WO1999036629A1

WO1999036629A1 - Raised pavement marker

Info

Publication number: WO1999036629A1
Application number: PCT/US1999/000685
Authority: WO
Inventors: Michael T. Fleury; Jeffery S. Held; Robert D. Giese; Richard R. Figlewicz
Original assignee: Quixote Corporation
Priority date: 1998-01-13
Filing date: 1999-01-12
Publication date: 1999-07-22
Also published as: AU2317599A

Abstract

A raised, snow-plowable pavement marker (10) includes a base (12) having a radially inwardly facing seal surface (34). The pavement marker also includes a reflector assembly (22) mounted to a membrane assembly (14), and the membrane assembly includes a resilient membrane (20), a retainer (18) embedded in the outer portion of the membrane, and a radially outwardly facing seal surface (64). When the retainer (18) is snapped in place into the base (12), the two seal surfaces (34, 64) cooperate to impede the flow of water into the base. The membrane assembly (14) can be replaced by cutting the membrane to gain access to the interior of the base, pushing the retainer (18) out of its latched position in the base (12), and then snapping a replacement membrane assembly and reflector assembly into position on the base.

Description

RAISED PAVEMENT MARKER

BACKGROUND

This invention relates to improvements to raised pavement markers of the type that are typically installed in a roadway, as for example to mark lane lines. The raised pavement markers described in U.S. patent applications

Serial No. 08/780,378, filed January 8, 1997 and 08/905,468, filed August 4, 1997 show exceptional promise. These patent applications are assigned to the assignee of the present invention, and they are hereby incorporated by reference in their entirety. As explained in these applications, the disclosed pavement markers are easy to install, light in weight, and able to survive snow plowing operations without damage.

The present invention is directed to various improvements that can be applied to pavement markers of the types described in the above-identified U.S. patent applications. In addition, certain of these improvements can be applied generally to any suitable raised pavement marker.

SUMMARY

The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. By way of introduction, it can be said that the raised pavement marker described below provides a number of important features, including the following:

1. The pavement marker includes a membrane assembly that supports a reflector assembly for vertical movement. The radially outer edge of the membrane assembly defines an elastomeric seal surface, and the complimentary, radially inwardly facing surface of the base defines a rigid seal surface. These two seal surfaces cooperate to restrict the flow of water into the region between the membrane assembly and the base.

2. Complimentary mechanical latching elements are provided on the base and the membrane assembly of the pavement marker. These latching elements releasably latch the membrane assembly to the base, and they allow a worn membrane assembly to be unlatched from the base and replaced with another membrane assembly.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded perspective view of a pavement marker that incorporates a presently preferred embodiment of this invention.

Figure 2 is a cross sectional view of the installed pavement marker of Figure 1 ;

Figure 3 is an exploded sectional view of the pavement marker of Figure 2.

Figure 4 is a fragmentary perspective view showing a portion of the base of the pavement marker of Figure 1.

Figures 5 and 6 are upper and lower fragmentary perspective views, respectively, of portions of the retainer of Figure 1. Figure 7 is a perspective view of the membrane assembly of the pavement marker of Figure 1.

Figure 8 is a block diagram of a method for replacing the membrane assembly of the pavement marker of Figure 1.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Turning now to the drawings, Figure 1 shows an exploded perspective view of various components of a pavement marker 10, and Figure 2 shows the pavement marker 10 installed in a roadway R.

As most clearly shown in Figure 1 , the pavement marker 10 includes a base 12, a membrane assembly 14 and a reflector assembly 22. The membrane assembly 14 includes an inner ring 16, a retainer 18, and a membrane 20. In this embodiment the membrane 20 is molded around the portions of the inner ring 16 and the retainer 18 such that both the inner ring 16 and the retainer 18 are molded in place (preferably by a conventional insert molding operation) in the membrane 20. The reflector assembly 22 includes a reflector housing 24 that is substantially rigid such that it preserves a substantially constant shape as highway traffic and snow plows travel over the pavement marker 10. The reflector housing 24 supports two retro-reflectors 26, one of which is shown in Figure 1. The reflector assembly 22 can be formed substantially identically to the reflector assembly described in detail in U.S. patent application Serial No. 08/905,468.

