ADJUSTABLE SHOCK ABSORBER ASSEMBLIES

• US 3,677,561 A
• Filed: 01/05/1971
• Issued: 07/18/1972
• Est. Priority Date: 01/05/1971
• Status: Expired due to Term

• Current Assignee: Sellers B. Mcnally
• Original Assignee: Sellers B. Mcnally
• Inventors: McNally, Sellers B.
• Primary Examiner(s): Goodman, Philip
• Application Number:
  US05/104,117
• Time in Patent Office: 560 Days
• Field of Search: 267/65 280/124
• US Class Current: 280/124.157
• CPC Class Codes: B60G 13/08 hydraulic
• CPC Class Codes: F16F 9/443 manually adjusted while the damper is fully retracted or extended in a non-operational mode by rotating mechanical means that have engaged between the piston and one end of the cylinder

Abstract

A set of direct, double acting, hydraulic shock absorbers for use in a racing vehicle having front and rear wheels, one pair of shock absorbers being adapted for mounting in the front suspension system and a second pair of shock absorbers for mounting in the rear suspension system; manually adjustable means in the form of a variable flow passage and an adjustable valve are provided for controlling the damping characteristics of each of the shock absorbers of the set so that the shock absorbers may be used on a vehicle under ordinary road conditions and be adjusted to meet the conditions encountered when the vehicle is used in high-speed races.

Claims

1. In a suspension system for a vehicle having a sprung mass and an unsprung mass, the unsprung mass including the front and rear wheels, a first pair of direct-acting, hydraulic shock absorbers adapted to be connected between the sprung mass and the front wheels and a second pair of direct-acting, hydraulic shock absorbers adapted to be connected between the sprung mass and the rear wheels, each of said shock absorbers comprising a tubular structure defining a cylindrical chamber and a fluid reservoir, said chamber having an end wall and a piston slidable therein toward said end wall in a compression stroke and away from said end wall in a rebound stroke, a piston rod extending from one side of said piston away from said end wall and outwardly of said chamber, means at the end of said chamber opposite said end wall for closing said opposite end and forming a fluid-tight seal about the portion of said piston rod extending therethrough, said chamber having means for controlling fluid flow between said chamber and said reservoir and said piston having means for controllably restricting fluid flow in said chamber so that, when said piston moves through a compression stroke, fluid will flow from the other side of said piston to said one side and from said chamber to said reservoir, and when said piston moves through a rebound stroke, fluid will flow from said one side of said piston to said other side and from said reservoir to said chamber, said flow restricting means including means defining a fluid passage through said piston, a valve seat formed in said passage and pressure actuated control means carried by said piston for cooperating with said valve seat to control fluid flow through said passage, said control means of said first pair of shock absorbers being selectively adjustable with respect to said valve seat between a first position wherein the resistance to fluid flow through said passage when said piston moves through a compression stroke, is approximately equal to the resistance to flow therethrough when said piston moves through s rebound stroke, and a second position wherein fluid flow through said passage, when said piston moves through a compression stroke, is substantially prevented and, when said piston moves through a rebound stroke, the resistance to fluid flow is decreased relative to the resistance to flow therethrough when said control means are in said first position;

said control means of said second pair of shock absorbers being selectively adjustable with respect to said valve seat between a first position wherein the resistance to fluid flow through said passage where said piston moves through a compression stroke is approximately equal to the resistance to flow therethrough when said piston moves through a rebound stroke, and a second position wherein fluid flow through said passage, when said piston moves through a compression stroke is substantially prevented and, when said piston moves through a rebound stroke, the resistance to fluid flow is increased relative to the resistance to flow therethrough when said control means are in said first position.

2. The direct acting, hydraulic shock absorbers as claimed in claim 1, wherein said tubular structure includes a pair of substantially concentric tubular members, one member being disposed radially interiorly of the other, said one member defining said cylindrical chamber and said other member cooperating with said one member to define said fluid reservoir, and means are provided for closing the opposite ends of said other member, said means for closing the end through which said piston rod extends including a closure cap for sealingly engaging the wall of said other member and a portion of the wall of said one member, said closure cap having a central recess for receiving a packing ring for forming a fluid-tight seal about the portion of said piston rod extending therethrough.

