US3613804A

US3613804A - Drilling apparatus for rotary drilling

Info

Publication number: US3613804A
Application number: US859024A
Authority: US
Inventors: Nils Gunnar Jonsson
Original assignee: Atlas Copco AB
Current assignee: Craelius AB
Priority date: 1968-10-04
Filing date: 1969-09-18
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19
Also published as: JPS4932161B1; GB1238109A; DE1946733A1; FI52893B; FI52893C; FR2019900A1; CH517243A; SE324747B; NO125058B

Abstract

A rock drilling apparatus for rotary drilling has a chuck which is axially movable by means of a double-acting, pressure fluid actuated feed motor. It has also a stationary chuck. The movable chuck grips a drill string when supplied with pressure fluid; the stationary chuck grips the drill string when relieved of pressure fluid. During inserting or withdrawing of the drill string, the supply conduits of the chucks are connected to either of the supply conduits of the feed motor so that, automatically, the chucks operates concordantly with the feed motor.

Description

ilitd ties Mimi 1 swam lnventor Nils Gunner Jonsson Jakobsherg, Sweden Appl. No. 359,024

Filed Sept. 18, 1969 Patented Oct. 19, 1971 Assignee Atlas Copco Alrtiebolag Naciia, Sweden Priority Oct. 41, 1968, Dec. 4, 1968 Sweden 13476/63 and 13476/68 DRILLING APPARATUS F OR ROTARY DRILLING 8 Cs, 6 Drawing Figs.

11.8. CI. I 173/149,

173/32, 173/147, 254/29, 279/4 11m. Cl E21c 1/110 Field oliSearch 173/149,

[56] References Cited UNITED STATES PATENTS 931,611 8/1909 Hutchings 173/149 2,830,788 4/1958 Bentley et al. 254/31 3,212,591 10/1965 Tucker 173/149 3,399,735 9/1968 Ikeda 173/149 Primary Examiner-Ernest R. Purser Attorney-Eric Y. Munson 12 new PATENTEUncT 19 l97| SHEET 10F 4 NILS GUNNAR .mrmsow lNVliN'l'OR.

ERIC Y. MUNSON,

Attorney PATENTEBnm 19 Ian- SHEET l BF 4 INVIL'NTUK ERIC Y HUHSON Attorney DRILLIING APPARATUS FOR lRO'llY DRILLING This invention relates to rock and earth drilling apparatus for rotary drilling which includes an axially stationary, pressure fluid actuated chuck, and an axially movable, mechanically rotatable, pressure fluid actuated chuck which is arranged to be moved forward and backward by means of a reversible pressure fluid driven feed motor. The feed motor has a pressure fluid supply conduit for each direction. The chucks are arranged to alternately grip a drill string, which is composed of a number of string elements, so that the drill string can be withdrawn from or inserted in a drill hole by means of the chucks.

A prior form of such adrilling apparatus has a number of manually operated control devices. It is therefor complicated to operate and the operator must be skilled. It is an object of the invention to create a drill apparatus which has only a few manually operated control devices so that it will be simple to operate and the net drilling time will therefore be increased in relation to the gross drilling time.

In connection with the drilling apparatus according to the invention, withdrawing of the drill string from a drill hole and, alternatively, inserting of the drill string in the drill hole are effected by means of a single manually operated control device because the chucks alternate the engagement automatically when the axially movable chuck shifts from moving in one direction to moving in the other. Besides, the drill string is retained automatically by the chucks if the supply of pressure fluid fails.