The base 12 includes external ribs 28 that assist in securing the base 12 in place in a roadway. The uppermost portion of the base 12 forms four tabs 30, each positioned to rest on the upper surface S of the roadway R

(Figure 2) in order to locate the base 12 properly. As shown in Figure 1 , two of the tabs 30 include arrows 31 as an aid to orientation during installation. The tabs 30 are similar to the locating tabs of U.S. patent application Serial No. 08/905,468, except they are somewhat thicker and are designed to remain attached to the base 12 during its entire life. The external upper perimeter of the base 12 defines an array of pockets 32 that assist in securing the base 12 in place in the roadway recess, as described in the above-identified patent application Serial No. 08/905,468.

The interior of the base 12 forms an inwardly facing, smooth, rigid seal surface 34 positioned above an array of support columns 36. Each of the support columns 36 defines a projecting portion 38 that extends upwardly. Four latch components 40 are molded in place to the base 12, and each of the latch components 40 includes a respective enlarged head 42. Figure 4 provides a more detailed view of the support columns 36 and the latch component 40.

The base 12 also defines a rim 44 extending around the perimeter of the base 12 between the tabs 30, and a centering feature 46 (Figure 2). In practice, the base 12 can be molded from a rigid polymeric material such as 33% glass-filled Nylon 6. As best shown in Figures 1 , 5 and 6, the retainer 18 includes openings 52, and the retainer 18 is embedded in an outer portion 50 of the membrane 20. The retainer 18 defines an upper surface 54 that protrudes upwardly beyond the membrane 20 to protect the membrane from tire wear. The retainer 18 supports four latch components 56, each of which includes a pair of spaced spring arms 58 configured to mechanically latch on to the respective one of the enlarged heads 42. As shown in Figure 6, the retainer 18 includes a flat surface 60 around each of the arms 58. This flat surface 60 cooperates with a sealing surface of the insert mold (not shown) to block the flow of membrane material to the region around the arms 58. The radially outermost portion of the retainer 18 forms an upper ledge 61 , and the lowermost portion of the retainer 18 between the arms 58 forms an array of supports 62. The supports 62 are positioned to rest on respective ones of the support columns 36. The retainer 18 is preferably molded from a rigid polymeric material such as 33% glass-filled Nylon 6/6. In Figures 5 and 6, the cross hatched areas 59 show the edge of the fragmentary view; if the entire retainer were shown, the retainer 18 would be seen to be continuous across the areas 59.

Returning to Figure 1 , the inner ring 16 includes openings which are filled by the membrane material once the inner ring 16 is insert molded in place in the membrane 20. The inner ring 16 defines a pair of snap latch engagement surfaces 74 that receive and latch the reflector housing 24 to the inner ring 16.

Figure 7 shows a perspective view of the membrane assembly 14 in its fully assembled configuration. Note that the retainer 18 and the inner ring 16 are embedded in the membrane material 20, and that the upper surface 54 of the retainer 18 extends above the membrane material and protects it from road wear. The retainer 18 is provided with multiple openings and protruding ledges to provide a high strength mechanical inter-lock between the retainer 18 and the membrane 20. During the insert molding operation, the membrane material is extends radially outwardly of the retainer 18 to form an elastomeric seal surface 64. This seal surface includes three protruding sealing ridges 66 that extend radially outwardly from a cylindrical base 68. The ridges 66 and the base 68 form the radially outwardly facing sealing surface 64.

As shown in Figure 7, the elastomeric membrane material also forms an upper seal 70 immediately under the upper ledge 61 of the retainer 18. This upper seal 70 is positioned to engage the rim 44 of the base 12

(Figure 1 ) and to form a water-tight, interference fit around the base of each of the tabs 30 (Figure 1 ).

Figure 2 shows a cross sectional view of the pavement marker 10 mounted in place in the recess R1 formed in the upper surface S of the roadway R. A conventional adhesive such as bichumem A fills the gaps between the outside of the base 12 and the recess R1. Figure 2 shows the manner in which the reflector housing 24 is snapped in place to the inner ring 16 and the air vents openings 80, 82 that allow air to be exhausted from the interior of the pavement marker 10 when the reflector housing 24 moves downwardly, supported by the membrane 20. Figure 2 shows the manner in which the arms 58 form a snap latch with the enlarged head 42. Figure 2 also shows the manner in which the support columns 36 support the support surface of the retainer 18, and the manner in which the projecting portions 38 extend upwardly from the base of the retainer 18 to prevent the retainer 18 from moving radially inwardly in response to highway loads. In Figure 2, the ridges 66 of Figure 7 are not apparent due to the elastic deformation of the seal surface 64 against the seal surface 34 of the base. The ridges 66 provide sharp edged projections around the entire circumference that act as redundant seals against water penetration. Typically, a conventional lubricant is used during assembly as the seals are under compression when assembled.

