GB2355177A

GB2355177A - A lighting column bracket

Info

Publication number: GB2355177A
Application number: GB9924321A
Authority: GB
Inventors: David Clark
Original assignee: Mallatite Ltd
Current assignee: Mallatite Ltd
Priority date: 1999-10-15
Filing date: 1999-10-15
Publication date: 2001-04-18
Anticipated expiration: 2019-10-15
Also published as: GB2355177B; GB9924321D0

Abstract

A lighting column bracket for attachment to the top of a column (11) comprises an upright tubular collar (10) with an outwardly extending arm (13) having a part of its length inserted into the collar (10) and welded thereto. Attached by welding to the inner end region of the arm (13) is a saddle-shaped plate (20) which is welded along its upright side edges to the internal wall of the collar (10) and has two depending legs (21) which locate within slots (17) in an upright tubular spigot (12). The plate (20) being welded to the arm (13) and the collar (10) and located within the slots (17) serves to strengthen the assembly and prevent rotation of the collar (10) by wind forces acting on the arm (13).

Description

2355177 A LIGHTING COLUMN BRACKET THIS INVENTION concerns lighting columns

of the kind used for illuminating roads, car parks and similar areas. Such a column typically consists of a main column extending almost to the maximum height of the appliance but topped off with what is usually referred to as a bracket which itself consists of a short upright length of tubing to which is welded and from which extends generally horizontally an arm which carries at its remote end the lamp.

The main column and upright tubular part of the bracket are connected together by an internal spigot which is usually welded or otherwise attached to the top of the main column to extend above it and the upper part of which is received within the lower part of the upright tubular bracket. An alternative method is to swage down a short length of the top of the column to form the spigot.

Wind forces acting on the lamp arm create a torsional force which is transmitted to the top of the column and would, if not restrained, cause the lamp arm to rotate about the vertical axis of the column, rather in the manner of a weather vein.

In order to prevent such rotation there is conventionally provided, at the upper edge of the spigot which connects the main column to the tubular bracket a castellated top defining angularly spaced vertical slots being typically 25mm in depth and 15mm in width.

A cross bar having a diameter somewhat less than the width of each castellated slot extends diametrically and internally across the tubular bracket and is usually welded thereto. When the bracket is placed over the spigot the cross bar engages in two diametrically opposed slots of the castellated top thus preventing or at least limiting any rotational movement of the arm, there being a slight rotational tolerance permitted by the excessive width of the slots when compared with the diameter of the cross bar.

In order to fix the bracket in its exact required rotational position a number of grub screws are inserted through the wall of the tubular bracket and tightened against the outer cylindrical surface of the spigot. However, should the grub screws become loosened or fail to grip the spigot sufficiently to hold the arm in place then the cross bar is maintained within the slots of the spigot to prevent excessive rotation.

Difficulties have been experienced in maintaining the strength and integrity of the assembly comprising the arm, the upright bracket and the spigot and in properly distributing the forces experienced by lighting columns, particularly in heavy climatic conditions. In addition to the provision of a cross bar and grub screws it has been found necessary to include, in some cases, a vertical plate welded to the interior of the tubular bracket and to the inner end of the arm which protrudes through the wall of the tubular bracket and is welded thereto.

According to the present invention there is provided a lighting column bracket for attachment to the top of a column, the bracket comprising an upright tubular collar and an outwardly extending arm having a part of its length within the collar, the arm being adapted to carry, at its remote end, a lamp, the bracket having anti-rotation means adapted to engage a castellated formation at the top of the column, characterised by a member attached to the arm within the collar, and to the collar, and having a part for location within the castellated formation at the top of the column.

Preferably, the member is saddle shaped thus to lie over and alongside the inner end region of the arm and having two depending portions which engage within the castellated formation.

The member preferably extends generally at right-angles to the arm thus crossing it transversely.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a part-sectional elevation showing the conventional manner of construction of a lighting column bracket of the type with which this invention is concerned; Fig. 2 is a plan view of the bracket illustrated in Fig. 1; Fig. 3 is a view similar to Fig. I but illustrating a bracket made in accordance with the invention; Fig. 4 is a plan view of a bracket illustrated in Fig. 3.

and Fig. 5 is an isometric view of an anti-rotation plate shown in Figs. 3 and 4.

Referring now to Figs. I and 2, in a conventional lighting column bracket, an upright tubular bracket 10 being of a diameter similar to that of the main column 11 is attached to the latter by means of a spigot 12 which is welded or otherwise formed at the top of the column 11 and extends upwardly therefrom to be received within the lower region of the tubular bracket 10.

