond the base 18 and the base gate 25 limit compound flow and define the width of the stripe 40 produced.

In operation the tractive box 100 is placed proximate a surface 50 to be striped or marked. The composition well is filled with compound 22 such as is marketed under the brand name DURASET™ and manufactured by ENNIS PAINT of Salem, Oreg. The tractive box is moved, drug or propelled along the surface 50. When marking is desired, any combination of the base gate and the comb gates may be opened.

When a flat stripe 40 is desired, the base gate is actuated to slide to the open position to permit the compound to flow from the composition well onto the surface 50 as depicted in FIG. 3. As the tractive box 100 is moved along the surface 50, the desired stripe 40 is produced.

When a durable overlapping protuberance stripe is desired as depicted in FIG. 8, the comb gates 24a and 24b are actuated to slide to the open position exposing the comb 20 and permitting the compound to flow through the comb 20 producing an overlapping protuberance stripe 42. The overlapping pattern is created by allowing both gates to open and close independent of each other. The timing of the gates opening and closing can be adjusted depending on the pattern desired.

In the preferred embodiment the opening and closing of gates 24a and 24b are timed to form successive elongated protuberances 50 overlap along the longitudinal direction 60 (see FIG. 8-11). The distance 61 between the elongated protuberances 50 should be less than that of the length 62 of the elongated protuberances 50 such that trailing ends of the elongated protuberances overlap 55 leading ends of other elongated protuberances along the longitudinal axis. The overlapping nature of the protuberances 50 substantially reduces the digging action of snowplow blades 70 by providing an essentially uninterrupted horizontal plane for the snowplow blade to travel (see FIG. 9).

Further, it is disclosed that both the comb gate 24a, 24b and the base gate 25 may be opened and closed together to produce intermittent profiled sections of striping when desired.

Throughout the specification the aim has been to describe the invention without limiting the invention to any one embodiment or specific collection of features. Persons skilled in the relevant art may realize variations from the specific embodiment that will nonetheless fall within the scope of the invention. For example, the protuberances 50 need not be elongated and is not limited to any one shape or form. The material 22 can be any material used in the art of road marking. The number of independent gates is not limited to just two. The number of protuberances is dependant on the number of comb gates and the pattern of the comb 20 and should not be limited to any single embodiment.

Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.

Claims

1. A tractive box for applying a traffic stripe to a surface, said tractive box comprising:

a base, a front wall, a pair of side walls and a rear wall defining a composition well,

slideably mounted to said rear wall are an at least two independent comb gates as to selectively occlude a comb disposed along said rear wall and proximate said base.

2. The tractive box of claim 1 further comprising a base gate slideably mounted to said base as to selectively open said base permitting said composition well to be exposed to a surface to be striped.

3. The tractive box of claim 1 where in said comb is removably attached to permit alternate comb tooth patterns to be used.

4. The tractive box of claim 1 where in said at least two independent comb gates open and close independently.

5. A method of producing a surface stripe comprising:

Providing a tractive box with a base, a front wall, a pair of side walls and a rear wall defining a composition well,

slideably mounting to said rear wall are an at least two independent comb gates as to selectively occlude a comb disposed along said rear wall and proximate said base,

slideably mounting to said base is a base gate as to selectively occlude open said base permitting said composition well to be exposed to a surface to be striped,

filling said composition well with a compound for use in striping,

moving said tractive box linearly along a surface,

opening said base gate to permit the release of said compound onto said surface.

6. The method of claim 5 comprising the further steps of opening and closing said at least two comb gates at different intervals to permit the release of said compound onto said surface through said comb to form a polarity of protuberances overlapping along a longitudinal axis.

7. The method of claim 5 comprising the further steps of successively opening and closing said at least two comb gates at different intervals to permit the release of said compound onto said surface though said comb to form a polarity of successive protuberances overlapping along a longitudinal axis.

8. A method of producing a surface stripe comprising:

Providing a tractive box with a base, a front wall, a pair of side walls and a rear wall defining a composition well,

slideably mounting to said rear wall are an at least two independent comb gates as to selectively occlude a comb disposed along said rear wall and proximate said base,

filling said composition well with a compound for use in striping,

moving said tractive box linearly along a surface,

opening said at least two independent comb gates to permit the release of said compound onto said surface.

9. The method of claim 8 comprising the further steps of opening and closing said at least two comb gates at different intervals to permit the release of said compound onto said surface through said comb to form a polarity of protuberances overlapping along a longitudinal axis.

10. The method of claim 8 comprising the further steps of successively opening and closing said at least two comb gates at different intervals to permit the release of said compound onto said surface though said comb to form a polarity of successive protuberances overlapping along a longitudinal axis.