Importance

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Abstract

A well drilling assembly of the type in which a rotary device is attached to a drawworks, for example to the hoisting hook on a derrick, to which rotary device a hollow shaft is coupled, having a threaded end which is adapted for connection to a complementary threaded end on the drill string, and wherein a clamping/lifting means known as an elevator is suspended below the rotary device by two hanger struts. The shaft connected to the rotary device is telescopic. Outside the shaft a lifting means is provided for the lower part of the telescopic shaft. The two hanger struts which carry the elevator for one end of the pipe are means of a sliding holder known as a link hanger. The link hanger is axially movable by means of hydraulic cylinders. The lifting means for the lower part of the telescopic shaft consists of hydraulic cylinders which are constructed as a unit together with the hydraulic cylinders, the cylinders constituting piston rods for the hydraulic cylinders.

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First Claim