FIELD OF THE INVENTION

This invention relates generally to delineators that are used to control vehicle traffic on roadways and the like. The invention also relates to associated articles, systems, and methods.

BACKGROUND

Traffic delineators are known. Delineators are typically used on or near roadways or other paved or unpaved surfaces where automobiles, trucks, or other motorized or unmotorized vehicles travel. Often a series of delineators are arranged along a road, lane, or path so as to highlight or increase its visibility for the benefit of vehicle operators. FIG. 1 is an idealized perspective view of a roadway 110 along which delineators 112 have been placed to mark the path or direction of the roadway. Delineators can also be used in construction work zones to help guide vehicles along rerouted paths that may be unfamiliar to the vehicle operators. Perhaps because delineators can be used to direct or "channel" traffic in a given direction, they are sometimes also referred to as channelizers.

In some cases, delineators may be used in applications where visibility from only one direction is considered important. In other cases, e.g., when placed between lanes of traffic that move in opposite directions, it may be important for the delineator to exhibit high visibility from both such directions. In still other cases, such as at intersections, it may be important for the delineator to exhibit high visibility from four or more different directions, e.g., north, south, east, and west.

An example of a known delineator design is simply a post attached to a base. For improved visibility, the post may comprise high visibility materials. For daytime visibility, the post may be fabricated from bright diffuse materials, such as white or orange paint. For nighttime visibility, retroreflective sheeting may be wrapped around a portion of the post. Retroreflective sheeting has the characteristic of directing incident light back in the general direction from which it came, regardless of the angle at which the light impinges on the surface of the sheeting. Thus, as a vehicle approaches a roadway sign or other structure on which a retroreflective sheet is mounted, light from a vehicle headlamp may impinge on the sheeting, which then reflects the light back in the general direction of the headlamp. The retroreflection occurs in a small but finite angular cone, which cone encompasses the eye of the vehicle operator so that the operator perceives the sign as being conspicuously bright and highly visible.

FIGS. 2 and 3 are provided for background purposes to exemplify two angles that may have some significance when discussing retroreflective sheeting, or other reflective sheeting. FIG. 2 is a top view of a vehicle 210 traveling in a direction 212 along a roadway 214. Reflective sheeting 216 is provided near the side of the road. Sheeting 216 is assumed to be flat and planar, and the axis 218 is perpendicular to the plane of the sheeting. (In cases where the reflective sheeting is not flat, each portion of the sheeting may be considered to be flat if the size of the portion is small enough.) Axis 220

represents the direction along which light from the vehicle headlamp impinges upon the sheeting 216. The angle β between the axes 218 and 220 is referred to as the entrance angle for the light. A side view of this situation is shown in FIG. 3, where the vehicle headlamp (or other light source) is shown separately and labeled as 310, and the eye of the vehicle operator (or other observer) is shown separately and labeled 312. An axis 314 extends directed between the headlamp 310 and the sheeting 216. Another axis 316 extends between the sheeting 216 and the observer 312. The angle a between the axes 314, 316 is referred to as the observation angle.

BRIEF SUMMARY

Delineators are occasionally the subject of theft, vandalism, and/or tampering. In one form of vandalism or tampering, a person may remove a retroreflective sheet, or a portion thereof, from the delineator. For example, in the case of a retroreflective sheet wrapped around a post, the person may locate an edge of the sheet, force a fingernail or other implement between the post and the sheet at such edge, and begin peeling the sheet away from the post. After some or all of the retroreflective sheet is removed from the post, the nighttime visibility of the delineator can be substantially degraded.

We have developed a class of delineator designs that incorporate an outer shell and inner core construction. These design concepts encompass a wide range of different embodiments, each of which may possess a number of design advantages relative to conventional delineators. At least some of the embodiments, however, can incorporate design features to guard against the tampering behavior described above. Thus, the core/shell construction of at least some of the disclosed delineators can help to protect reflective sheeting in the delineator from tampering and vandalism. The delineator may include an outer shell, and an inner core that fits inside the outer shell. Further, a reflective sheet may be applied to an outer surface of the inner core, the sheet having one or more edges. One or more apertures may be formed in the outer shell to provide a window region, the window region adapted to expose at least some of the reflective sheet when the inner core is positioned inside the outer shell. The window region may be configured to avoid exposing at least some of, and in some cases any of, the one or more edges of the sheet. In such cases, the outer shell proximate the window region may cover some, or all, of the sheet edge(s) so that such sheet edge(s) are less accessible to vandals.

Related methods, systems, and articles are also discussed.

