US3522790A - Bridge failure warning device - Google Patents

Description

United States Patent Robert J. Cambre Chalmette, Louisiana;

Inventors:

Vincent R. Valley, Metairie, La.

Application No.: 743,416 g Filed: July 9, 1968 Patented: Aug. 4, 1970 Assignee: Boh Bros. Construction Company, Inc. New Orleans, Louisiana a Corp. of Louisiana BRIDGE FAILURE WARNING DEVICE 5 Claims, Drawing Fig.

References Cited UNITED STATES PATENTS 7/1877 Forbes Primary Examiner Louis R. Prince Assistant Examiner Daniel M. Yasich Alt0rney1(ingsland, Rogers, Ezell, Eilers and Robbins ABSTRACT: The device disclosed is an automatic warning to alarm approaching vehicle operators in the event a bridge slab or section is knocked out of position. An elongated tubular unit, pivotally mounted at the end of each adjacent span, counter-weighted to swing it to an upright position. At the other end of each tubular unit there is a flare having a pull cord by which it can be ignited, engaged over a pin on the opposite bridge section, located so as to dispose the unit in a horizontal, inactive position. 1f the spans shift relative positions, the cords are pulled, causing flares in each unit to ignite, and releasing the units so that they can swing into upright position on their respective spans by the action of the counterweights. This places the burning flares in a clearly visible position above the roadway to warn of the bridge condition.

Patented Aug. 4, 1979 3,522,790

- IA/ VENTORS: ROBERT J. CAMBRE VIA/CENT FIJA L L EY U.S. PATENT 3,522,790 BRIDGE FAILURE WARNING DEVICE SUMMARY OF THE INVENTION activated when the arm moves to active, upright position. The

alarm device is preferably a flare, and the pull cord for the flare, which also acts to retain the element in its inactive position, extends across to the adjacent span of the bridge so as to constitute both the flare actuator and a means for holding the illustrated at 35. The flare is held in place by a set screw, this arm down. If the spans shift their relative positions, the pull cord is stretched and actuates the flare at the same time releasing the element to swing to activated position. The upright shifting preferably is done by a counterweight arrangement and should be long enough to extend above the hand rail of the bridge.

In the drawing:

FIGURE 1 is a side elevation of bridge spans with the warning alarms in place, the same being shown in full lines in their inactivated positions and in dotted lines in their activated positions;

FIGURE 2 is an enlarged reproduction of the central portion of FIGURE 1; and

FIGURE 3 is a view partly in section of one of the elements.

Two abutting bridge spans and 11 are illustrated in FIG. I. The span 10 is shown as having a pier I2 and the span 11 as having a pier 13. These structures may be of appropriate material and form. They are here diagrammatically illustrated as being made of concrete and providing a road bed, constituted by the road bed section 14 on the span l0 and the cor responding section 15 on the span 11. A continuous hand rail 16 may be provided with a post 17 to the span l0 and a post 18 to the span 11. The hand rail may be discontinuous if desired.

The two spans 10 and I1 abut or substantially so. A gap 20 is illustrated between them in FIGURES l and 2. The size of this gap will vary in accordance with the construction factors and location of the bridge, but it normally does not exceed a given amount.

There have been accidents to traffic passing across bridges after a displacement of one of the slabs or spans with respect to the other, caused by the collision of some object in the water with a pier of the span, or other mishap. The present invention is designed to give a warning that such an event has occurred. It incorporates at least one swivelled alarm unit, although preferably there are facing units on the adjacent spans. Here two identical units 24 and 25 are shown on the respective spans 10 and 11. The unit 24 is freely swivelled at 26 onto the span I0, and the unit 25 is freely pivoted at 27 to the span 11. The units 24 and 25 are designed to be swung down to an inactive, here horizontal, position until they abut stops 28 and 29, respectively, to be releasably held there until actuated, as will appear. The stops 28 and 29 may take any suitable form such as that of bolts or pins.

FIGURE 3 shows an enlarged and more detailed view of the unit 25. It consists of a tube 31 preferably of galvanized pipe, through which the pivot pin 27 passes. At its short end it has a counterweight 32, this being the preferred but not only usable yieldable means to urge the unit to upright position. The tube 31 is long enough to raise the long end of the unit above the hand rail when the unit is pivoted by the counterweight to upright position illustrated in dotted lines in FIGURE 1. The pivoting arrangement must be free and not subject to corrosion that would prevent the swivelling action when the device is actuated. Appropriate plastic bushings or the like may be used for this purpose.

The long end of the tube 31 is adapted to receive a flare such as a red flare fusee with a thirty-minute burn period, here arrangement permitting the flare to be replaced after use, for further operation of the device. A pull cord 36 with an end loop 37 projects from the end of the flare 35. When the cord is pulled, it will actuate the flare so that the same is ignited.

The unit 24 is identical to the unit 25 having its counterweight 40, flare 41 and pull cord 42.

OPERATION In the inactive position into which these units are installed,

the pull cord 36 is attached by having its loop 37 passed over the stop 28 on the opposite structure 10, while the cord 42 is similarly attached to the stop 29.

When either of the spans of the bridge is moved with respect to the other, the pull cords are pulled and cause the flares to ignite. In this action, the pull cords are withdrawn from the flares, freeing the units to swing to vertical positions under the action of their counterweights. This disposes the ignited flares in readily visible warning positions where they will continue to appear for the duration of the period of the flare, such as for thirty minutes. This provides a warning to approaching vehicles that the roadway has been disrupted and prevents accidents.

While the device has been described as applied to one or more bridge spans, it is useful on other structural combinations subjected to the possibility of relative displacement, as is evident; although it has particular applicability to bridge spans because of their being subject to the impact of floating objects. As noted, the alarm may take the form of other things than a flare, and where a flare is used, it may have any desired character of light or duration of burn, or means of attachment and replacement. It is required that the alarm be normally kept inactive, and be actuated by relative displacement of'the structural elements upon which the device is mounted.

Various changes and modifications may be made within the process of this invention as will be readily apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined by the claims appended thereto.

We claim:

1. In an alarm device of the kind used to warn of relative displacement of two structures such as bridge spans that are normally disposed in an adjacent relationship to each other; the combination of a pivotable visual signal member having a swivel portion for attachment to the one structure for pivoting thereon from an inactive to an active and visible position; means normally to urge the pivotable member to the active position; means to hold the member in inactive position including a connecting element connected at one portion to the member and adapted to be attached at another portion to the other structure, whereby when the structures are displaced the connecting element will become disconnected and the pivotable member can move to its active position wherein it constitutes a visible warning, and alarm means on the pivotable member actuated to deliver an alarm when the pivotable member moves to active position.

2. In the device of Claim 1: the means to urge the pivotable.

. be more visible where the pivotable member moves higher.

3. In the device of Claim I: the connecting element being a cord, and the alarm means being a flare, the cord being connected to cause the flare to ignite when the cord is pulled, and when connected to the other structure, being adapted to be pulled when the structures are relatively displaced.

4. In the device of Claim 1: the pivotable member comprising an elongated tube having its swivel portion between its ends; the means to urge the member being a counterweight on one end of the tube; the alarm means being a flare removably and replaceably disposed in the other end of the tube, the con-- necting element comprising a pull cord for the flare, and having a loop means on its free end for attachment to the opposite structure.

5. In the device of claim 4: the combination including the two relatively displaceable structures, each having a pin stop against which its pivotable member is brought to rest when in

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