Patent ID: 6460663
Filing Date: 2002-10-08
Classification: F16F

Abstract:
A hydraulic dashpot for motor vehicles comprising:a cylinder containing shock-absorbing fluid; a piston rod traveling axially in and out of said cylinder through a sealed opening; a shock-absorbing piston at an inner end of said piston rod; said piston separating said cylinder into two compartments and having passages controlled by throttle-valve assemblies; a bypass associated with compression and decompression stages; said bypass having a width varied by at least a three-stage solenoid comprising a coil accommodating a valve in form of a plunger traveling in and out dependent on an electromagnetic force exerted by said coil and opens at least two bypasses one after another in succession; at least a first one of said bypasses opened by said plunger when leaving a bypasses-closed position accommodates a constriction at a distance from said plunger, said at least three-stage solenoid being a solenoid with at least three operating positions, said at least two bypasses remaining separated independent of said plunger so that only after one of said two bypasses is fully opened is the other one of said bypasses opened for reducing effects of constantly varying fluid forces when flow through said bypasses is controlled; said plunger being a cylinder and said bypasses extending radially out from a common axis; the plurality of bypasses being stacked on top of one another, said plunger blocking and releasing said bypasses' innermost openings one after another.