Highway crash cushion and components thereof

Abstract

A highway crash cushion includes a single, central, rigid, guide tail that guides the crash cushion in axial collapse. diaphragm assemblies are each provided with recessed legs, and a central guide that slides along the rail while locking against the rail in a lateral collision. The diaphragm assemblies support fender panels that include four longitudinally extending ridges, a central slot, and a tapered trailing edge that reduces vehicle snagging. energy absorbing elements are disposed between the diaphragm assemblies, and each includes an indicator that clearly indicates when the element has been compressed and possibly damaged.

Description

BACKGROUND OF THE INVENTION

The present invention relates to improvements to a highway crash cushion of the type having an array of diaphragms, a plurality of energy absorbing elements disposed between the diaphragms, and an array of fender panels extending alongside the diaphragms.

Highway crash cushions of this general type have proven to be successful in a wide variety of applications. Walker U.S. Pat. No. 3,982,734 describes one early version of such a crash cushion, and Meinzer U.S. Pat No. 4,321,989 discloses another. Typically, such crash cushions are used alongside highways in front of obstructions such as concrete walls, toll booths and the like.

In the event of an axial impact, the crash cushion is designed to absorb the kinetic energy of an impacting vehicle as the crash cushion collapses axially. In such an axial collapse, the diaphragms move closer to one another, the fender panels telescope over one another, and the energy absorbing elements are compressed. After such a collision many of the component parts can be reused by repositioning the diaphragms and fender panels in the original position, and replacing the energy absorbing elements and other damaged components.

The performance of such a highway crash cushion in lateral rather than axial impacts is also significant. When an impacting vehicle strikes the fender panels obliquely, it is desirable that the crash cushion act as a guard rail, which redirects the impacting vehicle without sending it back into traffic at a steep angle, and without allowing the impacting vehicle to move into the region on the other side of the crash cushion protected by the crash cushion.

Another aspect of such crash cushions is the need for simple maintenance and repair. Typically, such crash cushions are positioned alongside a high speed roadway, and it is therefore important to minimize traffic disruption and to minimize exposure of maintenance personnel to the hazards of adjacent traffic in maintenance and repair procedures.

In view of the foregoing operational and maintenance requirements for crash cushions, there is a need for an improved crash cushion that provides increased rigidity in a lateral a, which includes a plate 106. This plate 106 has sides shaped to conform to the adjacent ridges 82, and forward and rearward edges that are bevelled to reduce vehicle snagging. The plate 106 is relatively large, and can for example be 25 cm in length, and can define a lug extending downwardly into the respective slot 88. This arrangement provides a system in which the fender panels telescope smoothly against one another in an axial collapse, and in which pull out of the fastener 104 is substantially prevented.

The improved geometry of the fender panel 16 is not restricted to use with highway crash cushions, but can be used with a variety of other roadside barriers, including guard rails. In some of these applications the slot 88 may not be required.

The Energy Absorbing Element

FIG. 10 shows an exploded view of one of the energy absorbing elements 22. This energy absorbing element 22 includes an outer housing 108 that is formed in two parts that meet at a horizontally oriented seam 110. The housing defines front and rear surfaces 112, 114 that are positioned against the adjacent diaphragm assemblies 14. Each housing 108 also defines a respective top surface 116. The top surface 116 defines a zone of increased compressibility 118 that in this embodiment defines an array of parallel pleats or corrugations 120. These corrugations 120 extend generally parallel to the front and rear surfaces 112, 114. The zone of increased compressibility 118 ensures that in the event the housing 108 is compressed axially between the front and rear surfaces 112, 114, this compression is initially localized in the zone 118. Simply by way of example, the housing 108 can have a length, height and width of about 82, 57, and 55 cm, and the zone 118 can have a width of about 11 cm.

The housing 108 can be molded of any suitable material, such as linear, low-density polyethylene having an ultraviolet inhibitor for example. The housing 108 can contain any suitable energy absorbing components 109, and this invention is not limited to any specific choice for these components 149. For example, the energy absorbing components can be formed as described in U.S. Pat. No. 4,352,484, using a paper honeycomb material (5 cm cell diameter and 5 cm layer thickness) and a polyurethane foam. Alternately, the energy absorbing elements 109 can be formed as four metal honeycomb elements 111, each 17.8 cm thick, with a cell diameter of 3.8 cm. The elements are preferably formed of low carbon, fully annealed steel sheets (0.45 mm thick in one element and 0.71 mm thick in the other three). In the embodiment described here, the forward energy absorbing elements use the paper honeycomb material and the rearward energy absorbing elements use the steel material, both as described above. If desired, the brackets 52, 54 can be deleted and replaced with brackets (not shown) on the panels 48 that support the housing 108 at the lower, protruding edge of the upper part of the housing, adjacent the seam 110.

