US3696872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill string joint breaking means
Assignee: Craelius AB
•
Filing: 1971-05-28
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Granted: 1972-10-10
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Expires: 1991-05-28
Abstract
Abstract A rock drill has a chuck which is arranged to be displaced along a feed bar by means of a feed motor. The chuck is of the kind which is hydraulically actuated and grips the drill pipe when pressurized and it is rotated by means of a reversible hydraulic motor having two alternative supply conduits. The chuck is connected to the supply conduit for providing reverse rotation by means of a conduit in which a delaying valve is arranged. Thus, when the supply conduit for providing reverse rotation is pressurized upon actuation of a manually operated valve, the drill pipe being firmly held by a drill pipe holder, the delaying valve delays the supply of hydraulic fluid to the chuck until the hydraulic rotation motor and thereby the chuck has started its backward rotation so that the kinetic energy of the chuck and the motor is utilized for breaking a drill string joint located between the holder and the chuck.
Inventors
- 👤 Nils Gunnar Jonsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:26
CPC Classifications
E; E21; E21B; E21B19/00; E21B19/16; E21B19/161; E21B19/163; Y; Y10; Y10T; Y10T279/00; Y10T279/12; Y10T279/1208; Y10T279/1274; Y10T279/1283
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
154 words
Drill string joint breaking means in connection with a rock or earth drill, comprising a drill string holder and a rotatable chuck in axial alignment for gripping a drill string and breaking a drill string joint between the holder and the chuck, said chuck being of the kind which is fluid-actuated and grips when loaded by pressurized hydraulic fluid, a hydraulic motor for rotating the chuck, a fluid supply conduit for supplying pressurized hydraulic fluid to the motor And including a control valve, a branch conduit of said supply conduit connected to said chuck for supplying pressurized hydraulic fluid to the chuck so as to actuate the chuck, and a delaying valve in said branch conduit adapted for delaying the supply of pressurized hydraulic fluid to the chuck until the hydraulic motor and thereby the chuck is rotating upon a pressurization of the supply conduit of the motor by means of the control valve.
Claim 2
Dependent Claim
154 words
Drill string joint breaking means in connection with a rock or earth drill, comprising a drill string holder and a rotatable chuck in axial alignment for gripping a drill string and breaking a drill string joint between the holder and the chuck, said chuck being of the kind which is fluid-actuated and grips when loaded by pressurized hydraulic fluid, a hydraulic motor for rotating the chuck, a fluid supply conduit for supplying pressurized hydraulic fluid to the motor And including a control valve, a branch conduit of said supply conduit connected to said chuck for supplying pressurized hydraulic fluid to the chuck so as to actuate the chuck, and a delaying valve in said branch conduit adapted for delaying the supply of pressurized hydraulic fluid to the chuck until the hydraulic motor and thereby the chuck is rotating upon a pressurization of the supply conduit of the motor by means of the control valve.
Claim 3
Dependent Claim
68 words
Means according to claim 1 in which said delaying valve comprises a valving member which is biased into a closed position but arranged to move a distance into an open position when acted upon by the pressurized hydraulic fluid when said supply conduit of the rotation motor is pressurized, and means is arranged to moderate the speed of the valving member during this movement to the open position.
Claim 4
Dependent Claim
20 words
Means according to claim 2 in which said means for moderating the speed of the valving member comprises a dashpot.
Claim 5
Dependent Claim
18 words
Means according to claim 3 in which said valving member has a head moving in a dashpot chamber.
Claim 6
Dependent Claim
18 words
Means according to claim 4 in which said head is biased by a spring towards said closed position.
Claim 7
Dependent Claim
26 words
Means according to claim 5 in which the dashpot has a one-way passage connected to permit rapid return of the valving member to the closed position.
Claim 8
Dependent Claim
20 words
Means according to claim 6 in which said one-way passage is a passage through the head of the valving member.
Claim 9
Dependent Claim
16 words
Means according to claim 1 in which said branch conduit is drained through a restricted passage.
Claim 10
Dependent Claim
54 words
Means according to claim 1 in which said rotatable chuck is arranged to be axially displaces along a feed bar by means of a feed motor, and said rotation motor is reversible and has an alternative second supply conduit through which it is supplied with pressurized hydraulic fluid during making joints and/or during drilling.
Claim 11
Dependent Claim
82 words
Means according to claim 9 in which the control valve, when in a first position, connects the first mentioned supply conduit to a source of pressurized hydraulic fluid and said second supply conduit to drain and, when in a second position, connects the first supply conduit to drain and the second to the source of pressure fluid, said control valve having also a position in which it isolates both the first and the second supply conduits from the source of pressure fluid.
Claim 12
Dependent Claim
48 words
Means according to claim 10 in which a connection conduit is connected between said second supply conduit and said branch conduit and a one-way valve is arranged in this connection conduit so as to permit flow only in the direction from the second supply conduit to the chuck.
Claim 13
Dependent Claim
183 words
A drilling apparatus for rotary drilling, comprising an elongated feed bar, a slide mounted on said feed bar, a feed motor for displacing the slide along the feed bar, a drill string holder at one end of the feed bar, a rotatable chuck on said slide, said chuck being of the kind which is fluid actuated and grips when loaded by pressurized hydraulic fluid, a reversible hydraulic motor for rotating the chuck, a first fluid supply conduit for supplying pressurized hydraulic fluid to the motor so as to effect forward rotation of the motor, a second fluid supply conduit for supplying pressurized hydraulic fluid to the motor so as to effect backward rotation of the motor, a branch conduit of said second supply conduit connected to said chuck for supplying pressurized hydraulic fluid to the chuck so as to actuate the chuck, and a delaying valve in said branch conduit adapted for delaying the supply of pressurized hydraulic fluid to the chuck until the hydraulic motor and thereby the chuck is rotating upon a sudden pressurization of the supply conduit of the motor.
Claim 14
Dependent Claim
183 words
A drilling apparatus for rotary drilling, comprising an elongated feed bar, a slide mounted on said feed bar, a feed motor for displacing the slide along the feed bar, a drill string holder at one end of the feed bar, a rotatable chuck on said slide, said chuck being of the kind which is fluid actuated and grips when loaded by pressurized hydraulic fluid, a reversible hydraulic motor for rotating the chuck, a first fluid supply conduit for supplying pressurized hydraulic fluid to the motor so as to effect forward rotation of the motor, a second fluid supply conduit for supplying pressurized hydraulic fluid to the motor so as to effect backward rotation of the motor, a branch conduit of said second supply conduit connected to said chuck for supplying pressurized hydraulic fluid to the chuck so as to actuate the chuck, and a delaying valve in said branch conduit adapted for delaying the supply of pressurized hydraulic fluid to the chuck until the hydraulic motor and thereby the chuck is rotating upon a sudden pressurization of the supply conduit of the motor.
References Cited (Backward Citations)
US3021739A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |