US3552073A

US3552073A - Breakaway lighting standard

Info

Publication number: US3552073A
Application number: US768478A
Authority: US
Inventors: Paul A Millerbernd
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-10-17
Filing date: 1968-10-17
Publication date: 1971-01-05
Anticipated expiration: 1988-01-05

Abstract

A BREAKAWAY LIGHTING STANDARD IS PROVIDED INCLUDING A BASE PLATE, AND A STANDARD BASE TO WHICH THE LIGHT STANDARD IS SUPPORTED. THE STANDARD BASE IS FORMED OF SHEET MATERIAL, AND IS ANCHORED TO THE BASE PLATE WITH A SERIES OF SPACED AREAS OF ATTACHMENT WHICH WILL WITHSTAND NORMAL STRESSES ACTING UPON THE STANDARD, BUT WHICH WILL SUCCESSIVELY SHEAR WHEN THE STANDARD BASE IS STRUCK BY A VEHICLE, PERMITTING THE VEHICLE TO CONTINUE MOVEMENT TO LESSEN DAMAGE TO THE VEHICLE AND STANDARD.

Description

1971 I P. A. .MIL LERB ERND 3,

' BREAKAWAY LIGHTING STANDARD Filed 0st. 17, 1968 3 Sheets-Sheet 1 INVENTOR R401. M/LLERBER/VD BY Ma d ATTORNEY P. A. MILLERBERND BREAKAWAY LIGHTING STANDARD 7 Jan; 5; 1971- V 3 Sheets-Sheet 2 Filed m, 17, 196 8 INVENTOR PA UL A. MILLERBERND ATTORNEY- P. A. MILLERBERND 3,552,073

, r BREAKAWAY LIGHTING STANDARD Filed Oct. 17, 1968 3 Sheets-Sheet 5 FIG, 12

v V .INVENTOR P404 4. M/LLEPBERND ATTORNEY United States Patent 3,552,073 BREAKAWAY LIGHTING STANDARD Paul A. Millerbernd, Winsted, Minn. 55395 Filed Oct. 17, 1968, Ser. No. 768,478 Int. Cl. E0211 27/42 US. Cl. 52--98 Claims ABSTRACT OF THE DISCLOSURE A breakaway lighting standard is provided including a base plate, and a standard base to which the light standard is supported. The standard base is formed of sheet material, and is anchored to the base plate with a series of spaced areas of attachment which will withstand normal stresses acting upon the standard, but which will successively shear when the standard base is struck by a vehicle, permitting the vehicle to continue movement to lessen damage to the vehicle and standard.

This invention relates to an improvement in breakaway lighting standard and deals particularly with a light weight non-shattering breakaway lighting standard or pole which may be sheared off when struck with little damage to the pole itself, and with little damage to the vehicle striking the standard.

Considerable damage is normally caused when an automobile or other vehicle strikes a conventional light standard of the type used to illuminate streets, highways, intersections and the like. Even when the vehicle is traveling at a relatively low rate of speed, the impact will normally ca-use several hundred dollars in damages to the vehicle body. Often times, in such accidents, the light standard either bends or snaps off causing the upper portion of the standard to fall upon the top of the vehicle. Many fatalities have been recorded due to the standard smashing the roof of the vehicle and crushing one or more of the occupants.

In the past, attempts have been made to increase the strength of the poles so that they can not snap off and strike the top of the car, even though the force of the impact is great. Small cars striking such poles come to an abrupt stop, often killing the occupants. I have found that better results may be obtained if the lighting standard is made of light weight material and is mounted at its base in such a manner that the mounting will progressively shear off when struck. Tests made and photographed at accelerated film speeds show that at speed over fifteen miles per hour, the light standard struck will immediatelyshear 01f. The lower end of the pole and standard base are thrown forwardly and upwardly while the upper portion of the pole and the luminaire are on the way down. The complete pole is in a substantially horizontal position suspended in mid air as the car passes over the pole base anchorage, out ahead of the pole. The impact causes the pole to follow the direction of travel of the car, and it usually is in a substantially horizontal position 01f the roadway when it strikes the ground.

I have found that by providing a base plate which is bolted or otherwise securely attached to a footing of concrete or the like, and by providing a relatively light weight pole secured to a breakaway base which is anchored to the base plate, the base and base plate may be fastened together securely enough so that the light standard will be firmly supported to withstand any normal amount of wind, while at the same time the fastening may be such as to progressively shear in the event the pole is struck by a moving vehicle.

In a preferred form ofconstruction of lighting standard, a shaft which may be of octagonal cross-section is formed of relatively light weight material such as 16 gauge type 304 stainless steel. Other material such as aluminum or high strength carbon steel may be used. The standard base may be of similar material, the base often being rectangular at its lower end, and tapering inwardly to provide an octagonal shape at its upper end. In one form of construction, a slip fitter is welded or otherwise attached to the top of the tapered base, this slip fitter being designed to telescope into the lower end of the shaft. In another style, the base of the pole is bolted to a flat plate at the top of the base.

In one form of construction, a base plate of heavy material such as K -inch stainless steel plate comprises a horizontal top plate adapted to be bolted to a suitable footing and having a do'wnturned peripheral flange adapted to fit snugly within the standard base. Normally an access door is provided in one of the four sides of the base. The other three sides of the base are secured to the corresponding three sides of the base plate with a break-away attachment. Accordingly, when the base or the light standard is struck with sufficient force, the standard base will progressively shear away from the base plate.

In a second form of construction, the breakaway base comprises a hollow frusto-pyramidal body having a generally square frame of steel at its lower end, and a frame of smaller dimensions at its upper end. The frames may be five eighths of an inch in thickness, the frames taperingin size from fifteen and one quarter inches at the bottom to about twelve and one half inches at the top. The wall may be fourteen gauge mild steel. The upper frame plate is welded about its periphery to the body. However, the lower frame is button welded to the body. The button welds provide an accurate shear strength. Where the base is struck by a moving vehicle, the base bends inwardly, shearing off the welds in succession as the flexing continues. According to photographic checks, when the base is sheared off, the base tends to return to its normal shape, and moves ahead of the vehicle somewhat similar to the action which takes place when a football is kicked.

A feature of one form of construction of the invention resides in securing the standard base to the base plate with a series of relatively small diameter areas of connection, which may be rivets, spot welding, 'bolts, shear pins or the like. Button welds have been found both economical and accurate. The arrangement is such that the strength of the fastening means is such that the pole will be sheared from its base plate more readily than the base plate will break or bend, thereby minimizing the injury to the vehicle body as well as to the light standard which is struck.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification.

FIG. 1 is a side elevational view of the light standard and base, showing the general arrangement of the parts.

FIG. 2 is an elevational view of the standard base and the lower portion of the light standard shown, in somewhat enlarged form.

FIG. 3 is an enlarged elevational view of a side of the standard base, showing the fastening means used for holding the standard base to the base plate.

FIG. 4 is a plan view of the base plate.

FIG. 5 is a vertical sectional view through the base plate, the position of the section being indicated by the line 5-5 of FIG. 4.

FIG. 6 is a detail showing the manner in which the door reinforcing member is formed.

FIG. 7 is a perspective view of a modified form of standard base.

FIG. 8 is a side elevational view of the base shown in FIG. 7.

FIG. 9 is a plan view of the top plate of the base.

FIG. 10 is a bottom plan view of the base, the position of the view being indicated by the line 1010 of FIG. 8.

FIG. 11 is a sectional view on the line 11-11 of FIG. 8.

FIG. 12 is a plan view of the base plate after the body has been sheared off.

FIG. 13 is a sectional detail through a bottom welded area.

The breakaway lighting standard is indicated in general by the letter A, and is designed to support a light fixture which may be indicated in general by the letter B. The shaft 10 which is illustrated in the drawings is of the davit type which is curved as indicated at 11 near its upper end to terminate in a substantially horizontally extending arm 12. Obviously, the shape of the standard 10 may be varied. In the arrangement illustrated, the shaft 10 is formed of 16 gauge type 304 stainless steel, and tapers toward its upper ends, and may be a minimum of about 6% inches across at the base, and inch across at the upper end. These sizes are given merely as examples of the proportions rather than limiting figures. The shaft may be of other material such as aluminum or high strength carbon steel.

The lighting standard A is mounted upon a footing [3, usually of concrete or the like, having a series of four equally spaced studs 14 projecting upwardly therefrom in spaced relation. A base plate 15, best illustrated in FIGS. 4 and 5 of the drawings, is mounted in parallel relation to the flat upper surface of the footing 13. The base plate 15 includes a substantially flat top panel 16 which is of generally square form with the corners angled to fit the shape of the standard base. The panel 16 is reinforced by a generally cylindrical flange 17 defining a circular aperture 19 in the panel 16. The periphery of the panel 16 is provided with a downturned flange or lip 20 which is angled downwardly and outwardly to fit within the tapered standard base, as will be described.

The panel 16 of the base plate 15 is provided with a series of angularly spaced radially extending raised bearing areas 18 which include equally spaced apertures 21 extending therethrough near the corners of the base plate. These apertures 21 are designed to accommodate the upper ends of the vertical studs 14 in the footing 13. In preferred form, nuts 22 are threaded onto the studs beneath the base plate 15, and cooperable nuts 23 are threaded onto the studs above the base plate 15. This permits the base plate to be perfectly leveled in spite of the fact that the footing 13 might not have a completely level upper surface 24.

