GB2407149A

GB2407149A - Lamp assembly of traffic light

Info

Publication number: GB2407149A
Application number: GB0324104A
Authority: GB
Inventors: Wen-Yao Lin; Chien-Feng Chang; Ju-Yuan You
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-10-15
Filing date: 2003-10-15
Publication date: 2005-04-20
Anticipated expiration: 2023-10-15
Also published as: GB2407149B; GB0324104D0

Abstract

A lamp assembly for a traffic light includes a base 12 defining an interior space having a front opening to which a transparent cover 14 is mounted. A light source is arranged inside the base for giving off light traveling through the interior space and the cover. A lens 27 is fixed in the interior space and includes a plate-like body 28 having a front face 30 opposing the cover and an opposite rear face 32 receiving the light from the light source. The rear face forms a plurality of horizontally extending raised strips 46 each having an arcuate upper edge (48, fig 4A) for refracting and directing the light through the lens body in a predetermined angle and an inclined edge that forms a sharp included angle with respect to the upper edge of the next strip. The front face 30 forms groups of horizontally extending segments (60, 62, 64, fig 4B) including a flat segment (60) having a frosted surface and two successively inclined segments (62, 64) each having an inclined surface extending in a downward and frontward manner to define a predetermined angle with respect to a vertical plane. The surface of each inclined segment forms a plurality of vertically extending grooves (66, fig 4A) having arcuate configuration. The cover has an inclined front surface 72 for reflecting incident sunlight in a direction not to glare at the drivers and pedestrians.

Description

24071 49 LAMP ASSEMBLY OF TR4FlIC LIGHT

BACKGROUND OF THE INVENTION

1. Field of the Invention

1] The present invention relates generally to a traffic light, and in particular to a lamp assembly of traffic light that effectively prevents glaring light projecting onto drivers and pedestrians.

2. The Related Art [0002] Traffic lights have been widely used in modern cities, especially heavy traffic regions, for regulating and controlling traffic flows. The traffic lights comprise at least one lamp assembly, but often a number of lamp assemblies, each comprised of a light source, such as a light bulb and a light emitting diode based illuminator, giving off a light beam toward and through a transparent cover that is often colored to thereby project out a color light beam, such as green light, yellow light and red light. Moving or stopping of an automobile or a pedestrian is determined based on the color of light projected from the traffic light.

3] To avoid confusion of the color of the light projecting from the traffic light to the drivers, especially for those driving in high speeds, the lamp assembly of the traffic light must be configured to eliminate glaring light caused by reflection of intense sunlight by the cover of the lamp assembly. Also the light emitted by the lamp assembly itself must be projected in limited viewing angle for effectively guiding the movement of the drivers and the pedestrians.

SUMMARY OF THE INVENTION

4] Therefore, a primary object of the present invention is to provide a lamp assembly of a traffic light that effectively eliminates glaring caused by reflection of sunlight.

5] Another object of the present invention is to provide a lamp assembly of traffic light that projects light within a proper angular range.

6] To achieve the above objects, in accordance with the present invention, there is provided a lamp assembly of a traffic light comprising a base defining an interior space having a front opening to which a transparent cover is mounted. A light source is arranged inside the base for giving off light traveling through the interior space and the cover. A lens is fixed in the interior space and comprises a plate- like body having a front face opposing the cover and an opposite rear face receiving the light from the light source. The rear face forms a plurality of horizontally extending raised strips each having an arcuate upper edge for refracting and directing the light through the lens body in a predetermined angle and an inclined edge that forms a sharp included angle with respect to the upper edge of the next strip.

The front face forms groups of horizontally extending segments including a flat segment having a frosted surface and two successively inclined segments each having an inclined surface extending in a downward and frontward manner to define a predetermined angle with respect to a vertical plane. The surface of each inclined segment forms a plurality of vertically extending grooves having arcuate configuration. The cover has an inclined front surface for reflecting incident sunlight in a direction not to glare at the drivers and pedestrians.

BRIEF DESCRIPTION OF THE DRAWINGS

7] The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which: [0008] Figure 1 is a perspective view of a lamp assembly of traffic light constructed in accordance with the present invention; [0009] Figure 2 is an exploded view of the lamp assembly of the present invention; [0010] Figure 3 is a side elevational view, in exploded form' of the lamp assembly of the present invention; [0011] Figures 4A and 4B are an enlarged view of a portion of a lens of the lamp assembly of the present invention, and a side elevational view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

2] With reference to the drawings and in particular to Figure 1, a lamp assembly constructed in accordance with the present invention, generally designated with reference numeral 10, is comprised of, at least partly, a traffic light (not shown).