FIGS. 11 and 12 show two views of an indicator 122 that is mounted on the top surface 116 of the energy absorbing element. This indicator 22 includes a plate 124 that has an outer surface. This outer surface can for example be covered with a reflective material. The plate 124 is mounted for pivotal movement by a mounting 126 on a first side of the zone 118. The indicator 122 includes a lip 128 on the opposite end of the plate 124. A retainer 130 is mounted to the top surface 116 on the opposite side of the zone 118. As best shown in FIG. 12, the indicator 122 is pivotally movable between a first position in which the plate 124 is alongside and recessed into the top surface 116, and a second position in which the plate 124 is pivoted upwardly and outwardly to a position substantially perpendicular to the top surface 116. The first and second positions can each correspond to a range of positions. In the second position the plate 124 is clearly visible from outside the energy absorbing element 122. A spring 132 biases the indicator 122 to the second, more visible position.

As shown in FIG. 12, the indicator 122 is initially installed in the first or lower position. In this position the retainer 130 overlaps the lip 128 by a selected distance, which can correspond to a range of distances. In this embodiment, the selected distance is about 1 to 2 cm. The indicator 122 is mounted to the housing 108 at a first location, and the retainer 130 is mounted to the housing at a second location.

In the event that the housing 108 is distorted even temporarily in a low speed event such that the first and second locations approach one another by more than the selected distance of overlap between the lip 128 and the retainer 130, then the indicator 128 moves out of engagement with the retainer 130, and the spring 132 moves the indicator 122 to the upper position shown in FIG. 11.

A maintenance inspector can readily determine if any of the energy absorbing elements 22 has been compressed excessively simply by looking for indicators 122 in the extended position. This can be done at a considerable distance, and does not require close inspection.

Of course, many alternatives to the indicator 122 are possible. For example, the spring does not have to be a separate element, and the desired biasing force can be obtained by bending of the indicator 122 itself. Furthermore, the zone of increased compressibility can be formed with many geometries, and corrugations are not always required. If desired, the retainer 130 can engage the indicator 122 along the side rather than the end of the indicator 122. Furthermore, the indicator can move between the first and second positions with translational rather than pivoting movements.

Conclusion

From the foregoing detailed description it should be apparent that an improved crash cushion has been described. The central guide rail reduces vehicle snagging and simplifies installation while providing excellent rigidity against lateral movement and controlled axial collapse. The improved diaphragm assembly utilizes recessed legs that again reduce vehicle snagging. These assemblies are rigid, and are designed to lock against the guide rail in a lateral impact. The improved fender panels are stronger, with an improved cross-sectional shape that increases pull out resistance and enhances a controlled axial collapse. The tapered trailing edge further reduces vehicle snagging in a wrong-way collision. The energy absorbing element indicator indicates remotely to a maintenance inspector that the element has been compressed and possibly damaged, and is therefore in need of replacement.

Of course, it should be understood that a wide range of changes and modifications can be made to the preferred embodiment described above. It is therefore intended that the foregoing detailed description be considered as illustrative and not as limiting. It is the following claims, including all equivalents, that are intended to define the scope of this invention.

Claims

1. In a highway crash cushion of the type comprising an array of diaphragms, a plurality of energy absorbing elements disposed between the diaphragms, and an array of fender panels extending alongside the diaphragms, the improvement comprising:

a single rail disposed under the crash cushion and anchored to a support surface;

a plurality of guides, each coupled to a respective one of the diaphragms and substantially centered with respect to the respective diaphragm;

said guides mounted on the rail to slide along the rail and to restrict movement of the respective diaphragms with respect to the rail in both lateral directions;

said rail substantially centered with respect to the diaphragms;

at least some of the diaphragms each coupled to a respective leg assembly extending beneath the respective diaphragm on both sides of the rail to support the diaphragm on a support surface.

2. The invention of claim 1 wherein the rail comprises a plurality of interconnected rail segments.

3. The invention of claim 1 wherein the rail comprises first and second flanges, and wherein the guides extend under the flanges to prevent excessive upward movement of the diaphragms with respect to the rail.

