For pipe fitting attached a screw with a fatigue resistance, the elements of a lighted tube-shaped screws and pipe joint attached to screw the resulting

摘要

(57) In particular, load Frank sides with respect to (13), screw with the [summary] screw tube element has multiple tangent intersection area radius of one (21) at least in the screw base. (21) has a (23) Principal arc with (rp1) radius cut Frank (13) in (PRF1) point support circle this area. The tangent at (PRF1) point to this circle, make a (D) positive angle correctly (13) and Frank. Second arc having the (rT1 and rS1) radius less than (rp1) radius (25, 27), Frank relative to (13), screw base for (19), the tangential intersection of the principal arc one hand bring. Radius (rp1), and passes through the (PRF1) and standard point-circles at each intersection of the tangent area alone radius of (29) (rH1) larger. Screw such elements provides a threaded fitting that incorporates good resistance to repetitive stress and static.