This invention relates to apparatus for absorbing energy when impacted by a vehicle. More specifically, the apparatus relates to a guardrail crash absorbing assembly utilized as a barrier which dissipates the energy of moving vehicles impacting an end impact structure of the assembly.
It is well known to provide impact absorbing systems, often called “crash attenuators” or “crash cushions” in association with guardrails. The guardrails may be disposed along roadways or utilized adjacent to rigid structures such as pillars, bridge abutments, lighting poles and the like for the purpose of absorbing vehicle impact energy and minimizing the effects of impact on the vehicle, the vehicle occupants and any ancillary structure being protected.
There are many forms and types of energy absorbing barriers. The following patent documents are believed to be representative of a variety of crash attenuator systems including patents disclosing such systems on or in connection with guardrails employing a plurality of overlapping side panels which are relatively movable and telescope in the event of a vehicle collision with an end of the structure:
U.S. Pat. No. 4,838,523, issued Jun. 13, 1989, U.S. Pat. No. 4,655,434, issued Apr. 7, 1987, U.S. Pat. No. 4,739,971, issued Apr. 26, 1988, U.S. Pat. No. 7,926,790, issued Apr. 19, 2011, U.S. Pat. No. 8,360,400, issued Jan. 29, 2013, U.S. Pat. No. 8,424,849, issued Apr. 23, 2013, U.S. Pat. No. 4,330,106, issued May 18, 1982, U.S. Pat. No. 7,086,805, issued Aug. 8, 2006, U.S. Pat. No. 5,851,005, issued Dec. 22, 1998, U.S. Pat. No. 6,811,144, issued Nov. 2, 2004, U.S. Pat. No. 9,051,698, issued Jun. 9, 2015, and Patent Application Publication No. US 2013/0140510, published Jun. 6, 2013.
As will be seen below, the present invention incorporates sliders of a distinctive character in operative association with overlapping rail panels of a crash absorbing guardrail panel assembly.
The use of sliders per se are known generally in the crash absorbing guardrail art, but the structural combination and manner of operation of the present invention differ considerably from such known impact slider arrangements.
U.S. Pat. No. 7,926,790, issued Apr. 19, 2011, shows an impact slider assembly for a guardrail including a slider connected to a first rail and a slider substantially surrounding the first rail, so that in use, the slider gathers and retains the first and any subsequent rails which telescopically overlap with each other during an impact.
U.S. Pat. No. 8,424,849, issued Apr. 23, 2003, discloses an impact slider assembly for a guardrail which includes: a slider mechanism attached to a first rail and a second rail which substantially conforms with a rail profile; and an integral means for attachment to the first rail, wherein the slider mechanism gathers telescoping rails while substantially maintaining the strength of the rails in a fully re-directing manner.
The present invention relates to a guardrail crash absorbing assembly.
The assembly includes an elongated first rail panel having a first rail panel front portion, a first rail panel rear portion, a first rail panel top edge portion and a first rail panel bottom edge portion.
An elongated second rail panel is also incorporated in the assembly, the elongated second rail panel having a second rail panel front portion, a second rail rear portion, a second rail panel top edge portion, and a second rail panel bottom edge portion. The first rail panel rear portion and the second rail panel front portion are in side by side, overlapping relationship.
An impact end structure is operatively associated with the first rail panel and responsive to vehicle frontal impact on the end terminal to move the first rail panel rearwardly lengthwise along the second rail panel.
A braking structure is attached to the first rail panel engaging and deforming at least one of the second rail panel top edge portion and the second rail panel bottom edge portion during rearward lengthwise movement of said first rail panel relative to the second rail panel to dissipate kinetic energy of the first rail panel sliding along the second rail panel and absorb impact forces.
Other features, advantages and objects of the present invention will become apparent with reference to the following description and accompanying drawings.
Referring to
The assembly 10 includes an elongated outer rail panel 12 and an elongated inner rail panel 14. The rail panels are conventional W-beams. As also is conventional, the rail panels are supported by support posts 16, suitably formed of wood for example, which are separated from one another and spaced along the guardrail.
