Methods to Increase Friction on Threaded Back-Up Rings
Publication Date: 2014-Apr-30
The IP.com Prior Art Database
Modifications made to the surface on the outer diameter of a threaded back-up ring as shown in attached drawing below describing outer diameter surface defined by .635"/.645" reference linear, .370"/380" radius and tangent surface at 40 degree angle,) can be utilized to increase the coefficient of friction with mating surfaces in production casing. Increased friction between mating surfaces can help prevent movement of the threaded back-up ring with respect to the production casing, thereby preventing rollover (or other failure modes) of the threaded back-up ring when exposed to high loads. This concept is different from existing designs that utilize a smooth, cylindrical surface on the outer diameter of the threaded back-up ring. Numerous methods and features exist that can be added to the surface on the outer diameter of the threaded back-up rings, alone or in combination, to increase the coefficient of friction between mating surfaces, such as : 1) wickers, 2) buttress threads, 3) special profiles or geometry, 4) sharp edges, 5) grooves, 6) knurling, 7) rough surface finish, 8) abrasive coatings, 9) abrasive adhesive materials, 10) dimpling, and 11) general surface imperfections. Any new designs would be based on the attached drawing and would be similar in geometry with exception to new features added to the surface on the outer diameter to produce the aforementioned effect.