DRILLING DEVICE WITH IMPROVED AUTOMATIC DISCONNECTING TONGS Russian patent published in 1998 - IPC

FIELD: mining machinery and equipment. SUBSTANCE: this relates particularly to drilling devices used for drilling blast holes. Drilling device has base frame, mast located on base frame, automatic disconnecting tongs intended for turning one section of drill pipe relative to other pipe section for their disconnection. Tongs have clamping jaw which is operated by power cylinder. Force transmitted by power cylinder to jaw located at drill pipe side does not reduce clamping effort. Unscrewing power cylinder is located so that torque created by power cylinder presses tongs against pipe. Drilling device is also provided with turning unit which is adapted for turning relative to mast. Turning of this unit is guided by three pins. Clamping jaw can be turned on one of pins which guide motion of turning unit. Mounted on turning unit is grip, and at least one gasket is located between grip and clamping jaw. Method of fixing gaskets ensures their convenient setting and removal. Application of aforesaid embodiment of drilling device provides for convenient operation with pipes of various diameter at required effort without disturbing of pipe joints. EFFECT: higher efficiency. 13 cl, 10 dwg