BREAKAWAY UTILITY POLE WITH DECORATIVE BASE COVER

Abstract

A breakaway pole installation includes a vertical pole having an anchored lower section anchored to a foundation and including a breakaway device for fracturing upon an impact of predetermined force. A decorative cover extends around the pole's lower section. The cover includes a lower foot and an upper lip. The pole includes an outward bump-out situated within the cover. The bump-out includes an energy transfer portion spaced below the cover's lip and above the cover's foot for transferring impact energy from the cover to the pole. The energy transfer portion has a height extending at least 60 mm above and 60 mm below a point of impact disposed about 450 mm above the foundation. The energy transfer portion has a maximum horizontal spacing from the cover of up to about 6 mm.

Description

BACKGROUND OF THE INVENTION

The invention relates to breakaway utility poles, in particular to such poles having a decorative base cover.

On occasion, utility poles, such as light poles, disposed along the side of a roadway are impacted by a vehicle. Accordingly, utility poles of the breakaway type have been utilized in order to reduce damage to the vehicle and injury to its passengers. The breakaway feature is provided at a lower portion of the pole such that the pole and/or fasteners joining the pole to a foundation will fracture in response to a predetermined impact force applied to the pole by the vehicle. The predetermined force must be high enough to enable the pole to withstand prescribed wind loads, and yet not so high that excessive damage to the impacting vehicle occurs.

In certain instances, it is desired to provide a decorative cover encompassing the lower portion of the pole. In the event of a vehicle impact, the cover would be impacted and fractured before the vehicle strikes the pole. The region of the cover located in the normal impact area is spaced horizontally from the pole by a gap sufficiently large for an appreciable amount of the impact energy to be absorbed by the cover as it fractures, thereby interfering with the breakaway performance of the pole. It would be desirable to prevent the presence of the cover from having an adverse effect on the breakaway performance of the pole.

SUMMARY

A breakaway pole assembly comprises a pole adapted to be anchored to a foundation by a breakaway device for fracturing upon an impact of predetermined force. A decorative cover extends around that lower section and includes a lower foot and an upper lip. The pole includes an outward bump-out situated within the cover. The bump-out includes an energy transfer portion spaced upwardly from the foot and downwardly from the lip for transferring energy from the cover to the pole. The energy transfer portion has a maximum horizontal spacing from the cover of up to about 6 mm.

A breakaway pole installation comprises a vertical pole anchored to a foundation by a breakaway device for fracturing upon an impact of predetermined force. A decorative cover extends around that lower section and includes a lower foot and an upper lip. The pole includes an outward bump-out situated within the cover. The bump-out includes an energy transfer portion spaced upwardly from the foot and downwardly from the lip for transferring energy from the cover to the pole. The energy transfer portion has a maximum horizontal spacing from the cover of up to about 6 mm.

A breakaway pole installation comprise a vertical pole having an anchored lower section anchored to a foundation and including a breakaway device for fracturing upon an impact of predetermined force. A decorative cover extends around the lower section and includes a lower foot and an upper lip. The pole includes an outward bump-out situated within the cover, the bump-out including an energy transfer portion spaced below the lip and above the foot for transferring energy from the cover to the pole. The energy transfer portion has a height extending at least 60 mm above and 60 mm below a point disposed about 450 mm above the foundation, and a maximum horizontal spacing from an inner surface of the cover is up to about 6 mm.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 depicts a conventional breakaway pole assembly anchored to a foundation.

FIG. 2 depicts the pole assembly of FIG. 1 having a decorative cover encompassing a lower portion of the pole.

FIG. 3 depicts a pole assembly in which the pole has a radial bump-out for transferring energy from the cover to the pole in the event of an impact.

FIG. 4 depicts the pole assembly of FIG. 3 with the cover shown in vertical section.

FIG. 5 is a top plan view of FIG. 3.

FIG. 6 depicts the pole of FIGS. 3 and 4 anchored by a different form of breakaway device.