A lamp arm 13 which, at its free end, carries the lamp (not shown) penetrates the wall of the upright bracket 10 and extends internally thereof, being welded around the point of entry. A strengthening gusset 14 is often welded to the arm 13 and bracket 10, and further, it is often found necessary to weld a plate 15 internally to and across the diameter of the tubular bracket 10 and to the upper region of the arm where it extends internally into the bracket. The plate 15 serves to strengthen the assembly and distribute the forces applied to the top of the column by movement of the arm 13 and lamp.

Conventionally, an anti-rotation device comprises a bar 16 which extends diametrically across and is welded to the wall of the bracket 10 so that when the bracket is lowered onto the spigot 12 the bar 16 locates within two diametrically opposed slots 17 of a castellated formation at the top of a spigot 12.

The necessity of providing the plate 15 and the bar 16 which require separate manufacturing steps results in unnecessary expenditure both in time and material cost. Furthermore, the cable which connects the lamp to the electrical supply at the base of the lighting column tends to become chafed where it may rub against the anti-rotation bar 16, particularly when the column is rocked in windy conditions. Chafing may also occur when the cable is first installed since it is usually inserted at the top of the column and drawn down to the base.

Referring now to Figs. 3, 4 and 5, in an improved assembly the plate 15 and anti-rotation bar 16 are omitted and replaced by a plate 20 preferably of saddle shape which is welded internally to the bracket 10 as shown in Fig. 4, and to the inner end region of the arm 13 as shown in Fig. 3. The plate or saddle 20 has a central slot 22 so that it may be inserted over the inner end of the arm 13 after the latter is inserted, and has two depending legs 21 which are of sufficient depth to become located in the slots of the castellated formation at the top of the spigot 12.

The plate or saddle 20 thus provides the two functions of strengthening the upper region of the tubular bracket 10 and the inner end of the arm 13 to assist in distribution of the forces, and also to act as an anti-rotation device by locating within the slots of the castellated spigot.

Once again, grub screws 23 may be used to tighten the tubular bracket 10 in its exactly required position about the axis of the column.

Considerable saving in time and material cost is achieved by the provision of the plate 20 when compared with the conventional requirement of plate 15 and anti-rotation bar 16.

The plate 20 may be of different shape. For example, it could simply be a rectangular plate with a central aperture to receive the inner end of arm 13, but in the case of the saddle-shaped plate the absence of any metal parts immediately beneath the inner end of the arm 13 ensures that there are no galvanised edges over which the cable can rub and become chafed.

A further advantage is achieved in that the plate 20 extends diametrically across the tubular bracket and thus more positively absorbs and distributes any forces created by a tendency for the arm 13 to rotate in windy conditions. Even in the event of weld failure the plate 20 will remain in place to maintain accurate location of the inner end of the arm 13 centrally within the column.

Also, by omitting the cross bar 16 which conventionally extends through the wall of the tubular member, there are thus no unsightly weld marks on the outer wall of the bracket 10.

As with conventional designs the entire assembly is preferably made from galvanised steel which is galvanised and the upper end of the tubular bracket 10 receives a metal or plastics cap to prevent ingress of water.

Claims

-8CLAIMS

1. A lighting column bracket for attachment to the top of a column, the bracket comprising an upright tubular collar and an outwardly extending arm having a part of its length within the collar, the arm being adapted to carry, at its remote end, a lamp, the bracket having anti-rotation means adapted to engage a castellated formation at the top of the column; characterised by a member attached to the arm within the collar, and to the collar, and having a part for location within the castellated formation at the top of the column.

2. A lighting column bracket according to Claim 1, wherein the member is saddle shaped thus to lie over and alongside the inner end region of the arm and having two depending portions which engage within the castellated formation.

3. A lighting column bracket according to Claim 1 or Claim 2, wherein the member extends generally at right-angles to the arm thus crossing it transversely.

4. A lighting column bracket according to any preceding claim, wherein the member is a plate welded at opposed outer edges to the bracket internally thereof, and to an inner end region of the arm.

5. A lighting column bracket according to any preceding claim, wherein the member extends diametrically across the tubular bracket and is attached at its ends thereto.

6. A lighting column bracket according to Claim 1, wherein the member comprises a rectangular plate with a central aperture to receive the inner end of the arm, the plate being welded to the inner wall of the bracket, and to the arm.

7. A lighting column bracket substantially as hereinbefore described, with reference to and as illustrated in Figs. 3 to 5 of the accompanying drawings.

- Q I F I, " 1