1
Brown Cicero C: Electric power swivel and system for use in rotary well drilling. October 23, 1973: US3766991 (110 worldwide citation)

An electric power swivel for rotating and handling drill pipe during well drilling, adapted for use with either conventional drill pipe or larger diameter casing strings and having fluid pressure cushioned suspension means to accommodate vertical movements required in making up and breaking out thre ...


2
Brown Cicero C: Rotating drive assembly. December 4, 1973: US3776320 (107 worldwide citation)

A rotating drive assembly which may be supported on a vertically movable traveling block suspended in a well derrick. The drive assembly may comprise an elevator assembly adapted for non-threaded engagement with a tubular member, for handling and transmitting torque thereto, and a power source conne ...