(19)
(11) EP 0 748 923 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.10.1997 Bulletin 1997/44

(43) Date of publication A2:
18.12.1996 Bulletin 1996/51

(21) Application number: 96109669.0

(22) Date of filing: 17.06.1996
(51) International Patent Classification (IPC)6: E21B 17/042
(84) Designated Contracting States:
DE FI GB IE SE

(30) Priority: 16.06.1995 GB 9512250

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

(72) Inventors:
  • Roberts, Nigel
    Co Tipperary (IE)
  • O'Brien, John
    Limerick (IE)
  • Andersson, Kjell
    433 63 Savdalen (SE)
  • Loughlin, Derek
    Co Kildare (IE)

(74) Representative: Copp, David Christopher 
Dummett Copp, 25 The Square, Martlesham Heath
Ipswich, Suffolk IP5 7SL
Ipswich, Suffolk IP5 7SL (GB)

   


(54) Drill rod


(57) A drill string for rock drilling has a drill rod with, at the bit end, a female threaded socket (4). The bit has a male threaded shank which (16) screws into the socket. The socket may additionally have an external male thread (3).






Search report