WO1996026323A1

WO1996026323A1 - A pavement marker and its method of manufacture

Info

Publication number: WO1996026323A1
Application number: PCT/AU1996/000089
Authority: WO
Inventors: John Gartlacher
Original assignee: Vitec Trading Pty. Limited
Priority date: 1995-02-23
Filing date: 1996-02-21
Publication date: 1996-08-29
Also published as: AUPN133295A0

Abstract

A pavement marker (1) includes a body (2) with a first wall (3) and an underface (6) and an opening (4) in the wall (3) into a cavity (5) in the body (2) accessible from the underface (6). A reflector unit (14) includes a body with an outwardly projecting ledge (10). The body of the reflector unit (14) is entered into the opening (4) and the ledge (10) is in abutting relationship with a land (7) within the cavity (5) and around the opening (4). The reflector unit is held in place by a plug (8) bonded into the cavity (5).

Description

APAVEMENTMARKERANDITS METHODOFMANUFACTURE

This invention relates to pavement markers of the type which are used to define lanes on roadways. The required characteristic of such markers is that they include a light reflecting means whereby the light from the headlights of a vehicle approaching the marker is reflected back at the vehicle.

Background Art

Numerous types of pavement markers have been developed over the years and each newly developed form has had its characterising features. Some have relied on reflective tape, some have incorporated integral panels profiled to provide reflective surfaces. Australian Patent No. 639369 discloses a marker having a saucer like shell body made of a plastics material. This marker comprises of a reflective panel integral with the body and a backing plate bonded there behind. An infill material within the shell body bears against the backing plate and forms the base surface for the marker. A number of problems are associated with such a marker. Firstly, as the marker incorporates an integral reflective panel, the material from which the body is made must be of a quality suitable for forming the reflective panel. Such plastics material is expensive. Secondly, the reflectivity can be degraded quite substantially by some of the manufacturing processes used in the manufacture of such markers subsequent to initial moulding of the body with the integral reflective panel. Thirdly, there is a tendency for the shell and infill material of such a marker to separate in use. This and other prior art pavement markers available to this time have been unable to provide the desirable characteristics of efficient reflectivity and durability, combined with simplicity of manufacture and acceptable price.

This invention has been devised to provide a marker construction whereby the desirable characteristics referred to above can be achieved.

Disclosure of Invention

In one aspect the present invention a pavement marker includes a body moulded from a plastics material , said body having at least a first wall and an underface, at least one opening in said first wall communicating with a cavity within said body accessible from the underface, a continuous land on an inner surface of said first wall around said opening , a reflector unit having a ledge which extends around a substantial portion thereof, said reflector unit being mounted through said cavity and fitted in close relationship within said opening with said ledge overlying said continuous land, and a reflector unit retaining plug member bonded within said cavity.

Preferably, the reflector unit includes a plurality of hermetically sealed chambers each containing reflective prismatic projections. Also, the reflector unit preferably comprises a first panel affixed to a second panel with a void therebetween, with the reflective prismatic projections projecting from the inner surface of the first panel.

Preferably the reflector unit retaining plug member may be bonded within said cavity by means of ultrasonic welding. In order to facilitate such ultrasonic bonding the reflector unit retaining plug member preferably may include a face with sacrificial ribs, which during ultrasonic welding are sacrificed to provide bonding with the body.

Preferably the reflector unit may be bonded to the body.

In a second aspect the present invention is a method of assembling a pavement marker in which said pavement marker includes a body having at least a first wall and an underface, at least one opening in said first wall communicating with a cavity within said body accessible from the underface, a continuous land on an inner surface of said first wall around said opening , a reflector unit having a ledge which extends around a substantial portion thereof, and a reflector retaining plug member, said method comprising the steps of:

(a) inserting said reflector unit into said body from said underface through said cavity and fitting it in close relationship within said opening, so that said ledge overlies said continuous land;

(b) inserting said reflector unit retaining plug member into said body from said underface into said cavity; and

(c) bonding said reflector unit retaining plug member to said body.

A particular feature of the pavement marker of the present invention is the provision of a quality reflector unit which incorporates a number of hermetically sealed chambers in each of which is an uncoated prismatic reflective surface, where the reflector unit is mounted in a pavement marker body member. A presently preferred embodiment of the invention will now be described with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 is a perspective view of a preferred embodiment of a pavement marker in accordance with the present invention.

Figure 2 is a bottom view of the pavement marker depicted in Figure 1.

Figure 3 is a bottom view of a body of the pavement marker of Fig.1 without the plug used to retain a reflector unit,

Figure 4 is a cross-sectional exploded view of the pavemen t marker through A-A in Figure 3 and

Figure 5 is a partial enlarged sectional view of the reflector unit and plug shown in Figure 4.

Mode for carrying out Invention

As illustrated in the Figures there is a marker 1 with a body 2 which has a number of sides and a cross-sectional shape as shown in Figure 4. The body 2 includes an inclined front wall 3 having an opening 4 which communicates with a chamber 5 in the body 2. The chamber 5 is accessible from the underface 6 of the marker body 2. Around the opening 4 on an inner face of the marker front wall 3 there is a continuous land 7. There is a plug 8 for mounting in the chamber 5. The plug 8 has a shape closely similar to that of the chamber 5.

