Abstract:
A span wire assembly for supporting a traffic control device. The span wire assembly includes a pair of vertical members or cast arms for attachment to the traffic control device. The cast arms are integrally formed with tubular ends and a centrally positioned wiring passage. A span wire assembly utilizing the inventive cast arms has fewer parts and, consequently, is simpler for the manufacturer to produce and for the customer to use.

Description:
FIELD OF THE INVENTION 
   The present invention generally relates to traffic control devices and, more particularly but without limitation, to span wire assemblies for supporting traffic devices. 
   BACKGROUND OF THE INVENTION 
   Traffic signals and other traffic control devices are mounted in a variety of ways, depending on the circumstances. Sometimes, signals and other devices are mounted horizontally, that is, they are attached to a support at the sides rather than at the top or bottom. For example, a multi-light signal housing often is mounted with the lights arranged side-by-side instead of vertically. Horizontal mounting typically is accomplished by using a framework called a span wire assembly, which suspends the housing between a pair of span wires above and below the signal housing. Span wire assemblies typically are formed of a number of tubular rods and joints. While these conventional assemblies are serviceable, there is a need for a span wire assembly with a simpler design and fewer parts. 
   SUMMARY OF THE INVENTION 
   The present invention comprises a span wire support assembly for supporting an electrically powered traffic signal having two ends. The span wire support assembly comprises upper and lower horizontal members, each having first and second ends. Also included are first and second vertical members, and hardware for attaching the traffic signal to the vertical members. 
   Each vertical member is integrally formed and has an elongate body portion with first and second tubular ends. Each first and second tubular end is sized to receive a different one of the first and second ends of the upper and lower horizontal members. Still further, a wiring passage is formed through the elongate body portion of each vertical member. 
   In another aspect, the present invention is directed to a vertical support member. The vertical support member is designed for use in a span wire support assembly adapted for supporting a traffic control device with two ends. The span wire support assembly comprises upper and lower horizontal members, each having first and second ends, and hardware for attaching the traffic control device to the span wire support assembly. 
   The vertical support member comprises an integrally formed elongate body portion with first and second tubular ends. Each first and second tubular end is sized to receive a different one of the first and second ends of the upper and lower horizontal members. A wiring passage is formed through the elongate body portion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a span wire support assembly constructed in accordance with the present invention supporting a three-light traffic signal horizontally. 
       FIG. 2  is a partially exploded perspective view of the span wire assembly of  FIG. 1  with the signal removed. 
       FIG. 3  is a front elevational view of one of the vertical members of the span wire assembly of  FIG. 1 . 
       FIG. 4  is a back elevational view of one of the vertical members shown in  FIG. 3 . 
       FIG. 5  is a side elevational view of the vertical member shown in  FIG. 3 . 
       FIG. 6  is an enlarged, exploded view of one end of the span wire support assembly shown in  FIG. 2 . 
       FIG. 7  is an enlarged, exploded view of the other end of the span wire support assembly shown in  FIG. 2 . 
       FIG. 8  is an exploded view of a prior art span wire support assembly. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Turning now to the drawings in general and to  FIG. 1  in particular, there is shown therein a span wire support assembly constructed in accordance with the present invention and designated generally by the reference numeral  10 . In this figure, the span wire support assembly  10  is shown fully assembled and supporting a conventional three-light traffic signal  12  horizontally between upper and lower span wires  14  and  16 . 
   The traffic signal  12  comprises an elongate housing  18  with two ends  20  and  22 . The wiring  24  for supplying electrical power to the signal  12  is shown exiting the signal at the end  22  and is attached to the upper span wire  14  in any suitable manner. 
   The signal  12  is suspended from the upper span wire  14 , also referred to as a messenger cable or catenary cable, by the span wire clamp assembly  28 . Referring now also to  FIG. 2 , which shows only the span wire support assembly  10  in exploded form, the signal  12  is secured to the lower span wire or tether cable  16  by the tether assembly  30  (shown only in  FIG. 2 ). In some cases, it is advantageous to employ more than one attachment point to the messenger cable  14  or to the tether cable  16  or both. 
   Each end  20  and  22  of the traffic signal  12  is attached to the span wire support assembly  10  by hardware, designated only generally by the numeral  32 . Although in this preferred embodiment, the hardware  32  attaches the signal by the ends  20  and  22  to the vertical members of the frame (described in more detail hereafter), the invention is not limited to this configuration. The hardware  32  could attach at different locations to the vertical members. 
   As shown in  FIG. 1 , the assembly  10  supports a three-light traffic signal  12  that is elongate, that is, it is substantially longer in one dimension than in another. It is to be understood, though, that the span wire support assembly  10  is adapted to support a wide range of traffic control devices, such as signs, alarms, detectors and sensors, which may or may not be electrical and may have different shapes. For example, the span wire assembly could be configured to support a square device. 
   Referring still to  FIG. 2 , in its preferred form, the span wire support assembly  10  preferably comprises upper and lower horizontal members  40  and  42 . Each of the horizontal members  40  and  42  has first and second ends  40   a  and  40   b  and  42   a  and  42   b , respectively. In the preferred practice of this invention, the upper and lower horizontal members  40  and  42  are elongate tubular members, preferably aluminum, that are identical and therefore interchangeable. However, the shape, material and identity of structure are not essential to the inventive assembly  10 . 
