GB2374972A

GB2374972A - Illuminated signal apparatus with adjustable mask.

Info

Publication number: GB2374972A
Application number: GB0110280A
Authority: GB
Inventors: Smith Philip Andrew Forrest; Miles Steven Wills; Keith Manston; David Antony Martin
Original assignee: Siemens PLC
Current assignee: Siemens PLC
Priority date: 2001-04-27
Filing date: 2001-04-27
Publication date: 2002-10-30
Anticipated expiration: 2021-04-27
Also published as: GB0110280D0; GB2374972B

Abstract

Signal apparatus (1) includes a mask (5) located at a position between a light source and a lens for selectively obscuring a light source (3). Keys (11-14) and a plurality of slots (17) enable registration of the mask (5) at different angular positions relative to an axis of the apparatus (1). This enables a symbol depicted by the mask (5) to be selectively displayed at the different positions. The signal apparatus is preferably a traffic light.

Description

Signal Apparatus This invention relates to signal apparatus particularly, but not exclusively, apparatus used for traffic lights.

Traffic lights include a light source, a reflector and a protective lens. The United Kingdom Highways Agency has developed a protective lens that serves a two-fold function. Firstly, to protect the light source from environmental conditions and secondly to reduce distracting reflections. The distracting reflections are reduced by moulding in the lens a large number of lens elements. These project light from the light source forward through holes in a matt black mask which covers the front of the lens. However any external environmental light, for example sunlight, is not reflected and the surface of the lens appears dark.

At the more elaborate of road junctions, it is necessary to convey to a road-user more than stop-go information. It is important that the user realises that the signal is appropriate for him or her. This is catered for by careful placement of the signal and also by the use of arrows, that is to say, the traffic light when illuminated provides a signal in the form of an arrow. That arrow will indicate a direction of travel.

In the past, the arrow has been provided by making the cover lens opaque or transparent in different regions. Such an arrangement would require a large number of

different lens mouldings to cater for the variety of road layouts. There is also a danger in that service personnel may repair such lights by using lenses"available to hand" which may not be the optimum.

According to the invention there is provided signal apparatus comprising a light enclosure for, in use, housing a light source, a lens for closing the light enclosure, a mask located at a position between the light source and the lens for selectively obscuring the light source wherein the mask and housing include at least one key and a plurality of slots for registration of the at least one key therein to enable location of the mask at different angular positions relative to an axis of the apparatus.

By providing a key and a plurality of slots, it is possible for the mask to be located at a number of angular positions. Where the mask provides a representation of an arrow, the arrow may be made to"point"in a number of directions. The number of directions will depend on the number of the slots available for the key to engage. In the specific embodiment the slots are provided at 22.5 degree increments.

A further advantage of this apparatus is that the key and slots provide a positive location of the mask at particular positions. This means that persons fitting the mask can more easily ensure that masks at different lights are fixed at matching angular positions. This uniformity is important in presenting information to a road user

because a variation in the angular positions may cause confusion, for example, by the user believing that the arrow signal is intended for another lane.

Preferably, more than one key is provided since this will enable more secure registration of the mask relative to the enclosure. The key or keys in the preferred embodiment are provided on the mask and the slots on the enclosure but, in alternative arrangements, they may be transposed, that is to say, the key or keys are provided on the enclosure and the slots on the mask.

In the specific embodiment, the lens is a flat enhanced optic lens made of polycarbonate plastics material. The mask is made of aluminium sheet with cutouts to represent an arrow symbol. Other symbols may be made and the mask may be constructed from other materials such as a plastics material rendered transparent and opaque as required rather than provided with cutouts.

A specific embodiment of the invention will now be described with reference to the drawing in which: Figure 1 shows a side view of a signal apparatus in accordance with the invention in a state of partial disassembly; Figure 2 shows an end view of part of the apparatus shown in figure 1; and

Figure 3 shows a major face of a mask used in the apparatus of figure 1.

As is shown in figure 1, the specific embodiment of the signal apparatus is a traffic signal light 1 comprising a generally hemispherical enclosure 2 holding a light source 3, a flat enhanced optic lens 4 being disc-like with its major plane into the paper and a disc-like mask 5 disposed between the lens 4 and the enclosure 2. An annular retainer 6 retains the lens 4 and the mask to the enclosure 2 by the action of threaded fasteners 7 passing through flanges 8 to engage threaded holes in a back face of the retainer 6.

Sealing gaskets are provided to prevent the ingress of dust and moisture.

The major face of the mask 5 is shown in figure 2. It can be seen that there are two apertures 9 and 10 forming an arrow symbol. The mask 5 is made of aluminium sheet of 4mm thickness and the apertures 9 and 10 are made by a punching process. The punching process also results in four keys 11-14. The four keys 11-14 are located on a peripheral edge 15 of the disc and extend radially outwardly therefrom at the twelve, three, six and nine o'clock positions if the face is likened to that of a clock.

The enclosure 2 has a rim 16 as shown in figure3. The rim 16 is provided with a number of slots 17 at angular intervals of (x being, in this case, 22. 5 .

The traffic signal light 1 is assembled by the keys 11-14 of the mask being aligned and then inserted into the slots 17 to give the correct angular orientation of the symbol.

Then the lens 4 is fixed over the mask and retained to the enclosure rim by the retainer 6 and the clamping action caused by the tightening of the threaded fasteners 7.

It will be appreciated that the arrangement enables the mask 5 to be located at a number of angular positions equal to the number of slots. In this case the number of possible variations is sixteen with each variation differing by 22. 5 .

In alternative embodiments of the invention, the number of keys and slots may be varied to offer less or indeed more variation in the position of the mask.

Claims

Claims 1. Signal apparatus comprising a light enclosure for, in use, housing a light source, a lens for closing the light enclosure, a mask located at a position between the light source and the lens for selectively obscuring the light source wherein the mask and housing include at least one key and a plurality of slots for registration of the at least one key therein to enable location of the mask at different angular positions relative to an axis of the apparatus. 2. Apparatus as claimed in claim 1 wherein the at least one key is provided on the mask and the slots on the enclosure. 3. Apparatus as claimed in claim 1 wherein more than one key is provided. 4. Apparatus as claimed in claim 1 wherein the slots are provided at substantially 22. 5 increments. 5. Signal apparatus substantially as hereinbefore described with reference to, and as illustrated by, the drawings. <Desc/Clms Page number 7> Amended claims have been filed as follows Claims

1. Signal apparatus comprising a light enclosure for, in use, housing a light source, a lens for closing the light enclosure, a mask located at a position between the light source and the lens for selectively obscuring the light source to, in use, provide a symbol to a viewer of the signal apparatus wherein the mask and housing include at least one key and a plurality of slots for registration of the at least one key therein to enable retaining location of the mask at different angular positions relative to an axis of the apparatus.

2. Apparatus as claimed in claim 1 wherein the at least one key is provided on the mask and the slots of the enclosure.

3. Apparatus as claimed in claim 1 wherein more than one key is provided.

4. Apparatus as claimed in claim 1 wherein the slots are provided at substantially 22. 5 increments.

5. Apparatus as claimed in claim 5 wherein the symbol is an arrow.

6. Signal apparatus substantially as hereinbefore described with reference to, and as illustrated by, the drawings.