US 2036373 A
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April 7, 1936. D TAYLOR 2,036,373
HIGHWAY MARKER Filed April 29, 1955 Swan MM 7 i af a 7 .5071 0 00!; Z). Way 3 Patented Apr. 7, 1936 PATENT OFFICE errant HIGHWAY MARKER,
Donald D. Taylor, Duncannon, Pa assignor to Advance Engineering Corporation, huncannou, Pa, a corporation oi Pennsylvania Applicationdnril ea recs, Serial No. irate lit tllaims.
My invention relates to the marking of streets and highways with surface indicia for defining tramc lanes, pedestrian crossings and'the like.
l-leretoiore, several expedients have been attempted for the general purposes with which the present invention is concerned. @ne of the first to be used and that which, to the present time, is most generally employed, consists in the painting of appropriate lines upon the road or street surface. Such lines have the great disadvantage of short life, due to the abrasive action of vehicle wheels rolling and dragging thereon, weathering, and to staining and obliteration by road tar and spent oil dropping from the engines and other lubricated parts of automobiles.
Because of this primary objectionto the painted line as a highway marker, numerous devices have been ofiered as substitutes, such devices, for the most part, being in the nature of studs provided with pin-like securing portions which are driven or otherwise anchored in the body of the highway at appropriately'spaced positions to give the appearance of a dotted or broken line. Such devices are expensive for the purpose, partially :3 because, to remain lustrous, they must be fabricated of, or jacketed with, expensive corrosionresisting metal such as Monel or stainless steel. In some instances, attempts have been made to jewel the exposed portions of otherwise nonlustrous studs with faceted pieces of glass which reflect light. The mounting of such jewel-like elements in studs of rugged character is similarly so expensive as to be almost prohibitive for the provision of a highway marker of general utility. Moreover, adequate anchorage of such stud-like road-marking devices, as a class, is extremely diflicult and further increases the cost of the finished highway line to such an extent that, as has been stated, painted lines, despite their short life, continue to be the expedient most generally used.
Relatively recently, efiorts have been made to employ a, ribbon or strip of lustrous metal and to anchor the metallic strip by means of. an adhesive such as asphalturn. While such a construetion has great merit from the standpoint of enhanced visibility and facility and rapidity of installation, the difliculty of obtaining an adhesive bond of adequate tenacity, especially on concrete highways, is self-apparent. Such a construction suffers damage not only by reason of the scraping and plucking action of vehicle wheels in lateral skidding and braking, especially when the wheels carry chains, but also by reason of the ingress of water, oil and dirt beneath the strip. In concrete roadways, particularly, con- (till. tit-1L5) siderable moisture reaches such a strip, or its adhesive backing, through capillary attraction due to inherent porosity of such roadway materials as concrete. Diflerential thermal expansion and contraction also eflects a buckling oi the strip during extremes of temperature, with the result that the strip may become so wrinkled as to periodically lift from the surface of the roadway. Under such conditions, dirt will enter between the strip and the underlying roadway surface at, numerous points, destroying the adhesive bond and assuring easy tearing and separation of the strip by vehicle wheels.
Other methods have been attempted, such as edgewise flanging of such strips into U term and the imbedding of the flanges in the material of the roadway. While the anchorage thus adorded is highly satisfactory, such structures are limited, for all practical purposes, to installation in new roadways during their construction. Such strips also are extremely expensive because at the highcost non-corrosive metals required, as well as the dimculty of drawing and shaping the strips. Moreover, the application of such a structure to curves .(which, incidentally, are the most common locations requiring marking) is practically impossible, except where the'strip is of preformed curved configuration. Fabrication of such flanged strips in sections having curvatures of varying intensity involves manufacturing and shipping expense which is substantially prohibitive. Glare resulting from reflection of sunlight and light from approaching vehicle headlights, as well as the hazard of skidding on such rolled metallic strips, are further complications which adversely affect their adoption.
