FIELD OF THE INVENTION

The invention relates to a traffic light pole assembly with a breakaway device and more particularly, but not exclusively, to a breakaway device for a traffic light pole assembly to prevent damage to the foundation of the pole during an accident.

BACKGROUND

Traffic light poles consisting of hollow steel poles or of poles such as the poles described in the patent specification of PCT/IB2009/055131 are anchored in the ground using various secure foundation units such as concrete. Such secure anchoring provides a difficulty in that it increases damage caused to a vehicle when a vehicle collides therewith. It may be preferable for the pole to break loose from its foundation, in case of a collision. However, if the pole breaks away to easily, it may become a projectile thereby posing a danger to people or other objects in close proximity at the time of a collision. If the break-away force required is too high, the foundation unit itself may also be damaged during an accident, making it difficult to fit a new pole thereto.

OBJECT OF THE INVENTION

It is an object of this invention to provide a traffic light pole assembly which, at least partially, alleviates some of the abovementioned disadvantages.

SUMMARY OF THE INVENTION

In accordance with this invention there is provided a traffic light pole assembly comprising a base for the pole; a connector connecting the base to the pole, the connector being made of a material that will break before the pole is permanently deformed when a transverse force is applied to the pole.

In accordance with another aspect of this invention there is provided a traffic light pole assembly comprising:

- an upright pole;

a base for supporting the pole;

a connector for connecting the base to the pole;

the connector having a weakened section so that it will break at its weakened section when a transverse force of predetermined strength is applied to the pole. The traffic light pole assembly includes a retaining device that is connected between two parts of the connector. The retaining device is, alternatively, connected between two parts of the traffic light pole assembly.

The retaining device is a cable. The connector is an elongate member and the weakened section is a reduced circumference thereof.

Alternatively, the connector is a round rod. The weakened section may be a section of smaller diameter than the rest of the connector.

These and other features of the invention are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is described below, by way of example only, and with reference to the accompanying drawings in which: Figure 1 shows a perspective view of a breakaway device for a traffic light pole in accordance to the invention;

Figure 2 shows a perspective view of the device of figure 1 , located within a traffic light pole;

Figure 3 shows a perspective view of the device of figure 1 , the device breaking on impact of, for example, a vehicle against the pole.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference to the drawings, a breakaway device is generally indicated by reference numeral 10.

The breakaway device 10 that facilitates the breaking off of a traffic light pole 18 from its base 14, under a predetermined transverse force on the pole, consists of an elongate body (1 and 12), which has a weakened section or intermediate neck formation 13 that fails on impact of the predetermined force so the pole breaks away from the base 14, without damaging the base 14 (see figure 3).

The device 10 has a short upper tubular body 11 and a longer lower tubular body 12 which fits into a passage 15, running through the pole sections 16 of the traffic light pole. The pole is made up of modular sections that fit on top of each other. The bodies (1 1 and 12) are spaced apart by the thin neck formation 13. Both these bodies have blind screw-threaded bores at their ends 17, so that the device 10 can be attached to the base 14, and to a tensioning cable 25 with complementary screw threaded male connectors (29 and 34).

The traffic light pole 18 is secured to the base 14 with a securing means as described in patent application number PCT/IB2009/055131 . The securing means consists of a resiliently extendable cord 25, and a coil spring 30. The base 14 is made of concrete and in the shape of a solid cylindrical frustum with a central co-axial cylindrical compartment 20 to receive a part of the securing means. The modular sections of the pole 18 are forced together by tightening (shortening) cable 25. A support plate 21 , in the form of a metal disc, is bolted on to the concrete base 14 by engaging holes in the plate over protruding ends of three L- shaped bolts 22 which are moulded into the concrete 14. In addition to the holes, three holes 33 are spaced in a triangular formation in the support disc. These holes are located over the compartment 20 when the disc 21 is bolted to the base 14. Three corresponding tubular channels 23 are moulded in the base 14. These channels 23 extend horizontally between the periphery of the compartment 20 and the periphery of the base 4 to form three passages from outside the base to the compartment. Power supply cables (not shown) are threaded through these passages and holes 33 during installation of a traffic light. The traffic light pole 18 consists of a plurality of modular pole sections 16. Each section 16 has a neck and collar formation (31 and 32). Each neck formation 31 fits into the collar formation 32 of a subsequent pole section (see figures 2 and 3), to form the pole. The passage 15 runs through the center of the pole wherethrough the device 10 locates and the securing line 25 is threaded through.

In use, the device 10 is screwed onto bolt 29 which extends from the base and protrudes through disc 21. A first pole section 16 is then stacked onto the base 14, over the device 10, so that the device protrudes through the top of the second section 16. The link formation 24 is attached to male connector or bolt 34 and screwed onto the upper body 11 of the device 10 to form an attachment point for the securing line or cable 25. The securing line 25 is then attached to the link formation and threaded through subsequent pole sections being stacked on the first pole section and then secured to the top section (not shown).

In this way, the neck formation 13 will break on impact of a vehicle, crashing against the pole 18 and the pole will fall over, from the second section 16 upwards. The first section will then stay secured to the base 14 and the base will be protected from being damaged by the impact (shown in figure 3).

A retaining device in the form of a line 40 such as a steel cable is attached between the bodies ( and 12) at points 41. In the case of a breakaway as shown in figure 3, the modular sections of the pole will be kept close to the base 14 and thus prevent these from becoming dangerous projectiles. The line will extend far enough to allow the pole to break away and fall close to the base 14.

This invention is not limited to the precise details as described herein, for example, the breakaway device may be a solid rod that is made of a material that will break when a transverse force of predetermined strength is applied to the pole. The strength of this force will preferably be determined such that it will note permanently deform the pole before the breakaway device fails.