Patent ID: 6267384
Filing Date: 2001-07-31
Classification: F16J

Abstract:
An improved thin 3-piece oil ring (1) of an axial width not greater than 2 mm, having a corrugated spacer expander (2) of a circumferentially successive, substantially U-shaped configuration, and circular, upper and lower side rails (3, 4) holding said spacer expander (2) therebetween; said spacer expander (2) having circumferentially spaced outer crowns (5) and circumferentially spaced inner crowns (6); each said outer crown (5) being connected with next adjacent ones of said inner crowns (6) on opposite sides thereof by a pair of connecting members (11); said spacer expander (2) having both of the most-end portions thereof extended radially outwardly from the most-end one of said inner crowns (6) thereof forming abutting members (15, 16) for abutting each other at the point of force (P); said outer crowns (5) at the upper and lower ends thereof having protrusions beyond the axial width of said outer crowns (5) forming upper and lower, outer supporting members (7, 8) bearing against the lower and upper sides of said upper and lower side rails (3, 4), at the outer portion thereof, respectively; said upper and lower, outer supporting members (7, 8) each having an angular-shaped cross section with the angled top thereof bearing against said lower and upper sides of said upper and lower side rails (3, 4), respectively, said angled top being positioned radially inwardly apart from the outer circumferential surface of said upper and lower, outer supporting members (7, 8) by a distance not less than 40% and not more than 50% of the radial width of said upper and lower, outer supporting members (7, 8); said inner crowns (6) at the upper and lower ends thereof having extensions beyond the axial width of said inner crowns (6) forming upper and lower, inner supporting members (9, 10) bearing against the inner edges of said upper and lower side rails (3, 4), respectively; each said connecting member (11) having a radially elongated oil slot (13) made therethrough; each said abutting members (15, 16) having a radially elongated guide bar slot (14) made therethrough; said spacer expander (2) having a guide bar (12) inserted through said guide bar slots (14) and a plurality of said oil slots (13), at least one portion of said guide bar (12) being fixed to said spacer expander (2) by caulking; wherein said guide bar slots (14) have the axial width thereof made equal to the outer diameter of said guide bar (12).