For these and other purposes I provide in a drilling apparatus for rotary drilling in rock, the combination of: a frame, a pressure fluid operated stationary chuck at said frame for gripping a drill string, a pressure fluid operated movable chuck for gripping said drill string and slidably carried by said frame, one of said chucks, preferably the movable one, being designed to grip the drill string when loaded by pressure fluid and release if when relieved of fluid pressure. The other of the chucks is designed to release the drill string when loaded by pressure fluid and grip it when relived of fluid pressure, a motor for rotating said movable chuck, a reversible feed motor for advancing and retracting said movable chuck along the axis of said drill string, a first supply conduit for supplying pressure fluid to said feed motor for effecting advance of the movable chuck, a second supply conduit for supplying pressure fluid to said feed motor for effecting retraction of the movable chuck, a supply conduit for supplying pressure fluid to the stationary chuck, a supply conduit for supplying pressure fluid to the movable chuck, and a control which includes a switch, said switch means having a position in which it effects pressurizing of said supply conduits to the chucks and one of said supply conduits of the feed motor and also having a position in which it effects relief of fluid pressure in said supply conduits of the chucks and said one of the supply conduits of the feed motor.

The above and other objects of the invention are obvious from the following description and from the accompanying drawings in which a preferred embodiment of the invention is described by way of example.

In the drawings FIG. 1 is a side view, partly in section, of a vertically arranged rock and earth drilling apparatus according to the invention;

FIG. 2 is a front elevation partly in section, of the drilling apparatus illustrated in FIG. 1;

FIG. 3 is an enlarged section on line 3--3 in FIG. 1;

FIG. 4 is an enlarged section on the lines 4-4 in the FIGS. 1 and 5;

FIG. 5 is an enlarged section substantially on line 5-5 in FIG. 1, a chuck being illustrated in section on line 5-5 in FIG. 4; and

FIG. 6 is a diagram of the pressure fluid system of the drilling apparatus illustrated in the FIGS. 1-5.

The drilling apparatus illustrated in the FIGS. 1-5 has a feed bar 11 which is supported by expanding units 12. Alternatively the feed bar may be carried by a wheeled substructure or be supported in another suitable way. A slide 13, carries a drill 14, and is slidable along the feed bar 11 by means of two parallel chains 15, a chain 16, and a feed motor 17 in the form of a cylinder with a reciprocating piston rod 20. The feed motor 17 has two

supply conduits

18, 19. If pressure fluid is supplied through the supply conduit 18, the piston rod 20 retracts and the chain 16 pulls the slide 13 forwards, i.e., downwards in FIG. 1. If, alternatively, pressure fluid is supplied through the supply conduit 19, the slide 13 is pulled backwards, i.e., upwards in FIG, 1, by means of the chains 15.

A stationary chuck 21 of the vise type is disposed at the forward portion of the feed bar 11. By means of Belleville springs 24, FIG. 3, its jaws 22 are biased into engagement with a drill string in the form of a drill pipe 23. By the action of pressure fluid upon a piston 240, the force of the springs 24 is overcome and the jaws 22 are forced to release the drill pipe 23. The pressure fluid is supplied through a conduit 25.

The drill pipe 23 comprises several pipe elements and a drill bit 26 which are joined by screw joints. For rock drilling, the drill bit 26 may be a pipelike diamond drill bit and the first pipe element may be a so-called core pipe for collecting a core. A swivel 49 supplies flush water to the drill pipe.

A chuck 27 with a housing 28 is a part of the drill 14, which in FIG. 5 is illustrated in a sectional view. This chuck 27 is rotatably joumaled in the housing 29 of the drill 14 by means of a roller bearing 38 and a ball bearing 31. Thus, the chuck 27 moves with the drill 14.

A reversible, pressure fluid actuated rotary motor 32 is arranged to rotate the chuck 27 over a gearing which comprises

gears

33, 34. The gear 33 is fixed to the output shaft of the rotary motor 32 by means of a key 35, and the gear 34 is fixed to the housing 28 of the chuck 27 by means of another key 35. The rotary motor 32 has two

alternative supply conduits

36, 37. When pressure fluid is supplied through the conduit 36, the motor 32 rotates forward, and when pressure fluid is supplied through the conduit 37, the motor reverses.

Pressure fluid to the chuck 27 is supplied to a passage 40 in the housing 28 of the chuck by means of a conduit 38 and an annular groove 39 in the housing 29. Oil is permitted to leak through an annular gap 41 between the rotating chuck 27 and the nonrotating housing 29. This oil is collected and conveyed back to a sump 52 by means of a drain conduit 42.

