Abstract:
A cable marker pole system is described for marking the location of buried utility cabling. The cable marker pole system includes a base for embedding in earth or concrete, and a two-part pole assembly that couples with the base. The two-part pole assembly includes a spring coupling the two pole members to allow the pole assembly to flex if struck. A sign is attached to the top of the pole assembly to indicate what is buried.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to marker poles for subterranean cable installations, and more particularly, to a marker pole having a spring-loaded portion extending above the ground to facilitate movement thereof in response to impacts from motor-vehicles, lawn mowers and the like. 
     Marker poles are commonly employed for marking the locations of various underground objects. For example, utility lines are often buried in the ground in many locations for aesthetic reasons. Marker poles are placed in the ground and disposed along the buried cable in order to show the location thereof. 
     In recent years fiber-optic cable networks have been installed in many parts of the country. A common installation procedure involves trenching or boring underground and placing the fiber-optic cables within protective plastic conduit. The fiber-optic cables have many advantages for telecommunications, including the ability to efficiently transmit large amounts of data. However, because relatively high revenues are typically generated from their transfer of correspondingly large amounts of data for telecommunications customers, there exists the potential for large losses in earnings associated with an inoperative fiber-optic cable. 
     Excavating equipment and operations pose significant threats to buried utility lines, including fiber-optic cables. Natural gas pipelines, for example, pose an explosion risk. Electrical power lines have attendant risks of damage and injuries related to electrical power. Accidentally severing a buried fiber-optic cable can subject an excavation contractor to significant liability for interrupted service. Severing fiber-optic cables can interrupt service unless transmissions can be rerouted. Depending upon the normal traffic volume in a buried cable, significant revenues can be lost before a splice can be made and service restored. 
     In order to control such risks, utility companies and service providers have marked the locations of their underground lines and provided information regarding same, such as toll-free numbers, which excavators are encouraged to “call before digging”. A common pre-existing type of marker includes a length of plastic pipe with one end embedded in the ground and the other end mounting a cap. The cap can have printed thereon warning information, and can be color-coded for the type of buried utility, e.g.: blue—water; yellow—natural gas; red—electric; orange (white)—fiber-optic, etc. Such utility markers tend to be relatively effective and are widely recognized in the art. Although they are relatively easy to install, many of the prior art designs can be easily destroyed by impact with moveable objects. 
     In view of the foregoing, there exists a need for a marker pole system that exhibits resistance to inadvertent impacts from motor vehicles, lawn mowers, and the like. 
     SUMMARY OF INVENTION 
     In accordance with an aspect of the present invention, a cable marker pole system is provided for marking the location of buried utility cabling. The marker pole system generally comprises a base adapted for being embedded in hardened earth or concrete, a two-part pole assembly and a spring. The pole assembly comprises a first elongated member defining a first end and a second end, and a second elongated member defining a first end and a second end. The spring connects the first end of the first member to the first end of the second member. The second member is constructed and arranged to fit within a receptacle defined in the base, such that when the pole assembly is connected to the base, the first member is permitted to move relative to the second member and the base. A sign containing indicia regarding buried cable is attached to the second end of the first member. Several embodiments are disclosed for attaching the pole assembly to the base, a first of which includes a threaded collar associated with the first member for mating with a complimentary threaded portion on the base, a second of which includes a threaded second member and complimentary threaded base receptacle that screw together, and a third of which includes a through-bolt arrangement. 
     These and other advantages of the invention will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is an exploded isometric view of a marker pole system in accordance with a first embodiment of the present invention; 
         FIG. 1B  is a sectional view along lines  1 B- 1 B in  FIG. 1A ; 
         FIG. 2A  is an exploded isometric view of a marker pole system in accordance with a second embodiment of the present invention; 
         FIG. 2B  is a sectional view along lines  2 B- 2 B in  FIG. 2A ; 
         FIG. 3A  is an exploded isometric view of a marker pole system in accordance with a third embodiment of the present invention; and 
         FIG. 3B  is a sectional view along lines  3 B- 3 B in  FIG. 3A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1A and 1B  depict a first embodiment of a marker pole system  100  in accordance with an aspect of the present invention. The marker pole system  100  is adapted to be partially embedded in the earth  102  over a buried utility line, such as a fiber optic cable  104 . The marker pole system may be embedded in hardened earth or concrete generally represented by the reference numeral  106 . 
     The marker pole system  100  includes a pole assembly  108  comprising a first elongated member  110  defining a first end  112  and a second end  114 , and a second elongated member  116  defining a first end  118  and a second end  120 . The first member  110  is connected to the second member  116  by a coil spring  122  that is attached to the first end  112  of first member  110  and the first end  118  of second member  116 , respectively. The first member  110  preferably consists of an elongated section of plastic pipe (e.g., polyvinyl chloride (PVC)), approximately 6 to 8 feet in length. Although a circular tubular body is shown, rectangular or other multisided configurations might be used within the scope of the invention. A sign  124  is affixed to the second end  114  of the first member  110 . The sign  124  may have indicia to provide an appropriate warning such as, for example, a “Call Before Digging” advisory with a toll-free number at which additional, pertinent information can be obtained. The sign  124  can be fabricated from a generally flat sheet of plastic material and provided with a cylindrical sleeve  125  for mounting the sign on the second end  114  of the first member  110  as shown. 
