US2242739A

US2242739A - Drill

Info

Publication number: US2242739A
Application number: US290311A
Authority: US
Inventors: Olof B Anderson
Original assignee: EJ Longyear Co
Current assignee: EJ Longyear Co
Priority date: 1939-08-15
Filing date: 1939-08-15
Publication date: 1941-05-20
Anticipated expiration: 1958-05-20

Description

y o. B. ANDERSON 2,242,739

DRILL Filed Aug. 15, 1939 2 Sheets-Sheet 1 D G M L v I? M j N VEN TOE 0/. OF B. ANDE/E 501v ATToRNE-YJ May 20, 19141; R ON 2,242,739

DRILL I Filed Aug. 15, 1939 2 Sheets-Sheet 2 A p I 3 2614223 272 270 3 8 Q? m4 new Y/Z ATTOKNEW Patented May 2%, 1941 DREL Olof B. Anderson, Minneapolis, Minn, assignor ts E. J. Longyear Company, Minneapolis, Minn, a

corporation of Delaware Application August 15, 1939, Serial No. 290,311

(or. 2ss 4s) 8 Claims.

The present invention relates to an improved earth drill which is particularly adapted for the high speed drilling of exploration and. blasting holes through rock and the like.

In the drilling of rock, the most commonly used. bit consists of a matrix or form in which there are set a plurality of cutting diamonds which serve as cutting and abrading edges to wear away the rock as the drill is rotated. In order to drill satisfactorily with diamond drills, it is necessary to provide a continuous stream of Water at the drill bit and to this end it has been customary to use a hollow drill rod and drill spindle through which water is forced to the bit while it is being rotated.

The water supply to the hollow drill spindle is normally made through a rotatable connection which is attached to the upper end of the drill rod.

In the drilling of deep holes, particularly in close quarters as where the drilling is being done within the close confines of a mine, it is necessary to use a drill rod composed of many sections, each of the sections being from 20 to 60 inches long, depending upon the working space avail able.

According to previous drilling practice, it has been customary to use a drilling machine having a hollow spindle through which the drill rods are advanced, each new section of drill rod being attached to the preceding sections above the machine and advanced through the machine as the drilling proceeds until finally the desired hole depth is obtained.

As explained above, the water connection is at the upper end of the hollow drill rod and hence in order to add each new section to the drill rod, it has been necessary to disconnect the water swivel from the drill rod, then add the additional section and finally again reconnect the water swivel for further drilling operations.

Time studies have indicated that frequently as much as 80% of the total operating time of the machine is consumed in the non-productive operations of adding the drill rod sections, connecting and disconnecting the water swivel, unchucking and rechuclring, running the drill spindle back, and the like, only 20% of the total time being used in actual drilling operations.

It is an object of the present invention to provide an improved drilling apparatus in which the time which must be consumed in non-productive operations is greatly reduced.

It is a further object of the invention to provide an improved drilling apparatus which is capable of much higher speeds than those heretofore obtainable, and capable of rapid connection and disconnection of the drill rod for the insertion and removal of drill rod sections.

It is also'an object of the invention to provide a drilling apparatus in which the drill rod sections may be connected and disconnected by power means obviating the use of hand tools for tightening and loosening the joints in the drill rod sections. I

It is a further object of the invention to provide an improved drilling machine in which, if desired, the raising and lowering of the drill rod spindle may be accomplished with great rapidity, or when desired slight movements completely under direct control of the operator may be accomplished during connecting and disconnecting operations of the drill rod.

It is a further object of the invention to provide an improved drilling apparatus in which the drill rod in the hole may quickly and firmly be held against movement during the connecting and disconnecting operations and then quickly released for the ensuing drilling operation.

It is a further object of theinvention to provide an improved drill rod gripping apparatus capable of use with the drill at any angle and in which regardless of the angle of drilling, the aforementioned rapid connection and disconnection of the drill rods may be accomplished.

Other objects 'of'the invention are those inherent'in and implied by the method and apparatus herein illustrated, described and claimed.

The invention is illustrated with referenceflto the drawings in which Figure 1 is a side elevational viewpartly in section of the drilling apparatus.

Figure 2 is an end elevational view in the direction of arrows 2-2 of Figure 1.

Figure 3 is a sectional view along the line 33 of Figure 2.

Figure 4 is a side elevational view partly in section of the drilling apparatus, the upper section portions being taken along the line 4-4 of Figure 2, and the lower sectional portions being taken along the line 55 of Figures 2 and 3.

Throughout the drawings, like numerals designate corresponding parts.

The illustrated embodiment of thepresent invention'includes a motor device M, which rotates in one direction, a gear box device G, which transmits the power of the motor in either direction of rotationand a drill D, which is the driven unit. In Figure 1, these parts are shown beneath the brackets designated M, G and I) re spectively. The motor M and gearbox G may be separate, or unitary devices the desideratum being rotary motion of the requisite horsepower available in either direction of rotation. The horsepower required varies widely from a few horsepower for shallow small diameter drilling to upwards of 20 horsepower and in some instances even more, for large diameter deep hole drilling. It is usually more convenient to use a unidirectional air motor or internal combustion engine, and a forward and reverse gear, but where electricity or steam is available reversible motive power units are more convenient.