In the chuck housing 28, a sleevelike piston element 43, which has flanges and is made of an elastomer, is sealingly clamped by means of a spacer sleeve 44 and a cover 45. When pressure fluid is supplied through the conduit 38, the piston element 43 forces four jaws 46 of the chuck 27 to grip the drill pipe 23. Spring plates 47 are disposed between the jaws 46 to hold the jaws in disengaged position when there is no pressure in the conduit 38. The jaws 46 are guided by guiding pins 48, which transmit torque directly from the housing 28 of the chuck 27 to the jaws 46 so that the piston element 43 is not subject to torque when the chuck is rotated.

In the conduit diagram, FIG. 6, the

chucks

21 and 27, the feed motor 17, the rotary motor 32, and the conduits l8, 19, 25, 36, 37, 38, 42 all of which are described above, are represented. The reference numeral 51 refers to a pressure fluid supplying unit, which comprises a sump 52 and a pump 53 which is driven by a motor E. Normally, the pressure fluid supplying unit 51 is situated some distance away from the drilling apparatus. The pump 53 supplies pressure fluid, preferably pressure oil, through a main conduit 54 to a control unit 56, which is indicated by means of dash-and-dot lines. Preferably the pump 53 is pressure compensated, so that it supplies oil of a constant pressure independently of the amount of oil utilized. By means of a return conduit 55, oil is returned from the control unit 56 to the sump 52.

A manually operated control valve 57 for the rotary motor 32 is supplied with pressure fluid from the main conduit 54. This valve 57, which is called the rotation control valve, has three alternative positions which (in FIG. 6) are referred to as positions a, b, and c and represented in FIG. 6 by the corresponding squares a, b, c of the symbol of the valve. With the rotation control valve in position b, as illustrated in the Figure, the

conduits

36, 37 are connected to the return conduit 55, and, thus, the rotary motor does not rotate. With the rotation control valve 57 in position a, the conduit 36 is supplied with pressure oil from the main conduit 54, and the conduit 37 is drained through the return conduit 55. Therefore, the rotary motor 32 rotates forward. With the valve in the position 0, the conduit 36 is drained and the conduit 37 is supplied with pressure oil so that the rotary motor 32 rotates in reverse direction.

The axial movement of the drill 14 is controlled by means of a manually operated control valve 58, which is referred to as the feed control valve. This feed control valve 58 has also three positions which are referred to as a, b, 0. With the feed control valve 58 in position b, as illustrated in the Figure, the two

supply conduits

18, 19 of the feed motor 17 are connected to the return conduit 55, and the drill 14 does not move axially. If, simultaneously, the rotation control valve 57 is in position b, the main conduit 54 is directly connected to the return conduit 55 and the entire drilling apparatus is idling. The feed control valve 58 is supplied with pressure oil through a conduit 59 independently of the position of the rotation control valve 57. With the feed control valve 58 in position a, pressure oil is supplied to the conduit 18, and the conduit 19 is connected to the return conduit 55. Thus, the drill l4 advances. With the feed control valve 58 in position b, pressure oil is supplied to the conduit 19, and the conduit 18 is drained. Therefore, the drill 14 now retracts.

The

supply conduits

25, 38 of the two

chucks

21, 27 are branches of a common supply conduit 60. With a manually operated selector valve 61 in a position a, the supply conduit 18 of the feed motor 17 is connected to the conduit 60. With the selector valve in a position 0, alternatively, the other supply conduit 19 is connected to the conduit 60. With the selector valve in a position b, the conduit 60 is not connected to either of the

conduits

18, 19. The conduit 38 of the movable chuck 27 is connected to both of the

supply conduits

36, 37 of the rotary motor by means of two connection conduits 62, 63. The connection conduits are provided with one-way valves 64 which permit flow only in the direction of the conduit 38. Between the functions of the connection conduits 62, 63 with the conduit 38 and the junction of the conduits 25 with the conduit 38, a one-way restrictor 65 is arranged in the conduit 38. A manually operated shutoff valve 66 is also arranged in the conduit 38.

