(19)

(11)

EP 2 035 702 A2

(12)

(88) Date of publication A3: 27.11.2008 (43) Date of publication: 18.03.2009 Bulletin 2009/12 (21) Application number: 07798436.7 (22) Date of filing: 12.06.2007

(51) International Patent Classification (IPC):  F04B 17/00(2006.01) F04B 35/04(2006.01) E21B 19/18(2006.01) (86) International application number: PCT/US2007/070989 (87) International publication number: WO 2007/146931 (21.12.2007 Gazette 2007/51)

(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 MT NL PL PT RO SE SI SK TR Designated Extension States: AL BA HR MK RS (30) Priority: 12.06.2006 US 812795 P (71) Applicant: Unico, Inc. Franksville, WI 53126-0505 (US)	(72) Inventors: BECK, Thomas L. Union Grove, Wisconsin 53182 (US) ANDERSON, Robb G. Eden Prairie, Minnesota 55347 (US) PETERSON, Ronald G. Racine, Wisconsin 53405 (US) MACDONALD, Michael A. Racine, Wisconsin 53402 (US) (74) Representative: Copsey, Timothy Graham et al Kilburn & Strode, 20 Red Lion Street London WC1R 4PJ London WC1R 4PJ (GB)