Guardrail terminals have evolved from blunt-end spears to complex energy-absorbing devices. However, guardrail panels are essentially metallic beams that, when subjected to compressive loads, bend or buckle at points of failure. The bending or buckling of a guardrail beam may create a steel elbow that can be very sharp and destructive when in the path of an errant vehicle. Many crashes involving guardrails result in a guardrail beam spearing the vehicle and potentially injuring its occupants. The spearing is usually caused by large compressive forces induced when a guardrail terminal, or a front of a guardrail, is hit by a vehicle.
Some guardrail terminals are gating devices, meaning they open like a gate and allow the vehicle to pass behind the guardrail system when the vehicle hits the terminal at an angle. This is accounted for by highway safety engineers that generally ensure that an area behind a guardrail in the vicinity of the terminal is free of any fixed hazards. Highway safety engineers also extend the length of the guardrail system such that the length-of-need is about 12.5 feet upstream from the end of the terminal. This can add 12.5 feet of W-beam guardrail and the accompanying bolts, nuts, posts, and block-outs. When installed in large quantities, this additional section of rail can increase construction costs, which is an important issue for state and federal governments. Other disadvantages of traditional systems will become apparent in the following discussion.
Various embodiments for a coiled containment guardrail system and terminal are described. A guardrail system can include, for example, a terminal head configured for placement at a distal end of a guardrail beam in a direction facing oncoming traffic. The terminal head can include a canister having a hollow interior and an impact surface. A chute can be coupled to the terminal head, where the chute is configured to guide at least a portion of the guardrail beam into the terminal head in response to an impact being experienced at the impact surface.
The terminal head may further include a guardrail deforming device, such as a flattening device, coupled to the chute. The guardrail deforming device may be configured to flatten or otherwise deform the guardrail beam in response to the impact being experienced at the terminal head. Further, the arrangement of the guardrail deforming device and the canister can coil and store the guardrail beam as deformed by the guardrail deforming device (e.g., as flattened by the flattening device) in the hollow interior of the canister, for example, in response to the impact being experienced at the terminal head. As the guardrail beams progress through the chute during an impact, the cable coupling mechanisms may come into contact with a cutting plate. The force from the impact will force the cutting plate to shear off the cable coupling mechanisms (e.g., U-bolts) from the guardrail beam. As a result, various embodiments for a guardrail system are described that overcome the hazards posed by traditional guardrail systems.
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The present disclosure relates to a coiled containment guardrail system and terminal. According to various embodiments, a guardrail system is described that lessens the ability of a guardrail beam to bend or buckle, which often creates a projectile capable of injuring occupants in a vehicle. The guardrail system can be designed to interface with existing guardrail beams, such as W-beams commonly used in highway guardrail systems.
In various embodiments, the guardrail system can include, for example, a terminal head configured for placement at a distal end of a guardrail beam in a direction facing oncoming traffic. The terminal head can include a canister having a hollow interior and an impact surface. A chute can be coupled to the terminal head, where the chute is configured to guide at least a portion of the guardrail beam into the terminal head in response to an impact being experienced at the impact surface. The terminal head may further include a guardrail deforming device coupled to the chute. The guardrail deforming device is configured to flatten or otherwise deform the guardrail beam in response to the impact being experienced at the terminal head. In some embodiments, the guardrail deforming device is a flattening device that flattens the guardrail beam. The canister can be configured to coil and store the guardrail beam as flattened by the flattening device in the hollow interior of the canister.
Referring now to
As such, according to various embodiments of the present disclosure, the guardrail system 100 can include a terminal head 112 configured to receive an impact of a vehicle or other object at an impact surface (e.g., a front) of the guardrail system 100. To this end, the terminal head 112 can be configured for placement at a distal end of a guardrail beam 103 in a direction towards oncoming traffic. The terminal head 112 can include a hollow interior for storage of a deformed portion of a guardrail beam 103, as will be discussed. In some embodiments, the terminal head 112 can include an impact surface, where the impact surface can include, for example, a non-uniform surface on a face of the terminal head 112 that can be positioned towards traffic. The non-uniform surface can be employed to engage or affix the terminal head 112 with a portion of a vehicle upon an impact with the terminal head 112. To this end, the terminal head 112 can include projecting plates on an impact surface of the terminal head 112 that “bite” into or otherwise catch or attach to a front of a vehicle, thereby locking or otherwise affixing the terminal head 112 to a front of the vehicle during an impact. However, in other embodiments, the terminal head 112 can include a substantially flat or other uniform or non-uniform surface.