These and other aspects of the present application will be apparent from the detailed description below. In no event, however, should the above summaries be construed as limitations on the claimed subject matter, which subject matter is defined solely by the attached claims, as may be amended during prosecution.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view of a roadway with delineators positioned along the roadway;

FIG. 2 is a top view of a vehicle on a roadway encountering a reflective sheet; FIG. 3 is a schematic side view of selected elements of the arrangement depicted in

FIG. 2;

FIG. 4 is a schematic elevational view of a delineator having a core/shell construction;

FIGS. 4a and 4b are schematic sectional views taken along lines 4a-4a and 4b-4b in FIG. 4;

FIG. 5 is an exploded elevational view of the delineator of FIG. 4;

FIG. 6 is an elevational view of a portion of a delineator, showing an exemplary window region;

FIGS. 7a, 7b, and 7c are elevational views of delineators having alternative window region combinations; FIGS. 8a-h are elevational views of a plurality of alternative delineators having still other window region designs;

FIGS. 9a-d are schematic views of some shapes that can be used for the cross- sectional shape of the inner core and/or the outer shell of the disclosed delineators;

FIGS. 10-12 are schematic sectional views of further delineators having core/shell constructions;

FIGS. 13a and 13b together depict in schematic sectional view another possible core/shell combination for a delineator;

FIG. 14 is a schematic perspective and exploded view of a portion of still another delineator having a core/shell construction; and

FIG. 15 is a schematic elevational view of a portion of a delineator, showing an exemplary window region.

In the figures, like reference numerals designate like elements. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In FIG. 4, we see a schematic elevational view of a delineator 410 having a core/shell construction. The delineator 410 includes an inner core 412 (not visible in FIG. 4 but shown in later figures), an outer shell 414, and a base 416. For reference purposes, a Cartesian x-y-z coordinate system is also included in the figure. A delineator axis 413, which is parallel to the z-axis, defines the longitudinal axis of the delineator.

The shell 414 is in the form of a tube having a first end 418 and a second end 420, the first end being adapted to fit tightly within an opening of the base 416 as shown. The base, which can be of any known design, has a sufficient weight and/or is provided with sufficient attachment mechanism(s) to the pavement or ground so as to keep the delineator in an upright position after installation. In some cases, the base may be integrally formed with the outer shell, while in other cases the base may be press-fit, adhered, or otherwise permanently, semi-permanently, or releasably attached to the shell 414. If the delineator is not omnidirectional, i.e., if it is designed to have one or more preferred viewing orientation, then the base 416 may be provided with a distinctive shape, marking, or other alignment feature that indicates to an installer how to properly orient the delineator relative to the direction of traffic or another characteristic of the surroundings. The shell 414 has a first window region 422 and a second window region 424, although less than two or more than two window regions can also be used as explained further below. In exemplary embodiments, these window regions comprise apertures formed in the shell 414. The window regions expose or reveal reflective sheeting that is located inside the outer shell as set forth further below. Significantly, the window regions can also be configured such that they do not expose at least some of, and in some cases they do not expose any of, the edges of such reflective sheeting. In the view of FIG. 4, exposed portions of the reflective sheeting are indicated by shading, and no edges of the sheeting are exposed through the window regions. This is because the sheeting edges are covered up by portions of the outer shell proximate the window regions, as seen more clearly in FIGS. 4a, 4b, and 5. By applying the sheeting to the inner core and then covering up the sheeting edges with the outer shell, vandals have little or no access to the sheeting edges and will be less likely to remove the reflective sheeting from the delineator. As seen below in FIGS. 4a-b, it can also be beneficial to provide a relatively close fit between the inner core and the outer shell so as to avoid significant gaps between the outer shell and the reflective sheeting. This can help to further reduce access to the reflective sheeting.

The window regions 422, 424 differ from each other in size, shape, and vertical position on the delineator, although in alternative embodiments one, some, or all of these differences may not exist. The region 422 comprises a plurality or cluster of closely spaced windows. If desired, such a cluster can used to expose a relatively large area of reflective sheeting while also providing a network of outer shell connective material. The network of connective material can help to maintain the mechanical strength of the outer shell 414.

In contrast to region 422, region 424 has only one window. The window of region

424 is in the form of an axial slot. By making the width of the slot a fraction of the corresponding width of the outer shell, e.g., less than ½, or less than 1/3, the mechanical strength of the outer shell 414 can be substantially maintained. The area of the slot can be increased by increasing the length of the slot. In the embodiment of FIG. 4, the length-to- width ratio of the axial slot is about 10: 1, although other length-to-width ratios can also be used. The second end 420 of the outer shell is preferably, but not necessarily, closed in order to prevent access to interior portions of the delineator by vandals. The closed design may be achieved by suitably molding the end 420 of the outer shell to form a solid top, or by attaching a cap or cover to the outer shell. A ring or loop (not shown) may also be affixed at the top of the delineator.

