WO2003058576A1

WO2003058576A1 - A traffic signal

Info

Publication number: WO2003058576A1
Application number: PCT/SE2002/002269
Authority: WO
Inventors: Anders ENGSTRÖM
Original assignee: Nordic Traffic Ab
Priority date: 2001-12-14
Filing date: 2002-12-10
Publication date: 2003-07-17
Also published as: AU2002367329A1; SE0104220D0; SE0104220L; SE523956C2

Abstract

The present invention relates to a traffic light assembly that comprises a lamp housing (1) which includes a front wall (2) with openings (40) for accommodating signalling lamps, a rear wall (21) spaced from said front wall, side walls (23) which connect between the rear wall (21) and the front wall (20), a top end wall (10) and a bottom end wall (11) that includes a sleeve for connecting the housing to housing to a post (2). The front wall (20), rear wall (21) and side walls (23) are all parts of a length of a single extruded hollow profile.

Description

A TRAFFIC SIGNAL

The present invention relates to a traffic light assembly which comprises a lamp housing that includes a front wall provided with openings for accommodating traffic signalling lamps, a rear wall spaced from said front wall, side walls which connect between the rear wall and the front wall, an upper end wall, and a lower end wall which includes a sleeve for connecting said housing to a lamp post.

Damage to such traffic lights is often the result of the lamp post being struck by a vehicle, causing the traffic light assembly to be accelerated, wherewith the mass of the assembly influences the forces to which said assembly is subjected.

Because the signalling lamps of the traffic light assembly can now be produced by light emitting diode fields of relatively low- weight, the requirements placed on the depth of the housing in the direction of the light beams emitted from the lamps have been reduced. However, when the depth of the housing is reduced in this direction, the flexural rigidity of the housing is also reduced in the most usual direction of acceleration, i.e. in the direction of the light beams. Nevertheless, there is a strong desire to limit the depth of the traffic light assembly, i.e. the thickness of said housing, since the traffic lights are often disposed in groups and oriented in directions that are mutually spaced through 90°, for instance, wherewith the lights can obscure each other.

Accordingly, one object of the present invention is to provide a traffic light assembly whose lamp housing has a small thickness but is, nevertheless, very strong in respect of normally occurring stresses.

A further object is to provide a housing which is also well-adapted for the use of light emitting diode fields, such as light bulbs, and to which a shield for shielding background light can be fitted readily and comfortably, and which enables a secondary traffic light assembly to be readily connected to the housing. A further object of the invention is to provide a traffic light assembly, which enables the lamps to be connected to and disconnected from signal cables and power supply cables that extend up through the lamppost. These objects are achieved either completely or partially with a traffic light assembly according to the invention. The invention is defined in the accompanying Claim 1.

Embodiments of the invention are defined in the accompanying independent claims.

According to one important feature of the invention, the housing is comprised of a tubular extruded hollow profile, preferably consisting of aluminium. A longitudinal section of the extruded hollow profile can foπn the housing side walls, the upper and lower ends of the housing being closed by lids or caps fitted to the ends of the profiled section. The bottom lid includes an opening facing towards the sleeve, and the hollow profile has a relatively wide front wall which includes lamp-receiving openings in which said lamps are fitted.

By providing ventilation openings in the upper end portion of the hollow profiled section, there is ensured a flow of cooling convection air through the housing, from the lamp post through the sleeve and the housing, said air flow being supported by the heat generated by the lamps.

By connecting the signal lines and power lines from the lamps to a cable that extends out through the sleeve and whose end is connected to a coupling element, and by connecting the corresponding wires or cables extending up through the lamp post to a co-acting electrical contact, the coupling elements can be easily reached for connecting together and parting said coupling elements with the housing removed from the lamp post.

Because the major part of the housing is comprised of a length of an extruded hollow profile, the profile can be provided with undercut longitudinally extending grooves in the narrow side walls of the housing. The top and bottom end walls covers of the housing include cut-outs, which leave the ends of the undercut grooves for free insertion of coupling elements of corresponding cross-section. Traffic light assemblies will preferably be provided with a screen for screening the background in the region nearest the traffic light assembly. The screen may be comprised of two parts, of which at least one has a U- shape that includes on its mutually facing, parallel leg edges projections having a profile that is complementary with the cross-section of the grooves. The corresponding part of the screen may thus be readily connected to the groove in the hollow profile, whereafter the other part of said screen can be connected readily to the first part thereof. Naturally, both parts of the screen may have a U-shaped opening with coupling elements for engaging the profile grooves, said screen parts tightly abutting one another and also the perimeter of the light assembly when fitted together. In one embodiment of the invention, the screen parts are provided with simple connectors in the close proximity of their edges, for instance snap-connectors or the like that facilitate at least initial assembly of the screen.

Because the housing is comprised of an extruded hollow profile, the side walls, front wall and rear wall of the housing are able to fit together effectively so that the housing will have a relatively high mechanical strength with regard to the stresses and strains to which it may be subjected.

The housing may be further stabilised and strengthened with the aid of pull rods comiected between the top and bottom end walls, preferably so that the hollow profile is symmetrically compression-loaded by the pull rods.

The invention will now be described by way of example with reference to the accompanying drawing.

Fig. 1 is a front view of a traffic light assembly according to the invention.

Fig. 2 is a sectional view taken on the line II-II in Fig. 1.

Fig. 3 is a schematic view taken on the line III-III in Fig. 1.

Fig. 4 is a schematic sectional view of the traffic light assembly shown in Fig. 1.

Fig. 5 illustrates the light assembly fitted with a screen.

Fig. 6 is a sectional view taken on the line VI- VI in Fig. 5.

