A pipe gripping device is taught which is useful for moving pipe into and/or out of a well. The pipe gripping device includes a first set of slips for holding a pipe in a pipe light condition and a second set of slips for holding a pipe in a pipe heavy condition. The second set of slips are actuatable...http://www.google.es/patents/US6199641?utm_source=gb-gplus-sharePatente US6199641 - Pipe gripping device