The guardrail system 100 may also include a chute 115 coupled to the terminal head 112. As shown in
Further, the guardrail system 100 can include one or more coupling arms 118 configured to maintain a position of the terminal head 112 relative to the chute 115 when an impact is experienced at the terminal head 112. For instance, the coupling arm 118 shown in
The guardrail system 100 may further include a terminal head post 121 that, like the guardrail posts 106, suspends the terminal head 112 at a predetermined height above the ground surface. As shown in
Further, in various embodiments, the terminal head coupling member 124 can include a component that intentionally deforms upon impact with a vehicle. To this end, the coupling member 124 can include a component configured to cause the terminal head 112 to break away from the terminal head post 121 upon impact. Similarly, the terminal head coupling member 124 can be configured such that it breaks away from the terminal head post 121 upon impact with an errant vehicle. In one example, the coupling member 124 includes a rectangular-shaped device having thin metal (or other material) that deforms when a predetermined amount of force is applied to the guardrail system 100. The predetermined amount of force can include a force similar to that of a collision with a vehicle.
In further embodiments, a cable 127 can be fixed along a length of the guardrail beam 103 to maintain tension in the guardrail beam 103 when an impact occurs at the terminal head 112, as can be seen in
The cable 127 can be pre-tensioned such that the compressive load of an impact will be partially offset by the pre-tension load. Also, by anchoring the cable 127 in the ground surface, for example, the cable 127 can keep the guardrail system 100 in a state of tension, preventing compression-induced buckling events which can form a spear that penetrates vehicles and injures occupants. In various embodiments, the cable 127 can be coupled to the guardrail beams 103 by one or more cable coupling mechanisms 130a . . . 130n (collectively “cable coupling mechanisms 130”) which, in some embodiments, can include a plurality of U-bolts positioned along the cable 127 and the guardrail beams 103 at predetermined distance(s) from one another, or other suitable coupling mechanism. Additionally, the cable 127 can be positioned in a recess 133 of the guardrail beam 103.
Near the terminal head 112, the cable 127 can be situated through the chute 115 and a cable outlet 136 positioned underneath a front portion of the terminal head 112. To maintain tension in the cable 127, a distal end or terminal end of the cable 127 can be secured to a cable mounting post 139 via a cable coupling member 142. In some embodiments, the cable mounting post 139 can be offset from the terminal head 112 such that the cable mounting post 139 is unlikely to be hit by an errant vehicle.
In further embodiments, the cable 127 can be secured to the ground surface via a cable coupling member 142 installed in the ground. The cable coupling member 142 can include a post having an anchor positioned at a top of the post, which causes a terminal end of the cable 127 to be fixed at a raised position relative to the ground. Additionally, the cable coupling member 142 can be offset from a longitudinal axis of the guardrail system 100. For instance, as shown in
Referring next to
Now, referring to both
Referring to
Moving on to
In order words, the deformation of the guardrail beam 103 aids in energy dissipation upon a vehicle impact with the guardrail system 100. Assuming the canister 148 were to fill up with the deformed guardrail beams 103 before the vehicle comes to a stop, in some embodiments, the canister 148 and/or the terminal head 112 can be configured to open in response to a predetermined amount of force indicative of the canister 148 being full, allowing the deformed guardrail beams 103 to safely burst out of a side of the terminal head 112. To this end, a particular weld pattern can be employed on the terminal head 112 that is intentionally deformed when the canister 148 is full, allowing the burst direction to be controlled such that the deformed guardrail beams 103 are deflected away from the vehicle or traffic that can be on the road.
As noted above, the guardrail system 100 includes the chute 115 which is coupled to the terminal head 112. The chute 115 includes a cage or similar structure having a hollow interior that is configured to receive at least a portion of a guardrail beam 103 when the guardrail system 100 is installed. The chute 115 can include one or more vertical members 117a . . . 117n (collectively “vertical members 117”) that connect a top of the chute 115 with a bottom of the chute 115. As shown above in
The coupling arm 118 of the guardrail system 100 may maintain a position of the terminal head 112 to the chute 115 when an impact is experienced at the terminal head 112. For instance, the coupling arm 118 shown in
The cable 127 can be fixed along a length of the guardrail beam 103 to maintain tension in the guardrail beam 103 when an impact occurs at the terminal head 112 which may prevent one or more portions of the guardrail beam 103 from buckling or bending during impact. Instead, the guardrail beam 103 is forced through the chute 115 into an interior of the terminal head 112. Near the terminal head 112, the cable 127 can be ran through the chute 115 and through a cable outlet 136 positioned underneath a front portion of the terminal head 112.
Turning now to
In some embodiments, the arms of the cutting plate 162 can be coupled to a backside of a vertical member 117 of the chute 115, while the extended base of the cutting plate 162 is positioned near or adjacent to the guardrail beam 103. As the guardrail beams 103 progress through the chute 115 during an impact, the cable coupling mechanisms 130 will come into contact with the extended base of the cutting plate 162. The force from the impact will force the cutting plate 162 to shear the cable coupling mechanisms 130 (e.g., U-bolts) from the guardrail beam 103.
It is understood that the components described herein can be formed of steel or other suitable material. The coupling of any two or more items can be accomplished by welding or other suitable method. Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., can be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present.
