EP0000370B1

EP0000370B1 - Roadway/traffic delineator

Info

Publication number: EP0000370B1
Application number: EP78100306A
Authority: EP
Inventors: Donald W. Schmanski
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-07-05
Filing date: 1978-07-04
Publication date: 1982-05-12
Also published as: CA1192371B; EP0017198A3; EP0017198B1; AU3806985A; EP0000370A1; AU526808B2; CA1097879A; EP0017198A2; US4092081A; AU3763878A

Description

This invention relates to an upright delineator of an impact resistant elongate web structure consisting of fibre reinforced synthetic material for driving into the ground.
Vehicle traffic control requires the use of road signs and markers as aids in solving the various problems associated with traffic safety and direction. It has been found that a useful characteristic for such signs and markers is that these posts have the ability to withstand vehicle impact, without requiring subsequent replacement. An attempt has been made to fill this need with various configurations of posts. However, the structural design of such posts has involved the consideration of two opposing structural features, i.e. the elasticity required during dynamic conditions to permit the post to nondestructively bend with vehicle impact and the longitudinal rigidity required during static conditions to withstand forces resulting as the post is driven into a hard surface.
The elasticity is necessary in view of frequent high speeds associated with impacts between a moving vehicle and stationary post. In such cases, if the post could not bend it would likely shear off, and would have to be replaced. Mere bendability, however, is not sufficient, since each time a post was bent it would have to be straightened before it could again be functional. This could involve high maintenance costs. Ideally, a post should also have sufficient elasticity that it will automatically assume its proper upright configuration after dissipation of any impact forces.
While elasticity is desirable, the elasticity may present a practical problem when installation of the post is considered. In the past, when deformable plastics have been used as post material, installation has frequently required predrilling a hole or insertion of some support receptacle into the ground, with the subsequent positioning of the plastic post into the hole or receptacle. These preliminary steps were required because such previously known elastic posts would not withstand a buckling force applied during attempts to drive the posts into hard surfaces. Consequently, the same elastic properties which permitted the nondestructive deformation upon impact caused the buckling of a post subjected to a driving force along its axis.
Numerous delineator devices of this kind which have flexible properties but which are not driveable are described and illustrated in BE-A-530 277, DE-B-1 138082, FR-A-1 283 975, FR-A-1 326 604, FR-A-1 552818, FR-A-1 094 128, FR-A-1 551 596, GB-A-1 231 285, US-A-2 030 623 and US-A-1 778 110.
These delineators are positioned in a hole or receptacle and are cemented or otherwise fixed in place with backfill. This process is both expensive and time-consuming. Further, it prolongs exposure of maintenance personnel to the danger of fast moving highway traffic. Wood and steel posts, to the contrary have driveability but lack flexibility to undergo impact.
Delineator devices which do have neither flexible nor driveable properties are disclosed in CH-A-376 139, DE-B-1 165 637, DE-U-7 213 603, DE-U-1 896 546, DE-A-2039298 and US-A-3 450 387. It is necessary for the installation of these delineator devices to either dig a hole in the ground or to provide a receptacle.
Driveable delineators having no flexible properties are described and illustrated in CH-A-421 168 and US-A-3 720 401.
Attempts have been made to incorporate the dual requirements of elasticity and rigidity by utilizing a spring within an otherwise rigid post, and with the rigid parts of the post being secured on opposite ends of the spring. Installation was by compressing the spring and then pounding along the now rigid longitudinal axis. After installation, the deformable character of the post was accomplished by the transverse elastic property of the included spring.
This configuration, however, has several apparent disadvantages. The rigid portion of the structure has customarily been made of strong materials which may dent or otherwise damage the impacting vehicle. Furthermore, the use of such rigid materials and springs and the assembly requirements result in excessive costs for the posts.
U.S. Patent No. 3,875,720 discloses a second approach to the problem, of providing elasticity in a post that can be driven. In this patent a post is formed by a bundle of flexible rods that are clamped together to obtain the desired rigid property required during the static installation stage of the post. Deformation of the post during dynamic conditions is permitted by deflection of the various flexible rods away from the central axis of the post structure. Here again, however, economic factors appear to have impeded utilization of such structure despite the growing need for such a post.
