US2133564A

US2133564A - Apparatus for drilling wells

Info

Publication number: US2133564A
Application number: US147343A
Authority: US
Inventors: Clement B Patton
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-06-09
Filing date: 1937-06-09
Publication date: 1938-10-18
Anticipated expiration: 1955-10-18

Description

Oct. 18, 1938. c. B. PATToN APPARATUS FOR DRILLINGl WELLS Filed June 9, 1937 2 Sheets-Sheet 1 ,w Rim wm ,mp m ma M m# n A am A z m f 27 2 5 002AM 3 3 ma M7 5 x55 www/O i B n MJ! ff Af II\|I1|\ o 6W f 4 .NM1 W ..yo M Il 5 .,u. wm 4 74. 9 3 7 55 28 5 320 4V3 f 4 2M ma@ rII . Oct. 18, 1938. c. B. PATToN 2,133,564

APPARATUS FOR DRILLING WELLS Filed June 9, 1937 2 Sheets-Sheet 2 BYQMM *MM A TTORNIYS.

Patented ocrls, 193s UNITED STATES PATENT ori-ICE 2,133,564 'APPARATUS Foa Damme WELLS a clement n. Patton, columbus, om Application June 9, 1937,. Serial No. 147,343

"1o claims. (c1. 2st- 4) My invention relates to'apparatus for drilling wells. It has to do, more particularly, with apparatus for drilling wellsinto the earth for oil, gas, water, sulfur or other minerals found below the earths surface. It relates more specifically to the rotary type of well-drilling apparatus.

With the rotary method of well-drilling now commonly in use it is necessary to have a driving shaft, composed of a plurality of sections coupled l0 together,- running from the drilling tool at the bottom of the hole upwardly through the hole to the surface where the driving power unit is located. Obviously, because it is necessary for the driving shaft to be so long, it is quite costly. Due to the extreme length of the driving shaft, considerable power will be required for rotating the shaft and the bit connected to the end thereof. Furthermore, because of .the extreme length of the driving shaft, itfrequires considerable time 1:0 and effort to progressively connect the sections `thereof together and lower it into the well casing. Also, when the tool is pulled from the casing it is necessary to provide powerful means for lifting .the heavy drive shaft from the casing and A 2li considerable time and effort is required for' uncoupling the sections of the drive shaft. Also,

with this method of drilling much power is needed to operate the expensive equipment necessary to force water down through the drill stem and back :m to the surface on the outside of the drill stem to carry away drillings.

Several devices have been proposed in the past in an attempt to overcome these disadvantages. Some of these. devices have embodied an electric 'm motor locatd in the casing directly adjacent the drilling tool. However, these prior art devicesv have been of such a structure that they have not4 been successful or practical. Another difficulty experienced in the priory art is the provision of a i satisfactory tool which will undercut the casing to allow lowering thereof but will fold up so that it can b'e raised without removing the casing. It

is desirable to provide a satisfactory grinding type drilling tool, which is needed in hard structures, butlsuch a tool is not provided with most prior artdevices.

'I'he well-drilling apparatus which I have provided overcomes all of the Vabovevindicated disadvantages and is successful and prac-- not benecessary to have a driving shaft extending from vthe tool to the surface.

Another object of my invention is to provide the above-indicated device in combination with a well-drilling tool which is of such a nature thatit will undercut the casing to allow lowering thereof buty which will fold up so that it may be moved through the casing.

Another object of my invention is to provide' well-drilling apparatusy of A the type Vindicated which may be quickly and easily lowered into the casing or raised through the casing.

Another object of my invention is to provide well-drilling apparatus of the type indicated which is of simple structure but which is of very sturdy construction and which will effectively and economically drill the well.

Another object of my invention isto provide a well-drilling device of such a type that the casing is carried within a few feet of the bottom of the boreA so that the side walls of the bore will be protected from movement of the drilling device thereby diminishing tendency of the side walls to cave in. f

In its preferred form my invention contemplatesthe provision of a well-drilling unit which is adapted to be disposed within the well casing at the lower end thereof. This unit embodies an electric motor and a well-drilling tool located directly adjacent each other. 'I'he well-drilling tool is rotated by means of an angular drilling -stem which slides through the motor and is connected to the dnmng tool. The drilling tool is of such a nature that at the time it is lowered or raised through the well casing it will be folded up and will not interfere with movement of the well-drilling unit through the casing. However, when. it reaches the lower end of the casing, the

tool will automatically unfold and will project beneath the casing so that it will undercut the casing and permit lowering thereof. Folding and unfolding of the well-drilling tool is accomplished automatically merely by raising and lowering the well-drilling unit.