The pavement marker 10 can be originally installed by first forming the recess R1 in the upper surface of the roadway R and applying a suitable adhesive to the interior of this recess. Then the fully assembled pavement marker 10 is pressed in place into the recess R1 until the tabs 30 come to rest on the upper surface S. This installation procedure is described in detail in the above-identified U.S. patent application Serial No. 08/780,378, and will not be repeated here. Note that the base 12 is shaped to conform closely to the recess R1 in order to reduce the quantity of adhesive A required to fill up the intervening air gaps. In the event the reflector assembly 22 or the membrane assembly 14 is damaged in use, it can be replaced without disturbing the location of the base 12 in the roadway R. The main steps of such a replacement procedure are flow-charted in Figure 8. The first step 90 is to cut the membrane 20 around the reflector assembly 24 and to remove the reflector assembly 22 to gain access to the interior of the base 12. Step 90 can be accomplished by cutting the membrane 20 in the region 96 completely around the reflector assembly 22 (Figure 2).

Once access has been gained to the interior of the base 12, a tool (not shown) can be used in step 92 to push upwardly on lower surfaces of the retainer 18, such as for example, the lower surfaces 98 of the arms 58 in order to snap the arms off of the enlarged heads 42 (Figure 2). The centering element 46 can be used to locate such a lifting tool. Those skilled in the art will recognize that a suitable tool can readily be designed using jack screw, leverage, or hydraulic techniques. Once the original retainer and associated portions of the membrane have been unsnapped from the base 12, a replacement membrane assembly 14 including a replacement reflector assembly 22 can be snapped in place as described in step 94 of Figure 8 and as shown in Figure 3. Once assembled, the support columns 36 and the projecting portions 38 substantially immobilize the retainer 18 in order to minimize movement between the seal surfaces 64, 34 and hence wear of the seal surfaces 34, 64. When the membrane assembly 14 is snapped in place in the base 12, the upper seal 70 is compressed slightly against the rim 44 to provide yet a further barrier against the entry of water. By way of example, the reflector housing 24 can be molded of 60% long glass fiber reinforced polyurethane, and the reflectors 26 can be formed of suitable polycarbonate or acrylic materials. The membrane 18 may be formed of silicone or EPDM synthetic rubber having a durometer of 40 to 50 (Shore A).

If desired, an elastomeric seal can be fitted to the reflector housing 24 in the region of the air vent opening 80 (Figure 2). The seal can be made of an elastomeric material designed to move to an open position to allow air to exhaust quickly out of the base as the reflector housing is moved downwardly, and then to relax to a closed position in which neither air nor water is allowed to enter the base. Air leakage is allowed through one or more small openings in an upper portion of the reflector housing to allow the reflector housing in the membrane to resume the position shown in Figure 2.

Note that the retainer 18 provides full surface support to the elastomeric seal surface 64, holding the elastomeric seal surface in constant contact with the rigid seal surface 34. The support columns 36 and the projecting portions 34 cooperate with the latch components 40, 56 to substantially immobilize the retainer 18 in place with respect to the base 12.

Of course, it should be recognized that many changes and modifications can be made to the preferred embodiment described above. Materials, shapes and configurations can all be changed as appropriate for the particular application. The latch arrangement described above can be used with other types of sealing arrangements, and vice versa.

The foregoing detailed description has described only a few of the many forms that this invention can take. For this reason, this detailed description is intended by way of illustration and not by way of limitation. It is only the following claims, including all equivalents, that are intended to define the scope of this invention.

