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Publication numberUS3701389 A
Publication typeGrant
Publication dateOct 31, 1972
Filing dateApr 23, 1971
Priority dateApr 30, 1970
Also published asCA948621A1, DE2120714A1
Publication numberUS 3701389 A, US 3701389A, US-A-3701389, US3701389 A, US3701389A
InventorsEgnelov Gunnar Kristoffer, Eriksson Sune Vilhelm
Original AssigneeAtlas Copco Ab
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Wire line core drilling apparatus
US 3701389 A
Abstract  available in
Images(3)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

United States Patent Egneliiv et al.

[451 Oct. 31, 1972 [54] WIRE LINE CORE DRILLING APPARATUS [72] Inventors: Gunnar Kristofler Egneliiv; Sune Vilhelm Eriluson, both of Sundbyberg, Sweden [73] Assignee: Atlas Copco Aktiebolag, Nacka,

Sweden [22] Filed: April 23, 1971 [21] Appl.No.: 136,804

[30] Foreign Application Priority Data March 30, 1970 Sweden ..6007/70 [52] US. Cl. ..l75/246 [51] Int. Cl. .152: 25/00 [58] Field of Search 175/246, 254, 244, 236, 239

[56] References Cited UNITED STATES PATENTS 1,427,268 8/1922 Dodds ..175/246 1,716,092 6/1929 Smith 175/246 2,020,599 11/1935 Barrett et a1 ..l75/246 X 2,906,341 9/1959 Kellner et a1. ..175/246 X 3,103,981 9/1963 Harper 175/246 X 3,120,283 2/1964 Braun ..l75/246 3,441,098 4/1969 Martinsen ..l75/246 3,461,981 8/1969 Casper et al ..l75/246 3,485,308 12/1969 Martinsen 175/236 X Primary Examiner-David H. Brown Attorney-Bauer & Goodman [5 7] ABSTRACT A wire line core drilling apparatus comprising a tubular drill stem, an annular drill bit mounted at the forward end of the drill stem and an inner core tube assembly, the latter of which is provided with at least one latch dog for being lockable against longitudinal displacement relative to the drill stem and for being connectable to a retrieving device introduced in the drill stem.

8 Claims, 4 Drawing Figures WIRE LINE CORE DRILLING APPARATUS This invention relates to a wire line core drilling apparatus having a retrievable inner core tube assembly.

The main object of the invention is to provide a means for locking the inner core tube assembly relative to the drill stem without causing an undesirable reduction of the inner core tube diameter.

Other objects and advantages of the invention will be apparent from the following detailed description and drawings in which FIG. 1a is a longitudinal section through a core drilling apparatus according to the invention and shows the locking means of the inner core tube assembly in its transport position. FIG. lb shows the same apparatus having its inner core tube assembly locked in its core receiving position. FIG. 2 shows the forward end of the drilling apparatus shown in Figs. 1a and lb. FIG. 3 is a longitudinal section through a core drilling apparatus according to another embodiment of the invention being arranged in a core receiving position.

In FIGS. la, lb and 2 there is shown a wire line core drilling apparatus consisting of a multisectional tubular drill stem 1 which is provided with an annular drill bit 2 at its forward end. The drill stem 1 is adapted for receiving an inner core tube assembly which comprises an inner core tube 3, an intermediate piece 4 and a housing 5. The intermediate piece 4 comprises a swivel which allows the inner core tube to rotate relative to the housing 5. In the housing 5, one or preferably two identical latch dogs 6 are pivotably mounted on a stub axle 7. One of these latch dogs are reversed relative to the other. The latch dogs 6 are pivotable between an inner core tube assembly locking position (see FIG. lb) and a transport position (see FIG. la). In the latter position the latch dogs are cooperating with a retrieving device 8 by means of which the inner core tube assembly is manouverable within the drill stem 1.

