1. Field of the Invention
This invention relates to a sliding sign and more particularly to a sliding sign which is mounted on an elevated truss which extends over a roadway. More particularly, the invention relates to a sliding sign which allows the sign to be selectively moved to one end of the truss to facilitate maintenance of the sign at the shoulder of the roadway.
2. Description of the Prior Art
Various types of trusses such as box trusses are extended over roadways in an elevated condition to support signs. If the signs require maintenance or replacement, traffic lanes must be closed to enable workers to gain access to the signs by the way of lift buckets, ladders, etc. Lane closures are not only dangerous but are costly.
A sliding sign is described which is mounted on a truss such as a box truss or the like extending over a roadway. The truss includes top and bottom chords which are interconnected by various truss members. A first elongated rail is secured to the top chord of the truss and a second elongated rail is secured to the bottom chord of the truss. A plurality of horizontally spaced-apart and vertically disposed beams are movably mounted on the first and second rails and support one or more signs at the front side thereof. Wheels having V-shaped peripheries are secured to the upper and lower ends of the sign supporting beams and roll upon the first and second rails, respectively. The wheels at the lower ends of the sign supporting beams transfer gravity and lateral loads to the bottom chord of the truss while the wheels at the upper end of the sign supporting beams transfer lateral loads to the top chord of the truss. The V-shaped peripheries of the wheels prevent the wheels from disengaging from the respective rails. A bidirectional motor with brake is connected to the sign supporting structure so that the sign supporting structure and the sign mounted thereon may be moved from a position over the roadway to a position at one end of the truss so that maintenance may be performed on the sign at the roadway shoulder thereby preventing traffic lane closures.
It is therefore a principal object of the invention to provide a sliding sign for an overhead roadway sign structure.
Another object of the invention is to provide an overhead sign structure for use over roadways wherein the sign supporting structure thereon may be moved from a position over the roadway to a position near the roadway shoulder to facilitate maintenance and/or replacement of the sign.
A further object of the invention is to provide a sliding sign for an overhead truss wherein lateral and gravity loads are transferred from the sign structure to the top and bottom chords of the truss structure.
Yet another object of the invention is to provide a sliding sign which incorporates wheels having V-shaped peripheries which not only tend to clean the rails upon which they are mounted but which also transfer loads to the chords of the structure.
Yet another object of the invention is to provide a sign structure of the type described which includes a bidirectional motor connected to the sliding sign to enable the sliding sign to be moved from a position over the roadway to a position adjacent the shoulder of the roadway.
Still another object of the invention is to provide a sliding sign structure which may be easily mounted on an existing overhead truss without extensive modification thereof.
These and other objects will be obvious to those skilled in the art.
The numeral 10 refers to a truss which extends over a roadway for supporting one or more sign structures thereon. Although most of the sign supporting trusses are of the box beam truss construction as shown in the drawings, other types of truss structures are also employed. Regardless of the truss structure, the structure will include a top chord 12 and a bottom chord 14 which face the direction of traffic. If a box beam truss structure is employed, a pair of top chords and a pair of bottom chords are employed, as illustrated in
Normally, a sign structure 17 will be supported on the truss over the roadway. If maintenance or replacement of the sign structure is required, one or more traffic lanes beneath the sign structure must be closed to enable workers to gain access to the sign structures by lift buckets, ladders, etc. The instant invention eliminates the need for lane closures when sign maintenance/replacement is required.
A first elongated rail or tube 18 is secured to the top chord 12 by clamps 20 or any other convenient means. The rail 18 extends from the shoulder end of the truss to a point over the roadway. A second elongated rail 22 is secured to the bottom chord 14 by clamps 20 or any other convenient means. The rail 22 also extends from the shoulder end of the truss to a point over the roadway.
Vertically disposed and horizontally spaced sign supporting beams 24 are positioned between the chords 12 and 14 and have wheels or rollers 26 mounted thereon at the upper end thereof and wheels or rollers 28 mounted thereon at the lower end thereof. Preferably, the wheels 26 and 28 have generally V-shaped peripheries which engage the rails 18 and 22, respectively, as seen in
Many different types of mechanisms may be provided for moving the sign structure along the rails 18 and 22. A preferred embodiment is illustrated in
Motor 42 may be operated in one direction to move the beams 24 and sign structure 30 from a position over the roadway to a position adjacent the shoulder of the roadway and vice versa. The brake on the motor 42 prevents the sign structure from moving until the motor 42 is activated.
Thus, it can be seen that the invention accomplishes at least all of its stated objectives.