The preferred embodiment of my invention is illustrated in the accompanying drawings wherein similar characters of' reference designate corresponding parts and wherein:

Figure 1 is a perspective view showing drilling unit in operative position.

Figure 2 is a vertical section taken through my well-drilling unit.

Figure 3 is a horizontal section taken substan tially along line 3-3 of Figure 2.

my well- Figure 4 is a horizontal section taken substantially along line 4-4 of Figure 2.

Figure 5 is a perspective view, partly broken away, of the well-drilling tool or bit and ther means for controlling folding and unfolding thereof, the bit being shown unfolded or inoperative position.

Figure 6 is a similar view but showing the bit folded up or in inoperative position.

f Figure '7 is a perspective View illustrating a different type of bit.

With reference tc the drawings, I have illustrated my well-drilling apparatus as comprising mainly a power unit I and to tool unit2 which is driven by the unit I. 4

The unit I is'illustrated best in Figure 2. It comprises an upper casing 3 of tubular form, a lower casing 4 of tubular form and an intermediate tubular portion 5 which is threaded to the lower end of member 3 and the upper end of member 4 and joins such members together. Thus, the members 3, v4 and 5 form a substantially cylindrical housing. This housing has its upper edge tapered inwardly as at 6 and vhas an opening 1 formed in the top thereof. The bottom of the housing is substantially closed by means of the enlarged upper end 8 of a substantially tubular member 9. This member 9 has a portion I threaded onto the lower end of the portion 4 of the housing. The lower edge of the enlarged portion 8 of member 9 hasteeth II formed thereon -which are adapted to t into corresponding notches formed on the interior of a collar I2 which is disposed in cooperative relationship thereto when the well-drilling device is in operative position within the well casing I3. This collar I 2 is threaded on the lower end of the well casing as at I4. The intertting portions of member 8 and the member I2 serve to prevent bodily rotation of my well-drilling apparatus.

I provide an electric motor indicated generally by the numeral I which is disposed mainly within the member 4 of the housing but part of which extends up into the member 5. This electric motor may be of the usual type. The motor comprises field magnets I6, carried by the member 4, an armature I'I, disposed within the magnet I6 and carried by a motor shaft I8, and motor brushes I9, carried by the member 5 of the hous- 0 ing. The lower end of member I1 is flared as at and has a wearing surface plate 2l attached thereto which can be removed and replaced. The plate 2| rests on a plate 22 which is provided with a depending annular shoulderI 23 that ts into a corresponding annulargroove formed in the top of member 9. Oil-intake valves 24 are provided for carrying oil into the chamber 25 surrounding portion 2|)k of member I1 for oiling the contacting surfaces of plates.'2| and 22. A collar 26 at the top of chamber 25 prevents oil from being thrown upwardly into the motor. The motor shaft I8 extends downwardly through the top of member 9. A packing gland 21 is provided between the interior of the member 9 and the exterior of the lower endof the shaft I8. l

The upperendrof the motor shaft I8 extends into a sleeve or journal 28. The journal or sleeve 28 has its upper end Athreaded to the upper end of shaft I8 as a 29. The sleeveA 28 is adapted to rotate within a bearing housing 30. This bearing housing 30 has an enlarged portion 3| `which is threadedkinto the upper endv of the member 5 4of the housing. A bearing 32 isslipped into the bearing housing 30.*and is prevented from rotating by means of the cooperating attened portion indicated at 33 in Figure 4. A packing nut 34 is threaded onto the upper end of the bearing housing 30. An oil duct 35 is provided for oiling the bearing 33. Sleeve 28 is provided with a cup 38 on its lower end for catching oil that drips from the bearing 32. A wire 36 passes downwardly past member 34 and is connected to a contact member 3l of the motor.

It will be apparent that both the upper and lower end of the motor are sealed and, consequently, there will be no danger of water reaching the interior of the motor. When the motor is operated the shaft I8/ will rotate due to rotation of the armature Il. The sleeve 28 will rotate within the bearing 32. The bearing 32, the

housing 30 and the packing gland nut 34 will all be stationary.

