Weatherford/lamb, Inc.

Weatherford Oil Tool Gmbh

Hans-Christian Bock

Jorg Erich Schulze-Beckinghausen

Bernd Reinholdt

A power tong assembly wherein a safety latch mechanism includes a power part equipped with two outlet side connections, one of which is connected to a control part for controlling the opening cross section of the tank side connection. The power part has a control element in the form of a piston-shaped valve body with equal sized surfaces on both end faces subject to the pressure of the working medium and with a bore running in the direction of the valve body movement. This bore has a conical extension of its inlet flow end. This blocks the direct connection of the supply with the return to the tank.

Hydraulic safety interlock system

A power tongs for threadedly connecting together pipes which are to constitute casings for boreholes has a platform for a reciprocable slide which supports a power-driven threading clamp and a counter device. The clamp and the counter device are connected to each other by several level compensating hydraulic cylinders each of which is movable horizontally within limits relative to the slide against the opposition of resilient support elements. The upper end portions of the cylinders are connected to a holding plate for the clamp.

Growing community of inventors

Burgdorf, Germany

Hans-Christian Bock