US3286605A

US3286605A - Apparatus and method for marking a surface

Info

Publication number: US3286605A
Application number: US400602A
Authority: US
Inventors: Leona E Wilson; Samuel E Wissinger
Original assignee: Prismo Safety Corp
Current assignee: Prismo Safety Corp
Priority date: 1964-09-30
Filing date: 1964-09-30
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22
Also published as: GB1083639A; BE694001A; FR1418508A

Description

Nov. 22, 1966 R. w. WILSON ETAL 3,286,605

APPARATUS AND METHOD FOR MARKING A SURFACE 2 Sheets-Sheet 1 Filed Sept. 50, 1964 F/GZ INVENTORSv SAMUEL E. WISSINGER RUFUS W. WILSON BY LEONA E. WILSON ,DECEASED ADMINISTRA TRIX BY Hem 0 50045 ATTORNEY Nov. 22, 1966 w. WILSON ETAL 3,286,605

I APPARATUS AND METHOD FOR MARKING A SURFACE Filed Sept. 30, 1964 2 Sheets-$heet 2 ATTORNEY T M NRE E E E5 VGDW mmM $0M SS1 Mum .W E fl 4 WM 2 mm m M M w w m M B KQRL ca 006 United States Patent Oflice 3,286,605 Patented Nov. 22, 1966 3,286,605 APPARATUS AND METHOD FOR MARKING A SURFACE Rufus W. Wilson, deceased, late of Huntiugdon, Pa., by Leona E. Wilson, administratrix, Huntingdon, Pa., and Samuel E. Wissinger, Huntingdon, Pa., assignors to Prismo Safety Corporation, Huntingdon, Pa., a corporation of Pennsylvania Filed Sept. 30, 1964, Ser. No. 400,602 6 Claims. (Cl. 9444) The present invention relates to surface coating apparatus and to a method of applying a coating to a surface. More particularly, the present invention relates to a method and apparatus for applying a liquid coating material to surfaces and simultaneously applying small particles of solid material into and onto the coating material.

A particular use of the present invention is in the application of markers to roads and highways. It is generally recognized in the art of applying road markers, such as center lines and lane margin lines, for example, that the use of reflecting elements, such as glass spheres, when mixed with a paint binder, is especially effective in promoting safety on the highway, particularly since the glass spheres have auto-collimating characteristics. Due to their auto-collimating characteristics, the small glass spheres are particularly effective in outlining the traffic lanes during night-time driving.

Prior to the present invention, various techiques have been employed in applying the road markers. The usual method has been to spray a premix of a paint binder mixed with the small glass spheres. A spray gun through which the mixture is sprayed is usually attached to a movable vehicle. The resulting marker is not immediately auto-collimating, because all of the glass spheres are completely embedded in the pigmented binder. The marker becomes auto-collimating after traffic has worn away the binder which covers the beads. In order to render such a marker immediately auto-collimating, it is customary to drop on additional glass beads onto the tacky paint binder.

It has been found that when the glass spheres are premixed with the paint binder and not applied immediately to the surface to be marked, the spheres which are initially suspended in the paint or binder solution, have a tendency to settle with the pigment to the bottom of the premix container, thereby forming a wet concrete-like mass. If the mass is allowed to remain undisturbed for even a short period of time, it becomes more solid, with the result being that paint lines, valves, strainers and accessory equipment become clogged.

In order to eliminate the difiiculties associated with the premixing technique, it has been found desirable to have the paint binder sprayed onto the road surface to effect the desired marker and simultaneously therewith to apply the glass spheres from a separate source. The apparatus as disclosed in Patent No. 2,821,890 includes a spray nozzle for spraying the paint binder directly onto the road surface in combination with a first spray nozzle for spraying glass spheres directly into the paint binder stream. Thus, before the paint spray has reached the surface to be marked, it has'become premixed with the glass spheres. A second spray nozzle is provided immediately after the paint spray nozzle for spraying spheres onto the upper surface of the paint binder While it is still tacky to effect a top or flash coat of spheres thereby providing for immediate reflectivity of the marker. The present invention is an improvement over the apparatus and process described in Patent No. 2,821,890.

It is an object of the present invention to provide means for applying a coating material to a surface and simultaneously applying therewith a stream of small particles from a single independent source to apply the particles both into the stream of coating material and likewise onto the surface thereof.

It is a further object of the invention to provide a method of applying a coating material wherein a transparent binder material is applied to the surface to be coated while simultaneously applying a stream of particles into and onto the coating formed.

Other objects and the nature and advantages of the instant invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a diagrammatic illustration of the apparatus embodied in the present invention;

FIG. 2 is a sectional view of the marker as applied by the apparatus embodied in the present invention;

FIG. 3 is a sectional view of a modified form of marker;

FIG. 4 shows in partial section a gun and deflector for the glass beads in accordance with the present invention; and

FIG. 5 is a side view of the deflector of FIG. 4.

Generally, the present invention relates to surface coating methods and apparatus for applying a coating to a surface and applying simultaneously therewith a stream of small particles which is applied both into the coating stream and onto the film of coating which has been applied onto the surface to be coated. A preferred application of the present invention is in marking a road surface or the like with traffic lines. The road marking apparatus embodied herein is adapted to be carried by a moving vehicle generally of the self-propelled type, and includes a spray gun that is located a predetermined distance from the road surface and is adapted to spray a paint binder thereon of a given width to effect a traffic lane stripe. Tiny glass spheres are adapted to be ejected in a continuous stream into the paint binder stream through a second spray gun which is provided with a deflector thereon which is so positioned rearwardly of the first spray gun so that the spheres are simultaneously ejected into the paint binder stream and also onto the freshly applied marker as a top or flash coat of spheres.

Referring now to the drawings and particularly to FIG. 1, the apparatus embodied herein is diagrammatically illustrated and includes a spray gun indicated at 10. The spray gun 10 is of the general type employed for traflic lane marking and includes a nozzle 12 through which an atomized spray of paint binder mist is ejected under the motive force of compressed air. The spray gun 10 and the conventional equipment associated therewith, such as the compressor and prime mover, are adapted to be mounted on a vehicle preferably of the self-propelled type, the vehicle also carrying a supply of paint binder, not shown, as well as a tank 14 for the glass spheres and a spray gun 16 for spraying the glass spheres. The spray gun 10 is connected to the supply of paint binder, the paint binder being ejected from the nozzle 12 in a fan shaped stream 18 onto a surface 20 to define a marker 22 of predetermined width. The width of the marker is determined by the height of the spray gun 10 from the surface 20 and the angle of the spray gun although it is usually maintained in a vertical direction.

As shown in FIG. 1, the spray gun 16 for the glass spheres is angularly positioned directly adjacent the spray gun 10 and is located rearwardly thereof with respect to the direction of travel of the vehicle, the direction of travel being indicated by the arrow shown above the spray gun 10in FIG. 1. The axis of spray gun 16 is seen to intersect the surface 20 at a point which is located slightly forwardly of the point of application of stream 18 thereon. The spray gun 16 is shown in detail in FIG. 4 and is connected by a line 24 to the hopper 14 which is maintained 3 pressurized by air under pressure. Air pressure to the tank 14 should be approximately 5060 lbs. and this is set and controlled by a pressure regulator valve 26. The air for pressurizing enters through a filter 28 and line 30 passing through stop cock 32, pressure indicator 34 and safety valve 36, and then into the tank 14. An exhaust valve 38 is provided for relieving the pressure from the tank. As shown, the tank is provided with a lid 40 which is clamped thereon. When the air pressure is applied on the glass tank 14, glass spheres are forced through the lines to the glass spray gun 16.

The glass spray gun 16 is shown in more detail in FIG. 4. In general, it is air operated with a spring tension closing action so that when air to the gun is removed, a needletype plunger shuts off the glass supply under coil spring tension. The glass gun comprises an operating cylinder 42 at the top thereof which houses the coil spring 44 operating on a piston 46. A needle-stem 48 is attached to the piston 46 and has a valve 50 at the lower end thereof. A fluid nozzle 52 is located immediately below the valve 50. Immediately below the fluid nozzle 52 is the deflector 54. Thus, when air pressure is admitted to the line 56, the piston 46 rises carrying the valve 50 from its seat and thereby permitting the glass spheres to flow through line 24, nozzle 52 and thence through the deflector 54. The deflector 54 is preferably made of brass and gives a controlled glass stream pattern, as shown in FIG. 1, that partially mixes with the paint stream 18 before it reaches the surface 20 and partially reaches the layer of paint which has already been deposited on the surface 20. Thus, the glass spheres which contact the stream of paint 18 issuing from the spray gun 20 are premixed therewith and are embedded in the line which is deposited. The glass spheres which reach the marker after it has been de posited become partially embedded in the upper surface thereof.