- 'Ihe motor should be wired so as to produce a low number` of revolutions per minute and it should be self-starting. It can either be made of a single segment or a number of segments. The motor speed should also be variable as the type of drilling tool being used and the kind of strata in which the tool is drilling will have different effects on the motor speed.

The motor shaft I8 is hollow and has an opening of square cross-section, as indicated in Figure 4, extending therethrough. A drilling stem or shaft 39 of square cross-section extends through the opening in the shaft I8 and projects from each end thereof. Since the shaft 39 is of square cross-section and the openingin the hollow shaft I8 is of similar cross-section, rotation of the motor shaft I8 will cause rotation of the shaft 39. However, the shaft 39 may be of any other desired angular cross-section.

The upper end of the shaft 39 is rounded so that it can rotate in a guide member 40. It passes through an opening in this member and is connected thereto by means of a nut 4I threaded on the upper end of the shaft. The guide member 40, as illustrated in Figure 3, has notches in its outer end which cooperate with vertically extending guide ribs 42 formed on the interior of the member 3 of the housing. Thus, the guide member serves to center the upper end of the shaft 39 but permits vertical movement thereof. Abuttments 43 are provided at the upper and lower ends of the ribs 42 to limit vertical movement of the guide member 40. The ribs 42 and the shaft 39 are longer than shown in the drawings in order to permit sufficient downward movement of the tool as it drills through the material. The guide member 40 has a yoke 44 connected thereto to which the lower end of cable 45 is connected. By means of this cable the entire apparatus may be raised or lowered in the casing and vertical movementof shaft 39 can be controlled. The cable 445 also may carry the power cable leading to the electric motor. A switch 46 is provided for starting the motor and a switch 41 is provided for stopping the motor. These switches are carried by the member 3 and are adapted to be operated automatically when the guide member 40 contacts therewith. The member 3 carries adjacent its upper end a plurality of radially extending lugs 48. These lugs 48 are pivoted to member 3 and are normally forced outwardly by means of springs. They serve to center the upper end of the housing within the well casing. However, when the well-drilling apparatusv is pulled upwardly through the casing, the guide member 40 will contact withl the inner ends of the lugs 48 and cause them to fall downwardly and inwardly into the slot 49 'in member 3 in which they are disposed.

The shaft 39 extends downwardly through the member 9 and has an enlarged square portion 50 on itslower end. This portion is disposed mainly within a housing 5| which. encloses the mechanism that controls folding and unfolding of the tool oibit. The upper end of the enlarged portion 56 passes through a square opening in the upper end of the housing 5| as at 52. The upper end of the housing5l is bevelled as at 53 and the extreme lower edge of member 9 is correspondingly bevelledat 54. A plurality of resilient lugs are secured to the upper bevelled end 53 of housing 5|. When the shaft 391s in its uppermost-.position the

surfaces

53 and 54 will be in contact with each other and the lugs 55 will extend upwardly into the interior of member 9. The enlarged portion 50 of shaft 39 will at this time force projections 56'o`n the ends of the lugs into sockets 51 formed on'the interior of member 9. When the lugs are in this position they serve to connect the housing 5| to the member 9. It is desirable for the housing 5| to be connected to member 9 during raising and lowering of theV apparatus through the well casing. a

Within the housing 5| al compression spring 58 is disposed in surrounding relation to the en-` larged portion 5|) of shaft 39.- This compression spring bears against the upper end of the housing 5| andv its lower end bears against a further enlarged bearing portion-59 formed on the shaft 39. This bearing portion 59 is square and slides vertically within the interior of the housing 5| which is of similar cross-section. The member 59 has a transversely extending slot 60 formed therein. This slot has avertical portiomand an foutwardly curved portion 6| at its lower end. 40.

The side walls of the housing 5| which are adjacent to the ends of the slot are provided with slots 62. Each of these .slots 62 comprises a vertical portion having a curved portion' 63 at its lower end which is curved in a direction opposite to that of the'curved portion 6|' of slot 60.

It will be noted from Figure 6 that the slot 62 is ing portions or arms 66 thereof having their lower ends rounded as at 69. The extreme lower end of the members are pivotally connected to a block orl bit-carryingmember 16 at a point adjacent one edge of this member. This mem 5 ber 10 is disposed within the arms 68 and is pivoted thereto as at 1| adjacent the edge of the block ormember 10 opposite to the edge where the members 65 are connected. The

member 10'has a square boss 12 on its upper 'sur-I ln face adapted to cooperate with a square socketJ 13 (Figure 2) formed in the lower end of the member 59. l The member 10 carries oppositely projecting grinders l14 which are rotatably mounted there- :|r,

on by means of.spindles 15. -These grinders 14 extend outwardly from` the member 10 through the spaces 61 between the portions 66 of the housing 5|.

