US2038351A - Highway guardrail - Google Patents

Description

:T jliv Examiner April 21, 1936. B F. FRIBERG HIGHWAY GUARDRAIL Filed July 22, 1935 INVENTOR. B; F. FRIBE RG ATTORNEY.

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Patented Apr. 21, 1936 UNITED STATES PATENT OFFICE HIGHWAY GUARDRAIL tion of Missouri Application July 22, 1935, Serial No. 32,527

11 Claims.

My invention relates to guard rails such as are installed along the sides of highways at dangerous points to prevent vehicles from leaving the road-bed at such points, and more particularly to the type of such devices employing flexible metal rail sections attached together end to end.

One object of my invention is to provide splicing means for the rail sections which will not project in front of the guard plate, and which will insure accurate alignment of the rail sections and which is so constructed that the bolts or equivalent connecting members will be subjected to longitudinal tension only when the rail is under stress, interlocking parts being provided to relieve the bolts of bending strain.

Another object of my invention is to provide means for the necessary adjustment of the rails in a, longitudinal direction, such means, in my preferred form, being provided by the connecting bolts.

A further object of my invention is to provide yielding means to compensate for the change in length of the rails due to variation in temperature, which yielding means can be so adjusted that no excess variation over that required for variations in temperature is provided for.

A still further object of my invention is to provide supporting means for the rails which will have the required rigidity to absorb forces acting longitudinally of the rails, but which have a yielding or springing action under forces acting perpendicularly against the face of the rail at or near the supporting means.

In the accompanying drawing, which illustrates a guard rail made in accordance with my invention, Figure 1 is a front elevation; Figure 2 is an enlarged section taken on the line 22 of Figure 1; Figure 3 is a section taken on the line 3-3 of Figure 2; Figure 4 is a section taken on the line 4-4 of Figure 3; Figure 5 is a view similar to Figure 3 but showing a modification; and Figure 6 is a section taken on the line 6-6 of Figure 5.

Referring first to Figures 1 to 4, the device comprises a number of posts I and rail sections 2, each of the latter being formed of a flexible strip of metal of suitable width and of a length slightly less than the center-to-center distance between posts I. Attached, preferably :by welding, to the rear face of each rail section at each end thereof is an interlocking member 3 having rigid rearward projections 4 providing bolt openings, and with rigid extensions 5 adapted to bear against the rear face of the adjacent rail section. The projections 4 and extensions '5 forming each interlocking member may be separate parts but are preferably formed from a single sheet of metal, as shown. The two adjacent interlocking members are connected by bolts extending longitudinally through the projections 4. In the specific construction shown, the upper and lower bolts 6 pass through aligning projections 4 while the two intermediate pairs of bolts 1 are welded or otherwise attached to the extensions 5, the cooperating projections being arranged in staggered relation to align with the bolts. The ends of the rails are drawn together by nuts 8 on the ends of bolts 6 and I to impart the necessary tension to the sections. As the ends of the sections are capable of considerable relative movement while maintaining the proper interlocking engagement, the desired tension may be secured notwithstanding slight variations in the length of the sections or in the distance between the posts.

In order to compensate for variations in the length of the sections due to change in temperature, I provide each bolt with elastic means permitting relative movement between the sections but maintaining the necessary tension thereon. This means may be provided by coil springs 9 interposed between nuts 8 and projections 4.

To support the guard rail from the posts I, I provide a pair of supports II) in the form of U- bolts having flanges I I engaging the front corners of the posts. The ends of the U-bolts pass through a strap l2 and are engaged by nuts 13. The front end [4 of the U-bolt is provided with an opening I5 for the passage of aplate i6 formed integral with or welded to the through bolt 6. Inter-posed between the guard rail and the end ll of the U- bolt is a leaf spring 11. A key l8 serves to lock the parts in position. This construction provides a rigid support for the guard rail against longitudinal movement, and at the same time permits movement of the rail toward the post and imparts resiliency to the rail under transverse forces.