4. The invention of claim 1 further comprising:

a plurality of leg assemblies, each leg assembly comprising an upper portion mounted to a respective one of the diaphragms, a lower portion, two side portions, and a centerline extending between the side portions;

each said lower portion connected to two feet shaped to support the respective leg on a support surface;

said feet extending outwardly from the respective leg assembly, away from the centerline, such that the feet are separated from the respective centerline by a maximum distance D_F, the side portions are separated from the respective centerline by a maximum distance D_L, and the ratio D_F/D_L is greater than 1.1.

5. The invention of claim 4 wherein the ratio D_F/D_L is greater than 1.4.

6. The invention of claim 4 wherein the ratio D_F/D_L is greater than 1.8.

7. The invention of claim 1 further comprising:

a plurality of leg assemblies, each leg assembly comprising an upper portion mounted to a respective one of the diaphragms, a lower portion, two side portions, and a centerline extending between the side portions;

each said lower portion connected to two feet shaped to support the respective leg on a support surface;

said feet extending outwardly from the respective leg assembly, away from the centerline, such that the feet are separated from the respective centerline by a maximum distance D_F, the side pardons are separated from the respective centerline by a maximum distance D_L, and the difference D_F-D_L is greater than 4 cm.

8. The invention of claim 7 wherein the difference D_F-D_L is greater than 8 cm.

9. The invention of claim 7 wherein the difference D_F-D_L is greater than 12 cm.

10. The invention of 4 or 7 wherein each foot angles downwardly and outwardly from the respective leg assembly.

11. The invention of claim 4 or 7 wherein each foot comprises a side plate adjacent a lower portion of the respective foot, each side plate extending outwardly and downwardly from the respective foot to create a ramp extending transversely to the respective diaphragm.

12. The invention of claim 4 or 7 wherein each leg assembly comprises a respective one of the guides centered on the centerline, each said guide comprising a first pair of spaced plates facing the centerline on one side of the centerline and a second pair of spaced plates facing the centerline on the other side of the centerline.

13. The invention of claim 1 wherein each leg assembly extends on both sides of the rail such that the leg assembly extends laterally outwardly of all of the respective guide and laterally outwardly of all of the rail.

14. The invention of claim 1 wherein each leg assembly comprises two legs, each leg extending on a respective side of the rail such that the legs extend laterally farther from a centerline aligned with the rail than both the guides and the rail.

15. The invention of claim 1 wherein each leg assembly comprises two legs arranged such that all of the rail and the respective guide are disposed between the legs.

16. The invention of claim 1 wherein at least a forward portion of the crash cushion is freestanding.

17. In a highway crash cushion of the type comprising an array of diaphragms, a plurality of energy absorbing elements disposed between the diaphragms, and an array of fender panels extending alongside the diaphragms, the improvement comprising:

a single rail disposed under the crash cushion and anchored to a support surface;

a plurality of guides, each coupled to a respective one of the diaphragms and substantially centered with respect to the respective diaphragm;

said guides mounted on the rail to slide along the rail and to restrict movement of the respective diaphragms with respect to the rail in both lateral directions;

said rail substantially centered with respect to the diaphragms;

wherein the rail comprises a plurality of interconnected rail segments;

wherein each rail segment forms a central protrusion at one end and a central recess at the other end, and wherein the protrusion of one rail segment is received within the recess of an adjacent rail segment.

18. In a highway crash cushion of the type comprising an array of diaphragms and a plurality of energy absorbing elements disposed between the diaphragms the improvement comprising:

a single rail disposed under the crash cushion and anchored to a support surface;

a plurality of guides, each coupled to a respective one of the diaphragms and substantially centered with respect to the respective diaphragm;

the guides mounted on the rail to slide along the rail and to restrict movement of the respective diaphragms with respect to the rail in both lateral directions;

the rail substantially centered with respect to the diaphragms;

at least some of the diaphragms each coupled to a respective leg assembly extending beneath the respective diaphragm on both sides of the rail to support the diaphragm on the support surface.

19. In a highway crash cushion of the type comprising a diaphragm and at least one energy absorbing element disposed adjacent the diaphragm, the improvement comprising:

a support structure comprising a single rail assembly disposed under the crash cushion and comprising a first end and a second end, the support structure being anchored to a support surface between the first and second ends and being substantially centered with respect to the diaphragm,

a guide coupled to the diaphragm and substantially centered with respect to the diaphragm,

the guide mounted to slide along the support structure and to restrict movement of the diaphragm with respect to the support structure in at least one lateral direction,

the diaphragm coupled to a leg assembly extending beneath the diaphragm on both sides of the rail assembly to support the diaphragm on the support surface.

