Patent ID: 7216871

Claim:
A non-contacting seal for sealing a gap between a rotating and non-rotating surface, the seal comprising: an outer support member; at least one segment including: a.) an inner pad spaced from the outer support member and having a wear resistant layer disposed on an inner diameter of the pad; b.) at least one lift-off geometry formed on the inner diameter of the wear resistant layer; c.) at least one finger spring supported at a first end by the inner pad and extending at an angle with respect to the inner pad and into contact with the outer support member, the at least one finger having a width, thickness and a length; a cover supported by the outer support member and the inner pad on an upstream, high pressure side of the seal, the cover being constructed and arranged to avert leakage through the space disposed between inner pad and the outer support member; and wherein the length, width, thickness and angle of the at least one finger spring are selected so that the spring is compliant in a radial direction during operation such that the at least one segment can be displaced radially by an opening force generated by the lift-off geometry of the inner pad, and wherein the spring remains sufficiently stiff so as to provide support to the cover against the upstream high pressure.