Other attempts to develop a driveable and flexible delineator are found in US-A-2 030 623 and DE-B-1 286 060. These illustrate flexible top sections of delineators fastened to rigid bottom sections which can be driven into the hard ground. The length of the delineator which can be driven into the soil is limited, however, to the length of the spike fixed at the delineator base. Furthermore, such delineators are not capable of withstanding a longitudinal impact at a top section of the delineator, whereas the prior art wood and steel delineators had that distinct advantage.
A fiberglass delineator (US-A-4 061 435) was developed which was capable of being driven at its top into the ground; however, flexibility was developed only after impact by a vehicle. Such impact caused a shearing-off of a rigid leg of the delineator leaving a very flexible upright section. This delineator was rejected by the industry due to its broken condition after impact with exposed fiber needles which represented a hazard to the public.
Other uses have been made of fiberglass in the highway industry.
US-A-3 233 870 discloses a guard rail structure, which consists of resin impregnated glass fibre of a web-like structure wherein longitudinally extending fibres are enclosed within strips of transversely extending fibres. The longitudinally extending fibres are forming strands having end projections beyond the guard rail. The guard rail is mounted between a pair of upstanding horizontally spaced supports. Fastening means are provided on these supports engaging the projecting ends of the strands and maintaining the guard rail stretched therebetween.
The guard rail has high elasticity and energy absorption ability on impact and can readily be bent during installation. Long lengths of guard rail are necessary to absorb the energy of impact.
The basic problem presented in this US Patent Specification is the need to provide a guard rail which can absorb energy and does not break. Therefore, the problems are completely different from those involved in a delineator which can withstand a driving load at its top for quick installation, with concurrent flexibility which does not require substantial destruction of the rigid support structure as in US-A-4 061 435. DE-A-2 121 347 discloses a delineator which purports to be moderately driveable in soft dirt; however, this delineator is formed of polyethylene which is thermoplastic whose elastic modulus is far below the range of thermosetting resins used in fiberglass compositions as described herein. Furthermore, soft dirt is seldom available for highway delineators in view of hard shoulder surface of typical road beds and a required penetration depth of up to 50 cm for the delineator. Therefore, the polyethylene delineator of DE-A-2 121 347 would be better classified as a flexible delineator which would require placement in a hole with cement or other form of backfill to permanently fix the delineator in position.
The present invention as characterized by the claims gives a solution for the task to provide a deformable post configuration having both longitudinally rigidity and bending elasticity to facilitate driving emplacement and subsequent impact without destructive deformation, and being producible at relatively low costs.
The invention provides an upright delineator consisting of a structure which does not damage a vehicle on impact and which can be manufactured within reasonable costs. The delineator according to the invention comprises an elongated web and associated reinforcing structure. The web portion of the delineator provides the flexible properties which permit bending of the delineator in response to a bending impact force. The reinforcing structure is necessary to develop a high modulus of elasticity along the longitudinal axis of the delineator. Such reinforcing structure is implemented by specific utilization of fiber orientation within the web structure. Other advantages and features will be obvious to a person of ordinary skill in the art from the following detailed description, taken with the accompanying drawings.
In the drawings:

Figure 1 is a fragmentary perspective view of a delineator of the present invention, having a partially cut away section.
Figure 2 is a perspective view of the delineator in combination with a roadway.
Figure 3 is a fragmentary, partially cut away view of the second embodiment of the present invention.
Figure 3a shows an enlarged, fragmentary view taken within the line 3a-3a of Figure 3.
Figure 4 depicts a fragmentary perspective view of an additional embodiment of the present invention.
Figure 4a shows an enlarged, fragmentary view taken within the line 4a-4a of Figure 4.
Figure 5 is a perspective view of a delineator immediately after impact with a moving object.
Figure 6a is a horizontal cross-section view, taken on the line 6a of Figure 5.
Figure 6b is a horizontal cross-section view, taken along the line 6b of Figure 5.
Figure 7 shows a fragmentary view of a delineator enclosed by a rigid-body casing, shown in perspective.
Figure 8 depicts a protective cap for use with the subject delineator.

