Patent ID: 7188841
Filing Date: 2007-03-13
Classification: F16J

Abstract:
1. A secondary sealing system for an internal combustion engine having at least one axially extending cylinder bore, a piston receivable within the cylinder bore and having an outer annular groove extending radially inwardly of an outer periphery of the piston, and a ring seal seated in the outer annular groove, a radial outer surface of the ring seal extending radially outwardly of the outer periphery of the piston to selectively engage an inner surface of the cylinder bore, a leak path from combustion gases being formed by the cylinder bore, the piston and the ring seal and the outer annular groove, the secondary sealing system comprising: a piston surface providing a first seat; a ring seal surface providing a second seat; a secondary seal with a generally annular body and an inner end and an outer end disposed between the piston and the ring seal, the inner end of the secondary seal engaging the first seat and the outer end of the secondary seal engaging the second seat, the seconds seal being selectively subjected to an axial force to controllably limit tae amount of outward radial excursion of the ring seal; wherein the leak path further includes the secondary seal, the leak path selectively receiving combustion gasses for applying the axial force upon the secondary seal; and wherein the secondary seal has a first pivot point located at a first distance radially outward from the inner end of the secondary seal and a second pivot point located at a second distance radially outward from the inner end of the secondary seal, the second seat being axially disposed from the first seat relative to the cylinder bore, the secondary seal selectively pivoting about the first and second pivot points to move the ring seal with respect to the outer annular groove.