In the operation of my apparatus, assume that .2n

the casing I3 is in positiondn the earth and the well-drilling apparatus is adapted to be lowered intothe casing. The drilling tool will be folded up so that the grinders 14 thereof will be within the tool housing as indicated in Figure 6. 'Ihe 2,-,

device will be hanging by the cable 45 which will pull the shaft 39-to its uppermost position. This causes the member 59, as indicated in Figure 6, to be in its uppermost position and the spring 58 to be compressed. At this time the vertical position by the members `65. The tool housing 5| will be connected to the member 9 by means of the lugs 55, the projections 56 ofwhich will be forced into the socket 51 by means of enlarged portions 50 of shaft 39 which will o be disposed upwardly within the member. 9.

lThe lugs 48 will be forced inwardly and the tolwill be folded up. Consequently, the entire well-drilling apparatus may then be lowered into the casing.

. v 45 'Ihe apparatus is lowered into the casing, the

slightly out of alignment with the slot 60. In reality the upper end of the slot 62 -is disposed substantially in alignment with the extreme lower end of the curved portion 6| in slot 60.

\ distance from the bottom 'of the hole, by means of the cable 45 until it reaches the lower end of the casing where the collar 6 on the housing 50 lower end of lwhich is spaced apredetermined .A

A pin 64 is passedr through the slots 60 and 6'2 when the portion 59-of the shaft 39, is in its uppermost position within the housings 5|. At this time the lower end -of the curved' portion of the slot 60 will be in alignment with the upper ends of slots 62, as indicated in Figure 6. The

pin 64 pivotally carries a pair of downwardly extending curved connecting members 65.` The vupper portions of these members 65 are disposed within the housing 5|,\between the member 59'and the wall of the housing, cut-away portions 66 being provided in the outer surface curved portions 63 of the slots 62 extendover the slot 60 while thepurved portion 6| of the Slot 66 extends over the slots 62. Furthermore,v

it will be noted that the lower end of the housing 5| has its other sidewalls cut away as at 61'so that the lower end of the housing is of substantially inverted U-shape, the downwardly extendinter-fits with the collar |2fon the lower end of the casing. This will prevent bodily rotation of the apparatus within the casing. At' this time downwardk movementof the housing isstopped.

Continued feeding of the cable 45 downwardly 55- into the casing'will cause1 the shaft 39 to move downwardly through the hollow motorshaft I8.. The guide member 40 will move downwardly therewith. The lugs 49 will, consequently, be

permitted to swing outwardly and center the .60

upper end of the housing within the well casing. As the shaft 39 moves downwardly through the posed in the curved portion 6| of slot 60 will move downwardly through the slot 62. 'I'his downwardmovement ofv member 59 will cause 7() themembers 65 to swingl member 10 about the pivot A1| towards a horizontal position. When the pin .64 reaches the curved lower ends 63 of the slots 62, the bits 14 of the tool will be horizontally disposed.V The curved portions 63 of` 75 vslots sz serve to 1ook the tool in horizontal position until the pin 64 is actually pulled upwardly by means of shaft 39. It will be obvious that upward forces tending to cause the member 10 to swing'about the pivots'1l will ordinarily merely force the pin 64, by means of member 65, into the extremity of the curved portion 63 of slots 62. The curved portion 6I of slot 60 similarly functions to lock the tool in vertical position until --the shaft 39 is actually moved downwardly.

hole before it is swung outwardly completely.'

Contiued downward movement of shaft 39 will cause the member 59 to move closer to the member 19. This further movement of vmember 59 will cause the pin 64 to occupy a position in the upper end of the slot 60. When the member 59 contacts with the member 19, the boss 12 will nt into the socket 13. 'I'he member 5| will also -move away from the member 9, as indicated in Figure 1. Substantially at the instant when the member 59 reaches the member 10, guide member 40 contacts with switch 45 and permits current to pass to the motor. 'I'his will rotate the shaft 39 and the drill tool connected to the lower end thereof.

