(19)
(11) EP 0 462 821 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
27.01.1993 Bulletin 1993/04

(43) Date of publication A2:
27.12.1991 Bulletin 1991/52

(21) Application number: 91305550.5

(22) Date of filing: 19.06.1991
(51) International Patent Classification (IPC)5: E21B 4/14, E21B 7/26
(84) Designated Contracting States:
AT BE CH DE DK ES FR GB GR IT LI LU NL SE

(30) Priority: 20.06.1990 US 541054

(71) Applicant: ALLIED STEEL & TRACTOR PRODUCTS, INC.
Solon Ohio 44139 (US)

(72) Inventor:
  • Baron, Michael
    Orange, Ohio 44122 (US)

(74) Representative: Senior, Alan Murray et al
J.A. KEMP & CO., 14 South Square, Gray's Inn
London WC1R 5LX
London WC1R 5LX (GB)


(56) References cited: : 
   
       


    (54) Swivel assembly for a pneumatic underground piercing tool


    (57) A swivel assembly (48) for supporting a valve sleeve (41) in a cavity of a striker (28) in a pneumatic underground piercing tool. A valve supporting means (51,52) supports the valve sleeve (41) on a valve body (40) by cooperating spherical seat and bearing members (56,57) to allow angular movement between the valve sleeve (41) and valve body (40). A retaining mechanism (64) is provided for resiliently securing the valve supporting means (51,52) to the valve body (40).






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