Patent ID: 7878554

Claim:
A coupling device, comprising: a tubular body having a first end and a second end configured to co-operate, respectively, with a first duct and a second duct, the first end configured to engage a threaded portion within an end portion of the first duct; and an anchor washer, configured to be fitted within the end portion of the first duct, the anchor washer comprising a planar annular portion surrounding a central axis and configured to be received in a groove on the first end of the tubular body, the anchor washer further comprising at least one tooth extending from the annular portion, the at least one tooth having an inner radial face, an outer radial face, two side surfaces, and two coupling surfaces, wherein the outer radial face is a sliding surface facing away from the central axis, the sliding surface extending continuously between a topmost and a bottommost portion of the tooth, the sliding surface further continuously extending from a first coupling surface connected to a first of the two side faces and a second coupling surface connected to a second of the two side faces, wherein the at least one tooth is inclined relative to the central axis such that the tooth is oriented outwardly from a center of the annular portion, wherein the at least one tooth is shaped such that at least one of the coupling surfaces is distanced from the sliding surface such that the at least one of the coupling portions is configured to be maintained at a distance from the wall of the first duct when the tubular body, with the anchor washer received in the groove, is inserted into the threaded end portion of the first duct, and wherein the coupling surfaces are selected from the group consisting of i) chamfered surfaces, ii) convex shaped surfaces, and iii) rounded surfaces, to prevent the at least one tooth damaging the threaded surface within the end portion of the first duct.