The standard base is indicated in general by the nu meral 25. The base 25 is generally rectangular at its lower end, being similar in cross-sectional shape to the outline of the base plate 15. The generally square base is shaped to provide an octagonal upper extremity 26. An untapered octagonal slip fitter 27 is welded to the similarly shaped upper end 26 of the standard base 25. The lower end of the slip fitter 27 is split and bent to provide eight tabs 29 in face contact with the inner surface of the octagonal upper end 26 of the standard base 25, the tabs 29 are spot welded to the base 25 as indicated at 30 the lower end of the shaft 10 is untapered and fits Onto the slip fitter 27 with a moderate press fit. The shaft may be solely sup ported in this way, although intermittent spot welds or button welds may be used.

One side of the standard base 25 is provided with an inverted U-shaped access opening 31 which is normally closed by a similarly shaped removable door 32. The door may be held in place by any suitable means, such as locking strips 28 at the lower end of the door and a clamp 28' actuated by a bolt or screw 33 near its upper end. The details of construction are not illustrated, as they are not of importance to the invention. The door opening 31 is reinforced by a channel of inverted U-shaped form, the

channel being indicated in general by the numeral 34. The channel 34 includes a base portion 35 which is secured flush against the inner surface of the standard base 25 to overlap into the door area, or to extend somewhat inwardly to the door opening 31. The parallel flanges 36 of the channel 34 extend inwardly toward the interior of the standard base. The channel is flattened out at its ends as indicated in FIG. 6 to extend over the base plate flange or lip 20. A series of three rivets 37 extend through the standard base 25, through the flattened end 39 of the channel 34, and through the flange 20 of the base plate 15.

As indicated in FIG. 3 of the drawings, the other three sides of the generally rectangular lower end of the standard base 25 are secured to the flange 20 of the base plate 15 by a series of eight rivets. The first rivet 40 near each corner of the standard base is positioned as near to the corners as is convenient, and the remaining rivets 41 are spaced from the rivet 40 and from each other an equal distance of perhaps one inch. Thus in the arrangement illustrated, there are thirty rivets securing the standard base to the base plate 15.

On a typical construction, the standard will safely withstand a wind velocity of 100 miles per hour. The thickness of the material forming the standard base and the base plate have been indicated as examples. The rivets used in this construction have been stainless steel rivets of inch diameter, having a yield strength of 37,500 pounds per square inch. Thus, while the standard will withstand the force of wind up to the normal maximum velocities attained, they may be sheared off when the standard base is struck by a moving vehicle. It has been found that when struck by a vehicle traveling as slow as 15 miles an hour, the rivets will progressively shear and the standard and standard base will become detached from the base plate 15. Even when traveling at higher speeds, the poles have been knocked over with but little damage either to the pole or to the vehicle.

A modified form of light standard is indicated in general by the letter C, the structure being shown in FIGS. 7 through 13 inclusive. As indicated, the base C is frustalpyramidal in shape including similarily tapering side panels 45 forming three of the sides of the base. These panels 45 are provided with offset central areas 46 which serve to reinforce the sides, the ofiset areas 46, following the general contour of the panels 45. As is indicated in FIG. 8 of the drawings, the fourth panel 47 is provided with an access opening closed by a door panel 49 held in place by fixed clamps 50 along the lower edge of the door panel, and by a pivotal clip 51 along its upper edge held in place by a clamping bolt 52. In view of the fact that the access opening and the door are unimportant except from a functional standpoint, this structure is not shown in detail. The upper end of the frustal-pyramidal body 5,3 is closed by a closure plate 54 shown in FIG. 9 of the drawings. The closure plate is generally rectangular with slightly rounded corners 55. An octagonal opening 56 is shown at the center of the plate, the opening being designed to reduce the weight to provide an opening for the wiring. Four diagonally elongated slots 57 are located near the corners of the plate to accommodate bolts holding the light standard 59 in position.

The plate 54 may be made of steel or other suitable metal which is perhaps 41 to inch in thickness. The upper periphery of the base body 53 is Welded to the plate 54 so as to securely attach the standard to the plate. With reference to FIG. 7 of the drawings, the light standard 59 is shown as including at its lower end a mounting flange 60 which is bolted in face contact with the plate 54 by means of bolts 61.