The lamp assembly 10 is comprised of a base 12 made of opaque material that does not allow for transmission of light therethrough, and a cover 14 made of transparent materials. The base 12 forms, on a rear side thereof, a chamber 16 inside which an illuminator or a light source and associated circuits and electronics (all not shown) are mounted for giving off light through a front side of the base 12. The cover 14 is mounted to the front side of the base 12 for projecting the light from the illuminator to drivers and pedestrians looking at the traffic light.

3] Also referring to Figures 2 and 3, in the embodiment illustrated, the base 12 is comprised of a cylindrical body 18 having a bottom 20 on which the chamber 16 is formed and a cylindrical side wall 22 extending and surrounding the bottom 20 to delimit a cylindrical interior space (not labeled). The cylindrical body 18 has a front opening (not labeled) forming a circumferential shoulder 24 onto which a circumferential flange 26 of the cover 14 is tatted.

4] A lens 27 is comprised of a plate-like lens body 28 received and fixed in the cylindrical body 18 of the base 12. The lens body 28 has a front face 30 that opposes the cover 14 and an opposite rear face 32 that opposes the bottom 20 of the base 12 for receiving the light from the illuminator. A plurality of projections 34 extends from the rear face 32 of the lens body 28. Each projection 34 forms a bore 36 extending through both the projection 34 and the lens body 28 for receiving a fastener (not shown). Corresponding to the projections 34 of the lens 27, posts 38 are formed on and extend from the bottom 20 of the base 12 for partially fitting into the bores 36 of the lens 27 for positioning the lens body 28 in the cylindrical body 18 of the base 12. The fasteners that are received in the bores 36 engage holes 40 defined in the posts 38 to secure the lens body 28 in position.

5] Also referring to Figures 4A and 4B, the rear face 32 of the lens body 28 is formed with a plurality of raised strips 46 that are substantially parallel to each other and extend in a horizontal direction in a regular operation condition. Each raised strip 46 has an arcuate upper edge 48 and an opposite lower edge 50 with a straight line connection 52 extending between the upper and lower edges 48, 50.

The lower edge 50 of a first strip 46 is connected to the upper edge 48 of a next, second strip 46 by a sharp included angle therebetween.

[00161 The upper arcuate edge 48 is comprised of three curves, 54, 56, 58, respectively having different radii of curvature which increase from the first section 54 to the third section 58 with that of the second section 56 having a value between those of the first and third sections 54, 58. The radii of curvature of the curves 54, 56, 58 may arbitrarily selected in accordance with the requirement of designs or stipulation of regulations. For example, the radii of curvature of the first, second and third sections 54, 56, 58 of the upper edge 48 may be 6.5mm, 12mm and 20mm, respectively. The difference in the radii of curvature of these sections 54, 56, 58 is used to refract and thus direct light from the illuminator in a direction down to the drivers and pedestrians who are usually located below and at a horizontal distance apart from the traffic light. The radii of curvatures of these sections 54, 56, 58 can be selected in accordance with local regulations and specifications for the traffic lights.

Further, the number of the arcuate sections 54, 56, 58 can be changed in accordance with requirement of designs.

7] The front face 30 of the lens body 28 is comprised of groups of horizontally extending segments. Each group is comprised of three segments 60, 62, 64. The first segment 60 is substantially vertical. In other words, the first segment has a flat surface that is substantially coincident with a vertical plane. To prevent glaring of sunlight, the flat surface of the first segment 60 is made frosty or frosted.

The second and third segments 62, 64 both have an inclined surface with respect to the vertical plane with an included angle, preferably 6 degrees. Thus, the second segment 62 forms a step with respect to the first segment 60, from which the second segment 62 extends downward and frontward at the inclined angle, namely 6 degrees with respect to the vertical plane. Similarly, the third segment 64 forms a step with respect to the second segment 62, from which the third segment 64 extends downward and frontward at the 6 degree inclined angle with respect to the vertical plane. The inclination of the second and third segments 62, 64 are provided for reflecting the incident sunlight in a direction away from the drivers and the pedestrians in order to eliminating the glaring light caused thereby.

8] The second and third segments 62, 64 can be combined together as a single segment. However, to avoid excessively thickening the lens body 28, it is preferred to divide the inclined portion into two successively inclined segments as illustrated in the drawings.