20. In a highway crash cushion of the type comprising a diaphragm and at least one energy absorbing element disposed adjacent the diaphragm, the improvement comprising:

a support structure comprising a single rail assembly disposed under crash cushion and anchored to a support surface, said single rail assembly substantially centered with respect to the diaphragm,

a guide coupled to the diaphragm and substantially centered with respect to the diaphragm,

the guide mounted to slide along the support structure and to restrict movement of the diaphragm with respect to the support structure in at least one lateral direction, the guide mounted to slide along the support structure without extending below a lower surface of the support structure,

the diaphragm coupled to a leg assembly extending beneath the diaphragm on both sides of said rail assembly to support the diaphragm on the support surface.

21. The invention of claim 19 wherein the guide is mounted to slide along the support structure without extending below a lower surface of the support structure.

22. The invention of claim 19 wherein the guide is mounted to slide along the support structure and to allow contact between a lower surface of the support structure and the support surface.

23. The invention of claim 20 wherein the guide is mounted to slide along the support structure and to allow contact between the lower surface of the support structure and the support surface.

24. The invention of claim 20 wherein the support structure comprises a first end and a second end and is anchored to the support surface between the first and second ends.

25. The invention of claim 19 or 20 wherein the support structure is anchored to the support surface under the crash cushion.

26. The invention of claim 19 or 20 wherein the support structure is anchored to the support surface under the diaphragm or the at least one energy absorbing element.

27. The invention of claim 19 or 20 wherein the support structure is anchored to the support surface at a first location and wherein the diaphragm moves past the first location during collapse of the crash cushion.

28. The invention of claim 19 or 20 wherein the support structure comprises a plurality of axially aligned, releasably interconnected support structure segments.

29. The invention of claim 28 wherein at least one support structure segment forms a recess at one end, the recess adapted to receive a protrusion extending outwardly from an adjacent support structure segment.

30. The invention of claim 29 wherein the protrusion extending outwardly from the adjacent support structure segment is formed in the adjacent support structure segment.

31. The invention of claim 19 or 20 wherein the guide and the leg assembly provide resistance to overturning in the at least one lateral direction.

32. The invention of claim 19 or 20 wherein the guide is mounted to restrict movement of the diaphragm with respect to the support structure in both lateral directions.

33. The invention of claim 19 or 20 wherein the support structure comprises first and second flanges, and wherein the guide extends under the flanges to prevent excessive upward movement of the diaphragm with respect to the support structure.

34. The invention of claim 19 or 20 wherein the leg assembly extends on both sides of the support structure such that the leg assembly extends laterally outwardly of all of the guide and laterally outwardly of all of the support structure.

35. The invention of claim 19 or 20 wherein the leg assembly comprises two leas, each leg extending on a respective side of the support structure such that the leas extend laterally farther from a centerline aligned with the support structure than both the guide and the support structure.

36. The invention of claim 19 or 20 wherein the leg assembly comprises two legs arranged such that all of the support structure and the guide are disposed between the legs.

37. The invention of claim 19 or 20 wherein at least a forward portion of the crash cushion is freestanding.

38. The invention of claim 19 or 20 further comprising an additional diaphragm and an additional energy absorbing element disposed between the additional diaphragm and the first-mentioned diaphragm.

39. The invention of claim 38 further comprising a fender panel extending alongside the additional diaphragm and the first-mentioned diaphragm.

40. The invention of claim 38 further comprising an additional guide coupled to the additional diaphragm, wherein the additional guide is mounted to slide along the support structure and to restrict movement of the additional diaphragm with respect to the support structure in at least one lateral direction.

41. The invention of claim 40 wherein the additional guide is mounted to restrict movement of the additional diaphragm with respect to the support structure in both lateral directions.

42. The invention of claim 38 wherein the sport structure is anchored to the support surface between the additional diaphragm and the first-mentioned diaphragm.

43. The invention of claim 19 or 20 further comprising an additional diaphragm and an additional energy absorbing element disposed between the additional diaphragm and the first-mentioned diaphragm, wherein the additional diaphragm is coupled to an additional leg assembly extending beneath the additional diaphragm on at least one side outboard of the support structure to support the additional diaphragm on the support surface.

