GB2373844A

GB2373844A - Means for attaching visor to signal light housing

Info

Publication number: GB2373844A
Application number: GB0107842A
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: 2001-03-29
Filing date: 2001-03-29
Publication date: 2002-10-02
Anticipated expiration: 2021-03-29
Also published as: GB2373844B; GB0107842D0

Abstract

A signal, for instance a traffic light, comprises a light housing and light source and a visor 7 wherein the visor 7 and the light housing include a set of mutually engaging members 11, such as lugs or teeth, to prevent relative rotation of the visor 7 and housing and to permit positioning of the visor 7 at a number of angular positions. The invention provides directionality to the signal light to prevent road users seeing a signal intended for other road users.

Description

Signal Apparatus This invention relates to a signal apparatus, particularly, but not exclusively a traffic signal.

Traffic signals often require visors or hoods to be placed around a front optic. This is needed to shade the optic from sunshine which might otherwise cause the signal to be"washed out". A further reason for the use of visors is to prevent a problem known as"see through"."See through"is a problem of a road user seeing the status of a light which controls another direction of traffic rather than the user's own. The user may then anticipate a signal change and move off before it is safe to do

so.

The problem of see through is reduced by rotating the visor when it is installed to screen the light from users of other lights. It is however difficult for the installer to do this in a consistent way for all the lights without careful measurement.

According to the invention there is provided signal apparatus comprising a light housing for, in use, holding a light source, and a visor wherein the visor and light housing include a set of mutually engaging members to prevent relative rotational movement therebetween.

The mutually engaging members in the specific embodiment are a set of lugs or keys, and key-ways for registration of the lugs or keys. In the

specific embodiment a plurality of keys are provided but these may alternatively be replaced by one key.

The keys are formed on the visor for engagement with key-ways formed on the light housing. However, the opposite arrangement may be alternatively be used, that is to say, the keys may be formed on the light housing and the key-ways formed on the visor. In the preferred embodiment the visors are made of plastics material although other materials may be used. The keys are integrally moulded with the rest of the visor in the specific embodiment but may be formed in other ways.

A specific embodiment of the invention will now be described, by way of example only, with reference to the drawing in which: Figure 1 shows a side view of a traffic light including a number of signals in accordance with the invention; Figure 2 shows a visor used in the traffic light shown in figure 1; and Figure 3 shows a light housing also used in the traffic light of figure 1.

As is shown in figure 1, a traffic light 1 comprises a post 2 to which is attached a light cluster 3. The light cluster is formed from three modules 4 to 6 each enclosing a light source (not shown) and having a visor 7 to 9. More or indeed fewer than three modules may be used depending on the required signalling for the particular set of circumstances.

The visors 7 to 9 are formed of plastics material and are generally open ended cylinders as shown more clearly in figure 2. The longitudinal wall of the cylinder tapers to the front over part of its length with the remaining part disposed to the rear of the hood 7 a constant diameter.

The longitudinal wall is incomplete over the tapering part to render the visor 7 open over the lower part 10 of its circumference. As is shown in the plan view figure 2 (a) the rear of the visor 7 is provided with a set of radially extending keys 11. These are integrally moulded with the rest of the visor 7 during manufacture.

Figure 3 shows a plan view of one of the light modules and it will be seen that it is provided with a plurality of key-ways 12. In use, the visor 7 is positioned to register the keys 11 with the key-ways 12 and pushed home. The keys 11 have a friction fit in the key-ways 12 to retain the visor to the module. Additional securing means such as threaded fasteners or plastics material barbed fasteners called"Christmas Tree Clips"may be used to create a more secure fixing.

It will be appreciated that the visor may be placed at a number of angular positions on the module to reduce the problem of"see through"where a user of another traffic light monitors this one in order to anticipate a change in signal. In order to assist service personnel with the alignment the keys and key-ways may be marked with numbers and letters or other identifying indicia.

Claims

1. Signal apparatus comprising a light housing, in use, holding a light source, and a visor wherein the visor and light housing include a set of mutually engaging members to prevent relative rotational movement therebetween.

2. Apparatus as claimed in claim 1 wherein the mutually engaging members comprise at least one key and a plurality of key-ways.

3. Apparatus as claimed in claim 2 wherein the at least one key is provided on one of the visor and light housing and the key-ways are provided on the other of the visor and light housing.

4. Apparatus as claimed in claims 1 to 3 wherein the at least one key is integrally formed with the visor or housing.

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