Bridge sway and deflection detection system
BACKGROUND OF THE INVENTION 
     The instant invention relates generally to motion detection systems, and more particularly, to a bridge sway and deflection detection system. 
     Numerous electronic detection systems have been provided in the prior art that are adapted to detect motion. For example, U.S. Pats. Nos. 4,472,883 of Ortega; 4,296,485 of Clemens and 4,288,158 of Frungel, all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purpose of the present invention as hereafter described. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide a bridge sway and deflection detection system that will overcome the shortcomings of the prior art devices. 
     Another object is to provide bridge sway and deflection detection system that will employ the use of a laser beam to detect motion that it dangerous in a bridge structure. 
     An additional object is to provide a bridge sway and deflection detection system, which will be so designed, as to send signals to a central monitoring station, when a dangerous motion of a bridge is detected, so as to avoid a catastrophe. 
     A further object is to provide a bridge sway and deflection detection system that is simple and easy to use. 
     A still further object is to provide a bridge sway and deflection detection system that is economical in cost to manufacture. 
     Further objects of the invention will appear as the description proceeds. 
     To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only and that changes may be made in the specific construction illustrated and described within the scope of the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     The figures in the drawings are briefly described as follows: 
     FIG. 1 is a fragmentary perspective view of a typical bridge with the instant invention installed thereon; and 
     FIG. 2 is a schematic block diagram of the instant invention per se. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning now descriptively to the drawings, in which like reference characters denote like elements throughout the several views, a system 10 includes a pair of spaced plates 12 mounted fixedly to a pair of vertical columns 14 of a bridge 16. Plates 12 are spaced above the water 18, and a second pair of plates 20 align with the plates 12 and are mounted fixedly to the opposite sides of columns 14, for passage of a laser beam 22 from laser gun 24 which passes through apertures 26 provided through plates 12 . A pair of mirrors 28 are provided and are mounted fixedly to a structure of bridge 16, in a manner (not shown), for reflecting the beam 22 to the opposite side of the bridge 16, as shown by arrows 30, so as to enter the laser receiver 32. 
     The design of system 10 is such that the laser receiver 32 is coupled by cable 34 to processing circuitry 36 that is coupled by cable 38 to a modem 40, and the output of modem 40 is coupled by telephone cable 42 to a central monitoring station 44, where visual readout and alarms are actuated in the event that a blockage occurs to obstruct the path of laser beam 22. Power cable 46 couples to a power source and supplies electrical power to 24, 32, 36 and 40 for the continuous operation of system 10. 
     Blockage may occur if any one aperture 26 of the plates 12 and 20 becomes disaligned and causes the laser beam 22 from the laser gun 24 to strike either of the plates 12 and 20 instead of passing through apertures 26 thereof to be reflected back to the laser receiver 32. 
     In operation, laser gun 24 emits laser beam 22 that under normal conditions will beam through the apertures 26 of plates 12 first. This beam then strikes a first mirror 28 in its path and is reflected to the second mirror 28 where it reflects reversely back through the apertures 26 of the second pair of plates 20 and is picked up by the laser receiver 32 where it is fed into the processing circuitry 36. This data is fed to the modem 40 and into the telephone line 42 connected to the central monitoring station 44. 
     Lateral sway along the longitudinal axis, vertical mis-alignment of either of the columns 14, lowering of one side of a column 14, and total washout or other destruction of bridge 16, is immediately transmitted into the central monitoring station 44, because the path of laser beam 22 will be blocked from returning to the laser receiver 32. 
     It is to be distinctly understood that, while the text and drawings illustrate that a laser is to be employed to produce a detectable energy beam, that other embodiments of the same invention can use a light beam, a microwave beam, a radio frequency beam, or possibly some other detectable energy source without departing from the spirit of the invention. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing from the spirit of the invention.