Patent ID: 7520511
Filing Date: 2009-04-21
Classification: F16J,F16L,Y10S

Abstract:
1. An O-ring for a clamp-type joint used in a clamp-type joint for a vacuum apparatus, said joint including a center ring having a concave groove formed therein and an outer ring between which said O-ring is positioned, said O-ring engaging said concave groove at an outer circumference edge of said center ring, wherein the O-ring has a circular arc portion located on a side thereof in contact with the outer ring and wherein, in an unclamped state, the concave groove of said center ring has a circular arc portion which has a radius which is greater than that of said circular arc portion in contact with the outer ring, wherein the outer ring comprises a base forming an outer circumferential side and a pair of brims respectively extending from a top and bottom of the base toward the center axis of the joint, an inner side of the brims comes into contact with the O-ring which is in the form of a convex sector, wherein the radius of the circular arc forms a sector which is in a range of 0.3-2.5 mm, and wherein a thickness (t wherein t 1 is the thickness (mm) of the center ring at a point engaging with the O-ring.