Claims
- 1. A hydraulic impact tool for use in a well having a control valve (22, 20; 45, 43) adapted to be influenced through an increase of the fluid flow rate, said impact tool adapted to supply impact energy to an object stuck in the well in order to loosen the object or to crush it, and which comprises:
- an elongate tubular housing (1) for flow of fluid therethrough in the longitudinal direction and for, in a longitudinal upstream portion thereof, accommodating an end piece (8) having an axial through-going fluid channel and carrying the impact hammer (9) as well as being connected to a hydraulic, axially displaceable piston (16; 41) having an axially through-going channel (20; 43), and wherein an axially displaceable sealing body (22; 45) is adapted to close or expose, respectively, one orifice of the piston channel (20; 43), so that hydraulic power developed by fluid under pressure supplied to the impact tool in the closed position of the piston channel (20; 43) can displace the piston (16; 41) and the hammer (9) as well as tension a spring assigned to the hammer (9), said spring being released in tensioned condition when said piston channel orifice is exposed upon the following axial displacement of the sealing body (22; 45), to move the hammer (9) to bear against a stop (10) in order to impact, simultaneously as the piston (16; 41) returns to the inoperative position of readiness, wherein said sealing body (22; 45) has an elongate, axially extending stem which, upstreamly, terminates into a head (23; 46) formed with a downstreamly conical sealing face (23') for resting sealingly against a complementarily shaped, upstream seat face (21; 44) in said piston channel orifice, the axially extending stem passing with clearance through the piston channel (20; 43) upon closed as well as open piston channel (20; 43) and, with its downstream portion, is axially displaceably mounted in an axially movable slide (25; 48) formed with longitudinal, through-going fluid passage grooves (26), a spring (27; 49) being tensioned between the sealing body (22; 45) and the slide (25; 48), said spring attempting to direct the sealing body (22; 45) toward an end position where the conical sealing face (23') on the head (23; 46) thereof does not bear sealingly against the seat face (21; 44) of the piston channel (20; 43) at said orifice, the slide (25; 48) having a spring (29; 50) forcing the slide (25; 48) in a position in which the sealing body (22; 45) exposes the piston channel (20; 43) so that, when the fluid flow rate through the impact tool is increased sufficiently, the sealing body (22; 45) is moved to rest sealingly against the piston (16; 41) in order to initiate impact action.
- 2. A hydraulic impact tool as defined in claim 1, wherein the head (23; 46) of the sealing body (22; 45), besides its conical sealing face (23') facing in the downstream direction and periodically cooperating sealingly/closingly with the seat face (21) at the upstream orifice of the piston channel (20; 43), is formed with an oppositely directed, conical sealing face (23") adapted to cooperate with a complementary seat face (15') formed at the downstream orifice of said axially through-going channel (15) through said hammer-carrying end piece (8).
- 3. A hydraulic impact tool as defined in claim 1 wherein the piston channel (20; 43), downstream of the seat face (21; 44) thereof, has a substantially cylindrical, longitudinal portion passing into a downstream portion becoming trumpet-like wider in a direction away from the piston channel orifice exhibiting the seat face (21; 44).
- 4. A hydraulic impact tool as defined in claim 1, wherein internally within the elongate tubular housing (1), a rest (10) has been disposed for the hammer (9) in the inoperative position thereof and a shoulder (28) for the slice (25; 48) in its upstream position, the sealing body (22; 45) being provided with a shoulder (30: 51) adapted to come to bear against the upstream end of the slide (25; 48).
- 5. A hydraulic impact tool as set forth in claim 1 wherein said impact tool is mountable as an extension of a pipe string.
- 6. A hydraulic impact tool as set forth in claim 2 wherein the piston channel (20; 43), downstream of the seat face (21; 44) thereof, has a substantially cylindrical, longitudinal portion passing into a downstream portion becoming trumpet-like wider in a direction away from the piston channel orifice exhibiting the seat face (21; 44).
- 7. A hydraulic impact tool as set forth in claim 2 wherein internally within the elongate tubular housing (1), a rest (10) has been disposed for the hammer (9) in the inoperative position thereof and a shoulder (28) for the slice (25; 48) in its upstream position, the sealing body (22; 45) being provided with a shoulder (30: 51) adapted to come to bear against the upstream end of the slide (25; 48).
- 8. A hydraulic impact tool as set forth in claim 3 wherein internally within the elongate tubular housing (1), a rest (10) has been disposed for the hammer (9) in the inoperative position thereof and a shoulder (28) for the slice (25; 48) in its upstream position, the sealing body (22; 45) being provided with a shoulder (30: 51) adapted to come to bear against the upstream end of the slide (25; 48).
Priority Claims (1)
Number |
Date |
Country |
Kind |
964600 |
Oct 1996 |
NOX |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.K. Application No. 9800130.8 filed Jan. 6, 1998.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/NO97/00281 |
10/27/1997 |
|
|
4/30/1999 |
4/30/1999 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO98/19041 |
5/7/1998 |
|
|
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
WO 9418428 |
Aug 1994 |
NOX |