Patent Application
20190024334
This invention relates to apparatus positioned at a guardrail lead end portion for absorbing energy resulting from vehicle impact.
It is well known to provide vehicle impact energy absorbing systems, often called “crash cushions”, “crash attenuators”, or “guardrail end terminals” adjacent to roadways as well as at other locations.
It is known generally to incorporate attenuators in operative association with end terminals for guardrails wherein a flattening or reshaping structure is employed at a guardrail lead end, which upon vehicle impact is movable along the guardrail to flatten or reshape the guardrail to absorb crash energy and decelerate the vehicle. The following patent documents are believed to be representative of the current state of the art in this field: U.S. Pat. No. 4,928,928, issued May 29, 1990, U.S. Pat. No. 5,078,366, issued Jan. 7, 1992, U.S. Pat. No. 8,905,382, issued Dec. 9, 2014, U.S. Pat. No. 6,719,483, issued Apr. 13, 2004, U.S. Pat. No. 5,775,675, issued Jul. 7, 1998, U.S. Pat. No. 7,185,882, issued Mar. 6, 2007, U.S. Pat. No. 8,517,349, issued Aug. 27, 2013, U.S. Pat. No. 6,715,735, issued Apr. 6, 2004 and U.S. Pat. No. 7,694,941, issued Apr. 13, 2010.
As compared to existing vehicle crash absorbing systems which employ pre-crimped pre-fed guardrail lead ends prepositioned in and passing through a housing or “chute” of a guardrail crash absorbing device, the proposed invention requires no such feature.
When utilizing the present invention, the exiting guardrail has substantially the same configuration (profile) as the initial guardrail. Thus, it is possible to revise a good portion of the guardrail after the system has been employed.
The system does not feed the rail out of the chute directly in alignment with the downstream rail.
The present invention relates to apparatus positioned at a guardrail lead end portion for absorbing energy resulting from vehicle impact. The guardrail has an elongated top edge, an elongated bottom edge spaced a predetermined substantially uniform vertical distance from said elongated top edge and opposed side surfaces extending between said elongated top edge and said elongated bottom edge.
The apparatus additionally includes an impact terminal and a support structure supporting the impact terminal at or adjacent to the guardrail lead end portion. The support structure supports a guardrail engagement structure defining an interior, a guardrail receiving opening communicating with the interior receiving the guardrail lead end portion, and a guardrail discharge opening communicating with the interior.
The support structure and the guardrail engagement structure are operable upon vehicle impact on said impact terminal to move along the guardrail and cause the guardrail to pass through said guardrail engagement structure and exit the guardrail discharge opening.
The guardrail engagement structure comprises a chute having inner chute surfaces defining the interior. The inner chute surfaces have a generally rectangular configuration along substantially the full length thereof whereby the interior has a generally rectangular cross sectional configuration along substantially the full length thereof, the chute twisted between the guardrail receiving opening and the guardrail discharge opening.
The guardrail is in frictional engagement with the inner chute surfaces, and the chute applies torquing forces on the guardrail during passage of the guardrail through the forming structure to cause twisting of said guardrail from a first guardrail orientation whereby said guardrail exits the guardrail discharge opening while maintaining substantially the same profile in a second guardrail orientation with the elongated top edge and the elongated bottom edge displaced sideways relative to one another and vehicle collision impact energy is absorbed.
Other features, advantages and objects of the present invention will become apparent with reference to the following description and accompanying drawings.
Referring now to
The guardrail has an elongated top edge 16, an elongated bottom edge 18 spaced a predetermined substantially uniform vertical distance from the top edge and opposed side surfaces 20, 22 extending between the elongated top edge and the elongated bottom edge.
Apparatus 10 includes an impact terminal 30. The impact terminal is supported by a support structure 32 which in this embodiment includes a support framework 34 and a housing 36 surrounding the support framework. The apparatus support structure 32 further includes a skid 38 positioned at the end of apparatus 10 downstream of the impact terminal 30.
A guardrail engagement structure in the form of an open ended chute 40 is supported and reinforced by the support framework 34. The chute 40 defines an interior 42. A guardrail receiving opening 44 of the chute communicates with the interior and receives the guardrail lead end portion 12.
The chute also has a guardrail discharge opening 46 communicating with the interior. The discharge opening is not in alignment with the guardrail. That is, it is offset sideways and downwardly of the guardrail entering the guardrail receiving opening of the chute.
The support structure 12 and the chute are operable upon vehicle impact on the impact terminal 30 to move along the guardrail and cause the guardrail to pass through the chute and exit the guardrail discharge opening 46.
In the embodiment under discussion, and as shown in
Chute 40 has inner chute surfaces defining interior 42. The combined inner chute surfaces have a generally rectangular configuration along substantially the full length of the chute; that is, the interior has a generally cross sectional configuration along substantially the full length thereof.
The chute 40 is twisted 90 degrees between the guardrail receiving opening and the guardrail discharge opening, the guardrail 14 being in frictional engagement with the inner chute surfaces and the chute applying torquing forces on the guardrail 14 during passage of the guardrail through the chute to cause twisting of the guardrail from a first guardrail orientation, i.e. the vertical orientation shown in the drawing figures and as supported by posts 56 to a second orientation of the guardrail while maintaining substantially the same profile as it exits the guardrail discharge opening. In this second guardrail orientation, the elongated top edge 16 and the elongated bottom edge 18 are displaced sideways relative to one another and vehicle collision impact energy is absorbed.
More particularly, the inner surfaces of the chute are configured to twist the guardrail 14 substantially 90 degrees to the second orientation wherein the opposed side surfaces of the guardrail are substantially horizontally disposed when exiting guardrail discharge opening 46.
The chute 40 inclines downwardly from the guardrail receiving opening to the guardrail discharge opening and the discharge opening is disposed at or closely adjacent to and above ground level.
The impact terminal 30 and the guardrail receiving opening 44 are substantially in alignment with the post mounted guardrail 14 downstream from the chute.
The chute 40 extends laterally sideways between the guardrail receiving opening and the guardrail discharge opening whereby the discharge opening is disposed laterally relative to the impact terminal 30 and is out of alignment with the guardrail 14 downstream from the chute as supported by the support posts.
In this embodiment the chute 40 is oriented to direct the guardrail passing therethrough upon vehicle impact to a position on the ground wherein the guardrail after exit thereof from the discharge opening is substantially parallel to but not in alignment with the path of movement of the impact terminal during vehicle impact.
Use of the cutting tooth minimizes shard interaction with the guardrail going through the chute assembly and reduces heat, sparks, etc. from under the impacting vehicle.