44. The invention of claim 19 or 20 further comprising an additional diaphragm and an additional energy absorbing element disposed between the additional diaphragm and the first-mentioned diaphragm, wherein the additional diaphragm is coupled to an additional leg assembly extending beneath the additional diaphragm on both sides outboard of the support structure to support the additional diaphragm on the support surface.

45. The invention of claim 19 or 20 further comprising:

an additional diaphragm;

an additional energy absorbing element disposed between the additional diaphragm and the first-mentioned diaphragm;

an additional leg assembly, the additional leg assembly and the first-mentioned leg assembly each comprising an upper portion mounted to a respective one of the additional diaphragm and the first-mentioned diaphragm a lower portion two side portions and a centerline extending between the side portions;

each said lower portion connected to two feet shoed to support the respective lea assembly on the support surface;

the feet extending outwards from the respective leg assembly, away from the centerline such that the feet are separated from the respective centerline by a maximum distance D_F, the side portions are separated from the respective centerline by a maximum distance D_L, and the ratio D_F/D_L, is greater than 1.1.

46. The invention of claim 45 wherein the ratio D_F/D_L is greater than 1.4.

47. The invention of claim 45 wherein the ratio D_F/D_L is greater than 1.8.

48. The invention of claim 45 wherein each foot angles downwardly and outwardly from the respective leg assembly.

49. The invention of claim 45 wherein each foot comprises a side plate adjacent a lower portion of the respective foot each side plate extending outwardly and downwardly from the respective foot to create a ramp extending transversely to the respective one of the additional diaphragm and the first-mentioned diaphragm.

50. The invention of claim 45 wherein the first-mentioned leg assembly comprises the guide and wherein the additional leg assembly comprises an additional guide, the guide and additional guide each centered on the centerline and comprising a first pair of spaced plates facing the centerline on one side of the centerline and a second pair of spaced plates facing the centerline on the other side of the centerline.

51. The invention of claim 19 or 20 further comprising:

an additional diaphragm,

an additional energy absorbing element disposed between the additional diaphragm and the first-mentioned diaphragm,

an additional leg assembly, the additional leg assembly and the first-mentioned leg assembly each comprising an upper portion mounted to a respective one of the additional diaphragm and the first-mentioned diaphragm, a lower portion, two side portions and a centerline extending) between the side portions,

each said lower portion connected to two feet shaped to support the respective leg assembly on the support surface,

the feet extending outwardly from the respective leg assembly, away from the centerline, such that the feet are separated from the respective centerline by a maximum distance D_F the side portions are separated from the respective centerline by a maximum distance D_L, and the difference D_F-D_L is greater than 4 cm.

52. The invention of claim 51 wherein the difference D_F-D_L is greater than 8 cm.

53. The invention of claim 51 wherein the difference D_F-D_L is greater than 12 cm.

54. The invention of claim 51 wherein each foot angles downwardly and outwardly from the respective leg assembly.

55. The invention of claim 51 wherein each foot comprises a side plate adjacent a lower portion of the respective foot each side plate extending outwardly and downwardly from the respective foot to create a ramp extending transversely to the respective one of the additional diaphragm and the first-mentioned diaphragm.

56. The invention of claim 51 wherein the first-mentioned leg assembly comprises the guide and wherein the additional leg assembly comprises an additional guide, the guide and additional guide each centered on the centerline and comprising a first pair of spaced plates facing the centerline on one side of the centerline and a second pair of spaced plates facing the centerline on the other side of the centerline.

57. The invention of claim 19 or 20 wherein the support structure comprises at least three axially aligned, releasably interconnected support structure segments wherein the support structure is anchored to the support surface near a first end of the support structure, near a second end of the support structure, and intermediate the first and second ends of the support structure.

58. The invention of claim 19 or 20 further comprising an additional element the energy absorbing element being disposed between the diaphragm and the additional element.

59. The invention of claim 58 further comprising a fender panel extending alongside the diaphragm and the additional element.

60. The invention of claim 19 or 20 wherein the rail assembly comprises first and second laterally separated elements positioned to restrict upward movement of the guide said elements extending long an axial direction defined by the rail assembly.

61. The invention of claim 60 wherein the guide comprises first and second guide elements positioned below the first and second rail assembly elements, respectively.

62. The invention of claim 60 wherein the first and second rail assembly elements comprise respective downwardly-facing surfaces.

63. The invention of claim 60 wherein the first and second elements comprise respective horizontally-extending flanges.