ATBECHDEDKESFRGBGRITLILUNLSEMCPTIESILTLVFIROMKCYALJDIM350 (Ver 2.1 Jan 2001) 1620000/00940236EUROPEAN PATENT APPLICATIONA320020109EP99660028.419990217EnEnEn98049019980304FI20020109200202199909081999367 7B 28D 1/14 AdeVerfahren und Vorrichtung zum Bohren von Entwasserungslöchern in einem HohlkernplatteenMethod and apparatus for drilling dewatering holes into a hollow-core slabfrProcédé et dispositif pour forer des trous de déshydratation dans des plaques creuses2Addtek Research & Development Oy Ab02556281302487P.O. Box 9903101 NummelaFIKankkunen, HeikkiKirjurinkatu 703600 KarkkilaFILangenskiöld, Tord Karl Walteret al00082971Oy Jalo Ant-Wuorinen Ab, Iso-Roobertinkatu 4-6 A00120 HelsinkiFIATBECHCYDEDKESFIFRGBGRIEITLILUMCNLPTSEALLTLVMKROSI20020109200202

Method and apparatus for drilling dewatering holes into the lower surface of a concrete hollow-core slab (5). The apparatus comprises at least two drills (10) connected with a slab lifting crane. The drills (10) are attached to a detachable beam (9), and the apparatus is provided with at least two interchangeable beams with different mutual distances between the drills. The beam (9) is fastened to the apparatus by means of a quick-release fastener.