For these purposes the latch dogs 6 are provided with two arms 9 and 10 which extend backward from the stub axle 7. One of these arms 9 constitutes a locking heel provided for cooperation with a first shoulder 11 at the drill stem inner wall so as to lock the inner core tube assembly against backward displacement. The other arm 10 on each latch dog 6 constitutes a gripping jaw and is provided with a hook 12 at its free end, which gripping jaw is intended to cooperate with a coupling means 13 of a retrieving device 8. This coupling means 13 consists of a rod having a spear at its forward end. The coupling means is connectable to the inner core tube assembly by introduction of the spear between the gripping jaws and by being caught thereof. Moreover, the retrieving device 8 is provided with an axially shiftable releasing sleeve 14. In order to release the latch dogs 6 from the coupling device 13 the releasing sleeve 14 is shifted towards the spear so as to press apart the arms 10 of the latch dogs 6, making it possible for the coupling means 13 to be withdrawn.

Furthermore, the latch dogs 6 are provided with forward extending arms 15 which are arranged to cooperate with a second shoulder 17 on the drill stem inner wall to lock the inner core tube assembly against forward movement relative to the drill stem. The arms 15 are also arranged to be acted upon by aspring 16 for biasing the latch dogs toward an inner core tube assembly locking position.

Thus, the axial locking of the inner core tube assembly with the drill stem 1 is obtained by cooperation of the latch dogs 6 of the inner core tube and the two shoulders 11 and 17 on the drill stem inner wall. The shoulders are constituted by annular grooves in the drill stem inner wall and do not cause any reduction of the inner core tube diameter. As the latch dogs 6 are reversed relative to each other they will cooperate with the shoulders on the drill stern inner wall in diametrically opposite points whereby a symmetric and proper locking is obtained.

The inner core tube assembly 3 is introduced in the drill stem 1 by means of the retrieving device 8 and is connected to the latter by means of the latch dogs 6. When the inner core tube assembly has reached its proper drilling and core receiving position it is released from the retrieving device by means of the releasing sleeve 14. Thereupon, the arms 9 and 10 are brought into cooperation with the shoulders 11 and 17 on the drill stern by means of the spring 16. Now, the inner core tube assembly is locked against axial movement and core drilling can be performed.

When the inner core tube 3 is filled with a core the drilling is interrupted. The retrieving device 8 is re-introduced in the drill stem 1 and is brought into cooperation with the latch dogs 6. Hereby, the spear presses the gripping jaws of the latch dogs 6 aside so that the arms 9 and 15 are moved inward breaking their cooperation with the shoulders 11 and 17. At further downward movement of the retrieving device 8 the gripping jaws catch the spear. The inner core tube assembly has now been released from the drill stem 1 and has simultaneously been interconnected with the retrieving device 8 and may now be withdrawn from the drill stem.

The core drilling apparatus shown in FIG. 3 is provided with two latch dogs of a modified type which are identical but reversed mounted relative to each other on a transverse stub axle 107. These latch dogs 106 extend rearward from the stub axle 107 and at their free ends 110 they are provided with gripping jaws 1 10, provided with hooks 112. These gripping jaws are adapted for cooperation with a coupling means 113 of a retrieving device 108.

Moreover, the latch dogs 106 are provided with locking heels 120 which are arranged to cooperate with a first shoulder 111 on the drill stem inner wall to lock the inner core tube assembly against backward movement as the inner core tube is in its core receiving position. The latch dogs are also provided with forward extending arms 115 which are arranged to cooperate with a second shoulder 117 on the drill stem inner wall to lock the inner core tube assembly against forward movement relative to drill stem. The arms 115 are also arranged to be acted upon by a spring 116 for biasing the latch dogs toward the inner core tube assembly locking positions.

The coupling means 1 13 of the retrieving device 108 consists of a tubular sleeve provided with an internal annular shoulder at its forward end. The retrieving device 108 is arranged to be connected to the inner core tube assembly by shifting the coupling sleeve 1 l3 forward over the ends of the latch dogs 106 whereby the hooks 112 seize the shoulder of the coupling means 113. Moreover, the retrieving device is provided with an axially shiftable releasing sleeve 114 which is arranged to be shifted forward toward the annular shoulder so as to press the gripping jaws together and release the latch dogs 106 from the coupling means 1 l 3.

The retrieving device 108 can now be withdrawn from the drill stem.

The invention is not limited to the shown and described embodiments but can be freely varied within the scope of the following claims.

