Two position valve with face seal and pressure relief port

1. A shock absorber having a rod guide assembly for housing at least one digital valve assembly, the shock absorber comprising:

a pressure tube defining upper and lower working chambers;

a reserve tube disposed around the pressure tube;

a reservoir chamber being defined between the pressure tube and the reserve tube;

a guide member disposed in the rod guide assembly and forming a sleeve, and having an inlet in communication with one of the upper working chamber and the reservoir chamber, defined by the shock absorber and an outlet in communication with the other of the upper working chamber and the reservoir chamber, one of the inlet and the outlet being formed adjacent a distal end of the sleeve to open directly into the reservoir chamber;

a digital valve assembly having a spool movably disposed within the guide member between first and second positions, the spool movable between the first position, where the spool and the guide member form a face seal, and the second position to establish a flow path from the one of the upper working chamber and the reservoir chamber into the digital valve assembly;

the spool having a side face having a toroidal groove formed with an annular surface facing toward the sleeve, an edge of the toroidal groove forming a seal with the guide member when the spool is in the first position, and wherein the toroidal groove helps to form a portion of a flow path around the spool when the spool is moved into the second position;

a coil assembly disposed adjacent the spool configured to make the spool move between the first and second positions.

2. The shock absorber according to claim 1 , wherein the shock absorber further comprises a second valve assembly disposed between the lower working chamber and the reservoir chamber.

3. A shock absorber having a rod guide assembly for housing at least one digital valve assembly, the digital valve assembly comprising:

a guide member disposed in the rod guide assembly and in fluid communication with an upper working chamber and a reservoir chamber defined by the shock absorber;

the guide member further forming a sleeve;

a digital valve assembly disposed within the guide member, the sleeve defining an inlet flow path in communication with one of the upper and reservoir chambers and an outlet in communication with the other of the upper and reservoir chambers, at least one of the inlet and the outlet formed at a distal end of the sleeve and opening directly into the reservoir chamber;

a spool having a toroidal groove with an annular surface on a sidewall bearing surface thereof, and being movably disposed within the sleeve, the annular surface of the spool facing toward the sleeve, and the spool being movable from a first position abutting a surface adjacent the inlet flow path so as to form a face seal and a second position to establish a flow path from the one of the upper and reservoir chambers into the digital valve assembly using the toroidal groove as part of the flow path; and

a coil assembly disposed adjacent the spool for moving the spool between the first and second positions.

4. The shock absorber according to claim 3 , wherein the sleeve has a first protrusion defining a first metering surface and wherein the sidewall bearing surface is configured to move in relation to the first metering surface to form the face seal.

5. The shock absorber according to claim 4 , wherein the toroidal cavity has the annular surface defined about the first protrusion.

6. The shock absorber according to claim 4 , wherein the spool moves in relation to the sleeve from the first position to the second position in response to a signal sent to the coil assembly, and wherein travel of the spool with respect to the sleeve is limited by interaction of the first surface with the first metering surface.

7. A shock absorber having a rod guide assembly for housing at least one digital valve assembly, the digital valve assembly comprising:

a guide member disposed in the rod guide assembly and in fluid communication with an upper working chamber and a reservoir chamber defined by the shock absorber;

the guide member forming a sleeve;

a digital valve assembly disposed within the sleeve, the sleeve defining an inlet flow path in communication with one of the upper and reservoir chambers and an outlet in communication with the other of the upper and reservoir chambers, the sleeve defining an annular protrusion having an annular protrusion bearing surface, and one of the inlet and the outlet opening directly into the reservoir chamber;

a spool, defining a portion of a toroidal cavity having an annular toroidal bearing surface facing toward the sleeve, the toroidal cavity opening on a sidewall portion of the spool at a distal end of the spool and extending around a full circumference of the distal end of the spool, the spool being movably disposed within the sleeve and movable from a first position abutting the annular protrusion bearing surface so as to form a face seal and a second position to establish a flow path from the one of the upper and the reservoir chambers into the digital valve assembly through the toroidal cavity, and the spool projecting partially into the reservoir chamber when the spool is moved into the second position; and

a coil assembly disposed adjacent the spool for moving the spool between the first and second positions.

8. The shock absorber according to claim 7 , wherein the annular toroidal bearing surface of the spool overlaps the annular protrusion of the sleeve, the annular toroidal bearing surface engaging the annular protrusion bearing surface when the spool is at the first position.