With the foregoing prior art structures and attendant problems in mind, my invention has, for its purpose, several well-defined objects. The primary object of my invention is to provide a zone-defining road marker which is rugged and will successfully withstand the numerous stresses and strains to which such markers areinherently acteristic of so diffusing light reflected from the additional traffic hazard.
It is an object of my invention to provide a low-cost traific marker which, like the painted line, is formed in situ upon the road surface.
It is an object of my invention to provide a trafilc marker which may be installed upon existing highways with facility equal to installation upon new highways.
It is an object of my invention to provide a traffic marker which, when worn, as may occur after along period of severe use, may be renewed,
or built up, with facility equal to the renewal of the painted line.
It is an object of my invention to provide a traffic marker which, though low in cost of installation, is not subject to injury by corrosion.
It is an object of my invention to provide a traflic marker which has a satisfactory coefficient of friction, and which, therefore, will not materially increase the road hazard known as skidding.
, It is an object of my invention to provide a road marker which is inherently bonded to the highway surface and which requires no adhesive binding.
It is an object of my invention to provide a road marker which may be installed with such rapidity that no interference with the normal use of the highway is occasioned.
It is an object of my invention to provide a highway marker which may be installed with accurate uniformity and which will present a pleasing appearance to the eye.
Further objects and objects relating to details and economies of construction and use will definitely appear from the detailed description following. In one instance, I accomplish the objects of my invention by the means set'forth in the following specification. My invention is clearly defined in the appended claims. A structure constituting a preferred embodiment of my invention is illustrated in the accompanying drawing, in which:
Figure 1 is a perspective view of a section of highway provided with a central longitudinal highway marker constituting a preferred embodiment of my invention;
Fig. 2 is a cross-sectional view of a portion of concrete highway provided with a highway marker of the form illustrated in Fig. 1;
Fig. 3 is a diagrammatic view of a portionof apparatus employed for the installation of a highway marker of the type illustrated in Figs. 1 and 2, portions of said apparatus, as well as of the highway and marker, being shown in crosssection; and
Fig. 4 is a diagrammatic view of a preferred form of apparatus for forming the highway marker illustrated in Figs. 1 and 2.
Similar reference numerals refer to similar parts throughout the several views.
In general, my invention consists inthe provision of a narrow, band-like highway marker consisting of a narrow, tape-like, lustrous, corrosionresistant strip of metal formed upon the surface of the highway and mechanically bonded directly thereto by casting thereon in situ.
More particularly, and with reference to the accompanying drawing, in which I have illustrated a preferred embodiment of my invention, there is shown a cast strip in of zinc of elliptical cross-section embedded, inlay fashion, in a complementary trough or channel ll, formed in the surface of a conventional highway l2. Preferably, though not by way of limitation, my inven- -headlamps of approaching vehicles as to offer no tion has particular application to monolithic highways such as are conventionally formed of concrete and provided with periodic expansion Joints or gaps l3 suitably filled with resilient or compressible material I4. In employing the term casting, particular reference is made to that method of casting which is effected by the spraying of molten metal in atomized form, and in which the atomized particles are in an unstable physical condition characterized by temporary plasticity such that solidification occurs at, or directly after, the moment of their deposit upon the surface being sprayed.
This general method of casting by atomization and projection of molten metal is well-known and, for an understanding thereof, reference is made to the patent of Donald D. Taylor, No. 1,934,891, granted November 14, 1933, which patent discloses an apparatus of the general type adapted for the production of metal coatings generally. In Figs. 3 and 4, there is diagrammatically illustrated apparatus including several metal-spraying nozzles I5 of the general type illustrated in the Taylor patent aforesaid, assembled in staggered relation. About the nozzles I5 is mounted a shield l6 consisting of side plates i1 and I8 inclined toward their lower edges to constitute a mask held in slightly spaced relation with respect to the roadway surface by a suitable carriage (not shown). The carriage also supports .one or more sand-blasting nozzles l9, which are directed to discharge sand upon a narrow, bandlike portion of the highway, directly in advance of the metal-spraying nozzles IS. The sandblasting nozzles are also preferably so inclined with respect to the band-like portion of the roadway surface as to not only clean the same of foreign matter, but also to provide a myriad of minute pits for a purpose later to be described. The shield member iii of the apparatus, in addition to the side plates I! and I8, is provided with a forward plate 20, the lower edge of which is similarly maintained in close proximity to the roadway surface. Mounted upon the plate 20, and disposed intermediate said plate and the sand-blasting nozzles I9, is an air jet 2| arranged to discharge a broad jet of compressed air direct- 1y forward of the plate 20 to constitute an air curtain as well as a cleaner for removing such loose particles of sand as remain upon the bandlike, pitted surface of the roadway prior to the spraying thereof with plastic metal discharged from the jets I5. Following the jets IS in close proximity thereto, is a rotary wire brush 22 journaled in the carriage (not shown) which supports the jets l5 and the shield l6.
