DIPROSE, Andrew, Richard (35 White Friars Crescent, Westcliff-on-sea Essex SS0 8EX, GB)
DIPROSE, Andrew, Richard (35 White Friars Crescent, Westcliff-on-sea Essex SS0 8EX, GB)
| Claims 1. A traffic mast (10) comprising a ground-engagable support element (12) for stationary fixing to the ground, an arm element (14) for holding a traffic communication device (58) and which is rotatably supported by the support element (12), and movement means in the support element (12) for remotely rotating the arm element (14) relative to the support element (12), the support element (12) including an access opening (28) and an access cover (30) for closing the access opening (28), the movement means (16) including a gearbox (42) for transmitting drive to the arm element (14), the gearbox (42) being disengagable in situ from the rest of the movement means (16) and removable from the support element (12) through the access opening (28). 2. A traffic mast (10) as claimed in claim 1, wherein at least part of the longitudinal extent of the arm element (14) is arcuate. 3. A traffic mast (10) as claimed in claim 1 or claim 2, wherein the arm element (14) is bent. 4. A traffic mast (10) as claimed in any one of the preceding claims, wherein the movement means includes a stop (52) for limiting rotation of the arm element (14) relative to the support element (12). 5. A traffic mast (10) as claimed in claim 4, wherein rotation is limited to less than or equal to 180 degrees. 6. A traffic mast (10) as claimed in any one of the preceding claims, wherein the support element (12) is a traffic pole and the arm element (14) is a mast arm. 7. A traffic mast (10) as claimed in any one of the preceding claims, wherein the movement means includes an input element (44) accessible via the access opening (28) in the support element (12), and an output element engaged with the arm element (14). 8. A traffic mast (10) as claimed in claim 7, wherein the input element (44) is spaced from the arm element (14). 9. A traffic mast (10) as claimed in claim 7 or claim 8, wherein the input element (44) is manually operable. 10. A traffic mast (10) as claimed in any one of claims 7 to 9, wherein the input element (44) is operable by a hand crank element. 11. A traffic mast (10) as claimed in claim 10, wherein the hand crank element is removably engagable with the input element (44). 12. A traffic mast (10) as claimed in any one of claims 7 to 11, wherein the output element (40) is engaged with an interior of the arm element (14). 13. A traffic mast (10) as claimed in claim 12, wherein the output element includes a shaft (40) which extends to an interior of the arm element, the shaft (40) being removable from the support element (12) through the access opening (28). 14. A traffic mast (10) as claimed in any one of the preceding claims, wherein the access cover (30) is lockable for securely closing the access opening (28) in the support element (12). 15. A traffic mast (10) as claimed in any one of the preceding claims, wherein the support element (12) includes a base plate (18). 16. A traffic mast (10) as claimed in any one of the preceding claims, wherein the support element (12) has a stepped outside diameter. 17. A method of installing a traffic mast (10) as claimed in any one of the preceding claims, the method comprising the steps of : a) erecting the traffic mast (10) so as to be substantially parallel with an adjacent road; and b) rotating the arm element (14) of the traffic mast (10) to extend over at least one carriageway of the adjacent road. |
The present invention relates to a traffic mast for holding a traffic communication device, and preferably but not necessarily exclusively to such a mast which is positionable at a side of a road to hold the traffic communication device in an extended position over one or more carriageways.
Presently, the installation of a traffic control system involving overhead traffic signals requires the closing of one or more lanes of a road, and the consequent traffic congestion and disruption associated therewith. A typical overhead traffic control installation will include a traffic pole for location at a side of a road or on a central reservation, and a mast arm which extends out over one or more carriageways. The road therefore has to be closed to allow lifting equipment to lift the pole and associated mast arm into place, and then to allow technicians to hang traffic signals and to connect electricals.
One arrangement is suggested in US5772172. However, this utilises a pole with a standard received thereover, and an external winching movement mechanism. The external mechanism allows for vandalism, and also requires significant effort to operate.
The present invention seeks to prevent or limit lane closures during installation and thus mitigate traffic congestion, as well as simplifying removal and maintenance of parts of the movement mechanism.
According to a first aspect of the invention, there is provided a traffic mast comprising a ground-engagable support element for stationary fixing to the ground, an arm element for holding a traffic communication device and which is rotatably supported by the support element, and movement means in the support element for remotely rotating the arm element relative to the support element, the support element including an access opening and an access cover for closing the access opening, the movement means including a gearbox for transmitting drive to the arm element, the gearbox being disengagable in situ from the rest of the movement means and removable from the support element through the access opening.
This construction is also advantageous as it facilitates easy inspection and maintenance of the traffic communication device, such as for example, the replacement of light bulbs. However, with regular use the movement means, and especially the gearbox, is subject to wear and tear over time. By being releasably engageable, the gearbox may be removed from the traffic mast for inspection and/or maintenance before being replaced without requiring dismantling of the traffic mast. If necessary, the entire gearbox can be replaced by a substitute gearbox. This is useful as it obviates the need to potentially dismantle the entire traffic mast in order to carry out the required work, thereby reducing the inconvenience of repairs and replacements of the gearbox.
Preferably the movement means can be engaged with the traffic mast whilst the arm element is either extended over the carriageway, or substantially in parallel with the road. To clarify, the gearbox can be engaged with the arm element in either or both of the two positions, or indeed any position therebetween. This conveniently provides for a movement means having parts which are repairable and replaceable even whilst the arm element is in situ between its two primary positions.
Preferable and/or optional features of the first aspect of the invention are set forth in claims 2 to 16, inclusive.