3. The direct acting, hydraulic shock absorbers as claimed in claim 1 wherein said end wall of said cylindrical chamber carries said means for controlling fluid flow between said chamber and said reservoir, said flow controlling means including a first fluid passage through said end wall and first valve means for controlling flow through said first passage frOm said chamber to said reservoir when said piston moves through a compression stroke and second fluid passage through said end wall and second valve means for controlling flow through said second passage from said reservoir to said chamber when said piston moves through a rebound stroke.

4. The direct acting, hydraulic shock absorbers as claimed in claim 1 wherein said means for controllably restricting fluid flow further includes a plurality of grooves formed in the exterior peripheral wall of said piston and valve means carried by said piston for cooperation with said grooves so that when said piston moves through a compression stroke at a predetermined velocity fluid will flow from said other side of said piston to said one side through said grooves and when said piston moves through a rebound stroke, fluid flow through said grooves will be prevented.

5. The direct acting, hydraulic shock absorbers as claimed in claim 1 wherein said piston rod is formed with a fluid passage therein and a radial port is provided in said piston rod at one end of said passage spaced from said piston, the other end of said piston rod passage communicating with said fluid passage in said piston.

6. The direct acting, hydraulic shock absorbers as claimed in claim 1 wherein said pressure actuated control means carried by said piston comprises a cam ring fixed in said passage adjacent said other side of said piston, a retainer member rotatably disposed in said passage and having a surface for cooperation with said cam ring, spring means for maintaining said retainer member in contact with said cam ring, said retainer member and said end wall of said chamber being provided with means interengageable when said piston is moved adjacent to said end wall, said retainer member having a valve pin fixed thereto and extending longitudinally of said passage, a valve movable on said pin toward and from said valve seat, spring means carried by said retainer member for urging said valve into engagement with said valve seat, the end portion of said valve pin remote from said retainer member having portions of differing diameters and said valve having an opening through which said end of valve pin extends so that relative rotation between said piston and end wall when said means are interengaged will effect relative rotation between said retainer member and cam ring to adjust said retainer member inwardly or outwardly of said passage between said first and second positions to increase or decrease the spring load on said valve and to adjust said valve pin with respect to said valve seat between said first and second positions and thereby regulate the clearance between said opening in said valve and said valve pin.

7. The direct acting, hydraulic shock absorbers as claimed in claim 6 wherein said valve pin of said first pair of shock absorbers is formed at its end remote from said retainer member with a cylindrical head portion and a conical neck portion tapering inwardly from said head portion toward said retainer member, said opening in said valve having a diameter such that when said valve pin is in said first position, said neck portion will be disposed therein and a flow passage will be provided between the opening in said valve and said neck portion of said valve pin and, when said valve pin is in said second position, said head portion of said pin will be disposed in said opening so that fluid flow therebetween will be prevented.

8. The direct acting, hydraulic shock absorbers as claimed in claim 7 wherein, in said first pair of shock absorbers, said spring means carried by said retainer member for urging said valve into engagement with said valve seat comprises first and second coil springs disposed generally concentrically of said valve pin, said first spring having a larger diameter than said second spring and a smaller longitudinal dimension so that, when said retainer member is in said second position, said second spring will be in contact with said valve to urge said valve into engageMent with said valve seat and said first spring will be out of contact with said valve and, when said retainer member is in said first position, both of said springs will be in contact with said valve thereby increasing the spring load on said valve.

9. The direct acting, hydraulic shock absorbers as claimed in claim 6, wherein said valve pin of said second pair of shock absorbers is formed at its end remote from said retainer member with a cylindrical head portion and a conical neck portion tapering outwardly from said head portion to a diameter substantially equal to the diameter of the opening in said valve, the diameter of said head portion being less than the diameter of said opening so that, when said valve pin is in said first position, a flow passage will be provided between said valve opening and said valve pin and, when said valve pin is in said second position, fluid flow therebetween will be prevented.