Adjustable shock absorber

Claim 1

In an adjustable hydraulic shock absorber, the combination comprising: a. a piston cylinder filled with fluid and having one end enclosed by a cylinder head and having port means at the other end thereof; b. a fluid accumulator means connected to said port means for receiving fluid under pressure from said port means during a shock absorbing operation and for returning fluid to the port means after a shock absorbing operation; c. a fluid metering tube means filled with fluid and supported axially in said piston cylinder and provided with a plurality of fluid metering orifices communicating the interior of said metering tube means with said piston cylinder and providing a controlled flow of fluid from said metering tube means during a shock absorbing operation; d. a piston means slidably mounted in said piston cylinder and being telescopically mounted over said metering tube means for receiving a shock and for absorbing said shock during an inward movement from an initial position into the piston cylinder, and which is adapted to be moved outward to said initial position after the shock absorbing inward movement; e. adjustment means operatively connected to said metering tube means for adjusting the effective cross sectional area of said metering orifices to adjust the flow of metered fluid through said metering tube means to provide a controlled shock absorbing inward movement of said piston means; f. a first fluid passage means connecting the interior of said metering tube means to said port means for passage therethrough of fluid forced from the piston chamber and into said metering tube means during an inward shock absorbing movement of said piston means, and, a second fluid passage means connecting said port means to said piston cylinder during an outward movement of said piston means to said initial position for transferring fluid from said accumulator means to said piston cylinder; g. said fluid metering tube means comprising a fixed metering tube having a plurality of metering orifices, and an adjustable metering tube having a plurality of metering orifices adapted to be aligned with said metering orifices in said fixed metering tube and being connected to said adjustment means; h. said piston means including a tubular piston rod for telescopically receiving the inner end of said fluid metering tube means; i. said fixed metering tube having the outer end supported by said cylinder head; j. said adjustable metering tube being rotatably mounted within said fixed metering tube and being rotatably supported by said cylinder head and being connected to said adjustment means; k. said first fluid passage means including a plurality of ports formed through the inner end of said fixed metering tube which communicate with the interior of the metering tube means, and a first plurality of communicating passages through said piston means for connecting the interior of said meterinG tube means with said first named port means during an inward movement of said piston means; and l. said second fluid passage means including a second plurality of passages formed through said piston means and connected to said first plurality of passages through said piston means and communicating the piston cylinder with said port means, and each of said second plurality of passages through said piston means having a ball check valve operatively mounted therein for closing said second plurality of passages during a shock absorbing inward movement of said piston means and for opening said second plurality of passages during an outward movement of said piston means.