FIG. 7 depicts yet another form of breakaway device for the pole of FIGS. 3 and 4.

DETAILED DESCRIPTION

A conventional breakaway pole installation depicted in FIG. 1 includes a pole 10 having a lower or base portion 14 anchored by bolts 15 to a foundation such as a concrete foundation 12 or a granular subgrade 12a (shown in FIG. 7). The pole can be formed of any suitable metal such as aluminum or steel, or it could be a fiber reinforced polymer pole. The pole 10 is connected to the base portion 14 by a conventional breakaway device 13 constituted by the manner of welding and socketing the pole to the base portion. The design is such that the breakaway will occur in response to a predetermined impact force F occurring at an assumed point of impact situated above the foundation, e.g., about 450 mm above the foundation.

Other forms of breakaway devices could be used. For example, FIG. 6 depicts a conventional breakaway device in the form of breakaway couplings 40. FIG. 7 depicts a conventional breakaway device constituted by a weakened joint 50.

FIG. 2 depicts a conventional decorative cover 16 surrounding the base portion of the pole. The cover comprises two clam-shell shaped half-sections 16a, 16b which are held together along vertical interfaces 16c by frangible couplings (not shown) located respectively at upper and lower ends of the cover. Other cover shapes (not shown) are possible. The cover can be formed of any suitable material, such as aluminum, steel or reinforced polymer for example, and includes a lower foot portion 18 which converges into an upwardly converging a neck portion 20 and finally terminates in a radial upper lip 21 (see also FIG. 5). Other cover shapes are possible in which the neck does not converge upwardly.

The breakaway device 13 for the pole of FIG. 1 would normally be designed to fracture in response to a vehicle impact of no more than a predetermined force F acting on the pole at or near an assumed point of impact. However, with the cover 16 of FIG. 2 in place, the impact will first occur against a part of the cover which is spaced horizontally from the pole by a gap G sufficiently large for the cover, as it fractures under the impact, to absorb an appreciable amount of the impact energy, possibly adversely affecting the breakaway performance of the breakaway device 13.

To minimize the chances for that adverse affect to occur, there is shown in FIGS. 3-5 a pole assembly comprised of a pole 30 and a cover 16 encompassing the lower portion of the pole. The cover is the same as that described in connection with FIG. 2 and whose half-sections 16a, 16b are secured together by upper and lower frangible connectors 17a, 17b. The pole 30 includes an outward enlargement or bump-out 34 disposed at an elevation so as to be enclosed within the cover. A portion 34a of the bump-out located above the foundation 12 and below an upper lip 21 of the cover constitutes an energy transfer structure for maximizing the transfer of energy from the cover to the pole in the event of an impact (i.e., to minimize the absorbing of energy by the cover). The energy transfer portion 34a has a horizontal width and height dimensioned for that purpose. The horizontal width is such that the energy transfer portion 34a at least substantially contacts the inner surface of the cover, i.e., no portion of the energy transfer portion is spaced from the cover by a distance greater than about 6 mm. The height H of the energy transfer portion 34a extends at least 60 mm above and 60 mm below a point P (i.e., an assumed point of impact) located about 450 mm above the foundation 12.

The energy transfer portion 34a of the bump-out is thus located and dimensioned to virtually instantly transfer most of the impact energy from the cover to the pole. That is, in the event of a vehicle impact against the cover 16 at a point located within the height H, causing the cover 16 or its frangible connectors 17a, 17b to break, the fractured cover will instantly contact the energy transfer portion 34a of the bump-out and transfer substantially all of the impact energy thereto. That is, the amount of energy absorbed by the cover will be minimal, thereby producing minimal adverse effect on the breakaway performance of the pole's breakaway device.

If the cover is in the form of two clam-shells as shown in FIG. 2, wherein the neck of the cover converges upwardly, the shape of the energy transfer portion 34a of the bump-out conforms thereto by being upwardly converging, as shown in FIG. 3. Other cover shapes (not shown) are possible, and the bump-out can be correspondingly shaped.

