(19)

(11)

EP 1 809 853 A2

(12)

(88) Date of publication A3: 24.08.2006 (43) Date of publication: 25.07.2007 Bulletin 2007/30 (21) Application number: 05816992.1 (22) Date of filing: 20.10.2005

(51) International Patent Classification (IPC):  E21B 7/26(2006.01) E21B 11/02(2006.01) E21B 1/30(2006.01) (86) International application number: PCT/US2005/038123 (87) International publication number: WO 2006/047386 (04.05.2006 Gazette 2006/18)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (30) Priority: 25.10.2004 US 621970 P (71) Applicant: Allied Construction Products, LLC Cleveland OH 44114 (US)	(72) Inventors: PRESTON, Duane Mentor, OH 44060 (US) GRABNIC, Michael Walton Hills, OH 44146 (US) MARSALEK, Dan South Euclid, OH 44143 (US) (74) Representative: RACKETTE Partnerschaft Patentanwälte  Kaiser-Joseph-Strasse 179 79098 Freiburg 79098 Freiburg (DE)