   With continuing reference to  FIG. 2 , the span wire support assembly  10  further comprises first and second vertical members  46  and  48 . As used herein, “horizontal” refers to the relative position of the component relative to the earth&#39;s surface in the assembled device, namely, that the axis of the longest dimension of the structure is arranged generally parallel to the plane of the earth in the assembled support  10 . Likewise, “vertical” refers to the position of the structure in the assembly support  10  relative to the earth and denotes that the axis of the longest dimension of the structure is arranged generally normal to the plane of the earth. 
   Turning now to  FIGS. 3-5 , the preferred vertical member or “cast arm” configuration is shown in detail. In their preferred form, the vertical members  46  and  48  are both integrally formed, that is, cast in a single piece of metal or other suitable material, such as aluminum or plastic. In addition, the members  46  and  48  may be identically formed. In this way, each of the vertical members  46  and  48  are interchangeable. This simplifies manufacture as well as assembly of the support  10  by the user. 
   As the vertical members  46  and  48  are identically formed, only the member  46  is shown in  FIGS. 3-5 . The member  46  preferably comprises a solid elongate body portion  50 . Although the shape and relative dimensions may vary, one suitable shape includes a planar back portion  52  and a longitudinal rib  54  extending the length thereof. This provides good strength and resistance to deformation. 
   The vertical member  46  further comprises first and second tubular ends  46   a  and  46   b . Each of the ends is formed into a short tube sized to receive at least one of the ends  40   a ,  40   b ,  42   a ,  42   b  of the horizontal members  40  and  42 . If, as is preferred, the horizontal members  40  and  42  are identical tubes, and all the ends are therefore also identical, then any of the ends  40   a ,  40   b ,  42   a ,  42   b  is receivable in either of the ends  46   a  and  46   b.    
   Referring still to  FIGS. 3-5 , the body portion of the vertical member  46  is adapted to support one of the ends  20  and  22  of the traffic signal  12  or other traffic control device. To that end, the body portion  50  is provided with a two-sided attachment plate  56  to permit attachment of one of the ends of the signal  12  using the hardware  32  ( FIG. 2 ). In the embodiment shown, the attachment plate is configured for a tri-bolt attachment system, but a tri-stud configuration or other attachment device easily could be substituted. For that purpose, the attachment plate  56  is provided with a plurality of bolt holes, such as the three bolt holes designated collectively at  57 . In addition, bolts  59  may be included in the assembly  10 . Preferably, the attachment plate  56  comprises a serrated face on the inner aspect to engage a corresponding serrated face on the signal housing  18 , for example, as this prevents rotational shifting of the housing along the horizontal axis. The serrated face can be achieved by casting it as part of the arm or by using a lock ring. 
   As indicated previously, many of the traffic control devices that are supported in a span wire assembly are electrically powered and therefore have a power cord or electrical wiring, such as the wiring  24  ( FIG. 1 ), extending from one or both ends. Accordingly, in the preferred embodiment of the vertical member  46 , a wiring passage  58  is formed as an access opening through the attachment plate  56  of the elongate body  50 . The diameter of the passage may vary, though one-half to one inch is suitable in most applications. This allows the wiring to extend from either or both ends of the span wire support assembly  10 . In this embodiment, the bolt holes  57  are spaced circumferentially about the wiring passage  58 . 
   As shown in the enlarged exploded views of  FIGS. 6 and 7 , to which attention now is directed, each of the tubular ends  46   a  and  b  and  48   a  and  b  of the vertical members  46  ( FIG. 6) and 48  ( FIG. 7 ) preferably are adapted to be secured to the ends of the horizontal member  40  or  42  received therein. To that end, the ends  46   a  and  b  and  48   a  and  b  are provided with set screws  60  and set screw receiving openings  62 . Thus configured, the ends  40   a  and  40   b  and  42   a  and  42   b  of the horizontal members  40  and  42  can be rotated or advanced axially in either direction until the desired position is achieved. Then the set screw  60  can be tightened to secure the horizontal member in the selected position. Alternately, other mechanisms such as compression clamps can be employed. 
     FIG. 8  illustrates a conventional span wire support assembly designated generally at  70 . As seen, one of the vertical members  72  comprises two straight tubular portions  74  and  76 . In addition, the distal ends of the tubular member  74  and  76  attach to t-shaped horizontal slips  78  and  80 . The proximal ends of the tubular members  74  and  76  are connected by a cross-shaped member  82 . 
   Now it will be appreciated that the integrally formed vertical members  46  and  48  of the inventive span wire assembly  10  provide a much simpler structure. The single vertical member of cast arm  46 , as seen in  FIG. 2 , replaces five structures the conventional assembly  70 . This simplifies manufacture, inventory, parts tracking and shipping, and invoicing for the manufacturer. In addition, the assembly of the span wire support  10 , typically carried out by the customer in the field, is also streamlined, as so many parts and connections are omitted. 
   Changes can be made in the combination and arrangement of the various parts and elements described herein without departing from the spirit and scope of the invention as defined in the following claims.