     In accordance with the first embodiment of the invention, a collar  126  is rotatably mounted proximal to the first end  118  of the second member  116 . The collar  126  facilitates attachment of the pole assembly  108  to a base  128  that is partially embedded in hardened earth or concrete  106 . The collar is provided with a splined or grooved portion  130  that mates with a complimentary splined or grooved portion  132  near the first end  118  of the second member  116 . In this manner, the collar  126  can rotate in a fixed position around the second member  116 . The collar further includes an annular flange  134  having a threaded portion  136  adapted to mate with a complimentary threaded portion  138  defined in the base  128 . 
     The base  128  is preferably configured as a generally elongated tubular structure having a first end  140 , a second end  142 , and a centrally disposed elongated receptacle or bore  144  extending therethrough. The base  128  may be provided with a flange  146  to prevent the base from being pulled out of the hardened earth or concrete  106 . The base  128  is preferably constructed from galvanized steel, but other materials including plastics or composites may be utilized within the scope of the invention. 
     The pole assembly  108  is installed in the base  128  by inserting the second end  120  of the second member  116  into the bore  142 . The collar  126  and attached second member  116  is then locked to the base  128  by threading the collar  126  over the threaded portion  138  in the base  128 . In this manner, the first member  110  is able to move relative to the second member  116  by virtue of the spring  122  in the event of an impact between the first member  110  or sign  124  with motor vehicles, lawn mowers and the like. This freedom of movement enables the pole assembly to survive impacts that would otherwise damage the pole assembly  108 . 
     Referring now to  FIGS. 2A and 2B , there is depicted a second embodiment of a marker pole system  200  in accordance with an aspect of the invention. The marker pole system  200  includes a pole assembly  208  comprising a first elongated member  210  defining a first end  212  and a second end  214 , and a second elongated member  216  defining a first end  218  and a second end  220 . The first member  210  is connected to the second member  216  by a coil spring  222  that is attached to the first end  212  of first member  210  and the first end  218  of second member  216 , respectively. A sign  224  is affixed to the second end  214  of the first member  210 . The second member  216  is provided with a threaded portion  248  adapted to mate with a complimentary threaded portion defined in a base  228 . 
     As in the first embodiment, the base  228  is preferably configured as a generally elongated tubular structure having a first end  240 , a second end  242 , and a centrally disposed elongated receptacle or bore  244  having a threaded portion  250  extending therethrough. The base  228  may be provided with a flange  246  to prevent the base from being pulled out of the hardened earth or concrete  206 . The pole assembly  208  is anchored to the base  228  by simply screwing the threaded second member  216  into the threaded bore  244  in the base  228 . 
     Referring now to  FIGS. 3A and 3B , there is depicted a third embodiment of a marker pole system  300  in accordance with an aspect of the invention. The marker pole system  300  comprises a pole assembly  308  comprising a first elongated member  310  defining a first end  312  and a second end  314 , and a second elongated member  316  defining a first end  318  and a second end  320 . The first member  310  is connected to the second member  316  by a coil spring  322  that is attached to the first end  312  of first member  310  and the first end  318  of second member  316 , respectively. A sign  324  is affixed to the second end  314  of the first member  310 . 
     A base  328  is preferably configured as a generally elongated tubular structure having a first end  340 , a second end  342 , and a centrally disposed elongated receptacle or bore  344  sized and adapted for receiving a portion of the second member  316  of the pole assembly  308 . As in the first and second embodiments, the base  328  may be provided with a flange  346  to prevent the base from being pulled out of the hardened earth or concrete  306 . The pole assembly  308  is installed in the base by inserting the second member  316  into the bore  344  in the base  328 . The base  328  has apertures  352  extending transversely through the sidewalls of the base. The second member  316  of the pole assembly  308  includes a mating aperture  354  that is aligned with apertures  352  in the base  328  when the second member  316  is fully inserted into bore  344  of the base  328 . A bolt  356  is inserted through the respective apertures  352 ,  354  and locked down with a nut  358  in a conventional fashion. Of course it will be appreciated by those skilled in the art that many different kinds of fasteners can be utilized in lieu of bolt  356  within the scope of the invention. 
     The present invention has been shown and described in what are considered to be the most practical and preferred embodiments. It is anticipated, however, that departures may be made therefrom and that obvious modifications will be implemented by those skilled in the art. It will be appreciated that those skilled in the art will be able to devise numerous arrangements and variations which, although not explicitly shown or described herein, embody the principles of the invention and are within their spirit and scope.