As shown, the deflector 54 is curved downwardly to confine the stream of particles in a fan shaped controlled pattern similar to the fan shaped stream previously described as issuing from nozzle 12.

The glass spheres which are normally used for road marking purposes are graded by sieve analysis and are required to conform to the following gradation:

U.S. Standard Sieve Minimum, Percent Maximum, Percent Retained:

Passing With this gradation in size of the spheres, it is noted that the larger, heavier spheres will be sprayed somewhat further than the lighter spheres. Thus, the spheres which are heavier ranging from 20 to 50 US. standard sieve size, will tend to reach the spray 18 and to become embedded therein; whereas the lighter, smaller diameter spheres of 80 to 200 US. standard sieve size will not travel as far from the glass spray gun 16 and will become deposited on the top of the wet paint line. Thus, the finished marker, as shown in FIG. 2 will have the larger glass spheres 60 completely embedded in the paint binder 62 whereas the smaller spheres 64 will be partially embedded in the upper surface of the line, thereby yielding an instantly reflective layer of reflective spheres on a substantially premixed paint line. Thus, through abrasion, those spheres that are completely embedded are gradually uncovered through abrasion of traflic, thereby exposing their reflective qualities as the line is worn down.

As a modified method of operation, the material sprayed through the gun 12 may be a transparent binder material and the particles which are sprayed through the gun 16 may be a mixture of regular road glass spheres and colored resin-coated glass spheres. Thus, as shown in FIG. 3, a marker would be produced wherein the coated glass spheres 66 are included in the transparent binder 68 along with the uncoated glass spheres 70. The coated glass spheres may be coated with a resin coating Olf any desired color and will thereby add the desired daylight color to the line being sprayed without the use of the normal pigments. If the coated glass spheres are somewhat larger than the uncoated glass spheres, then the glass spheres which are coated will become completely embedded in the transparent binder layer and the uncoated smaller lglass spheres will form the partially embedded top coating so that the line beneath the top coating of spheres will have the color of the coated glass spheres.

Thus, it is seen for the first time it is possible to obtain an immediately reflective glass coated marker which also contains glass beads which are completely embedded in the marker without the use of a premix and without the use of two glass guns as heretofore proposed. In accordance with the present invention a single glass gun in combination with the deflector illustrated will simultaneously act to premix glass beads within the spray and to top the formed marker while it is still tacky with glass spheres. As illustrated, the deflector 54, is curved at its lower portion and is commonly referred to as a water knife. This deflector acts to enlarge the spray pattern of the glass spheres over a larger area so that it will contact both the spray 18 from the gun 12 as well as the ground 20 onto which the marker is being sprayed.

The binder which is sprayed through the spray gun 10 may be of any type of low viscosity, fast evaporating pigmented or non-pigmented material, such as alkyds, modified alkyds, vinyls and the like, which has been mixed with a solvent to a sprayable consistency to yield a fast-drying paint.

The idea of introducing the colored coated glass spheres into a clear, transparent binder at the gun at the time of application to a surface eliminates the necessity of separate tanks for each color marker which it is desired to be sprayed. Thus, a single tank containing a transparent binder can be utilized and the various colors of glass spheres can be utilized in the sphere tank, thus making the single piece of equipment available for spraying various colored lines without the necessity of cleaning and washing out the paint tank before changing color. It should also be noted that in addition to spraying the glass spheres and color coated glass spheres that the same apparatus can be utilized for spraying normal pigments into a transparent binder to yield conventional pigmented binders. This has the advantage of using a non-pigmented binder which does not settle out nor clog the lines and equipment upon sitting.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. Apparatus for applying a coating to a surface com prising first means for ejecting a stream of coating material onto said surface, the axis of said ejecting means being substantially perpendicular to said surface, and a second ejecting means located rearwardly of said first ejecting means with respect to the direction of travel thereof for ejecting a stream of particles, the axis of said second ejecting means being at an angle to the axis of said first ejecting means, the axis of said ejected stream of particles intersecting said surface slightly forwardly of the point of application of said first stream whereby a portion of the stream of particles is intimately mixed with said stream of coating material prior to the application thereof to said surface and a portion of the stream of particles falls onto said coating after application thereof to said surface.