More specifically, it will be noted that the staggered metal-spraying nozzles l5 are inclined with respect to the vertical and are so directed upon the sand-blasted portion of the highway surface as to deposit the densest portion of their respective streams of atomized metal along the median zone thereof and thus build up a "crowned strip having a maximum thickness along its central portion. Moreover, the pro-. jection of metal upon the pitted, band-like surface at an angle, and from two sides, insures an interlocking of the strip as formed, with the myriad of pits and projections in the roadway surface. As a result, the metallic strip becomes, in effect, an integral portion of the highway, such that dislodgment therefrom, even under the most severe stresses, is a practical impossibility.
A metal strip, cast in the manner described, has the characteristic of being rather crystalline in structure, as distinguished from a strip of metal which has been rolled or drawn. As a result, the appearance oi! the lustrous surface thereof, even when worn, is satin-like or slightly rough,
rather than brilliant and dazzling. This is an metals are relatively easy to spray, having low melting pointsand requiring low fuel consumption. They are amply light-reflective for the purpose, inexpensive, corrosion-resistant, and have good wearing properties.
Under some conditions, and in employing met-- ads which take a high polish under the action oflight tramc, it has been found desirable to diagonally striate the strip after formation. a For this purpose, the wire brush ft is employed, which brush is diagonally journaled upon the supporting carriage and driven by a motor (not shown) at a moderate speed. Preferably, such striations it are formed transverse the strip it at an angle such that they are substantially perpendicular to light rays forwardly and downwardly proiected from approaching vehicle lamps. These striations tend to break up or diffuse light otherwise refiected to the eyes of drivers traveling in the opposite direction.
With an apparatus of the type heretofore described, the rate at which the strip fill may be installed is limited and determined solely'by the desired thickness of the strip.
The strip illustrated in Figs. 1 and 2 is of elliptical cross-section and great thickness. For most purposes, a strip of far less thickness will sulhce. Where a strip having a thickness of as little as .010 of an inch is employed, it is unenecessary to countersink the same as shown, although a cleaning and roughening of the highway surface is essential to obtainadequate anchorage of the strip. With such interlocking of strip and roadway proper, diderential thermal expansion and contraction has been found not to sheet localized buckling or breakage of the strip, apparently because'the stresses are uniformly distributed for the full length of the strip section.
Preferably, where the strip is applied to con crete highways, it should be interrupted at the conventional expansion gaps or joints, as shown.
if am aware that the embodiment of my inven tion herein illustrated and described is susceptible of considerable modification without depar ture from the broad concept thereof. While zinc and aluminum have been found admirably well suited for the purpose of the present invention, other metals, pure or alloyed, may be employed. dimilarly, changes in the size and form of the strip are optional expedients. Likewise, though illustrated as a two-lane dividing tramc marker, it is equally applicable to definition of crosswalks in municipal areas. These and other variations will readily appear to those familiar with the objects and teachings of the present invention. f therefore claim my invention broadly, as indicated by the appended claims.
Wt f claim is:
l. h roadway having a roughened, band-like surface formed therein, and a metallic strip coextensive with said band-like surface, in direct contact with said band-like surface and integrally mechanically bonded thereto in interlocking relation therewith by casting.
