Illuminated free-swinging signboard

BACKGROUND OF THE INVENTION ²⁰

Outdoor signboards are subjected to wind loadings. Therefore, means have been developed for supporting the signboards to swing with the wind to dissipate much of the wind loading obviating costly support structure. 25 Simpler and more economical signboard support structures can thus be used. However, when the signboard must be illuminated, the swinging board introduces lighting difficulties. This difficulty is particularly evident in highway signs which are normally supported above the 30 street’s surface by guy wires between high sidewalk posts or to the cantilever structure that suspends overhanging traffic control signals. Care must be taken to direct the light to the signboard and not interfere with perception of the traffic signals, nor must the signboard illumination 35 radiate directly into motorists’ lines of vision.

It therefore becomes desirable to mount the illuminating lamps to move with the signboard. However, the problem of wind loading again appears with respect to the lamp housing. 40

SUMMARY OF THE INVENTION

The invention contemplates an illuminated free-swinging signboard which is normally supported in a vertical .. orientation such that it is free to swing about a horizontal ⁴pivot axis parallel to the extent of the signboard. A lamp housing contains one or more lamps for illuminating the signboard. Conventionally the lamps are fluorescent tubes whose length parallels the horizontal extent of the sign- ₅₀board. The housing comprises in part a perforated bottom and substantially vertical shielding side walls which block direct lamp radiation away from the signboard face. A power line extends from the lamps and lamp housing along an edge of the signboard. The power line then ex- ₅₅tends away from the signboard to a power source on a line that is a horizontal extension of the pivot axis of the signboard to the next point of line securing. Means secure the lamp housing to the signboard such that the housing, its lamps, and preferably the fluorescent lamp _fl0ballast swing with the signboard about the horizontal pivot axis.

While the illuminated signboard of the invention and the lamp and housing component thereof are particularly adapted to illuminating free-swinging highway signboards, the apparatus of the invention is applicable to many other signboard installations. Normally, conventional fluorescent tubes of various lengths are used to illuminate the signboard, preferably on both sides. However, it may be desirable because of peculiar local circumstances to use “black ray” or ultra-violet light shin- ^7Uing upon signboard indicia of a phosphorescent base.

Special fluorescent lamps in which a major portion of the radiated light is directed from a minor portion of the fluorescent tube periphery may also be utilized.

While it is preferred that the fluorescent lamp ballast be supported by the lamp housing, it is desirable in some instances for the ballast to be attached to a portion of the sign support structure or some other nearby support remote from the lamp housing.

Power to illuminate the lamps in the housing may be obtained in some instances from the power supply to the traffic signal indicators with which the roadway signboards are commonly associated at intersecting streets.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a fragmentary elevational view of a highway signboard and its support system in accordance with the invention;

FIG. 2 is a sectional elevation taken along line 2—2 of FIG. 1 and partly broken away;

FIG. 3 is a fragmentary elevational view of a preferred embodiment of the invention;

FIG. 4 is a plan view of the signboard and lamp housing of FIG. 3; and

FIG. 5 is a sectional elevation taken along line 5—5 of FIG. 3.

In the several figures like parts are identified by like reference characters.

FIGS. 1 and 2 illustrate a road identification signboard panel 11 suspended by a conventional swivel bracket 12 from a horizontal arm 13 of a traffic signal suspension system. A traffic control signal assembly 14 is attached to the end of the arm. A vertical pole 15 from which tension rods .16 extend supports the horizontal arm. As is best seen in FIG. 2, bracket 12 has a clamp 19 binding the bracket to the horizontal arm. The bracket, has a lockable swivel joint 21 and a horizontal pivot pin 22. The pivot pin establishes a horizontal axis about which signboard panel 11 is free to swing. The pivot pin is in a clevis 23 which is fastened to an elongate angle 24, fastened in turn to an upper edge 25 of the panel.

At a bottom edge 27 of the panel is a lamp housing 29. The lamp housing supports a pair of parallel fluorescent lamps 31, 32. The lamps and the housing extend the length of the signboard panel. The housing comprises a perforated bottom 34 and imperforate sides 35, 36, which are adjacent the outboard portions of the lamps The side walls may slope outwardly and upwardly so as to intervene between the lamps and a motorist’s line of vision, as indicated by arrows 38, 39, at various points as he approaches the sign.

The lamp housing is fixed to the signboard by means of a pair of spaced brackets 41, 42. Each bracket is an inverted T and has a bifurcated upper stem 44 and lower horizontal arms 45 secured to the bottom wall of the lamp housing. The lamp housing is thus fixed to the signboard panel to move with the panel as it swings freely about pivot pin 22 in response to wind loading.

A power supply cable 48 runs from the lamp receptacles 49 outwardly from the housing and upwardly along an edge of the panel. Clips 51 may secure the cord to the signboard edge. A run 53 of the power line then extends outwardly from the signboard and may enter into horizontal arm 13 and course therethrough downwardly to a fluorescent lamp ballast 55, which may be the intermediate source of power for the lamps illuminating the signboard.