Referring now to the drawings:

The present invention relates to the establishment of proper elastic and rigid mechanical properties within a delineator structure. The normal use of such a roadway delineator entails two separator forms of stress application. Initially, the delineator is subjected to installation stress as the delineator is driven into a hard surface, such as ground. Typically, this driving force is applied to the top end of the delineator and therefore represents a longitudinal force extending down the length of the delineator. It is noted that this stress arises when the delineator is in a static state, i.e. when no bending forces are being applied. The required mechanical properties necessary to avoid buckling of the delineator under the applied driving load are represented in the following formula:
where:
- E=elastic modulus
- I=m_om_ent of inertia
- L=Iength of the column
- P_E=maximum buckling load

Once the length L of the delineator is established the product of EI becomes determinative of the ultilate buckling load the post can withstand.
A second form of stress anticipated for the delineator is the bending stress applied upon impact by a moving object with a surface of the delineator. This form of stress, arising during dynamic conditions, is represented by the following relationship:
where:

f_b=bending stress
M=bending moment
C=distance from neutral axis to point of stress
I=moment of inertia

Bending moment M is defined by the expression:
where:

E=elastic modulus
I=moment of inertia
R=radius of curvature

In dealing with both forms of stress, thereforefore, it is imperative that the proper relationship be established between the elastic modulus E and the moment of inertia I.
From the equations defining the respective forms of stress applied to the delineator, it is apparent that rigid posts, such as those made of metal or wood, have a very high buckling load factor, P_E. With such materials both E and I may have very large values. This factor is favorable during installation, but may be catastrophic upon vehicle impact.
This adverse condition is apparent from equation (3), which may be rewritten in the form
In this case it is apparent that the large product of EI from the previous buckling formula (1) would result in a large radius of curvature R which is clearly adverse to applications for delineators to be subject to impact deformation. Customarily, such impact will usually involve a motor vehicle whose structure will require the delineator to deform to a radius of a curvature of approximately 18 inches (45.72 cm). Where the product of EI is high and the point of impact is approximately 18 inches (45.72 cm) above ground level (making M quite low in value) the resultant radius of curvature is far too large and the motor vehicle may simply shear off the delineator between the point of impact and ground level.
The present invention involves unique structural design to establish a proper balance between E, the elastic modulus and I, the moment of inertia. Whereas large values of E are required to maintain the necessary rigidity to withstand the longitudinal driving force arising during static conditions of installation, I is of minimal value to improve the bending ability of the delineator to achieve a low radius of curvature. The preferred delineator of the present invention also provides a variable EI response to the respective loading and bending stresses, to satisfy both static and dynamic conditions in a single embodiment.
Thus an important preferred aspect of the present invention is the recognition that, under typical uses of a delineator, the value of EI in the static condition during installation will not fully satisfy the bending requirements experienced during impact at a lateral surface. Inherent properties within the delineator are required which will develop a lower EI product during dynamic bending. Simply stated, the most versatile delineator must respond to a driving load with a high EI product to preclude buckling, but must experience a lower EI during bending subsequent to impact.
Attention is directed in this latter respect to our European Patent Application No. 80101688.2 which has claims directed to a delineator with variable EI product.
Figure 1 illustrates the first embodiment of the delineator wherein the appropriate balance between E and I is obtained by a combination of geometrical structure and material composition. The delineator, shown generally as 10, is constructed of a plastic binder with reinforcing fibers. The plastic binder may be any suitable plastic which is capable of withstanding the variations of temperature to which it will be subjected and which possesses the desired elongation characteristics to prevent massive fracturing upon impact.
