Piston ring formed from ring blank
AssigneeMahle International GmbH
InventorsSteven J. Sytsma, Timothy Andros, Robert J. Piccard
Life of this patent
Estimating the term…
Abstract
A piston ring is formed from a ring blank, e.g., a wire, that has a cross sectional profile including upper and lower surfaces that are generally parallel and disposed between inner and outer peripheral faces. The cross sectional profile also includes a hook area at the outer portion of the lower surface that includes a nose area. The nose area is provided with a radius that is as sharp as possible, and is disposed such that a grinding operation performed on the lower surface, e.g., with a single generally planar grinding surface, will also grind the nose area, thereby truncating the nose area and increasing sharpness of the nose area without having to perform additional machining operations.
Claims21
A method of constructing a piston ring, comprising:
- providing a ring blank having a cross-sectional profile that includes:
- generally parallel upper and lower surfaces disposed between inner and outer peripheral faces;
- a generally tapered nose area that is formed at the bottom of the outer peripheral face, wherein the nose area comprises a nose radius into which the outer peripheral face terminates;
- and
- a hook area adjoining the nose area, wherein the hook area defines a hook shaped groove in an outer portion of the lower surface;
- forming the ring blank into a ring shape;
- and
- grinding the lower surface and a lower portion of the nose area generally simultaneously with a generally planar grinding surface, thereby truncating a lower portion of the nose area while grinding at least a planar portion of the lower surface.
A piston ring, comprising:
- a ring blank formed into a generally annular shape, wherein the ring blank has a cross-sectional profile including:
- generally parallel upper and lower surfaces disposed between inner and outer peripheral faces;
- a generally tapered nose area that is formed at the bottom of the outer peripheral face, wherein the nose area comprises a nose radius into which the outer peripheral face terminates, wherein a lowest portion of the nose area is located so as to be substantially flush to an imaginary line tangent to the lower surface;
- and
- a hook area adjoining the nose area, wherein the hook area defines a hook shaped groove in an outer portion of the lower surface.
Dependencies are inferred from the claim text.