[00191 Each inclined segment 62, 64 of the front face 30 of the lens body 28 is comprised of a plurality of parallel, vertically extending grooves 66 having an arcuate configuration of a predetermined radius of curvature, of which an example is 1.5mm.

The arcuate groove 66 is used to expand the viewing angle in horizontal direction to accord with local regulation. Thus, the radius of the arcuate grooves 66 can be selected as desired.

0] The cover 14 is comprised of a cylindrical body 70 having a front end to which an inclined surface plate 72 is mounted and a rear end around which the flange 26 is formed. In the embodiment illustrated, the body 70, the surface plate 72 and the flange 26 is integrally molded with a transparent material. However, other manufacturing techniques can be employed. The inclined surface plate 72 reflects sunlight away and thus eliminates undesired glaring of sunlight to the drivers and the pedestrians.

1] To this point, it is noted that the lens 27 that is mounted between the base 12 and the cover 14 functions for(1) reflecting sunlight in a direction away from the driver and pedestrians thereby eliminating glaring caused by sunlight, (2) directing the light emitted from the illuminator of the lamp assembly 10 toward the drivers and pedestrians and (3) uniformly distributing the light from the illuminator within a given s range as possibly required by local regulations, while the cover 14 is provided with an inclined surface plate 72 that also helps reflect the sunlight in a direction away from the drivers and pedestrian. Such an arrangement effectively eliminates glaring of sunlight and properly projecting light of the lamp assembly toward the drivers and pedestrians. In addition, certain geometrical parameters can be selected by designers to suit for local regulations and requirements.

[00221 Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.

Claims

WHAT IS CLAIMED IS

1. A lamp assembly comprising: a base defining an interior space having a front opening adapted to allow a light emitted from a light source to travel therethrough; a transparent cover mounted to the front opening of the base; and a lens comprising a plate-like body received and fixed in the interior space of the base and substantially opposite to the cover, the lens body having a front face opposing the cover and an opposite rear face adapted to receive the light from the light source, the rear face forming at least one horizontally extending raised strip having an arcuate upper edge for refracting and directing the light through the lens body in a predetermined angle, the front face forming at least a horizontally extending segment having an inclined surface extending in a downward and frontward manner to define a predetermined angle with respect to a vertical plane, a plurality of vertically extending grooves having arcuate configuration being defined in the inclined surface of the segment of the front face.

2. The lamp assembly as claimed in Claim 1, wherein the front face of the lens body forms a flat segment substantially parallel to the inclined segment, the flat segment having a frosted, substantially vertical face.

3. The lamp assembly as claimed in Claim 1, wherein the front face of the lens body comprises another segment substantially parallel to the inclined segment, said another segment having an inclined surface similar to the inclined segment.

4. The lamp assembly as claimed in Claim 3, wherein the another segment forms vertically extending arcuate grooves.

5. The lamp assembly as claimed in Claim 1, wherein the arcuate upper edge of the raised strip of the rear face of the lens body comprises a number of sections having different radii of curvature.

6. The lamp assembly as claimed in Claim 5, wherein the upper edge of the raised strip of the rear face of the lens body comprises three arcuate sections.

7. The lamp assembly as claimed in Claim 6, wherein the three arcuate sections have radii of curvature of 6.5mm, 12mm and 20mm in sequence from top to bottom.

8. The lamp assembly as claimed in Claim 1, wherein the predetermined angle between the inclined surface of the segment of the front face of the lens body and the vertical plane is 6 degrees.

9. The lamp assembly as claimed in Claim 1, wherein the grooves formed in the inclined surface of the segment of the front face of the lens body has a radius of curvature of 1.5mm.

10. The lamp assembly as claimed in Claim 1, wherein the cover has a front surface that is inclined and adapted to reflect sunlight in a predetermined direction.

11. The lamp assembly as claimed in Claim 1, wherein the rear face of the lens body forms a plurality of parallel raised strips, each having an arcuate upper edge and an inclined lower edge, upper and lower edges of adjacent strips being connected by a sharp inclined angle.

12. The lamp assembly as claimed in Claim 1, wherein the front face of the lens body forms groups of segments, each group comprising a flat segment, a first inclined segment and a second inclined segment, all extending horizontally.

13. The lamp assembly as claimed in Claim 12, wherein the flat segment has a frosted surface.

14 A lamp assembly constructed and arranged substantially as described in relation to Figs I - 3, 4 and 413 of the accompanying drawings