An adjustable pressure reducing valve 67 in the conduit 18 sets an upper limit on the feed power. A manometer 68 indicates the feed pressure. Another manometer 69 indicates the pressure in the main conduit 54. In the conduit 19 of the feed motor 17, an adjustable valve 70 of the relief valve type is arranged. This valve closes automatically when the pressure in the conduit 19 is lower than a predetermined pressure. The purposes of this valve 70 are to compensate for the weight of the drill 14 and the drill pipe 23 during drilling and to prevent the drill with the drill string to move downward because of the weight only. A one-way valve 71 is connected in parallel with the valve 70, and retraction of the drill 14 is permitted. When drilling upward is to be eifected, the

valves

70, 71 are connected in the conduit 18 instead of the conduit 19.

For effecting idle run, both the rotation control valve 57 and the feed control valve 58 are set in the neutral positions, i.e., the positions b. The drill pipe 23 is then held by the stationary chuck 21. When drilling is to be started, at first the selector valve 61 is set into position b, then, the rotation control valve 57 is moved into position a. Now, pressure oil flows through the connection conduit 62 to the

chucks

21 and 27 so that simultaneously, the chuck 27 grips with the drill pipe, the chuck 21 releases the drill pipe, and the chuck 27 begins to rotate. Now, when the feed control valve 58 is moved to position a, the drill 14 advances. The advance stops automatically when the piston rod 20 of the feed motor 17 reaches its retracted stop position provided the feed control valve 58 is not shifted before this position is reached.

When the rotation control valve 57 is reset into the position b, the

chucks

21, 27 alternate the engagement and another pipe element can be manually screwed on to the drill pipe 23. Thereafter the swivel 49 is screwed on to the end of the drill pipe 23. When the feed control valve 58 is moved into position 0, the drill 14 is returned to its retracted position which is defined by the extended stop position of the piston rod 20 of the feed motor 17. The drilling starts again when the rotation control valve 57 and the feed control valve 58 are set in the positions a.

For withdrawing of the drill pipe 23, the selector valve 61 is set in position 0, and the rotation control valve 57 in position b. The feed control valve 58 is now used as a common control valve for the two

chucks

21, 27 and the feed motor 17. When the feed control valve 58 is moved from position b, the neutral position, to the position 0, the chuck 21 releases the drill pipe, but the chuck 27 grips the drill pipe, and withdraws it. When the feed control valve 58 is moved into position a, the chucks alternate engagement automatically, and the drill 14 advances without pushing the drill pipe forward. This is repeated, if necessary, until the drill pipe is withdrawn an appropriate length. Then, the feed control valve 58 is moved to the position b, the neutral position, and the rotation control valve 57 is moved to the position c. Now, the chuck 27 rotates in reverse direction and the supply conduit 60, common to the two

chucks

21, 27, is drained through the selector valve 61 and the feed control valve 58. Through the connection conduit 62, however, the movable chuck 27 is supplied with pressure oil. On account of the restrictor 65, there is oil pressure on this chuck 27, and the chuck 27 grips the drill pipe. The stationary chuck 21, maintains its grip since the flow through the restriction valve is drained through the common supply conduit 60 of the

chucks

21, 27. Therefore, if there is a screw joint of the drill rod between the chucks, this joint will be broken mechanically when the

control valves

57, 58 are in these positions. In order to facilitate breaking of very tight joints, the stationary chuck 21 may be rotatable a limited angle, e.g., an angle of 25 so that an impact results.

When it is desired to reinsert the drill pipe in the drill hole, the selector valve 61 is set in position a. The movable chuck 27 will now bring the drill pipe 23 forward when the drill 14 advances, and the stationary chuck 21 will hold the drill pipe during retraction of the drill. With the rotation control valve 57 maintained in the position b, the neutral position, this reinsertion is controlled by means of the feed control valve 58. When the drill pipe 23 has been introduced so far that the stationary chuck 21 holds the outer end of the pipe, another pipe element is manually screwed on loosely, and the drill 14 is retracted. Then the rotation control valve 57 is moved to the position a. As a result, the movable chuck 27 engages and rotates the pipe element, while the stationary chuck 21 holds the drill pipe 23 because of the restriction valve 65 which is the case also during breaking of joints. Thus, the joint is made. Then, the drill pipe 23 is again inserted so far that the chuck 21 will again hold the outer end of the drill pipe, and the sequence is repeated.

