Back to results
US 4,874,066 AGranted
Variable flow shock absorber and method
AssigneeS.U.I. Corporation
InventorIlan Silberstein
Life of this patent
Estimating the term…
Abstract
A shock absorber including a piston with two relatively movable elements defining a variable-sized, fluid-filled space. The size of the space is decreased when subjected to external fluid pressure and fluid flow through the piston is modified in response to such decrease.
Claims9
A shock absorber comprising, in combination:
- a cylinder having an interior with fluid therein;
- a piston rod;
- a piston mounted within said cylinder interior defining first and second chambers in said cylinder and a primary passageway permitting the flow of fluid from said first chamber into said second chamber as fluid is pressurized in said first chamber by movement of said piston, said piston including relatively moveable first and second piston elements defining a variable-sized, fluid-filled space in continuous communication with said second chamber through a fluid-flow restricting vent spaced from said primary passageway, formed in said shock absorber, and providing communication between said space and said second chamber, said first piston element being fixedly mounted relative to said piston rod, movable with said piston rod, and defining a recess, and said second piston element having a peripheral wall at least partially disposed within said recess and said second piston element being gradually displaceable relative to said first piston element toward said piston rod within said recess responsive to pressurization of fluid in said first chamber to force the fluid in said space through said fluid-flow restricting vent and into said second chamber whereby the size of said space is gradually reduced as a function of the amount of fluid forced through said fluid-flow restricting vent, said primary passageway including at least one flow path defined by said first piston element and communicating with said recess and at least one aperture defined by said second piston element in the peripheral wall thereof in communication with said flow path, relative movement of said piston elements gradually displacing said aperture relative to said flow path to gradually modify the effective size of said primary passageway in response to the gradual reduction of said space size caused by fluid pressure within said first chamber exceeding fluid pressure within said second chamber and fluid flowing through said fluid-flow restricting vent, said flow path including a groove defined by said first piston element about the periphery of said recess, said groove and said aperture being so configured as to be in continuous at least partial registry during gradual displacement of said aperture.
A method of controlling movement of a piston in a predetermined direction within a shock absorber cylinder containing fluid, said piston element defining first and second chambers within said cylinder on opposed sides of said piston, said piston including first and second relatively movable piston elements, said first piston element being fixedly mounted relative to said piston rod, movable with said piston rod, and defining a recess, said method comprising the steps of:
- disposing said second piston element in said recess to define a variable-sized space within said recess with said first and second piston elements;
- flowing a first portion of said fluid through a passageway formed in the piston from said first chamber to said second chamber;
- accommodating a second portion of said fluid in the variable-sized space formed in said piston by said first and second piston elements;
- during said flowing step, gradually diminishing the size of said space by exerting fluid pressure in said first chamber on said second piston element to gradually move said second piston element within said recess toward said piston rod and relative to said first piston element to pressurize said second fluid portion;
- simultaneously with the step of flowing said first fluid portion through said passageway, flowing at least some of said pressurized second portion through a continuously open fluid-flow restricting vent formed in said shock absorber at a location spaced from the passageway from said space and to said second chamber to control the rate of said gradual diminishment of said space size;
- and
- responsive to gradual diminishment of the size of said space, gradually changing the effective size of said passageway to control the flow of said first fluid portion, said passageway including a groove in one piston element and at least one aperture in the other piston element, the step of gradually changing the effective size of the passageway being carried out by maintaining said aperture and said groove in continuous at least partial registry and gradually moving said aperture relative to said groove.
4 more elements
Dependencies are inferred from the claim text.