The Karen systems automatic speed bump is configured to fold downward substantially flush with the roadway surface over a short but predetermined period of time when driven over by a motor vehicle. If the motor vehicle is traveling at a reasonable speed the retraction of the speed bump allows the vehicle to travel over the retracted speed bump with little or no vertical displacement of the vehicle. However, a motor vehicle traveling at a higher than permissible speed passes over the motorized speed bump too rapidly to allow the bump to retract, resulting in a significant jolt to the vehicle and its occupants. The mechanism incorporates a number of shock absorbers and springs to accomplish the effect. The strength of the shock absorbers and springs are determined according to the number of units installed, the anticipated speed of traffic, and numerous other factors .
The Karen automatic smart 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.
The Karen’s automatic speed sensitive speed bump having a base plate, a front plate hingedly connected to the base plate, and a spring that biases the front plate toward a raised position. A speed-sensitive lock mechanism for locking the front plate in the raised position when impacted by a vehicle tire traveling at a speed at or above a predetermined speed. However, when the vehicle is traveling below the predetermined speed, the front plate is not locked in the raised position and collapses to a horizontal position such that the vehicle does not experience a bump.