The base plate 62 which is at the lower end of the body 53 is best shown in FIGS. 11 and 12 of the drawings. The base plate 62 comprises a rectangular ring having slightly rounded corners 63 to fit within the lower end of the body 53. A series of four flat ended projections 64 extend outwardly from the frame on each side of each corner thereof. The projections 64 on each of the four sides of the frame 62 terminate on a common plane which is in face contact with the interior of the body 53. The projections 64 are button welded to the panels 45 of the body 53 as indicated at 65 in FIG. 13 of the drawings. In usual form, there are six such bottom welds provided on each of the four sides of the frame plate 62. The fourth projection 64, of each series provides a space for adding an additional button weld in the event that the base is used to support a light standard which is taller than usual or if it is necessary for the pole to withstand unusual stresses. The addition of the fourth button welds at each corner sacrifices some of the advantages of the present construction, as the failure of the base to break away as readily tends to cause more damage to the vehicle.

As is indicated in FIGS. 8, 10, 11, and 12 of the drawings, the light standard is mounted upon a footing of concrete or the like which is indicated at 66, the footing being provided with four equally spaced studs embedded therein and projecting upwardly therefrom. A substantially triangular gussett plate 69 is provided resting uopn each corner of the rectangular frame plate 62, and through which the studs 67 extend. The plates 69 accommodate for any slight error in the position of the studs 67, and permit the standard to be clamped to the footing 67 by means of nuts 70.

The button Welds have a minimum shear strength of three thousand pounds so that the body is firmly aflixed to the base plate. However, when struck forcefully by a moving vehicle, the body itself tears free, the resilience and flexibility of the body causing it to progressively shear until the body of the base is completely free from the mounting plate.

I have described the principles of construction and operation of my improvement in breakaway lighting standard, and While I have endeavored to set forth the best embodiment thereof, I desire to have it understood that changes may be made within the scope of the following claims.

I claim:

1. A breakaway light standard including:

a rectangular base plate,

anchoring means for securing said base plate in fixed horizontal position,

a standard base having a frusto-pyramidal lower end downwardly and outwardly inclined to accommodate said base plate,

a light standard secured to said standard base,

said standard base and light standard being formed of sheet material, resistant to breaking, and

a series of horizontally spaced means securing each side of said standard base to said base plate,

whereas an impact exerted against one side of said standard base by a moving object will create an upward force on the spaced means acting to shear off the securing means securing said one side of the standard base to the base plate, and,

Whereas the securing means on the sides of the standard base adjoining said one side will successively shear off, the securing means on the side of the standard base opposite said one side being the last to shear,

the impact against said standard base tending to flex said standard base inwardly during the shearing action, and said standard base tending to return to its original shape after the impact, thus tending to drive said standard base away from the moving object causing the impact.

2. The structure of claim 1 and in which said base plate includes a frusto-pyramidal peripheral flange in face contact with said standard base, said securing means securing said standard base to said flange.

3. The structure of claim 1 and in which said fastening means includes elements extending through said standard base and said base plate.

4. The structure of claim 1 and in which said light standard and standard base are formed of stainless steel.

5. The structure of claim I and in which said fastening means comprise rivets.

6. The structure of claim 1 and in which said securing means comprise button welded areas.

7. A breakaway light standard including:

a base plate,

anchoring means for securing said base plate in fixed horizontal position,

a standard base having its lower end shaped to accommodate said base plate,

a light standard secured to said standard base,

a' series of horizontally spaced means securing said standard base to said base plate, said securing means being progressively sheared when said standard base is subjected to an impact force less than that required to break the standard base and standard, and

said base plate comprising a plate having a substantially square outline, and including a series of outwardly extending projections on each side thereof near the corners thereof, said projections on each side terminating on a common plane in face contact with the inner surface of the standard base, and said securing means comprise button welds extending into said projections.

8. The structure of claim 7 and in which said standard base includes a top closure plate peripherally secured to the upper end of said standard base.

9. A breakaway light standard including:

a base plate,

anchoring means for securing said base plate in fixed horizontal position,

a standard base having its lower end shaped to accommodate said base plate,

a light standard secured to said standard base,

said standard base and light standard being formed of sheet material, resistant to breaking,

a series of horizontally spaced means securing said standard base to said base plate, said securing means being progressively sheared when said standard base is subjected to an impact force less than that required to break the standard base and standard, and

said base plate comprising a plate having a substantially square outline, and in which the marginal edge of said plate engages the inner surface of said standard base at spaced areas only on each of the sides of said base plate near the corners thereof, said securing means comprise button welds extending into said base plate at said spaced areas. 10. The structure of claim 9 and in which said standard base is substantially frusto-pyramidal in shape.

References Cited UNITED STATES PATENTS 1,499,445 7/ 1924 Clay 52232X 2,309,041 1/ 1943 Booker et a1 S2, 98X 3,308,584 3/1967 Graham 5298 3,349,531 10/1967 Watson 52296 PRICE C. FAW, JR., Primary Examiner US. Cl. X.R.