FIGS. 4a and 4b are schematic sectional views of delineator 410 taken along lines 4a-4a and 4b-4b respectively, and like numerals designate like elements. In these views we can clearly see the apertures in the outer shell 414 that form the window regions 422, 424. We can also now see that there are additional apertures formed in the "opposite side" of the outer shell, i.e., the side that is seen when viewing along the +x direction rather than along the -x direction (the view of FIG. 4). The additional apertures form additional window regions 423, 425 as shown. In one embodiment, the additional window regions 423, 425 may have the same appearance as the window regions 422, 424, respectively, such that the outer shell 414 (and optionally also the entire delineator 410) has 180 degree rotational symmetry about the axis 413. The term "180 degree rotational symmetry", which may also be described as "half-turn" rotational symmetry or "two way" rotational symmetry, means that the outer shell 414 (and optionally the entire delineator 410) is substantially the same if it is rotated 180 degrees about the axis 413. In alternative embodiments, the outer shell and/or the delineator 410 may exhibit other types of symmetry, such as mirror symmetry relative to the y-z plane. (In embodiments having other cross-sectional shapes for the outer shell, the outer shell and delineator may exhibit 120 degree (or "three way") rotational symmetry, 90 degree (or "four way") rotational symmetry, and so forth.) In still other embodiments, no window regions (and no apertures) may be provided in the "opposite side" of the outer shell, or the window regions 423, 425 may have substantially different shapes than the respective window regions 422, 424.

Another element of the delineator 410 that is clearly visible in the views of FIGS. 4a and 4b are the reflective sheets 432, 434, 433, and 435. These sheets are applied to an outer surface 412a (see FIG. 5) of the inner core 412, and may be adhered thereto by any suitable adhesive, such as a pressure-sensitive adhesive (PSA), hot melt adhesive, or the like, or by any other suitable attachment mechanism. Before attachment to the inner core, the reflective sheets typically, but not necessarily, are thin and flexible, and may be pieces that are cut from one or more rolls of thin, flexible reflective material.

Some edges of the sheets 432, 434, 433, and 435 are visible in FIGS. 4a and 4b, and all the edges of sheets 432, 434 are visible in FIG. 5. In the embodiment shown, the sheets 432, 434 are rectangular in shape, and thus have four distinct edges each. The four edges of sheet 432 are collectively labeled 432a, and the four edges of sheet 434 are collectively labeled 434a. Of course, other shapes for the reflective sheets can also be used, such as circular, elliptical, triangular, shapes with rounded ends, and other non- rectangular shapes. Edges of sheets 433, 435 are labeled 433a, 435a, respectively.

Significantly, none of the edges of any of the sheets are exposed by any of the window regions. Stated differently, portions of the outer shell 414 proximate the various window regions cover up the various sheet edges, so that none of the edges are exposed to vandals. In alternative embodiments, only some of the sheeting edges may be covered up by the outer shell.

As best seen in FIGS. 4a and 4b, it can be advantageous to select the shapes and sizes of the core 412 and shell 414 such that there is little or no gap between any given reflective sheet and the outer shell 414. Stated differently, it can be advantageous for a portion of the outer shell 414 around the border or periphery of a window region to be in contact with the associated reflective sheet, when the sheet is applied to the outer surface of the inner core and the inner core is fully and properly installed inside the outer shell.

Providing little or no significant gaps between the outer shell and the reflective sheeting can help to further reduce access to the reflective sheeting by vandals, and can also help to reduce or avoid accumulation of water or other debris inside the delineator.

Several design features of the delineator can affect the visibility of the reflective sheet, and of the delineator, as a function of the direction of observation. For delineators, the direction of observation can be defined for an observer located anywhere in or near the x-y plane, the direction being measured as an azimuthal angle Θ in the x-y plane relative to the x-axis, as shown in FIGS. 4a, 4b, or relative to some other desired reference direction associated with the delineator. Angular observation ranges 442, 443, 444, and 445, which are associated with window regions 422, 423, 424, and 425, respectively, are shown in

FIGS. 4a and 4b for illustrative purposes. The limits of these ranges may be specified by specifying a suitable minimum visibility threshold that may be applied to all of the various windows.