The outer rail panel 12 has a panel front portion 18 and a panel rear portion 20. Outer rail panel 12 also has a rail panel top edge portion 22 and a rail panel bottom edge portion 24. The top and bottom edge portions are outermost panel segments of the W-beam, a W-beam central generally curved portion 26 being located therebetween, as is conventional with respect to W-beams.
Elongated inner rail panel 14, has a rail panel front portion 28 and a rail panel rear portion 30, a rail panel top edge portion 32 and a rail panel bottom edge portion 34. A curved central portion 26 is located between top edge portion 32 and bottom edge portion 34 of the W-beam construction.
The panel rear portion 20 of outer rail panel 12 and the panel front portion 28 of rail panel 14 are in side by side, overlapping relationship.
An impact end structure in the form of an end terminal 40 is operatively associated with the outer rail panel 12 and responsive to vehicle frontal impact on the end terminal to move the outer rail panel rearwardly lengthwise along the inner rail panel. In the arrangement illustrated, end terminal 40 is located at forwardmost support post 16 supporting the outer rail panel front portion 18.
In
The guardrail crash absorbing assembly illustrated in
The braking structure of the assembly illustrated in
Each of the sliders 44, 46 includes a bracket-like housing 50 welded or otherwise fixedly attached to the top and bottom edge portions 22, 24 and defining an elongated recess 52 receiving the top and bottom edge portions 32, 34 of elongated inner rail panel 14.
The braking structure further includes a forming structure at each housing at the location of the elongated recess exerting forces on the inner rail panel edge portions 32, 34 during slidable movement of the outer rail panel relative to the inner rail panel to work and change the shapes of the inner panel top edge portion 32 and the bottom edge portion 34.
The braking structure additionally includes an elongated spacer and stabilizing structure in the form of spacer rods 56 extending between and secured to the housings 50. The elongated spacer and stabilizing structure additionally includes brackets 58 attached to and projecting from the housings and connected to the spacer rods by nuts.
The topmost housing 50 attached to outer rail panel 12 is positioned above the lower housing 50 whereby forces exerted by the forming structures on the inner rail panel bottom edge portion and the inner panel top edge portion are exerted substantially simultaneously. The inner rail panel is not deformed between the rail panel top edge portion 32 and bottom edge portion 34; that is, not at the central portion 26.
In the embodiment disclosed in
The folding or rolling over operation has been accomplished by a forming structure in each of the housings and in a manner sequentially carried out as illustrated in
In this arrangement the forming structure includes a plurality of ramps defining a serpentine or tortuous pathway for the inner rail panel bottom edge portion during relative slidable movement between the inner and outer rail panels. Any desired number of ramps may be deployed along the length of the housing.
In the embodiment illustrated two ramps 80 project from the inner housing wall surface in a generally upward direction and one ramp 82 projects in a downward direction between the ramps 80. The ramps 80, 82 are offset with respect to one another and define nips through which the inner rail panel edge portion passes during slidable movement of the outer rail panel relative to the inner rail panel. Thus, rearward lengthwise movement of the outer rail panel relative to the inner rail panel dissipates kinetic energy by working the metal of the outer rail panel as it slides along the inner rail panel and absorbs impact forces.
It is to be understood that the present invention is applicable not only to W-beams but also to guardrail constructions in general, including thrie beam or quad and box beam. Furthermore, the invention is applicable to guardrail end impact structures other than end terminals.
Number | Name | Date | Kind |
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4330106 | Chisholm | May 1982 | A |
4352484 | Gertz | Oct 1982 | A |
4655434 | Bronstad | Apr 1987 | A |
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4838523 | Humble et al. | Jun 1989 | A |
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6554256 | Ochoa | Apr 2003 | B2 |
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7926790 | James | Apr 2011 | B2 |
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8424849 | James | Apr 2013 | B2 |
9051698 | Anghileri et al. | Jun 2015 | B1 |
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Number | Date | Country |
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2650010 | Jan 1991 | FR |