As the tool drills the hole, the shaft 39 will move downwardly to progressively feed the tool through the material. When the shaft reaches the limit of its downward movement, the member 40 will contact switch 41 and interrupt flow of current tothe motor. Operation of the motor will stop and a meter, which may be provided at the surface, will indicate the drilling has stopped.

ing, being square,-wi1l serve to agitata the water in the lower part of the hole and will prevent the A borings from forming a sediment at the bottom unit.

of the hole. l

, It will beapparent'from the description of the operation of lowering the apparatus into the well casing that whenthe apparatusA is lraised from the casingby means of the cable 45, the tool will automatically fold up in the manner illustrated in Figure 6.

The tool illustrated in Figures and 6 is adapted to be used when drilling rock or other hard' substance. It will be noted that the cone-shaped grinding members v14 are removably mounted on the inclined spindles 15. The inclination of the spindles 15 is such that the bottom surface of the grinder 14 will be substantially horizontally disposed, as indicated in Figure 2. A rotatable cutting member or grinder 14 is disposed on the 'bottom of member 10 in order to remove material at the center of the hole below the^tool When drilling through soft substance, it is desirable to have a tool of the type illustrated in y Figure 7. This tool embodies 'a pair of oppositely tool unit, embodying a tool member mounted for projecting rigidly supported` arms 14a. These arms are flat on the bottom but the top surface thereof is inclined to form a knife edge on one edge thereof. Theknife edges of the two arms are oppositely disposed. A removable cutting member 1lb may be applied to the lower surface of each arm and is provided with a portion which projects over the cutting edge thereof. 'A transversely extending cutting edge 1lb is provided on the lower surface of member a for cutting away material at the center of the hole.

It will be apparent from the above description that I have provided well-drilling apparatus which is of the rotary type and which embodies a'power unit that occupies a position directly adjacent the drilling tool. Consequently, maximum power and maximum eillciency is obtained with the power unit. Itis not necessary to have' a long driving shaft extending from the surface to the bottom of the casing. Furthermore, the power unit and the drilling tool are connected to each other by sturdy connections. The connections between the power unit and the drillingtool control folding and, unfolding of the tool. The tool is automatically moved into inoperative position to permit movement through the well casing whenever the device is lifted throughthe casing. Furthermore, merely lowering apparatus into the bottom of the casing causes the tool to swing into operative position.

Many other advantages will be apparent from the preceding description, the drawings and the following claims.

Having thus described my invention, what I claim is:

l. A well-drilling apparatus of the rotary type adapted to be positioned at the end of a well casing comprisinga power unit, a tool unit, said tool unit embodying a tool member mounted for movement between an operative position where it drills and underreams the hole below the well casing and an inoperative position for permitting move-l ment thereof through the well casing to and from working position, a drilling stem adapted to be rotated by the power unit and being connected to the tool member for rotating it, said drilling stem being slidable longitudinally through the power unit, said drilling stem being connected to the tool member in such a manner that longitudinal movement thereof will cause movement of said tool member between operative and inoperative positions. f

2. A well-drilling apparatus of the rotary type adapted to be positionedat the end of a well casing comprising a power unit, a tool unit, said power unit embodying an electric motor, said tool unit embodying a tool member mounted'for movement between an operative position where it drills and inoperative positions.

3. A well-drilling apparatus of the rotary type adapted to be positioned'at the end of a well casing comprising a power unit, a tool l/unit, said power unit embodying an electric motor, said movement between an operative position where it shaft, said drilling stem being connected to the tool member in such a manner that longitudinal v movement ofthe stem will cause movement of said tool member between operative and inoperative positions.

4. A well-drilling apparatus of the rotary type adapted to be positioned at the end of a well casing comprising a power unit, a tool unit, said power unit embodying an electric" motor, said tool unit embodying a tool member mounted for swinging movement between an operative position where it projects outwardly and underreams the hole-below thwell casing' and inoperative position where it is so disposed that it will not interfere with movement thereof through the well casing to and from working position, said electric motor having a hollow drive shaft with an opening' extending therethrough of `angular cross-section, a'drilling stem of a corresponding angular cross-section extending through said shaft and being slidable longitudinally through said-hollow sliaft. said drillingl stem being connected to the tool member in such a manner that longitudinal movement of the stem will cause swinging movement of the tool member between operative and inoperative positions, and means operating automatically in response to longitudinal movement of said stem for controlling operation of said motor.