One design feature that can affect the visibility of the delineator is the entrance angularity of the reflective sheet itself. "Entrance angularity" in this regard refers to the ability of the sheet to maintain its visibility or brightness as a function of entrance angle (see FIG. 2). In the case of retroreflective sheeting, visibility can be characterized by the sheeting's coefficient of retrorefiectivity, which is typically measured in units of candelas per lux per square meter, or cd/(lux*m ² ). Retroreflective sheeting may in some cases have a retroreflective coefficient of at least 10, or at least 100, or at least 500 cd/(lux*m ² ) for head-on viewing (β = 0), but the retrorefiectivity may decrease or otherwise change with increasing entrance angle. The amount of decrease as a function of entrance angle depends on design details of the retroreflective sheeting.

Another design feature that can affect the visibility of the delineator is the range of orientations exhibited by the reflective sheeting over its exposed area. In the case of a reflective sheet that is flat over all of its exposed area, for example, there is only one orientation, namely, the direction perpendicular to the flat surface of the sheet. In contrast, a reflective sheet having an exposed area that wraps completely around a round post exhibits a full 360 degree range of orientations. In reference to FIG. 4b, the exposed portion of sheet 434 exhibits a relatively narrow range of orientations due to the small degree of curvature of the outer surface of the inner core 412 over the area of window region 424. As seen in FIG. 4a, however, the exposed portion of sheet 432 exhibits a wider range of orientations as a result of the angled portions 448a, 448b, which flank the central, flatter portion. The wider range of sheeting orientations can result in the observation ranges 442, 443 being wider than the observation ranges 444, 445.

We have found that, for purposes of enhanced long range visibility, it may be desirable to design the delineator such that a substantial portion of the exposed part of a reflective sheet, for at least one of the window regions, is substantially flat. "Substantially flat" in this regard encompasses surfaces that are precisely flat (within manufacturing tolerances) and also surfaces that have small amounts of curvature. For example, in FIG. 4a, the central flatter portion of reflective film 432 between the angled portions 448a, 448b may be slightly curved so that the inner core and outer shell (which have similar amounts of curvature) have increased structural strength. This central flatter portion has a radius of curvature that exceeds half of the maximum transverse dimension of the inner core, such maximum transverse dimension being associated with the y-direction in FIG. 4a. In one particular embodiment exemplified by FIGS. 4, 4a, 4b, and 5, the maximum transverse dimension of the inner core is about 85 mm, and the radius of curvature of the central flatter portion of the inner core is about 239 mm.

Another design feature that can affect the visibility of the delineator is the profile of the edge of the outer shell adjacent the window region. In FIGS. 4a and 4b these edges are shown as being beveled or tapered for each of the window regions 422, 423, 424, 425. Beveling or tapering the wall of the outer shell in this manner can help to increase the angular observation range of the delineator. However, in some cases the beveling or tapering of some or all of the outer shell wall edges can be omitted.

Turning now to FIG. 5, we see there the inner core 412 and outer shell 414 of delineator 410 in an exploded elevational view. Reflective sheets 432, 434 are applied to the outer surface 412a of the inner core 412. The shapes of the sheets 432, 434, their placement on the inner core 412, and the shapes and placement of the window regions 422, 424 in the outer shell 414, are preferably designed such that the sheet edges 432a, 434a are not exposed by the respective window regions. When the inner core is properly positioned in the outer shell, the sheet edges 432a, 434a preferably correspond to the dashed-line outlines that surround window regions 422, 424 respectively.

In some cases, the delineator may be designed to be substantially rigid and inflexible. In other cases, the delineator may be designed to be flexible so that it can bend by 90 degrees or more in response to a vehicle strike, and then rebound or recover to a vertical orientation. The choice of design may affect the choice of materials used for the inner core and outer shell. In a flexible delineator design, the core and shell may be made of a thermoplastic polyurethane, such as such as Desmopan™ 392LS/LE material sold by Bayer, or other suitable flexible materials such as a flexible rubber-like plastic or other plastic. In a rigid delineator design, the core and shell may be made of a harder plastic, such as polycarbonate 15% glass filled, polycarbonate acrylonitrile butadiene styrene (ABS) glass filled, nylon glass filled, sheet metal, or other suitable rigid materials. In flexible delineator designs, the exterior height of the inner core 412 may be made somewhat smaller than the interior height of outer shell 414, in order to provide a small gap between the top of the inner core and the bottom inside surface of the upper end of the outer shell, so as to allow for flexing. In this case, if the outer core is shaped to fit tightly around the inner core, one or more small holes may be provided in the outer shell to allow trapped air in the gap region (above the top of the inner core) to escape as the delineator bends.

The disclosed delineators, and components thereof, can be made of any suitable materials, including weatherable materials capable of long term use in outdoor

environments. The inner core and outer shell can be made of the same material, or different materials. The materials may both be rigid, or both may be flexible, or one material may be rigid and the other may be flexible. For example, the inner core may be rigid and the outer shell may be flexible. Further, the inner core of such an embodiment may be substantially the same length as the outer shell, or it may have a length that is a fraction, e.g., ½ or less or ¼ or less, of the length of the outer shell or otherwise less than the length of the outer shell. See e.g. FIG. 14, which is described further below.

In some embodiments, for example, an inner core made of a rigid material, such as high density polyethylene (HDPE), polypropylene, polycarbonate (PC), or acrylonitrile butadiene styrene (ABS), and of suitable wall thickness {e.g. 2 to 4 mm), may be mounted inside an outer shell made of a flexible material, such as thermoplastic polyurethane (TPU) or one or more thermoplastic elastomers (TPEs) of Shore A hardness 80-95 or 80- 90, such that the inner core helps to provide some rigidity to the delineator. Constructions of this type can help reduce the thickness of the outer shell which can help to reduce the total weight of the delineator, and can help to reduce cost as well. The inner core in such cases may have a shorter length than the outer shell, and may be mounted at an elevated position such that a lower portion of the flexible outer shell proximate the delineator base is not reinforced by the inner core, allowing the delineator to bend more freely near its base. A mechanical feature such as a smooth or abrupt change of the inner dimension of the shell may be used to ensure the inner core remains positioned above a short length of non-reinforced outer shell near the base of the delineator. For example, the shell may have a uniform outer diameter from top to bottom, but may have a greater wall thickness at the bottom {e.g., 4 to 6 mm) compared to the wall thickness elsewhere {e.g., 1 to 2 mm) so that the inner diameter changes to form a step or ledge on which the inner core may rest. The length of the inner core may be approximately 2/3 the length of the outer shell, such that approximately 1/3 or at least 10 centimeters, for example, of the outer shell is not reinforced by the inner core at the delineator base, thus allowing flexibility at the base and rigidity elsewhere along the delineator. In alternative embodiments the inner core may have a length that is about 70% to 90% of the length of the outer shell, whereby about 30% to 10% of the outer shell is not reinforced and more free to flex. If desired, the outer shell may be provided with a corrugated or bellows-type structure at the non-reinforced base portion to further promote flexing. One or more apertures may be formed in the outer shell, and one or more reflective sheets may be applied to the inner core in such a way that, when the core is full inserted into the shell, portion(s) of the sheet(s) are exposed through the aperture(s), preferably without exposing any edges of the sheet(s) as discussed herein.

The disclosed delineators and components thereof can be made using known manufacturing methods, such as injection molding, extrusion, roto-molding, sheet metal fabrication, and/or similar low cost fabrication processes.

The reflective sheets 432, 433, 434, and 435 may all comprise the same type of reflective sheeting, or they may all be different from each other. In exemplary

embodiments, the sheets 432, 433 may be the same, and the sheets 434, 435 may be the same as each other but different from the sheets 432, 433. In some embodiments, the sheets 432, 433 may comprise white (clear) retroreflective sheeting, and the sheets 434, 435 may comprise red-colored retroreflective sheeting. Sheetings of other colors may also be used, as desired. Although retroreflective sheeting from any vendor may be used, retroreflective sheeting sold by 3M Company is preferred. Such sheeting may include 3M™ Diamond Grade™ DG ³ Reflective Sheeting Series 4000, 3M™ Diamond Grade™ Conspicuity Markings Series 983, and/or 3M™ Diamond Grade™ Flexible Prismatic School Bus Markings Series 973, for example.

In cases where the delineator includes at least two distinct retroreflective sheets, which may correspond to at least two distinct window regions, it may be advantageous for one of the retroreflective sheets to have a first optical characteristic, and for the other retroreflective sheet to have a second optical characteristic that differs from the first optical characteristic. The optical characteristics may relate to the color of the

retroreflective sheets, and/or to the retroreflective coefficient or range of retroreflectivity of the sheets. In one case the sheets 432, 433 may comprise white 3M™ Diamond Grade™ DG ³ Reflective Sheeting Series 4000, and the sheets 434, 435 may comprise red 3M™ Diamond Grade™ Conspicuity Markings Series 983, for example. The latter sheeting (series 983) may be considered to provide enhanced retroreflectivity at long ranges, because its retroreflectivity is particularly high at very small observation angles a, which generally correspond to observation at large distances. The former sheeting (series 4000), even though it also provides very good retroreflectivity at large distances, may be considered to provide enhanced retroreflectivity at shorter ranges, because its

retroreflectivity decreases less than that of the series 983 sheeting as the observation angle a increases. Note that in addition to viewing distance, the observation angle a can also be affected by the vehicle size: in small vehicles, the distance from the vehicle headlamp to the vehicle operator's eye is generally smaller than for larger vehicles. Thus, at any given viewing distance, the operator of a small automobile, for example, will typically have a smaller observation angle a than the operator of a large truck or bus, for example.