What we claim is l. A wire line core drilling apparatus comprising:

a tubular drill stern having a forward facing and a backward facing shoulder on the inner wall thereof;

an annular drill bit mounted at the forward end of the drill stem;

an inner core tube assembly; and

connecting means for selectively connecting said inner core tube assembly to a retrieving device and for selectively locking said inner core tube assembly relative to the drill stern, said connecting means including at least one latch dog pivotably mounted on a transverse stub axle, said latch dog having a first locking portion for cooperation with said forward facing shoulder on the drill stem inner wall for preventing backward displacement of the inner core tube assembly relative to the drill stem, a second locking portion for cooperation with said backward facing shoulder on the drill stem inner wall for preventing forward displacement of the inner core tube assembly relative to the drill stem, said first and second locking portions being disposed at opposite sides of said stub axle, and a gripping jaw for cooperation with a coupling means on a retrieving device, by means of which the inner core tube assembly is manouverable within the drill stem.

2. A core drilling apparatus according to claim 1 including two latch dogs which are identical but reversed mounted relative to each other on the stub axle, said latch dogs being arranged so as to cooperate with the shoulders of the drill stem at diametrically opposite points.

3. A core drilling apparatus according to claim 1 wherein said at least one latch dog is biased toward inner dogs being arranged so as to cooperate with the shoulders of the drill stem at diametrically opposite points.

4. A core drilling apparatus according to claim 3 including two latch dogs which are identical but reversed mounted relative to each other on the stub axle, said latch dogs being arranged so as to cooperate with the shoulders of the drill stem at diametrically opposite points.

5. A core drilling apparatus according to claim I wherein said at least one latch dog has two rearwardly extending arms one of which comprises said first locking portion and the other of which comprises said sr pp sj 6. A core drilling apparatus according to claim 5 including two latch dogs which are identical but reversed mounted relative to each other on the stub axle, said latch core tube assembly locking positions, the latch 9am:essa ssstts ssskas as; t drill stem when said retrieving device is brought into cooperation with the gripping jaws.

7. A core drilling apparatus according to claim 1 further comprising said retrieving device and wherein said retrieving device coupling means includes a rod having a spear-shaped forward end selectively engagable with said gripping jaw of said at least one latch dog.

8. A core drilling apparatus according to claim 7 wherein said retrieving device coupling means further includes an axially shiftable sleeve mounted over said rod for selectively engaging said at least one latch dog to disengage said rod from said at least one latch dog.

* II! i l

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3874464 *Jun 3, 1974Apr 1, 1975Tigre TierraProcessing of drilling an earth formation
US4431225 *Oct 5, 1981Feb 14, 1984Craelius AbReleasing device in core barrel grapplers
US4466497 *Mar 19, 1982Aug 21, 1984Soinski Alexander FWireline core barrel
US4834198 *Apr 25, 1988May 30, 1989Longyear CompanyPositive latch wire line core barrel apparatus
US6820703 *Aug 24, 2000Nov 23, 2004Atlas Copco Craelius AbLocking device for a wire line core drilling system and a method for core drilling
DE3918132A1 *Jun 3, 1989Dec 14, 1989Diamant Boart Craelius AbDevice for securing a tool inside a pipe sunk in the ground
EP1212512A1 *Aug 24, 2000Jun 12, 2002Atlas Copco Craelius AbA locking device for a wire line core drilling system, a wire line system including said device and a method for core drilling
Classifications
U.S. Classification175/246
International ClassificationE21B25/02, E21B23/00, E21B23/02, E21B25/00
Cooperative ClassificationE21B25/02, E21B23/02
European ClassificationE21B23/02, E21B25/02
Legal Events
DateCodeEventDescription
Feb 23, 1981AS02Assignment of assignor's interest
Owner name: ATLAS COPCO AB
Effective date: 19810212
Owner name: CRAELIUS AKTIEBOLAG, SUNDBYBERG, SWEDEN
Feb 23, 1981ASAssignment
Owner name: CRAELIUS AKTIEBOLAG, SUNDBYBERG, SWEDEN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ATLAS COPCO AB;REEL/FRAME:003838/0265
Effective date: 19810212