Speed Limiting Apparatus

Abstract

The present invention is an apparatus for moderating the speed of a vehicle. A non-Newtonian fluid is encased in a durable, flexible enclosure that is positioned in a traffic area. An example embodiment is a form that is higher than a road surface. A vehicle approaching the apparatus at a low speed imparts an impact force below the threshold, causing the fluid to remain in its liquid state. This allows the vehicle's wheels to depress into the apparatus, thereby passing over the apparatus with little to no resistance. A vehicle approaching the apparatus at a high speed imparts an impact force above the threshold, causing the fluid to behave as a solid, thus impeding or stopping the vehicle's movement. Another embodiment is lower than a road surface and is configured to trap slow moving vehicles while allowing fast moving vehicles to pass.

1 . An apparatus for controlling vehicle speed comprising:
 a flexible enclosure having an interior space, said enclosure configured to be placed proximal to a surface traversed by vehicles; and   a non-Newtonian fluid contained within the interior space of the enclosure; wherein   the apparatus is configured to present different resistive properties to a vehicle based on the speed of the vehicle.   
     
     
         2 . The apparatus of  claim 1  wherein:
 the flexible enclosure is comprised of a material selected from the group consisting of rubber, castable elastomer and flexible polymers. 
 
     
     
         3 . The apparatus of  claim 2  wherein:
 the flexible polymer is high-density polyethylene. 
 
     
     
         4 . The apparatus of  claim 1  wherein:
 the non-Newtonian fluid is a shear-thickening fluid that increases in viscosity when subjected to a high shear rate thereby causing the apparatus to deform for a slow-moving vehicle and behave as a substantially solid mass to a fast-moving vehicle. 
 
     
     
         5 . The apparatus of  claim 1  wherein:
 the non-Newtonian fluid is a Bingham plastic that behaves as a solid until a specific yield stress is applied, thereby causing the apparatus to flex for a vehicle moving at or above a minimum threshold speed and behave as a substantially solid mass to a vehicle moving below the minimum threshold speed. 
 
     
     
         6 . The apparatus of  claim 1  wherein:
 the non-Newtonian fluid is a viscoelastic fluid that absorbs and dissipates energy from a vehicle passing over the apparatus. 
 
     
     
         7 . The apparatus of  claim 1  wherein:
 the apparatus is configured to reside above the road surface; wherein 
 a vehicle encountering the apparatus at a slow speed encounters the non-Newtonian fluid as a liquid and moves through the apparatus, while a vehicle encountering the apparatus at a high speed encounters the non-Newtonian fluid as a solid and meets the apparatus as an obstruction. 
 
     
     
         8 . The apparatus of  claim 1  wherein:
 the apparatus is configured to reside beneath the road surface; wherein 
 a vehicle encountering the apparatus at a slow speed encounters the non-Newtonian fluid as a liquid and falls beneath the road surface, impeding the vehicle, while a vehicle encountering the apparatus at a high speed encounters the non-Newtonian fluid as a solid and passes over the apparatus. 
 
     
     
         9 . A method for limiting the speed of a vehicle, the method comprising:
 placing an apparatus on a traffic surface, the apparatus comprising:   a flexible enclosure containing a non-Newtonian fluid; and   allowing a vehicle to pass over the apparatus; wherein   the non-Newtonian fluid changes its viscosity in response to the speed of the vehicle, thereby altering the resistive force exerted by the apparatus on the vehicle.   
     
     
         10 . The method of  claim 9  wherein:
 the non-Newtonian fluid is a shear-thickening fluid and the method further comprises: 
 increasing the rigidity of the apparatus in response to a vehicle passing over at a speed exceeding a predetermined threshold. 
 
     
     
         11 . The method of  claim 9  wherein:
 the non-Newtonian fluid is a Bingham plastic and the method further comprises: 
 maintaining the rigidity of the apparatus in response to a vehicle passing vet at a speed below a predetermined threshold.