Claims

1. A pavement marker comprising: a base configured to fit within a recess in a roadway, said base comprising a radially inwardly facing seal surface;

a membrane assembly comprising: a resilient membrane comprising a radially outer portion; and a retainer embedded in the outer portion of the membrane; said membrane assembly comprising a radially outwardly facing seal surface;

a reflector assembly secured to the membrane assembly and supported by the membrane, said reflector assembly comprising a rigid reflector housing preserving substantially a constant shape as the reflector housing is depressed toward the base, and at least one reflector mounted in the reflector housing;

said membrane assembly received in the base with said seal surfaces in contact with one another to form a seal operative to impede movement of water into a region intermediate the base and the membrane.

2. The invention of Claim 1 wherein the radially inwardly facing seal surface comprises a rigid material, and wherein the radially outwardly facing seal surface comprises an elastomeric material.

3. The invention of Claim 2 wherein the radially outwardly facing seal surface is integral with the membrane.

4. The invention of Claim 1 further comprising a plurality of snap latch components carried by the base and the retainer, said snap latch components mechanically interlocked to releasably hold the membrane assembly in the base.

5. The invention of Claim 1 wherein the base comprises an array of support columns engaging the retainer to support the retainer and limit movement of the retainer into the base.

6. The invention of claim 5 wherein at least some of the support columns comprise projecting portions engaging the retainer to restrain to the retainer against radially inward movement.

7. The invention of Claim 6 wherein the retainer holds the radially outwardly facing seal surface in place against the radially inwardly facing seal surface.

8. The invention of Claim 1 wherein the radially inwardly facing seal surface is substantially cylindrical in shape.

9. The invention of Claim 1 wherein an upper portion of the retainer extends over a radially outer part of the base.

10. The invention of Claim 1 wherein the retainer extends continuously around an outer perimeter portion of the membrane.

11. A pavement marker comprising:

a base configured to fit within a recess in a roadway;

a membrane assembly comprising; a resilient membrane; a retainer embedded in an outer portion of the membrane;

a reflector assembly secured to the membrane assembly and supported by the membrane, said reflector assembly comprising a rigid reflector housing preserving substantially a constant shape as the reflector housing is depressed toward the base, and at least one reflector mounted in the reflector housing; a plurality of latch components carried by the base and the retainer, said latch components mechanically interlocked to releasably hold the membrane assembly in the base.

12. The invention of Claim 11 wherein the latch components comprise snap latch components oriented to snap together along an axis aligned with a central axis defined by the base.

13. The invention of Claim 12 further comprising:

a rigid, radially inwardly facing seal surface formed by the base; and

an elastomeric, radially outwardly facing seal surface carried by the retainer;

said seal surfaces in contact with one another to form a seal operative to impede movement of water into a region intermediate the base and the membrane.

14. The invention of 13 wherein the latch components comprise:

first latch components carried by the base, each first latch component comprising a respective enlarged head; and

second latch components carried by the retainer, each second latch component comprising a respective pair of arms configured to latch onto the respective head.

15. A pavement marker insert comprising:

said seal surface comprising an elastomeric seal extending radially outwardly of the retainer.

16. The invention of Claim 15 wherein the radially outwardly facing seal surface is integral with the membrane.

17. The invention of Claim 15 further comprising a plurality of snap latch components carried by the retainer on a side of the membrane opposite the reflector.

18. The invention of Claim 15 wherein the seal surface comprises a plurality of annular sealing ridges protruding outwardly from a substantially cylindrical base.

19. A pavement marker insert comprising:

a plurality of downwardly facing snap latch components carried by the retainer, said latch components extending on a side of the membrane opposite the reflector and oriented to engage respective mating upwardly facing latch components.

20. A method for repairing a snow-plowable pavement marker comprising a base mounted in a recess in a roadway, a membrane assembly snap latched to the base, and a reflector assembly carried by the membrane assembly, said method comprising the following steps:

(a) cutting a membrane included in the membrane assembly to gain access to the base; then

(b) pushing on a downwardly facing surface of the membrane assembly to unlatch the membrane assembly from the base; and then

(c) snapping a replacement membrane assembly comprising a replacement reflector assembly onto the original base.

21. The method of Claim 20 wherein step (b) comprises the step of pushing upwardly on the downwardly facing surface to unlatch the membrane assembly from the base.

22. The invention of Claim 19 wherein the snap latch components carried by the retainer are disposed radially inwardly of an outer portion of the membrane assembly to avoid contact with roadway material when installed in a roadway.