Cover seals with latching locking features

1. Seal apparatus comprising:

a cover seal having a body and an extending cylindrical sleeve, the sleeve having a radial internal groove;

a piston having a circumferential groove therein;

a biasing element disposed within the internal and circumferential grooves, said biasing element comprising an elliptical coil spring, the internal groove includes a generally right angle shoulder, the circumferential groove includes an opposing angled shoulder and said elliptical spring is oriented by the right angle shoulder and angled shoulder with a point of contact between said elliptical spring and said angled shoulder spaced apart from an endpoint of a major axis of the spring to provide latching or locking between the seal and said piston; and

surfaces disposed in said internal and circumferential grooves and orienting said biasing element in order to effect sealing between a housing and the sleeve and an axial force to provide latching or locking between the seal and said piston.

2. The seal apparatus according to claim 1 further comprises an elastomer filling said elliptical spring.

3. Seal apparatus comprising:

a cover seal having a body and an extending cylindrical portion, the cylindrical portion having a circumferential groove;

a piston having a bore therein with a radial internal groove;

a biasing element disposed within the internal and circumferential groove; and

surfaces disposed in said internal and circumferential grooves and orienting said biasing element in order to effect latching or locking between the seal and said piston.

4. The seal apparatus according to claim 3 wherein said biasing element comprises an O-ring.

5. The seal apparatus according to claim 3 wherein said biasing element comprises an elliptical coil spring having an elastomer filling said elliptical spring.