Thermosetting resin material is particularly well suited for this application in as much as it is not dependent upon temperature to maintain its flexibility. To the contrary, many thermoplastic materials become too brittle when exposed to subfreezing temperatures and result in massive fractures upon impact with a moving vehicle. Where the thermoplastic resin is capable of withstanding temperature variation without concurrent hardening, however, such material may well be suited as binder material for the subject invention.
Further, thermosetting/thermoplastic resin combinations may well be suited as binder material as long as this combination is capable of withstanding a temperature variation without concurrent hardening and has a modulus of elasticity approximating that one of a thermosetting resin.
In order to establish the necessary rigidity to the delineator body 10, reinforcing fiber is embedded within the binder material. A portion 17 of this fiber is positioned longitudinally along the length of the delineator structure. For extra longitudinal strength, a high modulus fiber such as "Kevlar" (Trademark) may be used. A second layer 16 of fiber material is oriented in random direction to establish tensile strength and to contribute to the proper balance between rigidity and flexibility. A surface coating 15 is utilized to protect the contained binder/fiber combination from weather, ultraviolet rays and other adverse effects of the environment. In addition to the suggested form of Figure 1, the arrangement of longitudinal versus random fibers within the structure may be varied such that the randon fiber may form a core, with the longitudinal fiber comprising the second layer thereon.
It has been determined that at least seven percent by weight but no more than sixty percent of the fiber arrangement be in randon orientation. The remaining amount of fiber is longitudinally oriented to establish the rigidity required for driving the delineator into the ground. Furthermore, although random fiber orientation is described and is shown in Figure 1, similar transverse flexibility and tensile strength properties can be established where fiber orientation is directed at various predetermined transverse angles of orientation, such as is best shown at 36 in Figure 3. The terms and references to traversing fiber arrangement or orientation as used herein refer to fiber arrangements which have fiber components in traversing or crossing orientation with respect to other fibers within the arrangement. Fibers in traversing arrangement differ from fibers in random arrangement because the former fibers cross at predetermined angles or orientations. The random fibers are transverse with respect to each other; however, they do not cross each other at predetermined angles. Specifically, the transverse fibers at 36 in Figure 3 are in traversing arrangement because the fibers making up this portion of the delineator cross each other at predetermined angles (approximately 90°). This is in contrast to the "longitudinal fibers" which run substantially parallel with respect to each other. To prevent shearing of the rib, at least seven percent by weight of fiber therein would be in random or traversing orientation and intermingled or connected with the web.
It has also been found that where the binder material comprises twenty to forty percent by weight of the delineator structure, use of more than sixty percent random fiber adversely affects the elastic character which is required to restore the delineator to its original position after impact. Also, failure to use at least forty percent of the fiber in the longitudinal orientation, without other reinforcing structure, will result in insufficient resilience or elastic modulus to permit the delineator to be driven into the ground. This use of proper amounts of fiber coordinated between transverse and longitudinal orientations, represents an effective method of establishing the appropriate E and I within the delineator structure.
A second method for establishing sufficient elastic modulus while preserving resistance to a buckling load is accomplished through geometrical configurations such as shown for example by the rib structures 11 and 13 in Figure 1. In utilizing reinforcing ribs to obtain the momentum of inertia desired, it is important that such rib structure not extend a substantial distance away from delineator surfaces 14 and 18, since bending stresses arising therein during curvature of the delineator will result in longitudinal shearing along the junction of the rib and web portion 12 of the delineator body. The effect of slightly protruding rib structure, however, is to extend the apparent thickness of the delineator and thereby increase the moment of inertia I, without subjecting the rib structure to excessive stress during the dynamic bending phase. By reinforcing such rib structures 11 and 13 with longitudinal fiber, 17, the elastic modulus E is also increased resulting in even greater rigidity, without increasing rib thickness.
