Patent attributes
In a high-pressure cylinder with an axial plunger, a seal assembly for scaling the gap between the cylinder wall and the plunger. The assembly is disposed in an annual recess in the wall having an open end and a bottom opposite thereto, and comprises a plunger-sealing ring, a cylinder-sealing ring, a resilient low-pressure ring, and an annual seal holder. The seal holder urges the plunger-sealing ring against the cylinder-sealing ring and the low-pressure ring, and urges the latter two rings against the recess bottom and against each other. The plunger-sealing ring and the cylinder-sealing ring are metallic, their mutual contact surfaces are fitted to each other, and the plunger-sealing ring has sufficient section modulus to ensure that under high pressure the contact and bending deformations at the mutual contact surfaces will be sufficiently small as to keep a tight fit therebetween.