| CPC E21B 40/00 (2013.01) | 13 Claims |

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1. A ball-clamp type fall arrester for a drill pipe, comprising a base (1) and a steel ball seat (2) arranged in the base (1), wherein the steel ball seat (2) is provided with a liftable steel ball frame (3), a side wall of the steel ball frame (3) is provided with a plurality of limit holes (31), an inner wall of the steel ball seat (2) is provided with a guide ramp (20), each limit hole (31) is provided with a steel ball (4) which is movable radially, and wherein when the steel ball frame (3) is lifted or lowered, a radial position of each steel ball (4) in a corresponding limit hole (31) is positioned by the guide ramp (20), wherein the base (1) is provided with a fork (11), which is rotatably arranged on the base (1) through a pin (13), a top of the steel ball frame (3) is provided with a flange (32) extending radially outwardly, a front end of the fork (11) is clamped at the steel ball frame (3) and abuts against the flange (32).
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