In circumstances where less buckling stress is anticipated with respect to installation of delineator, rib structure may be omitted and both E and I can be satisfied by the use of proper orientations of reinforcing fibers in combination with a nonplanar (i.e. concavo-convex) web structure. Such a slightly concavo-convex delineator body, properly reinforced with fibers, can withstand a limited driving load imposed at the top thereof while retaining sufficient flexibility to bend without destructive deformation. The concavo-convex body may be additionally reinforced with longitudinal ribs at its side edges.
An additional configuration is illustrated in Figure 3 and 3a, in which a single rib 31 supplies the reinforcing strength to permit driving of the delineator into the hard surface. In this case, the reinforcing rib 31 is located on a non-impacting surface 34 of the delineator 30. The thickness of the web portion 32 will depend upon the anticipated impact force associated with the delineator environment. As with previous examples, the full web with reinforcing rib structure is fully reinforced with the appropriate combination of transverse and longitudinal fibers 36 and 37.
With the single reinforcing rib 31, a somewhat larger rib thickness might be desired to increase moment of inertia and longitudinal rigidity. Although this larger rib size will improve drivability, excessive size will reduce the desired flexibility required for withstanding bending stress. This reduction in flexibility may be partially alleviated by reducing longitudinal fiber content in the rib body and slightly increasing the transverse fiber arrangement to develop a minor fracture capability upon the initial impact of a bending force with the delineator. With this characteristic construction the delineator, prior to bending impact, has increased longitudinal rigidity to withstand the anticipated driving force to be applied during installation. After installation, however, a reduction of moment of inertia and improved flexibility to withstand bending stress is achieved upon an initial impact which develops transverse fractures 33 along the rib length.
When such impact occurs at the front surface 38, the delineator structure curves rearward, causing compression on the back surface 34 and reinforcing rib 31. Because of the shorter radius of curvature imposed upon rib 31, increased compression occurs longitudinally along the rib structure and with the reduced longitudinal fiber, minor transverse fracturing occurs 33. Total shearing or destruction of rib 31 is avoided by means of sufficient longitudinal and random fiber content within the rib portion, with random fiber arrangements being interconnected and intermingling with the attached web structure. The end result, therefore, is a rib reinforcement having small, multiple transverse cracks along its length to facilitate subsequent compliance to bending stress. At the same time, however, some stabilizing influence remains by reason of some surviving continuity of the rib structure.
An additional method of developing high EI in fiber reinforced plastics as described herein for drivability, but lower EI during bending movements is to incorporate a network of microspherical voids within the delineator structure. This concept is illustrated in Figure 4a. Such voids 45 can be introduced during fabrication by conventional techniques and will operate to lower the moment of inertia and thereby enhance flexibility. Furthermore, although longitudinal rigidity will be retained due to static strength inherent in this configuration, a violent lateral impact will cause the microspheres to partially collapse and operate as tiny hinges to facilitate bending movement.
As shown best in Figure 4, other geometrical configurations can be used in combination with the proper fiber and resins content as previously referenced to establish a balance between E and I. The particular configuration shown in Figure 4 utilizes structural thickness to develop the increased elastic modulus required to obtain drivability for the delineator 40. By utilizing rib structures 43 at the edges of the web structure 42 and a thicker central portion of web structure 41, an increased effective thickness is obtained to satisfy ultimate buckling load requirements. Such effective thickness extends from the front contacting edges of the forward extending ribs 43 through the rearward ridge of the central reinforcing rib 41.
