Piston ring
AssigneeBorgo-Nova SpA
InventorLudovico Bruni
Life of this patent
Estimating the term…
Abstract
An oil control piston ring is described comprising a pair of axially spaced apart side rails, the side rails each having a radially outer periphery forming a rubbing face with a co-operating cylinder wall, an expander having portions which lie between the inner radially extending faces of the side rails and maintain the outer peripheral rubbing faces thereof in a spaced apart relationship characterized in that the radially inner peripheral edge of each side rail is connected by bridging members extending intermittently over at least a part of the inner circumferential length. The side rails and bridge members may be formed from a substantially flat bottomed "U-shaped" channel section.
Claims11
A 2-piece oil-control piston ring, the ring comprising a first piece having a pair of axially spacedapart side rails, the side rails each having a radially outer periphery for forming a substantially continuous uninterrupted rubbing face with a cooperating cylinder wall and having a radially inner periphery, said inner peripheries being connected together by axially directed bridging members extending intermittently around at least a part of the inner circumferential length of said rails, a separate second piece in the form of an expander lying against the radially inner faces of the axially directed bridging members for expanding said side rails radially outwardly against a cooperating cylinder wall and having spring portions which lie between the inner, radially extending faces of the side rails, wherein the side rails diverge from said bridging members by up to 20.degree. such that the axially outer faces of said rails will bear against and form a gas seal with portions of radial side faces of a cooperating piston ring groove in which said 2-piece ring is mounted.
In combination, a piston having a piston ring groove and a 2-piece oil-control piston ring mounted in said groove, the ring comprising a first piece having a pair of axially spaced-apart side rails, the side rails each having a radially outer periphery for forming a substantially continuous uninterrupted rubbing face with a cooperating cylinder wall and having a radially inner periphery, said inner peripheries being connected together by axially directed bridging members extending intermittently around at least a part of the inner circumferential length of said rails, a second piece in the form of an expander lying against the radially inner faces of the axially directed bridging members for expanding said side rails radially outwardly against a cooperating cylinder wall and having spring portions which lie between the inner, radially extending faces of the side rails, said side rails diverging from said bridging memebers by up to 20.degree. such that the axially outer faces of said rails bear against and form a gas seal with portions of radial side faces of said piston ring groove.
Dependencies are inferred from the claim text.