In order to permit inserting of the drill bit and the first drillpipe element through the two

chucks

21, 27, the chucks must be open simultaneously. For this purpose, the operator closes the shutoff valve 66, sets the rotary control valve 57 in the position b, the neutral position, and sets the selector valve 61 and the feed control valve 58 in the position a. As a result, the drill 14 advances until it stops in its advanced stop position. The two chucks 21, 22 are now open. Alternatively, the selector valve 61 and the feed control valve 58 can be set in the position 0 so that the drill 14 stops in its retracted stop position.

In connection with the drilling apparatus described above, the two

chucks

21, 27 are thus controlled automatically. During drilling and during making and breaking of joints, the controlling of the chucks is accomplished by means of the control valve 57 of the rotary motor, and, during introducing of and withdrawing of the drill string, it is effected by means of the control valve 58 of the feed motor.

Especially in connection with large drilling apparatus, it can be desirable to drill with a relatively high rotary speed in hand rocks; a lower rotary speed and a higher torque is required for earth drilling and drilling in soft rocks and for making and breaking joints. For this purpose, a two speed gear box (nonillustrated) may be operationally connnected between the rotary motor 32 and the chuck 27 so that two different rates of transmission between the motor and chuck are achieved. In

connection with a modified nonillustrated design, the axial power and the torque is transmitted by means of a releasable clutch during drilling in hard rocks. This clutch is mounted at the back portion of the drill M and adapted to be screwed to the back end of the drill string. This clutch is rotated, over a gearing, with a higher speed than the chuck 27, which is prevented from engagement with the drill string when the shutoff valve as is closed. in connection with this modified design, the drill string is rotated by means of the chuck 27 with the lower speed higher torque only during the operations of making and breaking joints and drilling in soft rocks and earth.

The invention is not limited to the described embodiments, but may be modified in various ways within the scope of the claims.

1 claim:

ll. in a drilling apparatus for rotary drilling in rock, the combination of: a frame, a pressure fluid operated stationary chuck at said frame for gripping a drill string, a pressure fluid operated movable chuck for gripping said drill string said movable chuck being slidably carried by said frame, one of said chucks, preferably the movable one, being designed to grip the drill string when loaded by pressure fluid and release it when relieved of fluid pressure and the other of the chucks being designed to release the drill string when loaded by pres sure fluid and grip it when relieved of fluid pressure, a motor for rotating said movable chuck, a reversible feed motor for advancing and retracting said movable chuck along the axis of said drill string, a first supply conduit for supplying pressure fluid to said feed motor for effecting advance of the movable chuck, a second supply conduit for supplying pressure fluid to said feed motor for effecting retraction of the movable chuck, a supply conduit for supplying pressure fluid to the stationary chuck, a supply conduit for supplying pressure fluid to the movable chuck, and a control means which includes a switch means, said switch means having a position in which it effects pressurizing of said supply conduits of the chucks and one of said supply conduits of the feed motor and also having a position in which it effects relief of fluid pressure in said supply conduits of the chucks and said one of the supply conduits of the feed motor.

2. A drilling apparatus according to claim 11 further comprising a selector valve which, when in a position for inserting of the drill string into a drill hole, connects the supply conduits of the two chucks to said first supply conduit of the feed motor, and which, when in a position for withdrawing of the drill string, connects the supply conduits of the two chucks to said second of the two supply conduits of the feed motor, said switch means being a valve which has a position in which it connects said first supply conduit of the feed motor to a source of pressure fluid and the second supply conduit of the feed motor to a sump, and which has a position in which it connects said first supply conduit of the feed motor to the sump and the second supply conduit of the feed motor to the source of pressure fluid.

