GB682683A - Improvements in deep boring installations - Google Patents

Abstract

682,683. Boring apparatus. ROTHE, V. Sept. 29, 1949 [Oct. 19, 1943], No. 25076/49. Class 85 [Also in Groups XXII, XXIII and XXXVI] In a well drilling assembly, a plurality of strings of drill tools are each supported from one of a number of arms on a pillar derrick and each tool string has incorporated therein a motor which, with the means for raising and lowering the string, is automatically controlled by electrical contacts incorporated i n said structure. The upper unit of the drill string comprises a centring and clamping unit the base of which is recessed to receive a pin formed on the casing of an electric motor for driving the bit. On the bit encountering the bottom, electrical switches 28 are operated as the assembly slides down around the pin 23 towards the drill, so starting the drill motor and stopping the winch. The drill motor is stopped and the winch restarted when contact 27 is operated as the pin descends in the assembly. The drill string is raised until a switch is tripped to stop the winch and another string is moved into position for the next operation. The borehole casing is held by jaws in a sleeve externally threaded and engaging in complementary internal threads formed in a sleeve externally threaded to engage the base. Centrifugally operated internal pipe cutters, cam operated side sampling tools, and percussive drills are provided on the drill shaft. The Specification as open to inspection under Sect. 91, describes also how each string is supported from one of a number of arms formed on a rotatable sleeve on a pillar that is mounted on a portable base and carries a pulley over which passes the main portion of the supporting cable. The connection between the main portion of the cable and that portion supporting the drill string is formed as an electrical socket the two halves being connected together on a sealing ring. This subject-matter does not appear in the Specification as accepted.