(19)
(11) EP 0 182 551 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
30.09.1987 Bulletin 1987/40

(43) Date of publication A2:
28.05.1986 Bulletin 1986/22

(21) Application number: 85308116

(22) Date of filing: 07.11.1985
(84) Designated Contracting States:
AT BE CH DE FR GB IT LI LU NL SE

(30) Priority: 20.11.1984 GB 8429287

(71) Applicant: ALH SYSTEMS LIMITED
 ()

(72) Inventor:
  • Carruthers, Alec Reginald
     ()

   


(54) Mole


(57) A ground boring tool known as a mole is fitted within its conical head (1) with a pneumatic-powered rotatory vibrator (8) which generates severe radial vibrations. As a result the progress of the mole through resistant ground is speeded or made possible. The mole also may be used for upgrading existing ducts with or without the destruction of an existing lining to such ducts. For destruction of existing linings elongate ridges (16) may be positioned on the surface of the cone.






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