This effective thickness, of course, represents the static condition of the structure of the delineator. On impact, bending forces cause the contortion of the outer ridges 43 in angular rearward movement. This structural deformation facilitates improved bending because of the concurrent reduction of apparent thickness of the delineator body and moment of inertia. Such structure directly implements the concept of variable EI product in response to static and dynamic conditions. In Figure 5, the deformed delineator 50 is shown immediately after impact with an automobile 58. The elastic forces of the delineator are in the process of restoring the upper portion 59 of the delineator to its original upright position. Figure 6b illustrates the unflexed, apparent thickness of the delineator viewed at the cross-section view taken along line 6b. Here the hard ground structure forces the delineator to retain its static configuration, having an apparent thickness extending from i to iv. It is this extended thickness d_t which strengthens longitudinal rigidity in the otherwise thinned web structure between ii and iii, and provides the higher EI for this condition.
Such configuration is modified, however, during contortions illustrated in Figure 5, as represented in the Figure 6a view. The thinner structure of the web body 62 permits greater flexibility and causes rotation of the more massive ridge members 63 in angular rotation rearward. The effect of such contortion is to reduce the thickness of the delineator from its static thickness of d_t in Figure 6b to a reduced thickness d_; of Figure 6a. The relationship defined by Equation (2)
shows that any reduction in thickness causes a decrease in the value of C, the distance from the ,neutral axis to the point of stress. This factor assists in satisfying the requirement for reduced moment of inertia, or increased flexibility, to avoid destructive deformation of the delineator. This characteristic of lateral angular contortion is developed where reinforcing rib structure, having less flexibility than the attached web structure in the transverse direction, is subjected to such a bending impact force.
A common feature of each embodiment described and claimed herein is that a unibody construction exists which incorporates the intermingling of fibers and resin within composition ranges and fiber orientations which provide transverse flexibility and longitudinal rigidity in the same structure.
In the preferred embodiment (Figure 1) concurrent characteristic of driveability and flexibility are supplied by a combination of fiberglass and geometry. Proper amounts of fiber are coordinated between transverse and longitudinal orientation, and are coupled with a uniform geometrical configuration which is thin in a web section and supported along its length by rib structure or nonplanar configuration. The proper balance of E and I is realized when the amount of fiber used is sufficient to develop a high E for resilience and strength in the web and supporting structure to prevent splitting or breakage during impact, and (2) the cross- sectioned geometry includes a thin web section which permits flexibility supported by rib or non- planar structure which increases I to develop column strength.
It is apparent, therefore, that longitudinal rigidity for driveability is effected by both E and I. E is increased by loading the delineator with at least 4096 fiber in the longitudinal direction. I is increased by configuring the cross-section geometry with rib structure or non-planar shape to improve column strength.
Similarly, concurrent non-destructuve flexibility is maintained by imbedding sufficient transverse or random fiber in the web portion of the delineator to prevent splitting or breakage upon impact of a vehicle. Concurrently, web thickness is kept low to reduce and to further enhance flexibility. In summary, therefore, the first embodiment of this invention involves the construction of a delineator using fiber reinforced plastics wherein the E of the delineator material enables use of a geometric configuration with a low I to enhance flexibility. Column strength is concurrently developed with reinforcing rib structure by incorporating this geometric configuration and/or a non-planar configuration to increase I in the longitudinal direction without disrupting the low I required for flexibility.
It should be noted that the previously discussed second embodiment disclosed in Figures 3 and 4 adds an additional feature of flexibility to the first embodiment by means of permanently reducing I. As indicated, this occurs when the rib 31 suffers minor transverse, hairline cracks 33 which decrease I for that rib section. Such cracks do not result in substantial breakage in the delineator structure. A similar reduction of I occurs within the web when the microspherical voids 45 shown in Figure 4 collapse in part and create a surrounding network of tiny cracks or hinges. Such voids can be incorporated where a thicker web is needed to strengthen I during installation.
