Claims
- 1. A turned-down terminal for a guardrail system, comprising:
- a drop-down section of guardrail barrier fastened to a plurality of posts in a manner permitting them to be pulled free the guardrail barrier having a front side that normally faces away from the posts and a rear side opposite the front side that normally faces the posts;
- a turned-down section formed by twisting the guardrail clockwise to be at an angle so that the front side is positioned substantially facing the ground causing sufficient force and torque to pull at least a portion of the drop-down section of the guardrail barrier free upon being impacted with a vehicle.
- 2. A turned-down terminal in accordance with claim 1 in which certain of said plurality of posts include back-up plates, said back-up plates being bolted to said posts.
- 3. A turned-down terminal according to claim 2 in which certain of said back-up plates includes first and second sections integrally formed at an angle to each other, one of said first and second sections being fastened to said posts and the other to said guardrail.
- 4. A turned-down terminal for a guardrail system in accordance with claim 3 in which the backup plate has no second surface that exerts downward pressure on a guardrail barrier with a vertical projection into a horizontal plane of more than 4 square inches.
- 5. A turned-down terminal according to claim 1 having a first side, a second side, an end side and a connecting side, said first side being postiioned closer to a roadway than said second side, said end side being lower than said connecting side, said connecting side connecting the turned-down section to the drop-down section, the turned-down section of said guardrail barrier being twisted clock-wise when looking from said end side toward said connecting side and being fastened to at least certain of said posts on the first side of said posts.
- 6. A turned-down terminal in accordance with claim 5 in which certain of said plurality of posts include back-up plates, said back-up plates being bolted to said posts.
- 7. A turned-down terminal according to claim 6 in which certain of said back-up plates includes first and second sections integrally formed at an angle to each other, one of said first and second sections being fastened to said posts and the other to said guardrail.
- 8. A method of avoiding the spearing of vehicles or the launching or rolling of vehicles hitting a terminal end of a turned-down section of a guardrail, the turned-down section being formed by twisting the guardrail such that a front side of the guardrail which normally faces away from the guardrail posts is positioned substantially facing the ground, comprising the steps of:
- causing the vehicle to contact a low portion of a guardrail terminal at its end prior to contacting higher portions of the terminal;
- causing the portion of the terminal near its end to receive twisting forces in a clock-wise direction away from guardrail posts to pull free from the posts toward the roadway;
- causing forces impacted by the vehicle to force the guardrail to drop down.
- 9. A method in accordance with claim 8 in which posts are knocked over by breaking at a weakened point as the vehicle impacts them so as to slow the vehicle down.
- 10. A method in accordance with claim 8 in which the guardrail is pulled from back-up plates by the force of the vehicle.
- 11. A method of making a turned-down terminal for a guardrail comprising the steps of:
- mounting a row of posts along a roadside;
- mounting a terminal end section of barrier twisted in a clock-wise direction with the top twisting in the direction of the roadway and away from the posts so that it is substantially flat and turning its distal end down close to the ground with a front side of the barrier which normally faces away from the posts positioned to substantially face the ground, wherein a vehicle impacting the terminal end pulls the guardrail down.
- 12. A method of making a turned-down guardrail in accordance with claim 11 in which the step of mounting a barrier includes the step of fastening the barrier to certain of said posts by back-up plates.
- 13. A back-up plate for a guardrail system comprising:
- a first section adapted to be mounted to a post;
- a second section adapted to be mounted to a guardrail barrier;
- said second section being shaped and formed of a material that avoids resistance between a guardrail barrier and the back-up plate directed to prevent release of the barrier upon impacting of a turned-down terminal by a vehicle;
- wherein there is no upwardly slanted surface adapted to engage the guardrail barrier with an area greater than four square inches when projected vertically.
- 14. A method of operation of a drop-down guardrail system in which a vehicle exerting force on a guardrail pulls the guardrail free without binding between the guardrail barrier and a back-up plate above an undesirable limit, comprising the steps of:
- forming a back-up plate having first and second sections, wherein the first section is at an angle to the second section and the second section has rounded corners;
- bolting the first section to a guardrail post wherein the second section slants downwardly and outwardly from the post with no surface to bind the guardrail when downward force is applied; and
- bolting the guardrail to the second section.
- 15. A W-beam comprising:
- an upper peak and a lower peak with the upper peak having a first section adapted to extend outwardly in a relatively straight manner from a supporting post;
- a second section extending inwardly from the upper peak to the post at an angle;
- a third section extending from a web adjacent to a post outwardly to the apex of the lower peak; and
- a fourth section extending from the lower peak inwardly and downwardly toward the post and being relatively straight;
- said first section and third section being separated by a web portion with said first section being adapted to receive a back-up plate and be bolted thereto wherein the back-up plate is bolted to only one of the first, second, third and fourth sections;
- wherein the barrier is steel and is no thicker than 13 gauge with a distance outwardly perpendicularly from the base of the web to an apex of substantially 78 millimeters.
RELATED CASES
This application is a continuation-in-part of U.S. provisional application 60/009470 filed Dec. 28, 1995, for REVERSE TWIST TURNED-DOWN TERMINAL FOR ROAD GUARDRAIL SYSTEMS.
US Referenced Citations (5)