Deceleration-limiting roadway barrier
AssigneeThe United States of America as represented by the National Aeronautics and Space Administration
InventorsWilliam C. Schneider, P. James Locke
Life of this patent
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Abstract
Roadway barrier system and method are disclosed for decelerating a moving vehicle in a controlled manner and for retaining the decelerated vehicle. A net or mesh of the roadway barrier system receives and captures the moving vehicle. The net or mesh is secured to anchors by energy absorbing straps. The energy absorbing straps deploy under a tensional load to decelerate the moving vehicle, the straps providing a controlled resistance to the tensional load over a predefined displacement or stroke to bring the moving vehicle to rest. Additional features include a sacrificial panel or sheet in front of the net that holds up the net or mesh while deflecting vehicles that collide only tangentially with the roadway barrier system.
Claims22
A deceleration-limiting barrier adapted to be installed alongside a vehicular roadway for protecting occupants of vehicles that collide with the barrier, comprising:
- a net;
- a first and second sacrificial panel sandwiching the net therebetween wherein the first and second sacrificial panels are adapted to extend alongside the vehicular roadway and comprise a means for holding up the net in a vertical position;
- a plurality of anchors coupled to the first and second sacrificial panels and wherein the plurality of anchors does not comprise a means for supporting the net in a vertical position;
- and
- a flexible strip arranged to secure the net to the plurality of anchors, with portions of the strip joined together in a manner as to be susceptible to being pulled apart under a load that is less than a load capacity of the strip.
A barrier for limiting decelerating of a moving body, comprising:
- means for receiving and retaining the moving body;
- means for anchoring the receiving and retaining means wherein the means for anchoring is not a means for supporting the means for receiving and retaining in a vertical position;
- means for decelerating the moving body in a controlled manner to thereby limit the deceleration thereof to below a predefined maximum deceleration level;
- and
- a first and second sacrificial panel sandwiching the means for receiving and retaining therebetween and comprising a means for supporting the means for receiving and retaining in a vertical position.
A method of decelerating a vehicle moving along a vehicular roadway, comprising:
- supporting a net with a first and second sacrificial panel that is also capable of deflecting moving vehicles colliding tangentially therewith such that no other vertical support for the net is required;
- anchoring the first and second sacrificial panels to the ground;
- breaking away the first sacrificial panel;
- receiving the moving vehicle in the net;
- deploying a plurality of energy absorbing straps attached to the net;
- decelerating the moving vehicle-using the energy absorbing straps;
- and
- limiting the deceleration of the moving vehicle to a level below a predefined maximum deceleration level safe for occupants of the vehicle.
A barrier for decelerating a moving body, comprising
- means for receiving and retaining the moving body;
- means for anchoring the receiving and retaining means wherein the means for anchoring is not a means for supporting the means for receiving and retaining in a vertical position;
- a first and second sacrificial panel sandwiching the means for receiving and retaining therebetween and comprising a means for supporting the means for receiving and retaining in a vertical position;
- and
- means for decelerating the moving body in a controlled manner to thereby limit the deceleration thereof to below a predefined maximum deceleration level, the means for decelerating the moving body comprising at least one flexible, energy absorbing strap connected intermediate the means for receiving and retaining the moving body and the means for anchoring the receiving and retaining means, the at least one strap having a plurality of loops formed therein, mutually spaced along the strap and interconnected by unstitched portions of the strap, each loop being formed of mutually adjacent lengths of the strap stitched together by sacrificial stitching formed between the mutually adjacent lengths of strap and defining stitched portions in the respective loops, the tensile strength of the strap being greater than that of the stitches,
- wherein the load capacity of the energy absorbing strap is expressed by the equation:
- Load=Fr·(Xm1+Xm2+Xm3+ . . . +Xmi)
- wherein the energy absorbing stroke of each loop comprises the length of the respective stitched portion formed therein, and wherein the sum of Xm1, Xm2, Xm3, . . . , Xmi represents the total stroke provided by the individual loops, and
- wherein the load capacities of the loops differ.
A deceleration-limiting barrier adapted to be installed alongside a vehicular roadway for protecting occupants of vehicles that collide with the barrier, comprising:
- a net;
- a first and second sacrificial panel sandwiching the net therebetween, adapted to extend alongside the vehicular roadway, comprising a means for supporting the net in a vertical position, wherein the first sacrificial panel is formed of a smooth surface adapted to face the vehicular roadway and wherein the first sacrificial panel comprises a means for deflecting vehicles which collide only tangentially with the first sacrificial panel;
- a plurality of anchors coupled to the first and second sacrificial panels and wherein the plurality of anchors does not comprise a means for supporting the net in a vertical position;
- and
- a flexible strip arranged to secure the net to the plurality of anchors, with portions of the strip joined together in a manner as to be susceptible to being pulled apart under a load that is less than a load capacity of the strip.
Dependencies are inferred from the claim text.