(19)
(11) EP 0 419 436 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.12.1991 Bulletin 1991/49

(43) Date of publication A2:
27.03.1991 Bulletin 1991/13

(21) Application number: 90850317.0

(22) Date of filing: 24.09.1990
(51) International Patent Classification (IPC)5: B25B 23/14, B25B 23/145, B25B 23/147
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 22.09.1989 SE 8903135

(71) Applicant: ATLAS COPCO TOOLS AB
S-104 82 Stockholm (SE)

(72) Inventor:
  • Hansson, Gunnar Christer
    S-114 59 Stockholm (SE)

(74) Representative: Pantzar, Tord 
Atlas Copco Tools AB Patent Department
105 23 Stockholm
105 23 Stockholm (SE)


(56) References cited: : 
   
       


    (54) Method and device for tightening threaded joints


    (57) The invention relates to a method and a device for tightening threaded joints by applying torque on the joint by means of a power tool until a predetermined pretension level in the joint is reached, whereupon a control means connected to the power tool is arranged on one hand to initiate power shut-off and on the other hand to initiate continued successively decreasing power supply to the tool as the predetermined pretension level is passed.







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