During installation procedures the higher EI is realized in the reinforced sections of the delineator which operate as the primary load bearing element. Such occurs, for example, at the central ridges, distal ribs, or any areas of greater thickness. During bending contortions following impact, however, the angular contortion of the more flexible web portion of the structure provides a reduced moment of inertia and therefore a reduced stress due to the decreased distance between the neutral axis and the various points of stress along the delineator body.
As best shown in Figure 7 a removable, rigid-body casing 81 may be positioned around a portion of the delineator structure 80. The effect of this rigid-body casing is to reduce the length of the delineator exposed to buckling forces during installation procedures. This reduced length decreases the denominator of equation (1 thereby increasing the ultimate buckling load. It is noted that since the length parameter of the referenced equation is squared, any reduction in length greatly magnifies the increase in buckling load capable of being withstood.
Typical construction materials used for the rigid-body casing 81 would be steel or other heavy-duty substances capable of withstanding buckling pressures exerted by the delineator contained within the casing. Additionally, the casing may be capped with an impactable substance which serves to disperse the driving force along the top edge 83 of the delineator body 80. By utilizing such a rigid-body casing, the strength of the reinforcing rib material required for installation is reduced.
Naturally, the preferred structure for the rigid casing would have the inner surface conformed to the outer surface of the delineator body to be enclosed. This would restrain any lateral movement and essentially eliminate that enclosed section from the total length of the delineator subject to equation (1). ).
The reinforcing rib structure located at the contacting face of the various delineators illustrated herein may also provide protection for sign materials affixed to the delineator face. As disclosed in Figure 2, the sign material 21 will generally always be attached at the impacting surface of the delineator 20. Without protective ridging, the sign surface would be exposed to scraping or other destructive forces as it contacts the underside of cars or other impacting objects. The lateral ridges protruding forward from the contacting surface minimize contact with the actual sign surface attached thereto. Such protection is especially important with less durable sign surfaces such as reflective tape.
In connection with the affixation of sign surfaces to the subject delineators, environmental protection against weathering effects must also be considered. Mere attachment of reflective tape, for example, may have limited life expectancy, particularly where the local environment includes rain with freezing weather.
As a practical matter, water may locate behind the reflector covering, and upon freezing, dislodge the material from the delineator surface. For this reason, a small notch is located along a top edge 22 of the delineator surface. The top edge of the tap is then recessed into the notch and protected from the weathering conditions which would otherwise tend to detach the material.
An additional means of protecting the top reflector edge is to use a protective cap 91 as shown in Figure 9. The top edge 92 of the reflective surface 93 is retained within the enclosed region of the cap structure. In this configuration, exposure to rain, snow and other adverse weathering elements are minimized and reflector utility is preserved.
A supplemental benefit of the capped configuration is the protection given to the top edge of the delineator during impact with vehicles. During this impacting contact, the delineator will strike the underside of the vehicle numerous times in attempting to restore itself upright. After repeated occurrences, the top edge of the delineator will tend to fray or otherwise degrade. By using a thermoplastic cap having impact resilience and resistance to ultraviolet radiation, the top edge is protected from such abrasion. Typically, such a cap is fitted after placement of the delineator 90 into the ground, since the installation driving force is preferably applied to the rigid top edge of the delineator body.
Although the preferred forms of the invention have been herein described, it is to be understood that the present disclosure is by way of example and that variations are possible without departing from the scope of hereinafter claimed subject matter.