Fig. 7 is a schematic sectional view taken on the line VII- VII in Fig. 5.

Fig 1 illustrates a traffic light assembly 1 mounted on a post 2. The traffic light assembly 1 includes a top end wall 10 and a bottom end wall 11 that includes a downwardly projecting, centrally positioned connecting sleeve 12 which receives the top end of the post 2. The assembly also includes a housing whose vertically orientated walls are comprised of a length 14 of an extruded hollow profile. As will be seen from Fig. 2, the hollow profile has a generally rectangular cross-section and includes a front wall 20, a rear wall 21 and side walls 23 which each have an undercut groove or slot 30 formed in the extrusion process.

The front wall 20 of the profiled section 14 includes openings 40 in which corresponding lamps 41 are fitted. The lamps will conveniently comprise fields of light-emitting diodes. The lamp area has but a small thickness, therewith allowing the distance between the front wall 20 and the rear wall 21 of the profiled section to be also small.

The walls 20, 21, 23 of the housing 1 are integral with each other and are therefore very strong mechanically. The lids or covers 10 and 11 cover the internal cavity of the profiled section 14, preferably with the exception of the ends of the grooves or slots 23. The bottom lid or cover 11 includes an opening 18, which faces towards the sleeve 12. The rear wall 21 includes in the proximity of its upper end an opening 28 which is preferably shaped as a so-called gill so as to prevent rain or the like from entering the housing while permitting warm air to flow out therefrom.

The profiled section 14 is compression-loaded by means of tensioning bolts 50 that extend between the lids 10, 11.

The signalling and power supply lines of the lamps 41 are summarised in a cable 60 that extends from the housing 1 via the opening 18 and the sleeve 12. The end of the cable 60 is coupled to an electric contact 61 which can be connected to a corresponding electric contact 62 on a corresponding cable 63 extending up through the post 2. This enables the lamps 41 to be connected and disconnected comfortably while the housing 1 is dismantled from the post 2. Air can normally flow into the housing via the sleeve 12 and the post 2, this air flow being able to flow up and cool the lamps prior to departing through the opening 28. Alternatively, an air inlet may be provided in the lower part of the housing, preferably in the bottom lid 11. The pull rods 50 are conveniently comiected to inner attaclmients 51 on the underside of the top lid 10 and may extend out through openings in the bottom lid 11, wherein the protruding ends of said rods include a screw thread which engages with corresponding nuts on the underside of the bottom lid 11.

Fig. 5 is a view of the rear side of the traffic light assembly that includes a background screen 70. In the illustrated case, the screen 70 comprises two generally identical and essentially U-shaped plates 71 where the mutually facing and mutually parallel edges 72 of the legs of said plates include coupling elements 73 that conform to the cross-sectional shape of the undercut grooves or slots 30. The web 74 connecting the edges 72 extends at right angles to said edges such as to tightly abut the outer surface of the lids 10, 11. The lengths of the legs of the plates 71 are chosen so that the ends of said legs will provide a butt joint when the webs 74 lie against respective lids 10, 11. The plate portions 71 are mutually comiected at the join by fittings 80. The fittings 80 may conveniently have the form of snap-connectors that facilitate mounting of the screen 70. The snap-joints may, of course, be supplemented with safety devices, such as screw joints.

As will be seen from Fig. 7, it may be necessary to bend one (the bottom) plate 71 in a central region of the plate, so as not to interfere with the sleeve 12 and the post 2.

Although not shown, the grooves 30 also enable a secondary traffic light assembly to be connected to the main traffic light assembly 1 with the aid of a coupling element 73 connected laterally to the secondary traffic light assembly (not shown), although it may be necessary to provide additional fastening means to secure the secondary traffic light assembly to the main traffic light assembly 1 in a vertical direction.

Claims

1. A traffic light assembly comprising a lamp housing (1) that has a front wall (2) with openings (40) for accommodating signalling lamps, a rear wall (21) spaced from the front wall, side walls (23) which connect between the rear wall (21) and the front wall (20), a top end wall (10) and a bottom end wall (11), this latter wall including a sleeve for connecting the housing to a post (2), characterised in that the front wall (20), the rear wall (21) and the side walls (23) of said housing are all parts of a length of an extruded hollow profile.

2. A traffic light assembly according to Claim 1, characterised in that the top and the bottom end walls of the housing have the form of separate elements fitted to respective ends of the profiled section.

3. A traffic light assembly according to Claim 1 or 2, characterised in that each side wall includes an outwardly open, undercut groove or slot (30) that extends in the longitudinal direction of the profiled section.

4. A traffic light assembly according to Claim 2, characterised in that the signalling and power supply lines of the lamps are connected to an electric contact; in that said lines extend through the sleeve and through an opening established through the bottom end wall (11) and in alignment with said sleeve so that said electric contact can be connected to a corresponding electric contact accessible in the upper end-portion of said post when the lamp housing is dismantled therefrom.

5. A traffic light assembly according to any one of Claims 2-4, characterised in that an upper part of the housing, preferably the upper part of its rear wall (21), includes an opening for the evacuation of cooling air from the housing interior.

6. A traffic light assembly according to any one of Claims 3-5, characterised in that the top and bottom end walls of the housing include cut-outs corresponding to the cross- sectional profile of the undercut grooves; in that the assembly includes a background screen (78) for the lamp housing, said screen having an opening corresponding to the front wall (20) of the housing; in that the screen is a two-part structure, where at least the edges of the screen-receiving hole adjacent the side walls (23) of the housing has connecting elements (73) whose form corresponds to the undercut groove (30); and in that the assembly includes means (80) for detachably holding the screen parts (71) together.