公开(公告)号：US3598188A

公开(公告)日：1971-08-10

申请号：US3598188D

申请日：1969-05-22

Applicant: JAMES FOSTER

Inventor： FOSTER JAMES

IPC: E21B3/04

CPC classification number: E21B3/04

Abstract: An apparatus and method for rotating a kelly and drill string by the rotary of a drilling apparatus at a speed different than the speed of the rotary. The apparatus generally includes a housing or bushing spaced about the kelly which passes through the table, the housing or bushing being adapted to be received and rotated by the rotary. An anchor ring gear is provided concentrically within the housing and extends therefrom for attachment to the drilling apparatus structure. Epicyclic or planetary gear means couple with the bushing or housing and mesh with the anchor ring gear to transmit rotary motion from the housing to the kelly. Additionally, holding means secure the anchor ring gear to the drilling apparatus structure.