In addition to exhibiting differences as a function of observation angle a (FIG. 3), different retroreflective products also exhibit differences as a function of entrance angle β (FIG. 2). Thus, for example, the retroreflectivity of the series 983 conspicuity sheeting mentioned above decreases less (for a given observation angle) than that of the series 4000 sheeting as the entrance angle increases, and can thus be said to have a wider entrance angularity.

The dimensions of an exemplary delineator such as that shown in FIGS. 4, 4a, 4b, and 5 include: 800 mm for the height of the delineator; 440 mm for the height of the lower edge of window region 422; 770 mm for the height of the upper edge of the window region 422; 140 mm for the lower edge of the window region 424; 320 mm for the upper edge of the window region 424; and 90 mm for the maximum transverse dimension (width) of the outer shell.

Turning now to FIG. 6, we see there an elevational view of a portion of a delineator 610 showing an exemplary window region 622 provided in an outer shell 614. The window region 622, the general boundary of which is shown in broken lines, is substantially the same as window region 422 but is shown enlarged in FIG. 6 for clarity. The region 622 comprises a cluster of six discrete, closely-spaced windows 622a-f. The spaces between the windows (apertures) form a network of outer shell connective material that can help to maintain the mechanical strength of the outer shell 614. The narrow connective structures that make up this network are labeled 623a-e. The windows all have the same general three-sided (triangle) shape, but are rotated and displaced relative to each other such that the overall window region 623 has a nominally rectangular shape, and such that some of the connective structures, i.e., structures 623b, 623d, are horizontally oriented, and others of the connective structures, i.e., structures 623a, 623c, 623e, are slanted or inclined.

In some embodiments, such as that of FIG. 5, a single reflective sheet can be positioned on an inner core behind the window region 622. In such embodiments, the individual windows 622a-f expose different portions of the same reflective sheet. In other embodiments, two or more reflective sheets can be positioned on an inner core behind the window region. For example, a first reflective sheet can be positioned in an upper portion of the window region 622, a second reflective sheet can be positioned in a central portion of the window region 622, and a third reflective sheet can be positioned in a lower portion of the window region 622. In this case, windows 622a, 622b may expose different portions of the first reflective sheet, windows 622c, 622d may expose different portions of the second reflective sheet, and windows 622e, 622f may expose different portions of the third reflective sheet. Further, the connective structure 623b may cover up a lower edge of the first reflective sheet and an upper edge of the second reflective sheet, and the connective structure 623d may cover up a lower edge of the second reflective sheet and an upper edge of the third reflective sheet, for example. Many other combinations of individual windows and reflective sheets are also contemplated. The individual windows need not be the same shape, but can have different sizes and shapes. If multiple reflective sheets are used, they can have different optical characteristics, such as different colors or different retroreflective performance characteristics, and they can have the same shape or different shapes.

In alternative embodiments to the window region 622, one or some of the individual windows can be omitted, and one or some of the connective structures can be omitted. For example, if windows 622a and 622f are omitted, the overall shape of the resulting window region is a non-right parallelogram (a parallelogram with no 90 degree angles) rather than a rectangle. If connective structures 623b and 623d are omitted, then a large discrete triangular window takes the place of windows 622b, 622c, and the area formerly occupied by the connective structure 623b, and another large triangular window takes the place of windows 622d, 622e, and the area formerly occupied by the connective structure 623d. In still other embodiments, the window region 622 can be extended by adding more triangular-shaped windows similar to those shown in FIG. 6 above and/or below the region 622 in a manner to continue the repeating pattern. The window region 622 can also be shortened by omitting some of the windows shown, e.g. , windows 622a and 622b, and/or 622e and 622f. In other embodiments, the widths of the connective structures can be decreased by increasing the size of the individual windows, and can be increased by decreasing the size of the individual windows, for example.

