Thread structure for percussion drill elements
Номер патента: CA1122424A
Опубликовано: 27-04-1982
Автор(ы): John M. Holmberg
Принадлежит: Boart International Ltd
Опубликовано: 27-04-1982
Автор(ы): John M. Holmberg
Принадлежит: Boart International Ltd
Реферат: A B S T R A C T A coupling thread structure for percussion drill elements including a rod having an external thread and a sleeve having an internal thread with the threads, when the sleeve and rod are coupled, having abutting and non-abutting flanks and with the flanks being joined by bottom and crest portions, wherein the threads have at least two starts; the abutting flanks are substantially straight along their whole abutting contact portions and form an angle of between 10°and 25°, preferably 15° to 20°, with the drill axis; the pitch angle of the threads is in the range 9° to 20°, preferably 11° to 16°; the crest portions are substantially straight and intersect the abutting flank portions at a well defined edge ; the non-abutting flanks have a flank angle which is considerably greater than that of the abutting flanks ; the flank angle of the non-abutting flanks is in the range 50° to 80°, preferably 65°to 75°, with respect to the drill axis; and the bottom portions of the threads are curved.
Segmented ring mounting for a fluid-operated percussion drill tool
Номер патента: EP1004744A3. Автор: Joseph Purcell. Владелец: Minroc Technical Promotions Ltd. Дата публикации: 2001-05-02.