A reflector unit 14 is comprised of a number of hermetically sealed chambers 15 disposed between a front panel 16 and a rear panel 17 and defined by a reflector unit peripheral wall 26 and partition walls 27. The reflector unit body is dimensioned to be a close fit in the opening 2 and may optionally be glued or bonded by other means in position. The back surface of the front panel 16 is covered with corner cube reflectors 18 of known form. The reflector unit 14 has a ledge 10 which extends around a substantial portion of the reflector body and the ledge 10 overlies the land 7 between the edge of the opening 4 and the walls of the chamber 5.

The plug 8 is ultrasonically welded in place in the chamber 5. To facilitate the welding process there are sacrificial ribs 19 on the top face of the plug 8 adjacent the edges of the plug and on edges of the plug 8. In the welding process the ribs 19 are sacrificed to provide bonding between the respective components and to lock the reflector unit 14 in the opening 4 which causes firm engagement of the ledge 10 with the body land 7.

There are recesses 24 in the underface 6 of the body 2 and the underface 25 of the plug 8. The recesses 24 provide a keying means for the glue used to mount the pavement markers on a pavement. The recesses can be of any form but are preferably grooves with occasional bridge bars between the walls of the grooves.

As will be understood the reflector arrangement illustrated and described above can be duplicated on the opposed side of the body thereby providing a pavement marker with opposed reflective zones provided by two reflector units. With a modification of the marker body to provide a substantially square body of suitable size up to four reflectors can be mounted in the body.

As the high quality plastic need only be used in the present instance for the reflective member and the pavement marker body can be made of a low grade low cost plastics material, such as reclaimed plastic. This results in a considerable economic advantage with the construction of the present invention over the type where the reflector is integral with the reflector supporting body.

There is also at least one manufacturing advantage with the proposed marker construction. In the marker with the integral reflective panel the reflectivity can be degraded quite substantially by some of the manufacturing processes used in the manufacture of the markers subsequent to initial moulding of the body with the integral reflective panel. Those processes are not required in the present invention and thus the problem of reflectivity degradation resulting from those processes will not be a factor in the manufacture of the proposed marker.

It should be readily understood that in other not shown embodiments the pavement marker of the present invention may differ in shape and configuration without changing the scope and spirit of the present invention.

Claims

1. A pavement marker including a body moulded from a plastics material , said body having at least a first wall and an underface, at least one opening in said first wall communicating with a cavity within said body accessible from the underface, a continuous land on an inner surface of said first wall around said opening , a reflector unit having a ledge which extends around a substantial portion thereof, said reflector unit being mounted through said cavity and fitted in close relationship within said opening with said ledge overlying said continuous land, and a reflector retaining unit plug member bonded within said cavity.

2. A pavement marker as claimed in claim 1 wherein said reflector unit includes a plurality of hermetically sealed chambers each containing reflective prismatic projections.

3. A pavement marker as claimed in claim 2 wherein said reflector unit comprises a front panel and a rear panel held in spaced relationship by a peripheral wall and partition walls which define said chambers and the reflective prismatic projections in each chamber project from an inner surface of said front panel towards said rear panel.

4. A pavement marker as claimed in any one of the preceding claims wherein said reflector unit is bonded to said body.

5. A pavement marker as claimed in any one of the preceding claims wherein said reflector retaining plug member is bonded within said cavity by means of ultrasonic welding.

6. A pavement marker as claimed in claim 5 wherein the reflector unit retaining plug member includes a face with sacrificial ribs which during said ultrasonic welding are sacrificed to provide bonding with said body.

7. A method of assembling a pavement marker in which said pavement marker includes a body having at least a first wall and an underface, at least one opening in said first wall communicating with a cavity within said body accessible from the underface, a continuous land on an inner surface of said first wall around said opening , a reflector unit having a ledge which extends around a substantial portion thereof, and a reflector retaining plug member, said method comprising the steps of:

(c) bonding said reflector unit retaining plug member to said body.

8. A method of assembling a pavement marker as claimed in claim 7 wherein said reflector unit includes a plurality of hermetically sealed chambers each containing reflective prismatic projections.

9. A method of assembling a pavement marker as claimed in claim 8 wherein said reflector unit comprises a front panel and a rear panel held in spaced relationship by a peripheral wall and partition walls which define said chambers and the reflective prismatic projections in each chamber project from an inner surface of said front panel towards said rear panel.

10. A method of assembling a pavement marker as claimed in any one of claims 7 to 9 wherein said reflector unit is bonded to said body subsequent to step (a).

11. A pavement marker when made by the method of any one of claims 7 to 10 wherein in step (c) said reflector unit retaining plug member is bonded to said body by means of ultrasonic welding.

12. A pavement marker as claimed in claim 11 wherein the reflector retaining plug member includes a face with sacrificial ribs which during said ultrasonic welding are sacrificed to provide bonding with said body.

13. A pavement marker substantially as herinbefore desribed with reference to the accompanying drawings.

14. A pavement marker when made by the method hereinbefore described.

15. A method of making a pavement marker, substantially as hereinbefore described.