, 2. A roadway having at roughened, narrow, band-like surface formed therein, and a narrow metallic strip coextensive with said band-like surface, in direct contact with said band-like surface and integrally mechanically bonded thereto in interlocking relation therewith by fusion.
3. A roadway having a shallow, band-liketrough formed therein, the walls of which trough are roughened, and a narrow metallic inlay of strip form set in said trough, in direct contact with the walls thereof and mechanically interlocked therewith by fusion.
4i. a concrete roadway having a narrow, bandlike, pitted surface formed thereon, and a narrow metallic strip coextensive with said bandlike surface, said metallic strip having its lower face of a form complementary to said pitted surface and interlocked therewith by casting of said strip in situ upon said pitted concrete surface,
5. fl roadway having lateral convexity or "crown", the apex of said crown being provided with a. narrow, band-like surface of roughened character coaxial with said road, and a narrow metallic strip coextensivewitlr said band-like surface, said strip being complementarily rougherred on its under surface and interlocked with said roughened surface by casting thereon in situ.
d. A roadway having a narrow, band-like, pitted surface formed thereon, and a narrow cast metallic strip coextensive with said band-like surface, said metallic strip being of generally crescent cross-section and having its two faces tary to and interlocked with the pits of said band like roadway surface.
h. ll roadway having a superficial trough formed therein, the walls of which trough are provided with a myriad of minute pits and protuberances, and a thin metallic inlay of a thickness greater than said trough, said inlay being formed therein in situ and having its under face in direct con tact with said trough walls and of a roughened configuration complementary to and interlocked with said trough walls.
9. ll roadway having a roughened, narrow, band-like surface formed therein, and a thin strip of due cast directly upon said band like surface complementary thereto and mechanically interlocked therewith.
re. A roadway having a roughened, narrow, band-like surface formed therein, and a thin strip of aluminum cast directly upon said band- ,like surface complementary thereto and mechanically interlocked'therewlth.
' ll. h roadway having a roughened, narrowband-like surface formed therein, and a thin strip of corrosion-resistant metal cast directly upon said band-like surface complementary thereto, having its under face emaul u 1mm terlocked therewith, and having its exposed surface of roughened, light-diffusing character.
12. A roadway having a roughened, narrow, band-like surface formed therein, and a thin strip of corrosion-resistant metal cast directly upon said band-like surface complementary thereto, having its under face mechanically interlccked therewith. and having its exposed surface irregularly striated to afford a non-glaring traction surface.
13. A roadway having a roughened, narrow. band-like surface formed therein. and a thin strip of corrosion-resistant metal cast directly upon said band-like surface complementary thereto, having its under. face mechanically interlocked therewith, and having its exposed surface diagonally striated to afi'ord a non-glarin traction surface.'
14. A crowned roadway having a narrow, pitted, band-like surface formed therein, and a thin strip of corrosion-resistant metal cast directly upon said band-like surface complementary thereto, having its under face mechanically interlocked therewith, and having its upper face laterally curved on a radius shorter than the radius of lateral curvature of the road proper,
said differential curvature being such as to divergently reflect light beams projected axially of the roadway and insure continuity of the strip even though narrowed by long, continued wear.
15. The method of defining a traffic lane upon the surface of a. highway which consists in removing trafllc film from said surface along the boundary of the lane, roughening said surface along said boundary to provide a myriad of minute pits and projections therein, and so casting a strip of non-corrosive metal in situ upon said clean, roughened surface as to effect mechanical interlocking of said strip upon said boundary surface.
18. The method of defining a traffic lane upon the surface of a highway which consists in removing trafilc film from said surface along the ,boundary of the lane, roughening said surface along said boundary to provide a. myriad of pits and projections therein, so casting a strip of noncorrosive metal in situ upon said clean, roughened surface as to effect mechanical interlockin of said strip upon said boundary surface, and finally diagonally striating the exposed surface of said strip.
DONALD D. TAYLOR.