5. In combination with a well casing, a welldrilling apparatus of the rotary type adapted to be positioned at the end of the well casing and y comprising a powerlunit and a. tool unit, said power-unit comprising a housinghaving'an electric motor Adisposed therewithin", said tool unit' embodying a tool member mounted for movement between an operative position where it drills and underreams the hole below the well casing and an inoperative position where it will no't interfere with v movement'thereoi througli the well,

casing to and fromrworkin'g position, means on the lower end lof the casing for engaging said housing to prevent rotation thereof relativev to said casing,a drilling stem adapted to vberotated by .the electric motor, said drilling stembeing slidable longitudinally through the electric motor, said drilling stem being 4connected to the tool member in such a manner that longitudinal movement thereof will cause movement. of said tool' member between operative and linoperative positions. j

6. In combinationiwith a well casing, a welldrilling apparatus of the rotary type adapted to be positioned at the end of the well casing and comprising a power unit and' a`tool unit,I said power' nit comprising a housing having an velec-`p tric motor disposed therewithin, said tool unit embodying a tool mem er mounted for'movement between an operative osition wherelt drills. and underreams the hole below the well casing and an inoperative position where it will not interfere 5 me motor, said arming stem being sndabie umgitudially through the -electric motor, said drilling v stem being connected to the tool member. in suchl a manner that longitudinal movement lthereof will cause movement of said'tool member between operative and inoperative positions,v and means extending from the surface through the casing and connected to said apparatus for raising. and lowering it through the casing, said means controlling longitudinal movement of said drilling stem.

drilling apparatus of the rotary, type adapted to be positioned at the end oi' the well casing and comprising a power unit and a tool unit, saidpower unit comprising a housing having an electric motor disposed therewithin, said tool unit embodying a tool member mounted forv movement between an operative position where it drills and underreams the-hole below the -wellcasing and 7 In combination with awellcasing, a well-n an inoperative position where it will not interfe're with movement thereof through/the well cas-v lower -end of the casing i'or engaging said housing` to prevent rotation thereof relative to said casing, a drillingstem adapted to b e rotated by the electric motor, said drilling stem being slidable longitudinally through the electric motor, said drilling stem being connected to the tool member in such a manner that longitudinal movement thereof will cause movement of said tool member between operative and inoperativepositions, means extending from the surface through the casing f ,and connected to said apparatus for raising and lowering it through the casing, said Ameans controlling: longitudinal movement oi said drillingy stem and means operating automatically'in response to, longitudinal movementof said drilling stem for controlling said electric motor,

^ 8. In combination, aw drilling stem, a drillingrr tool housing connected to the end of said stem,

to said'housing, a drilling tool pivoted to said housing for novement between oplerative position where it projects from the housing and inoperative position where it is disposed substantially' Within the housing. means for connecting the end of the drilling stem to the tool in such a manu ner that longitudinal movement of the stem will cause movement of the tool between operative and inoperative positions', said means comprising members pivotally connected to the drilling stem by apivot pin passing through a `transversely extending 'vertically disposed slot formed in said stem, said members-having their opposite ends connected to the tool member at a point spaced from thepoint where the tool member isplvcurved portions each 'of which extends over the rotary adjacentlot.

9. A well-drilling apparatuspf the adapted to be positioned at the end of a well casing comprising a power unit, a tool unit, said tool unit embodying a. tool -member mounted for swinging movement between an operative position where it projects outwardly and drills and f underreams the hole below. the -well casing and an inoperative position where it -is so disposed that it will not interfere with movement thereof through the well casing to and from working position, a drilling stem adapted to be rotated by the power unit and being connected to the tool member for rotating it, said drilling stem being slidable longitudinally through the power unit, said drilling stem being connected to the tool member in such a manner that longitudinal movement thereof will cause swinging movement of said tool member between operative and inoperative positions. g

10. In combination, a drilling stem, a drilling tool housing, said stem having its end passing into said housing and being slidable longitudinally relative to said housng, a block pivoted to the lower end of said housing and having a drilling tool member mounted thereon, movement o1' said block about its pivot being adapted to move the tool member between an inoperative position where it is disposed substantially within the housing and an operative position where it projects from the housing, means for connecting the end of the drilling stem to the block in such a manner that longitudinal movement of the stem will cause the block to move about its pivot, said stem having an angular socket formed in its lower end adapted to receive an angular portion formed on said block when the tool member is in operative position so that the tool member may be rotated by the stem.

CLEMENT B. PATTON.