According to a second aspect of the invention, there is provided a method of installing a traffic mast in accordance with the first aspect of the invention, the method comprising the steps of: a) erecting the traffic mast so as to be substantially parallel with an adjacent road; and b) rotating the arm element of the traffic mast to extend over at least one carriageway of the adjacent road.
The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a traffic mast, in accordance with the first aspect of the invention; Figure 2 shows an enlarged view of a support element of the traffic mast; and Figure 3 shows an enlarged view of an arm element of the traffic mast.
Referring to the drawings, there is shown a traffic mast 10, typically formed of metal and/or plastics, which comprises a support element 12, an arm element 14 being in this case a mast arm, and a movement mechanism 16 for rotatably moving the arm element 14 relative to the support element 12. The support element 12 is a traffic post which is receivable in an opening in the ground. An outwardly extending flange base plate 18 is provided partway along the longitudinal extent of the support element 12.
The support element 12 preferably has a stepped outside diameter, thereby providing a thicker lower part 20 and a thinner upper part 22. A frusto-conical surface 24 is preferably provided at a transition between the lower part 20 and the upper part 22.
The support element 12 and at least part of the arm element 14 are hollow to define a cavity 26 in which is received the movement mechanism 16. To provide access to at least one end portion of the movement mechanism 16, the lower part 20 of the support element 12 above the base plate 18 includes an access opening 28 which is closable by a, typically hinged, lockable access cover 30.
The arm element 14 in this case is a mast arm which is rotatably mounted on an upper end of the upper part 22 of the support element 12. As such, in this embodiment, adjacent ends of the support element 12 and the arm element 14 are coaxial. To provide smooth rotation, one or both of the support element 12 and the arm element 14 may include at least one bearing or bushing.
Again, preferably a frusto-conical surface 32 may be provided as a transition between the support element 12 and the arm element 14.
In this embodiment, the arm element 14 is bent, having an arcuate or curved portion 34 intermediate proximal and distal straight or rectilinear portions 36, 38. In this way, the distal straight portion 38 extends laterally, and preferably at right angles or substantially right angles, to the proximal straight portion 36 and the support element 12.
Although preferably bent, the arm element may be fully straight, thus being mounted for rotation on the support element and wholly extending laterally to the support element.
The arm element 14 may also include two or more arm members, prongs or straight portions, and these may project in the same general direction or may project in opposite directions, for example, to provide a generally 'T' shape.
The movement mechanism 16 includes a shaft 40 which is rotatably mounted within the support element 12 and which extends internally within the traffic mast 10 to a position partway along the proximal straight portion 36 of the arm element 14. A gearbox 42 is provided at the end of the shaft 40 within the support element 12, at or adjacent to the access opening 28. An input element 44 of the gearbox 42 faces the access opening 28, and includes an opening for receiving a cranked handle 46 for hand cranking.
The access opening 28 is of sufficient size to allow the gearbox 42 to be disengaged from the rest of the movement mechanism and extracted through the access opening 28. This allows the gearbox to be repaired or replaced without dismantling or removal of the traffic mast.
The shaft 40 may also be sectional to allow removal via the access opening, whilst the traffic mast remains in situ.
The shaft 40 is connected, for example, via a spigot 48, to an output of the gearbox 42. The shaft 40 is supported within the traffic mast 10 by bearings 50, and a stop 52 is included at or adjacent to the gearbox 42 to prevent the shaft 40 from rotating through, preferably, more than 180 degrees. A detent or lock is also typically included to hold the shaft 40 and thus the arm element 14 in position. The detent or lock may conveniently be provided on or at the gearbox 42, and may allow selective angular locking of the shaft 40 so that the arm element 14 can be accurately positioned. An upper end 54 of the shaft 40 is fixedly connected to the arm element 14.
A junction box 56 for traffic signals and lighting on the traffic mast 10 can also be conveniently provided within the support element 12 at or adjacent to the access opening 28.
To install the traffic mast 10, a hole is prepared at a side of a road and the electricity supply cable is suitably sited. The support element 12 of the traffic mast 10 is then lowered into the hole by a lifting device provided at the side of the road and preferably away from the carriageway, so that the arm element 14 extends in substantially parallel with the road. The support element is held stationary and permanently in the hole in the ground, and the base plate 18 is fixed to the ground.
The arm element 14 includes suitable brackets 58 and one or more traffic signals or other traffic communication devices 60, such as a sign, lighting or display, are attached, typically to the distal straight portion 38 as shown in Figure 3.
The electricity supply, if required, is connected to the junction box 56, and the cable or cables of the traffic communication device or devices 58 are also connected.
The shaft 40 is unlocked, and the cranked handle 46 is then manually operated by an installer standing on the ground to rotate the shaft 40 and thus the arm element 14 in order to swing the arm element 14 out and over one or more lanes of the carriageway. Through this entire process, the road can remain open.
Once the arm element 14 is in position, typically by reaching the stop 52, the shaft 40 is locked, the handle 46 is removed, the junction box 56 is switched on, and the access cover 30 is closed and locked.
The base plate is not essential, but simply provides additional lateral support. Although a gearbox, typically having a reduction gearing therein, is suggested, any other suitable movement means can be provided. For example, the handle can be optional or dispensed with, and an electric motor or other motor can be utilised to move the arm element.
It is thus possible to provide a traffic mast which includes a remotely rotatable mast arm, so that installation can be undertaken without disrupting traffic. Resulting congestion is thereby eliminated or reduced. It is also possible to provide a rotatable traffic mast whereby the mast arm is rotatable by an installer from the ground, thus increasing safety.
The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims.
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