As explained earlier, the present invention can be used with breakaway devices other than the one depicted in FIGS. 1-5. For example, FIG. 6 depicts the provision of breakaway couplings 40 which space the pole's base above the foundation. FIG. 7 depicts a cylindrical device 46 embedded in a granular subgrade type of foundation 12a and which is connected to the bottom of the pole by a breakaway device in the form of a weakened joint 50.

Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications and substitutions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A breakaway pole assembly comprising: a pole adapted to be anchored to a foundation by a breakaway device for fracturing upon an impact of predetermined force; anda decorative cover extending around a lower section of the pole and including a lower foot and an upper lip;wherein said pole includes an outward bump-out situated within the cover, the bump-out including an energy transfer portion spaced upwardly from the cover's foot and downwardly from the cover's lip for transferring impact energy from the cover to the pole, the energy transfer portion having a maximum horizontal spacing from the cover of up to about 6 mm.

2. The breakaway pole assembly according to claim 1, wherein a height of said energy transfer portion of the bump-out extends at least 60 mm above and 60 mm below a point disposed about 450 mm above a lower end of the pole.

3. The breakaway pole assembly according to claim 1, wherein the cover comprises a plurality of sections joined together along vertical interfaces by frangible connectors.

4. The breakaway pole assembly according to claim 3, wherein said cover is formed of two clam-shell shaped sections forming a neck which converges upwardly, said portion of said bump-out converging upwardly in conformance to the neck.

5. The breakaway pole assembly according to claim 1, wherein the pole comprises metal.

6. The breakaway pole assembly according to claim 1, wherein the pole comprises fiber-reinforced polymer.

7. A breakaway pole installation comprising: a vertical pole anchored to a foundation by a breakaway device for fracturing upon an impact of predetermined force; anda decorative cover extending around said lower section and including a lower foot and an upper lip;wherein said pole includes an outward bump-out situated within the cover, the bump-out including an energy transfer portion spaced upwardly from the cover's foot and downwardly from the cover's lip for transferring impact energy from the cover to the pole, the energy transfer portion having a maximum horizontal spacing from the cover of up to about 6 mm.

8. The breakaway pole installation according to claim 7, wherein the cover comprises a plurality of sections joined together along vertical interfaces by frangible connectors.

9. The breakaway pole installation according to claim 8, wherein said cover is formed of two clam-shell shaped sections forming a neck which converges upwardly, said portion of said bump-out converging upwardly in conformance to the neck.

10. The breakaway pole installation according to claim 7, wherein the pole comprises metal.

11. The breakaway pole installation according to claim 7, wherein the pole comprises fiber-reinforced polymer.

12. A breakaway pole installation comprising: a vertical pole having an anchored lower section anchored to a foundation and including a breakaway device for fracturing upon an impact of predetermined force;a decorative cover extending around said lower section and including a lower foot and an upper lip;wherein said pole includes an outward bump-out situated within the cover, the bump-out including an energy transfer portion spaced below the lip and above the foot for transferring energy from the cover to the pole, the energy transfer portion having a height extending at least 60 mm above and 60 mm below a point disposed about 450 mm above the foundation, said energy transfer portion having a maximum horizontal spacing from an inner surface of the cover of up to about 6 mm.

13. The breakaway pole installation according to claim 12, wherein the cover comprises a plurality of sections joined together along a vertical interfaces by frangible connectors.

14. The breakaway pole assembly according to claim 13 wherein said cover is formed of two clam-shell shaped sections forming a neck which converges upwardly, said portion of said bump-out converging upwardly in conformance to the neck.

15. The breakaway pole installation according to claim 12, wherein the pole comprises metal.

16. The breakaway pole installation according to claim 12, wherein the pole comprises fiber reinforced polymer.