It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications can be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
Clause 1. A guardrail system, comprising: a terminal head configured for placement at a distal end of a guardrail beam, the terminal head comprising a canister having a hollow interior and an impact surface; a chute coupled to the terminal head, the chute being configured to guide at least a portion of the guardrail beam into the terminal head in response to a vehicular impact being experienced at the impact surface; the terminal head further comprising a guardrail deforming device coupled to the chute, the guardrail deforming device being configured to deform the guardrail beam in response to the impact being experienced at the terminal head; and wherein an arrangement of the chute and the canister directs the guardrail beam as deformed by the flattening device into the hollow interior of the canister in response to the vehicular impact being experienced at the terminal head.
Clause 2. The guardrail system of clause 1, further comprising the guardrail beam, the guardrail beam horizontally extending and mounted on a plurality of posts to suspend the guardrail beam from above a ground surface.
Clause 3. The guardrail system of any of clauses 1-2, wherein: the guardrail deforming device comprises a squeezer section and a flattening device positioned in the squeezer section, the flattening device being configured to flatten the guardrail using force received in response to the vehicular impact; and the canister is sized and positioned to cause the guardrail beam as flattened to coil as the guardrail beam is introduced into the hollow interior of the canister.
Clause 4. The guardrail system of any of clauses 1-3, wherein the canister is configured to open in response to a predetermined amount of force being applied by the guardrail beam as coiled in the hollow interior of the canister.
Clause 5. The guardrail system of any of clauses 1-4, further comprising a cable anchored to the ground upstream of the terminal head, directed through the terminal head, and fixed along a length of the guardrail beam, wherein the cable is positioned to impose tension on the guardrail throughout the vehicular impact.
Clause 6. The guardrail system of any of clauses 1-5, wherein the cable is fixed along the length of the guardrail beam using at least one cable coupling mechanism.
Clause 7. The guardrail system of any of clauses 1-6, further comprising a cutting plate positioned in an interior of the chute, the cutting plate being configured to remove the at least one cable coupling mechanism from a portion of the guardrail beam prior to the portion of the guardrail beam being introduced into the flattening device.
Clause 8. The guardrail system of any of clauses 1-7, wherein the at least one cable coupling mechanism is at least one U-bolt.
Clause 9. The guardrail system of any of clauses 1-8, wherein the terminal head further comprises a crash cushion.
Clause 10. The guardrail system of any of clauses 1-9, further comprising a terminal head post and a terminal head coupling member, the terminal head post being coupled to the terminal head coupling member and positioned underneath a front portion of the terminal head, the terminal head coupling member being configured to intentionally deform in response to the vehicular impact and cause the terminal head to break away from the terminal head post.
Clause 11. A method, comprising: providing a guardrail system, the guardrail system comprising: a terminal head configured for placement at a distal end of a guardrail beam, the terminal head comprising a canister having a hollow interior and an impact surface; a chute coupled to the terminal head, the chute being configured to guide at least a portion of the guardrail beam into the terminal head in response to a vehicular impact being experienced at the impact surface; wherein the terminal head further comprises a guardrail deforming device coupled to the chute, the guardrail deforming device being configured to deform the guardrail beam in response to the impact being experienced at the terminal head; and wherein the canister is configured to store the guardrail beam as deformed by the flattening device in the hollow interior of the canister in response to the vehicular impact being experienced at the terminal head.
Clause 12. The method of clause 11, further comprising: installing a guardrail beam raised from a ground surface using a plurality of posts positioned along the guardrail beam; and installing the guardrail system by positioning the guardrail system along a road such that impact surface of the terminal head is facing oncoming traffic.
Clause 13. The method of any of clauses 11-12, wherein: the guardrail deforming device comprises a flattening device, the flattening device being configured to flatten the guardrail using force received in response to the vehicular impact; and the canister is sized and positioned to cause the guardrail beam as flattened to coil as the guardrail beam is introduced into the hollow interior of the canister.
Clause 14. The method of any of clauses 11-13, wherein the canister is configured to open in response to a predetermined amount of force being applied by the guardrail beam as coiled in the hollow interior of the canister.
Clause 15. The method of any of clauses 11-14, further comprising positioning a cable anchored to the ground upstream of the terminal head, directed through the terminal head, and fixed along a length of the guardrail beam, wherein the cable as positioned imposes tension on the guardrail throughout the vehicular impact to prevent buckling, the cable being fixed along the length of the guardrail beam using at least one cable coupling mechanism.
Clause 16. The method of any of clauses 1-15, wherein the guardrail system further comprises a cutting plate positioned in an interior of the chute, the cutting plate being configured to remove the at least one cable coupling mechanism from a portion of the guardrail beam prior to the portion of the guardrail beam being introduced into the flattening device.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/678,432 entitled “Coiled Containment Guardrail System and Terminal,” filed May 31, 2018, the contents of which being incorporated by reference in their entirety herein.
Filing Document | Filing Date | Country | Kind |
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PCT/US19/34845 | 5/31/2019 | WO | 00 |
Number | Date | Country | |
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62678432 | May 2018 | US |