(19)
(11) EP 0 979 922 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
17.01.2001 Bulletin 2001/03

(43) Date of publication A2:
16.02.2000 Bulletin 2000/07

(21) Application number: 99305930.2

(22) Date of filing: 26.07.1999
(51) International Patent Classification (IPC)7: E21B 17/042
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 30.07.1998 GB 9816494

(71) Applicant: BOART LONGYEAR LIMITED
Co Clare (IE)

(72) Inventors:
  • Roberts, Nigel
    Birdhill, County Tipperary (IE)
  • Yao, James
    Mississauga Ontario Canada L5M 5E5 (CA)

(74) Representative: Copp, David Christopher et al
25 The Square Martlesham Heath
Ipswich, Suffolk IP5 3SL
Ipswich, Suffolk IP5 3SL (GB)

   


(54) Tube rod


(57) A tube rod for rock drilling has a female threaded end (12) into which a male thread (either on a male connector or on the end of another tube rod) can be screwed to form part of a drill string. The female threaded end (12) is (a) of larger external diameter than the central section (10) of the rod and (b) has an annular groove (42%) with an asymmetrical profile, the flank of this groove nearest to the threaded end being steeper than the other flank.






Search report