The path of run 53 of the power line coincides with an extension of the horizontal axis 57 of the signboard support bracket pivot pin. Thus, there is little distortion

3,484,973 of the power line as it and the signboard and the lamp housing swing in response to wind loadings about the horizontal axis of pin 22.

DESCRIPTION OF THE PREFERRED

EMBODIMENT 5

FIGS. 3, 4 and 5 illustrate the presently preferred embodiment. As in the previously described embodiment, a conventional suspension bracket 12A suspends a signboard panel 11 from a horizontal arm 13 which also carries a traffic control signal assembly 14. The horizontal arm extends from a vertical pole 15, conventionally set in the sidewalk, and is braced by horizontal tension rods, such as the rod 16 of FIG. 3. A lamp housing 61 is fixed to the bottom edge of signboard panel 11 by T brackets 41, j ₅42. The housing is an upwardly opening box having vertical side walls 63, 64, vertical end walls such as the end wall 65 of FIG. 5, and a bottom 66. Bottom 66 has a plurality of perforations 67. The lower horizontal arms 45 of the attachment brackets extend below the bottom ₂q wall of the housing adjacent a perforation, secured against the exterior of the bottom wall. Therefore, there is some support of the housing should be accidental loss of attachment means, such as the nut and bolt assemblies 69.

An upper horizotnal flange 71 surrounds the upper 25 opening of the lamp housing. Transparent dust shrouds 73, 74 may cover the upper opening of the lamp housing. The lower ends of the shrouds loop about the flange and may be secured to the housing at that point.

Lamps 31, 32 which are preferably of a special fluore- θθ scent type are held within the lamp housing in electrical receptacles 49. The special lamps have an interior coating covering approximately two-thirds of the inner periphery. The coating is substantially reflective and thus directs a greater proportion of the illlumination from the lamps _3i5outwardly through the uncoated portion of the lamp periphery. Depending upon the height of the signboard panel, the central axis passing through the arcuate midpoint of the uncoated area may deviate approximately 15 degrees from the vertical axis of the lamp such that the uncoated 40 area of the lamp periphery is directed toward the central portion of the sign panel.

Lamps manufactured by both General Electric and by Duro-Test have proved to be satisfactory. General Electric lamp No. FR40CW and Duro-Test lamps No. 3120 45 and No. 3127 have been successfully utilized.

The coated portions of the lamp peripheries emit a certain amount of light. That light is emitted downwardly through the perforations in the housing bottom to give a relatively dim downward light onto the highway or other 50 area directly below the sign. The interior walls of the lamp housing are coated with a light-reflecting materials, preferably white porcelain enamel. The light from the lamps not shining directly on the sign is in the main reflected from the reflective surfaces toward the sign to 55 augment the illumination.

In the preferred embodiment the ballast 55 which increases the source voltage to the correct voltage for firing the lamps may be contained within the lamp housing. Special light-weight ballast with a large temperature oper- 00 ating range are now commercially available.

Placing the ballast within the lamp housing simplifies electrical connection of the free-swinging signboard of the invention to existing cantilever traffic light installations. The power line 53 may be clipped to a vertical 05 edge of the signboard panel and thence run to the housing of the traffic control signal along an extension of the horizontal axis of pivot pin 22.

In the preferred embodiment then, the signboard panel 11, housing 61 and the lamps and lamp ballast swing as 70 a unit about the horizontal pivot point to diminish the ⁴ loads imposed by wind forces. Since there- is no disorientation of the lamps with respect to the sign, the illumination level of the sign does not change with its motion.

While the lamp housing has been shown suspended below the sign, there are instances in which the lamp housing could be attached to the upper portion of the sign. However, for highway use such positioning tends to distribute too much light at oncoming vehicles.

As can be seen from FIG. 5, perforations 67 not only afford free passage for wind, when the shrouds 73 are not used, but also tend to considerably lighten the lamp housing itself. The vertical walls 63, 64 of the lamp housing are effective to reflect lamp emissions which would otherwise impinge themselves upon oncoming vehicles.

A lamp housing with its lamps and ballast has been developed for use with 48-inch signboards weighing approximately twelve pounds. There is thus no appreciable additional loading upon the horizontal arm 13 of any traffic signal arm to which the signboard illumination assembly is added.

The apparatus of the invention affords an efficiently illuminated free-swinging signboard which may be economically added to existing cantilevered traffic light standards without imposing onerous loads upon the existing supports. The combination of the power supply cable aligned in its run away from the sign with the horizontal axis of the pivot pin meets the requirements of electrical safety codes with no complicated additional apparatus.

While only two embodiments have been shown, many variations within the scope of the invention will occur to those skilled in this particular field of art. Therefore, we wish the invention to be measured by the appended claims rather than by the purely illustrative disclosure heretofore set forth.