FIGS. 7a-c show elevational views of alternative delineators to that shown in FIG. 4. In FIG. 7a, delineator 710 comprises an outer shell 712 having a first end 712a and a second end 712b. The first end 712a is adapted to be attached to a base (not shown). The outer shell 712 comprises a first window region 714 proximate end 712b, and a second window region 716 proximate end 712a. The window regions 714, 716 may be substantially the same as that shown in FIG. 6, or any of the described alternatives thereof.

In FIG. 7b, delineator 720 comprises an outer shell 722 having a first end 722a and a second end 722b. The first end 722a is adapted to be attached to a base (not shown). The outer shell 722 comprises a first window region 724 proximate end 722b, and a second window region 726 proximate end 722a. The window regions 724, 726 may be substantially the same as the window region 424 of FIG. 4, or alternatives thereof.

In FIG. 7c, delineator 730 comprises an outer shell 732 having a first end 732a and a second end 732b. The first end 732a is adapted to be attached to a base (not shown). The outer shell 732 comprises a first window region 734 proximate end 732b, and a second window region 736 proximate end 732a. The window region 734 may be substantially the same as the window region 424 of FIG. 4, or alternatives thereof. The window regions 736 may be substantially the same as that shown in FIG. 6, or any of the described alternatives thereof.

FIGS. 8a-h are elevational views of a plurality of alternative delineators 810, 820, 830, 840, 850, 860, 870, and 880, which demonstrate still more window region designs that are contemplated herein.

The various different types of window regions disclosed herein can be applied to a delineator (having a core/shell construction) in any desired combination. The outer shell of the delineator may have a cross-sectional shape that is not limited to that depicted in FIGS. 4a-b, but can be selected from any of a wide variety of shapes. Some suitable cross-sectional shapes are provided in FIGS. 9a-d, but these should not be considered to be limiting. Shape 910 is substantially circular, but elliptical shapes can also be used. Shape 920 is somewhat flattened and elongated. Shape 930 is substantially triangular. Shape 940 is substantially square or rectangular. For outer shells having cross-sectional shapes such as these, window regions can be provided in one or more "sides" of the shell. In this regard, a "side" of the outer shell may refer to the portion of the outer shell that is visible from a particular azimuthal angle Θ (refer to FIGS. 4a-b). Thus, for example, the delineator 410 shown in FIGS. 4a-b has window regions provided in two opposed sides of the outer shell. As such, the delineator 410 may be referred to as a bidirectional delineator, since it can provide high visibility from two distinct directions. Similarly, window regions may be provided in only one side, or in multiple sides of outer shells represented by the shapes of FIGS. 9a-d. For shape 910, one or more window regions may be provided on only one side, to provide a unidirectional delineator, or window regions may be provided on two sides to provide a bidirectional delineator, or on more than two sides to provide a substantially omnidirectional delineator (which provides high visibility for any azimuthal angle). For shape 920, one or more window regions may be provided on only one of the long, flat sides, or on both such sides. Note that the relatively flat sides of shape 920 may be provided with a small amount of curvature to enhance mechanical strength. For shape 930, one or more window regions may be provided on only one, or only two, or on all three sides of the triangle, which may result in a unidirectional, bidirectional, or tri-directional delineator, respectively. For shape 940, one or more window regions may be provided in only one, or only two, or only three, or all four of the substantially flat sides of the outer shell.

In the disclosed delineators, the inner core may have substantially the same cross- sectional shape as the outer shell, but this is not always necessary. In this regard, the inner core may be said to have the same shape, or substantially the same shape, as the outer shell, even though the inner core is physically smaller than the outer shell, and even though there may be minor mechanical features or differences that may be provided to help the outer shell slidably engage the inner core, or to make allowance for the presence of one or more reflective sheets on the inner core.

FIGS. 10, 11, and 12 are schematic sectional views of further delineators having core/shell constructions, where cross-sectional shape of both the outer shell and of the inner core, when properly installed inside the outer shell, are depicted schematically. In FIG. 10, a delineator 1010 comprises an inner core 1012 and an outer shell 1014 that are both elongated and relatively flat, although again the discussion above relating to providing a slight curvature to the parts also applies here. In FIG. 11, a delineator 1110 comprises an inner core 1112 and an outer shell 1114 that are elongated but angled or beveled at opposed ends. In FIG. 12, a delineator 1210 comprises an inner core 1212 and an outer shell 1214 that are substantially circular. If a particular alignment is desired between the core 1212 and shell 1214, for example so as to ensure the proper alignment of a reflective sheet adhered to the core 1212 relative to a window region in the shell 1214 so that edges of the reflective sheet are not exposed by the window region, alignment features such as tongue-and-groove or slot-and-pin mechanism as indicated at 1213a, 1213b, or any other suitable alignment features, may be provided.

