| 摘要 |
A double nut thread friction locking safety cap device assembly consisting of several components, which are so constructed and assembled to resist the rotational effects of external forces. The resistance is achieved by the use and placement of opposing threads (right and left hand threads) with differing threads per inch and the containment of a compressed spring force and the use of the clearance between matching female and male threads. The outer cap nut and inner nut matching threads are axially aligned and the two are threaded together in opposite directions to compress a captured spring(s) or lock washer(s). This preloaded, three part assembly with matching inner female threads on both the outer cap nut and inner nut are axially aligned with each other is then rotated onto the threaded pipe end with matching male threads and is rotated until the pipe end is forced against a sealing surface of the cap nut or a sealing insert installed within the cap nut. Once in place and the pipe end is sealed the outer cap nut and inner nut are rotated in the opposite direction from each other, which transfers the preload to the male threaded pipe threads. This is due to the clearance between the two sets of male and female threads and to the threads per inch difference between the two sets. The outer cap nut and inner nut of the assembly can only be rotated in an opposite direction to each other until they meet the resisting force of the opposite hand thread interaction. The assembly is now in a load condition whereas to loosen itself from the pipe threads it must tighten itself against and overcome the spring force of the spring lock washer(s) or spring(s).
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