Claims

1. An upright delineator (10;30;40;50;80;90) of an impact resistant elongate web structure consisting of fiber (16, 17) reinforced synthetic material for driving into the ground, characterized in that said structure has concurrent drivability and flexibility characteristics wherein the product of EI (E=eiastic modulus; I=moment of inertia) for the delineator (10;30;40;50;80;90) is chosen such that it withstands buckling loads applied at the delineator top during static conditions along its longitudinal axis during installation and that it establishes elastic character in an exposed section of said delineator (10;30;40;50;80;90) to permit non-destructive deformation upon impact by a moving object and subsequent immediate restoration to an original, upright condition, said elongate web structure comprising a combination of random or traversing and longitudinally oriented fibers imbedded in 20 to 40% (w) resin binder, said fiber combination being comprised of at least 7% but not more than 60% fiber in random or traversing arrangement to increase tensile strength thereby to enable transverse flexibility, and said longitudinal orientation of fiber comprising the remaining percentage of total fiber content to provide longitudinal rigidity during said static conditions.

2. A delineator as defined in claim 1, characterized in that said resin is selected from the group consisting of thermosetting resins, thermoplastic resins having a modulus of elasticity within a range approximating a modulus of elasticity for said thermosetting resins and thermosetting/thermoplastic resin combinations having an overall modulus of elasticity approximating said thermosetting resin modulus.

3. A delineator as defined in claim 1, characterized in that it comprises a reinforcing longitudinal rib (11, 31) for improving resistance to said buckling loads by increasing moment of inertia for said delineator to enhance drivability, said reinforcing rib (11, 31) having unibody construction with said web (12) and having at least 7% by weight random or traversing fiber therein and intermingled from said web (32) to preclude longitudinal shearing of said rib (11, 31) during said impact.

4. A delineator as defined in claim 3, characterized in that said rib (31) is located along a non-impacting surface (34) of said delineator (30) and is adapted by suitable imbedded fiber arrangement to develop small transverse fractures (33) along a length of said rib (31) during bending impact, said fractures (33) being operable to improve said elastic character by reducing said moment of inertia.

5. A delineator as defined in claim 3, characterized in that said reinforcing rib is located along an impacting surface of said web to protect an exposed sign configuration affixed to said impacting surface during object contact with said delineator.

6. A delineator as defined in claim 1, characterized in that said web has a non-planar structure with a varying web thickness to increase moment of inertia and rigidity along said longitudinal axis.

7. A delineator as defined in claim 1, characterized in that it comprises one or more longitudinal rib sections (11, 13; 31; 41, 43; 61, 63) protruding from a surface of said web for permitting reduced thickness of non-ribbed web sections with concurrent reduction of said moment of inertia, said rib sections being operable to maintain said longitudinal rigidity.

8. A delineator as defined in claim 1, characterized in that it comprises a reflective surface (21; 93) affixed to a surface of said web structure (20; 90).

9. A delineator as defined in claim 8, characterized in that said reflective surface (21) comprises reflective tape, said delineator (20) further comprising a transverse notch (22) indenting from said affixed surface at a top edge . of said tape for providing a recessed point of attachment for said top edge to minimize weathering effects on said tape.

10. A delineator as defined in claim 1, characterized in that a protective cap (91) may be positioned over a top edge (92) of said delineator (90) for protecting said edge from destructive contact with said object during impact.

11. A delineator as defined in claim 10, characterized in that said cap (91) is adapted to receive and retain a top edge (90) of an attached sign configuration (93) to minimize weathering effects thereon.

12. A delineator as defined in claim 1, characterized in that a removable rigid-body casing (81) is provided for enclosing a portion of said delineator (80) during installation, said casing (81) having sufficient inner surface conformity with said delineator (80) to restrain bending movement of said portion when said driving load is applied.

13. A delineator as defined in claim 12, characterized in that said casing (81) comprises an impactable cap for receiving said driving force and for retaining said casing (81) at an upper portion (83) of said delineator (80).

14. A delineator as defined in claim 1, wherein said web structure is laterally contoured with relative non-planar web structure to increase moment of inertia and rigidity along said longitudinal axis.

15. A delineator as defined in claim 1, characterized in that said web structure comprises a network of microspherical voids (45) to reduce moment of inertia and provide differentiating response to a static, longitudinal load and a dynamic bending force.

16. A delineator as defined in claim 1, characterized in that said web structure is concavo-convex at the forward and rearward faces thereof.

17. A delineator as defined in claim 16, characterized in that said web structure comprises longitudinal rib structure at its side edges, said rib structure adding additional longitudinal rigidity to withstand said buckling loads occurring during installation of said delineator.