One-way pressure activated piston seal

A method for sealing between two elongate members (10a, 10b) movable axially with respect to one another in a one direction with low-leakage, while providing low drag in an opposite direction comprising:

• providing a groove (10c) in one of the two elongate members (10a);
• positioning an o-ring (12) in the groove (10c) in a non-contacting relationship with the other of the two members (10b) when in a non-energized state;
• and
• assembling an energizer ring (14) within the groove (10c) for axially reciprocal movement with respect to the o-ring (12), where the energizer ring (14) moves axially toward the o-ring (12) in response to fluid pressure against a surface (14a) opposite from the o-ring (12) and compresses the o-ring (12) thereby causing radial expansion of the o-ring (12) into sealing contact with the other of the two members (10b).

A solenoid actuated valve (10) for holding pressure and volume of an accumulator with low leakage and for providing low actuation drag during release stroke of the solenoid actuated valve (10) for dumping fluid contents of the accumulator at very low current draw comprising:

• two elongate valve members (10a, 10b) movable axially relative to one another with a groove (10c) formed in one of two valve members (10a);
• an o-ring (12) located within the groove (10c) in non-contacting relationship to the other of the two valve members (10b) when in a non-energized state;
• and
• an energizer ring (14) located within the groove (10c) for axial movement with respect to the o-ring (12), where the energizer ring (14) moves axially toward the o-ring (12) in response to fluid pressure against a surface (14a) opposite from the o-ring (12) and compresses the o-ring (12) causing the o-ring (12) to expand radially outwardly into sealing contact with the other of the two valve members (10b).