Automatic speed bump

Abstract

The automatic speed bump is installed in a roadway to discourage motor vehicle travel at excessive speeds. The device includes a box-like structure set into the surface, the box having upper edges flush with the surface. Two doors are hinged to the box along their opposite edges. Concentric spring and shock absorber assemblies lift the centers of the doors to create a speed bump. A guide strut is installed between each spring and shock absorber assembly to maintain alignment of the apparatus. The springs and shock absorbers retract at a predetermined rate when a standard motor vehicle encounters the raised doors at a reasonable speed. The doors folding flush with the surface to allow the vehicle to travel over a flat surface. The shock absorbers cannot retract faster than their predetermined rate, resulting in the doors remaining raised when a vehicle travels over the device at higher than reasonable speed.

1 . An automatic speed bump, comprising:
 an elongate, rigid box having a floor, mutually opposed first and second sides, mutually opposed first and second ends, and an open top, each of the sides of the box having an upper edge;   a first door pivotally attached to the upper edge of the first side, the first door having a free edge and a lower surface;   a second door pivotally attached to the upper edge of the second side, the second door having a free edge and a lower surface, the free edges of each of the doors facing one another;   a plurality of spring and shock absorber assemblies extending upward from the floor of the box, each of the spring and shock absorber assemblies lifting the free edges of the first door and the second door to a partially open state above the box when the spring and shock absorber assemblies are in an uncompressed state;   a crossmember having mutually opposed first and second ends;   an elongate cover seated on the crossmember; and   first and second rollers respectively disposed at the first and second ends of the crossmember, wherein said first and second rollers bear against the respective lower surfaces of the first and second doors adjacent their free edges thereof when the spring and shock absorber assemblies are in an uncompressed state such that said first and second rollers support the respective lower surfaces of said first and second doors;   wherein the box, the doors, and the spring and shock absorber assemblies collectively form a laterally symmetrical structure about a vertical plane parallel to the first and second sides of the box.   
     
     
         2 . The automatic speed bump according to  claim 1 , further comprising a plurality of alignment guides extending upward from the floor of the box, the alignment guides and the spring and shock absorber assemblies being disposed in an alternating array, wherein the elongate cover is affixed to each of the spring and shock absorber assemblies and to each of the alignment guides, the cover connecting the spring and shock absorber assemblies and the alignment guides to one another, the cover maintaining lateral alignment of the alignment guides and the spring and shock absorber assemblies. 
     
     
         3 . The automatic speed bump according to  claim 2 , wherein each of the alignment guides further comprises:
 a base tube having an open upper end;   mutually opposed first and second rollers disposed at the upper end of the base tube;   an alignment bar telescopically disposed in the base tube, the alignment bar having an upper end, wherein the crossmember is disposed across the upper end of the alignment bar.   
     
     
         4 . The automatic speed bump according to  claim 1 , wherein each of the spring and shock absorber assemblies has an upper end, the crossmember being disposed across the upper end of each of the spring and shock absorber assemblies. 
     
     
         5 . The automatic speed bump according to  claim 4 , wherein each of the spring and shock absorber assemblies further comprises:
 a base tube having an open upper end;   an upper tube telescopically disposed in the base tube, the upper tube having an upper end, the crossmember being disposed across the upper end; and   a coil spring and a shock absorber disposed concentrically within the base tube and the upper tube.   
     
     
         6 . The automatic speed bump according to  claim 1 , wherein each of the shock absorbers of the shock absorber and spring assemblies comprises a hydraulic shock absorber. 
     
     
         7 . The automatic speed bump according to  claim 1 , wherein each of the shock absorbers of the shock absorber and spring assemblies comprises a pneumatic shock absorber. 
     
     
         8 - 20 . (canceled)