A top drive system for drilling with casing includes a casing feeder and a torque head. In one embodiment, the casing feeder is adapted to position a casing for engagement with the torque head. The casing feeder includes a pair of conveying arms for engagement with the casing. Each conveying arm may...http://www.google.fr/patents/US20060000600?utm_source=gb-gplus-shareBrevet US20060000600 - Casing feeder
Numéro de demande: 11/185,281 Numéro de publication: US 2006/0000600 A1 Date de dépôt: 20 juil. 2005 Brevet délivré: US7669662 ( Date de délivrance 2 mars 2010)