2. Apparatus as set forth in claim 1 wherein a deflector is located at the end of said second ejecting means for effecting a fan-shaped spray of said particles.

3. Apparatus adapted to be attached to a moving vehicle for applying a coating to a surface comprising a first nozzle for ejecting a continuous stream of coating material under pressure toward said surface, and a second nozzle located rearw-a-rdly of said first nozzle with respect to the direction of travel thereof for ejecting a stream of particles, the axis of said ejected stream of particles intersecting said surface slightly forwardly of the point of application of said first stream whereby a portion of the stream of particles is intimately mixed with said stream of coating material prior to the application thereof to said surface and a portion of the stream of particles falls onto said coating after application thereof to said surface.

4. Apparatus as set forth in claim 3 wherein a deflector is located at the end of said second nozzle for controlling the pattern of said stream and directing it downwardly.

5. A method of applying an immediately reflective marker onto a road surface comprising the steps of spraying a fan-shaped stream of paint binder substantially perpendicularly onto said road surface from a moving external source, and simultaneously ejecting a stream of dry glassspheres in an atomized fan-shaped spray rearwardly of said stream of binder, said stream of spheres being ejected at an angle to the axis of said stream of binder so as to intersect said road surface slightly forwardly of the point of application of said stream of binder whereby a portion of the stream of spheres is intimately becomes partially embedded therein as a top coating for immediate reflectivity of said marker.

6. A method of applying an immediately reflective marker onto a road surface comprising the steps of spraying a fan-shaped stream of transparent binder substantially perpendicularly onto said road surface from a moving external source and simultaneously ejecting a stream of dry glass spheres in an atomized fan-shaped spray rearwardly of said stream otf binder, said stream of spheres being ejected at an angle to the axis of said stream of binder so as to intersect said road surface slightly forwardly of the point of application of said stream of binder whereby a portion of the stream of spheres is intimately mixed with said stream of binder prior to the application thereof to said road surface and a portion of the stream of particles falls onto said marker after application thereof to said road surface while it is still tacky, at least a portion of said ejected glass spheres being coated with an opaque colored coating whereby said colored coated spheres act as the colored pigment in said marker and the uncoated glass spheres act as retroreflective elements for immediate reflectivity of said marker.

References Cited by the Examiner UNITED STATES PATENTS 2,201,534 5/1940 Hallenbeck 9444 2,833,542 5/1958 Martin 94-44 X 3,057,273 10/ 1962 Wilson 9444 FOREIGN PATENTS 396,625 1/ 1933 Great Britain.

JACOB L. NACKENOFF, Primary Examiner.

Claims

1. APPARATUS FOR APPLYING A COATING TO A SURFACE COMPRISING FIRST MEANS FOR EJECTING A STREAM OF COATING MATERIAL ONTO SAID SURFACE, THE AXIS OF SAID EJECTING MEANS BEING SUBSTANTIALLY PERPENDICULAR TO SIAD SURFACE, AND A SECOND EJECTING MEANS LOCATED REARWARDLY OF SAID FIRST EJECTING MEANS WITH RESPECT TO THE DIRECTION OF TRAVEL THEREOF FOR EJECTING A STREAM OF PARTICLES, THE AXIS OF SAID SECOND EJECTING MEANS BEING AT AN ANGLE TO THE AXIS OF SAID FIRST EJECTING MEANS, THE AXIS OF SAID EJECTED STREAM OF PARTICLES INTERSECTING SAID SURFACE SLIGHTLY FORWARDLY OF THE POINT OF APPLICATION OF SAID FIRST STREAM WHEREBY A PORTION OF THE STREAM OF PARTICLES IS INTIMATELY MIXED WITH SAID STREAM OF COATING MATERIAL PRIOR TO THE APPLICATION THEREOF TO SAID SURFACE AND A PORTION OF THE STREAM OF PARTICLES FALLS ONTO SAID COATING AFTER APPLICATION THEREOF TO SAID SURFACE.