US Patent 7543650 Quill saver sub

A saver sub assembly has a body capable of coupling with a quill, and a split ring capable of coupling with the quill and the body and capable of keeping the quill and body together. The body has splines to prevent relative rotation between the quill and the body. The body may be hollow, and/or have a split ring retainer to maintain the position of the split ring. The saver sub assembly may also have one or more O-rings positioned between the body and the quill. The body of the saver sub assembly may have a threaded pin for engaging a drill string.