3. A drilling apparatus according to claim 2 in which said selector valve has a third position in which it blocks off the supply conduits of the chucks from both of the supply conduits of the feed motor, this third position being the position of the selector valve during drilling.

4. A drilling apparatus according to claim 2 in which the supply conduits of the chucks are branches from a common supply conduit in which said selector valve is arranged.

5. A drilling apparatus according to claim 4 in which the axially movable chuck is the chuck which grips the drill string when loaded by pressure fluid, the motor for rotating the movable chuck is a pressure fluid driven reversible rotary motor with two alternative supply conduits, and the supply conduit of the axially movable chuck is connected to each of the supply conduits of the rotary motor by means of connection conduits which include one-way valves which permit flow only in the direction towards the supply conduit of the chuck.

6. A drilling apparatus according to claim 5 in which said common supply conduit of the chucks is drained when the drilling apparatus is adapted for making joints and when adapted for breaking joints, and a restriction is arranged in the supply conduit of the movable chuck between the junctions of said connection conduits with the supply conduit of the movable chuck and the junction of said common supply conduit of the chucks with the supply conduit of the movable chuck so that, when the rotary motor is caused to rotate by pressure fluid being supplied through either of its supply conduits, pressure is maintained in the supply conduit of the movable chuck but the supply conduit of the stationary chuck is maintained substantially relieved of pressure.

7. A drilling apparatus according to claim 1 in which the jaws of the stationary chuck are spring-biased into gripping engagement with the drill string.

8. A rock drilling apparatus for rotary drilling comprising a frame, a first chuck having jaws, said jaws being spring-biased to grip a drill string, a first piston means which, when loaded by pressure fluid, causes said jaws to release the drill string, a second chuck having jaws which are biased to release said drill string, a second piston means which, when loaded by pressure fluid, causes the jaws of said second chuck to grip the drill string, one of said chucks being fixed to the frame, the other chuck being axially movably carried by said frame, a supply conduit for supplying pressure fluid to the first piston means, a supply conduit for supplying pressure fluid to said second piston means, said supply conduits being branches of a common supply conduit controlled by a valve which has a first position in which it connects said common supply conduit to a source of pressure fluid and which valve has a second position in which it connects said common supply conduit to a relief conduit.

Claims

1. In a drilling apparatus for rotary drilling in rock, the combination of: a frame, a pressure fluid operated stationary chuck at said frame for gripping a drill string, a pressure fluid operated movable chuck for gripping said drill string said movable chuck being slidably carried by said frame, one of said chucks, preferably the movable one, being designed to grip the drill string when loaded by pressure fluid and release it when relieved of fluid pressure and the other of the chucks being designed to release the drill string when loaded by pressure fluid and grip it when relieved of fluid pressure, a motor for rotating said movable chuck, a reversible feed motor for advancing and retracting said movable chuck along the axis of said drill string, a first supply conduit for supplying pressure fluid to said feed motor for effecting advance of the movable chuck, a second supply conduit for supplying pressure fluid to said feed motor for effecting retraction of the movable chuck, a supply conduit for supplying pressure fluid to the stationary chuck, a supply conduit for supplying pressure fluid to the movable chuck, and a control means which includes a switch means, said switch means having a position in which it effects pressurizing of said supply conduits of the chucks and one of said supply conduits of the feed motor and also having a position in which it effects relief of fluid pressure in said supply conduits of the chucks and said one of the supply conduits of the feed motor.

2. A drilling apparatus according to claim 1 further comprising a selector valve which, when in a position for inserting of the drill string into a drill hole, connects the supply conduits of the two chucks to said first supply conduit of the feed motor, and which, when in a position for withdrawing of the drill string, connects the supply conduits of the two chucks to said second of the two supply conduits of the feed motor, said switch means being a valve which has a position in which it connects said first supply conduit of the feed motor to a source of pressure fluid and the second supply conduit of the feed motor to a sump, and which has a position in which it connects said first supply conduit of the feed motor to the sump and the second supply conduit of the feed motor to the source of pressure fluid.