Patent Number: 6,308,940

Title: Rotary and longitudinal shock absorber for drilling

Abstract: A rotary and longitudinal shock absorbing apparatus with an mandrel therein is connected to a drill string assembly to absorb abnormal longitudinal shocks and abnormal torsional shocks by cooperating hydraulic and mechanical means, while allowing communication of drilling fluid through the body of the apparatus. The construction of the apparatus is such that torque shock absorbing action is independent of the longitudinal shock absorbing action and the apparatus provides balanced internal and external pressure to permit its operation at all levels of hydraulic pressure.

Inventors: Anderson; Edwin A. (Houston, TX)

Assignee: Smith International, Inc.

International Classification: E21B 17/07 (20060101); E21B 17/02 (20060101); F16F 009/18 ()

Expiration Date: 10/30/2018