FIGS. 13a and 13b together depict in schematic sectional view another possible core/shell combination for a delineator. An inner core 1312 is provided with a

substantially elliptical cross-sectional shape, and an outer shell 1314 is provided with a shape the same as or similar to the shape of the outer shell shown in FIGS. 4a-b. In this case, the inner core has a somewhat different shape than that of the outer shell, yet the inner core 1312 may still be suitable for insertion into the outer shell 1314, depending on the placement and details of the window region(s) formed in the outer shell, and depending on whether or not a tight fit of the reflective sheeting against the inner surface of the outer shell is required or desired for the particular application. In one embodiment, the inner core 1312 may be made of a relatively flexible material that can change its cross- sectional shape by an acceptable amount when the inner core is inserted into the outer shell, the changed cross-sectional shape being a closer match to the shape of the outer shell 1314. Alternatively or in addition, the outer shell 1314 may be made of a relatively flexible material that can change its cross-sectional shape by an acceptable amount in order to more closely match the shape of the inner core 1312.

Proceeding now to FIG. 14, we see there a schematic perspective and exploded view of a portion of still another delineator 1410 having a core/shell construction. The delineator 1410 comprises an inner core 1412 and an outer shell 1414, where the inner core is substantially shorter than the outer shell, and inserts into only a portion of the shell. For example, the inner core may have a length (height) that is less than half that of the outer shell, or less than one-fourth that of the outer shell, for example. A reflective sheet 1432 is applied to an outer surface of the inner core, e.g. by an adhesive or other suitable means. As applied to the core, the sheet 1432 has an upper edge 1432a, a lower edge 1432b, and an axial edge 1432c. A cap or cover 1450 is bonded or otherwise attached to one end of the inner core 1412. After the inner core 1412 is inserted into an upper end

1414b of the outer shell 1414, portions of the sheet 1432 are exposed by a window region 1422. Although any of the window regions discussed elsewhere herein may be used in this design, still another suitable window region 1422 is depicted in FIG. 14. In this case, the window region 1422 comprises a series of transverse slots formed in opposed sides of the outer shell. In the depicted embodiment, the slots are inclined at an angle relative to a horizontal plane, and the depth of the slots is great enough to expose to at least some portion of the reflective sheet 1432 for any given azimuthal angle over an entire 360 degree range. As a consequence, even though the window region 1422 may be adapted to avoid exposing the upper edge 1432a and the lower edge 1432b of the sheet 1432, portions of the axial edge 1432c will be exposed through at least some of the transverse slots (i.e., windows or apertures). Such a situation may well be acceptable, however, since only very small portions of the sheet edge 1432c may be exposed, depending on the design details of the transverse slots in the window region 1422. Further details of transversely slotted delineator designs can be found in copending U.S. Patent Application Serial No. 61/288603, "Transversely Slotted Delineator" (Attorney Docket No. 65820US002), filed on even date herewith and incorporated herein by reference, the teachings of which may be used in combination with the teachings of the present application.

FIG. 15 is a schematic elevational view of a portion of a delineator 1510, showing still another suitable design of an exemplary window region 1522. Window region 1522 is similar to window region 1422 of FIG. 14, except that a single continuous transverse slot of helical design is formed in the outer shell 1514. Details of such a helical-configured slot can be found in the copending U.S. Patent Application (Attorney Docket No.

65820US002) referenced above. The window region exposes portions of a reflective sheet 1532 that is wrapped around an inner core (not shown in FIG. 15). Upper and lower edges of the sheet 1532 are covered up by the outer shell, and a portion of a transverse edge 1532c is also covered up by the outer shell, but a small portion of the edge 1532c is exposed by the window region 1522. Unless otherwise indicated, all numbers expressing quantities, measurement of properties, and so forth used in the specification and claims are to be understood as being modified by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that can vary depending on the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present application. Not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, to the extent any numerical values are set forth in specific examples described herein, they are reported as precisely as reasonably possible. Any numerical value, however, may well contain errors associated with testing or measurement limitations.

Various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the spirit and scope of this invention, and it should be understood that this invention is not limited to the illustrative embodiments set forth herein. For example, the reader should assume that features of one disclosed embodiment can also be applied to all other disclosed embodiments unless otherwise indicated. It should also be understood that all U.S. patents, patent application

publications, and other patent and non-patent documents referred to herein are

incorporated by reference, to the extent they do not contradict the foregoing disclosure.