Adjustable shock absorbers

In a shock absorber including a body defining a cylinder, a piston in the cylinder, a rod for the piston having one end extending out of the cylinder and wherein the shock absorber includes means for securing the body and the end of the piston rod to a vehicle, the improvement in which:

• the piston rod is hollow and the shock absorber includes an adjusting rod extending into the piston rod and said adjusting rod is longitudinally and rotatably movable with respect to said piston rod;
• wherein the relative positions of the piston and rod combination control flow through at least one restricted flow path between opposite sides of the piston in the cylinder and
• wherein longitudinal relative movement of the adjusting rod with respect to the hollow piston rod makes a first adjustment in the flow in said at least one flow path and relative rotational movement of the adjusting rod with respect to the hollow piston rod makes a second adjustment in the flow in one of the flow paths between opposite sides of the piston;
• including at least one rebound flow path and one compression flow path, each of said flow paths including thermally responsive means included in at least said one flow path for independently restricting flow therethrough as the temperature of said thermally responsive means increases;
• wherein said thermally responsive means comprises at least one washer encircling said adjusting rod and bearing on flow control elements in the shock absorber to change their flow controlling position as a function of temperature.

A shock absorber comprising:

• a body defining a tubular cylinder;
• means closing one end of said cylinder;
• an end fitting for said shock absorber at said end including said closing means;
• a piston axially moveable within said tubular cylinder;
• a hollow piston rod secured to said piston and having one end extending into said cylinder and the opposite end extending out of said cylinder;
• a second end fitting for said shock absorber secured to said opposite end of said hollow piston rod;
• said piston having a pair of opposite faces and including at least one fluid flow passage for allowing fluid communication between opposite faces;
• means sealing said piston rod to said cylinder;
• whereby said cylinder end fitting and said piston define one variable volume chamber within said cylinder and said cylinder, piston and said piston rod sealing means defines a second variable volume chamber within said chamber;
• an adjusting rod within said hollow piston rod and extending from said piston region to said opposite end region of said hollow piston rod;
• means secured to said adjusting rod and responsive to longitudinal movement of said adjusting rod for changing the flow restriction characteristics of said fluid flow passage;
• means secured to said adjusting rod and responsive to rotational movement of said adjusting rod for changing the flow characteristics of said fluid flow passage;
• first means external to said cylinder for selectively moving said adjusting rod longitudinally to effect a change in said flow characteristics;
• and
• said means external to said cylinder for selectively rotating said adjusting rod to effect a different change in the flow characteristics of said flow characteristics.

A shock absorber comprising:

• a body defining a tubular cylinder;
• means closing one end of said cylinder;
• an end fitting for said shock absorber at said end including said closing means;
• a piston axially moveable within said tubular cylinder;
• a hollow piston rod secured to said piston and having one end extending into said cylinder and the opposite end extending out of said cylinder;
• a second end fitting for said shock absorber secured to said opposite end of said hollow piston rod;
• said piston having a pair of opposite faces and including at least one fluid flow passage for allowing fluid communication between opposite faces;
• means sealing said piston rod to said cylinder;
• whereby said cylinder end fitting and said piston define one variable volume chamber within said cylinder and said cylinder, piston and said piston rod sealing means defines a second variable volume chamber within said chamber;
• an adjusting rod within said hollow piston rod and extending from said piston region to said opposite end region of said hollow piston rod;
• means secured to said adjusting rod and responsive to longitudinal movement of said adjusting rod for changing the flow restriction characteristics of said fluid flow passage;
• means secured to said adjusting rod and responsive to rotational movement of said adjusting rod for changing the flow characteristics of said fluid flow passage;
• first means external to said cylinder for selectively moving said adjusting rod longitudinally to effect a change in said flow characteristics;
• and
• second means external to said cylinder for selectively rotating said adjusting rod to effect a different change in the flow characteristics of said flow characteristics;
• wherein said flow passage includes a pair of variable flow restrictors in series in the flow path between opposite sides of said piston whereby the operating characteristics of said shock absorber is a function of the combined effects of said flow restrictors with one of said flow restrictors being varied by rotation of said adjusting rod and the other of said flow restrictors being varied by longitudinal movement of said adjusting rod.