When a vehicle strikes the guard rail the rail will yield at the point of contact, the vehicle will slide against and along the rail, which exerts a pressure on the vehicle, returning it to the road. In the course of impact great longitudinal stresses are set up in the rail. My construction provides for adequate load transfer of these longitudinal stresses between adjacent rail sections. It also provides 'for the minimum amount of yield in the course of this load transfer, thereby deflecting the vehicle hitting the rail as quickly as is practical after the impact, so that the vehicle is not permitted to run any great distance beyond the original line of the rail before being deflected back onto the roadway. My construction also provides adjustability to compensate for variation in post spacing. It is, therefore, possible to provide supports rigid against forces acting along the guard rail. At the moment of impact these longitudinal forces are extremely large and my construction is such that it will transmit them to a number of posts at each side of the point of impact. Thus, the strength of the guard rail is increased and its lateral fiexure under impact decreased. My device is so constructed that the rail may be held under longitudinal tension at all times if desired, in which case the force deflecting a vehicle back onto the roadway at the impact point, is further increased.

In Figures 5 and 6 I have shown modifications in which the through bolts are omitted. In this construction the plates I6 are welded or otherwise secured to one of the interlocking members.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a device of the class described, the combination with a pair of rail sections, of a member carried on the rear face of each section at the end thereof, each of said members being provided with a rearwardly extending rigid portion projecting outwardly from the end of the section overlapping the adjacent section, and longitudinally extending means connecting said members.

2. In a device of the class described, the combination with a pair of rail sections, of a member carried on the rear face of each section at the end thereof, each of said members being provided with a rearwardly projecting rigid portion projecting outwardly from the end of the section and overlapping the adjacent section, each member having a bolt opening, and a bolt passing longitudinally through said openings and connecting the members.

3. In a device of the class described, the combination with a pair of rail sections, of a member carried on the rear face of each section at the end thereof, each of said members being provided with a plurality of rearwardly extending rigid members projecting beyond the end of the section and with bolt openings, the bolt openings of one member being in alignment with those of the other member, and bolts extending longitudinally through said aligning openings to connect the members.

4. In a device of the class described, the combination with a pair of rail sections, of an interlocking member carried on the rear face of each member at the end thereof, said members comprising rearwardly projecting portions and fingers extending beyond the ends of the sections, the fingers of one member extending between those of the other and overlapping the adjacent section, and longitudinally extending means connecting the members.

5. In a device of the class described, the combination with a pair of rail sections, of an interlocking member carried on the rear face of each member at the end thereof, said members comprising rearwardly projecting portions provided with bolt openings, said members having fingers extending beyond the ends of the sections, the fingers of one member extending between those of the other and overlapping the adjacent section, and bolts extending longitudinally through said openings to connect the members.

6. In a device of the class described, the combination with a pair of rail sections, of a member carried on the rear face of each section, each of said members being provided with a part extending beyond the end of the section and overlapping the adjacent section, and longitudinally extending means connecting the members, said means including a resilient part compensating for expansion and contraction of the rail section due to changes in temperature.

7. In a device of the class described, the combination with a pair of rail sections, of a member carried on the rear face of each section, each of said members being provided with a part extending beyond the end of the section and overlapping the adjacent section, said members being provided with aligning bolt openings, a bolt extending through said openings to connect the members, and a resilient member engaged by said bolt, said resilient member compensating for expansion and contraction of the rail section due to change in temperature.

8. In a device of the class described, the combination with a, highway guard comprising a pair of rail sections, of an interlocking member carried on the rear face of each rail section, bolts connecting said interlocking members, a support, and a member extending rearwardly from the guard and engaging the support to provide rigidity of the support in a longitudinal direction.

9. In a device of the class described, the combination with a highway guard comprising a pair of rail sections, of an interlocking member carried on the rear face of each rail section, bolts connecting said interlocking members, a support, a member extending rearwardly from the guard and having lateral sliding engagement with the support, and a spring opposing relative lateral movement between the guard and support, whereby longitudinal rigidity of the guard is secured and its lateral resiliency is augmerited.

10. In a device of the class described, the combination with a highway guard comprising a. pair of rail sections, of an interlocking member carried on the rear face of each rail section, bolts connecting said interlocking members, a support, and a member carried by a connecting bolt and engaging the support to resist relative longitudinal movement of the guard and support.

11. In a device of the class described, the combination with a highway guard comprising a pair of rail sections, of an interlocking member carried on the rear face of each rail section, bolts connecting said interlocking members, a support, a member carried by a connecting bolt and having a spring opposing lateral movement between the guard and support, whereby longitudinal rigidity of the guard is secured and its lateral resiliency is augmented.

BENGT F. FRIBERG.

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