Patent ID: 7654369

Claim:
A piston for a vibration damper that has a cylinder and a piston assembly with a rod extending out of the cylinder, the piston assembly includes a piston slideably received within the cylinder thereby defining a first chamber and a second chamber on opposite sides of the piston, with each chamber having fluid therein, the piston comprising: a piston body that has a bore, a first aperture extending from the bore to the first chamber, a second aperture extending from the bore to the second chamber, and a pilot passage opening into the bore and opening into the second chamber; a primary valve spool moveably received within the bore thereby defining a pilot chamber in the bore, wherein different positions of the primary valve spool in the bore control fluid flow between the first aperture and the second aperture; a control orifice that is directly connected to the first chamber and is directly connected to the pilot chamber; a pilot valve member disengaged from the primary valve spool and having a surface defining a variable orifice between the pilot passage and the pilot chamber; and an actuator operably connected to move the pilot valve member in response to a control signal.