Patent ID: 6010277
Filing Date: 2000-01-04
Classification: E01F

Abstract:
A variable speed bump apparatus comprising:a pivoting ramp element hinged at one end and arranged for angular motion about said one end;at least one piston and cylinder assembly supporting said pivoting ramp element, said at least one piston and cylinder assembly comprising a piston arranged for reciprocating sliding motion against a fluid in a cylinder, said cylinder having an orifice through which said fluid can be evacuated when said piston presses against said fluid; anda first flow control valve arranged to close against said orifice, an amount of closing of said first flow control valve against said orifice controlling the rate of passage of said fluid through said orifice,wherein a duration of a downward force applied against said ramp element causes an angular downward motion of said ramp element about said one end and causes said piston to press against said fluid, wherein a shorter such duration increases a pressure drop of said fluid through said orifice and retards the angular downward motion of said ramp element, and a longer such duration decreases a pressure drop of said fluid through said orifice and hastens the angular downward motion of said ramp element.