In the illustrated embodiment of the invention the motor mechanism M is a positive displacement pneumatic motor I which is supplied by an air feed line II, having a throttle valve I2 therein.

The motor includes a face plate I3 and a power shaft I4 to which there is attached a spur gear I5. Gear I5 meshes with spur gear IS on shaft I? of the gear box unit G.

The motor I5 which has an air relief valve 22, is attached to the gear box housing 20 by a plurality of bolts 2| and the housing 20 is in turn attached to the main gear housing 30 by means of bolts, not illustrated. At the base of the gear housing, there is a frame member 3! of any approved type, by which the entire apparatus is supported, the frame 3I being shaped so that it may readily be attached to a conventional table or jack such as are used for supporting drilling device.

At-Jthe motor end of the gear box housing 30, there is provided a bearing retainer 32, carrying a pair of ball bearings 33. The ball bearings 33 serve rotatably to support the shaft H, which receives'power from the motor by way of gears i6. and I5. The inwardly protruding end of shaft I'I isformed with a gear 40, which meshes with a large idler gear 4| on shaft 42. A second smaller idler gear 43 is formed integrally with gear M and rotates therewith and meshes with a reversing gear 44.

Within the gear portion 43 of shaft Il, there isa pilot bearing 58, preferably of the needle roller'type, which serves to support the end 55 of shaft 55, the other end of shaft 55 being rotatably mounted in a ball bearing race 56, carried on the gearing box housing 30 by means of thejbearing retainer fiii. The bearing 56 is held inth'e retainer 58' by means of a member 59, which also contains a grease packingring 60.

The shaft 55 is splined at 62 and upon it, there is mounted a sliding gear 51 which is illustrated in its neutral position in Figure 1. Gear 51 has internal teeth. 62, which mesh with the end of gear 4%! when the gearis moved to the right in the view Figure 1, and external teeth 63 which mesh with reverse gear 44 when the gear 51 is moved to the left in the view Figure 1. The gear 51' is provided with a groove 65 in which there is a forked shift lever 65, the latter being mounted for movement to the right and to the left (Figure 1) by means of a slide rod 61. The entire arrangement of slide rod' 61 and forked rod 66 mounted thereon is'arranged to be shifted by means of shift lever it. Thus the gear shifting apparatus has three positions, namely: forward, reverse and neutral, and the mechanism may be held in either of. these positions by the detent mechanism generally designated II.

The ratio of gaming housed in the gear box G. is such that the forward and reverse drives are approximately" the same speed for a given motor speed.

The gear box housing 39 isprovided with a smoothlyfaced-circular flange 80 at the left asshown inFigure 1, upon which there is mounted a circular ro-tation'plate 8I, having an internal. .TI-shaped circular groove 82. Suitable T-shaped bolts, not illustrated, have their heads in-groove 3 2 and protruding through the faced fla 35 of the gear box serve to attach the rotation plate 80 to the gear box. The rotation plate may be turned with reference to the gear box for shifting the drilling head as will be explained hereinafter.

At the outer end of shaft 55 of the gear box, there is provided a beveled gear I00, which serves to transmit power to a similar beveled gear IOI of the drill head generally designated D. The drill head consists of a shaped housing generally designated I20, which is provided with a conically surfaced edge I2I, which serves to position the drill head co-axially with respect to the shaft 55 of the gear box when the drill head is in operative position on the rotation plate 8|. The housing generally designated I20 is provided with a hinge I which cooperates with cooperating hinge parts I26 on rotation plate 8I. The hinge pin I21 couples the parts I25 and I25 together for hinging action about the pin.

At the opposite side, the drill head is provided with a pair of protruding lugs I30 and I3I, between which there is positioned an angularly shaped fastening bolt I33. The bolt I33 is bent at right angles and is preferably mounted upon the lugs I34 of rotation' plate 8|. The outer end of bolt I33 is provided with a nut I36 and as a result the drill head may be drawn into close engagement with the rotation plate by tightening the nut I36 on bolt I33. The conical surface I2I of the drill head housing which nests in the similar conical surface I 22 of the rotation plate thus serves accurately to position the drill head with reference to the rotation plate when the two are drawn together as just described.

In the lower part of the drill head housing, there is provided a bearing plate I40 which serves to mount the ball bearing I M, the latter being held in place by a retainer ring I42 by means of bolts I43. The retainer I43 also serves to carry a grease seal I44. Within the housing I20, there is another ball bearing l50, which is mounted upon the internal housing portion I5I, and the bearings MI and I serve rotatably to mount the hollow drill shaft generally designated I60. The drill shaft is provided near its-lower end with a flange IBI against which there is pressed a spur gear I62. Above the spur gear, there is pressed the bevel gear IOI, which, as previously described, meshes with the gear I00 on the gear box shaft. Below the flange IGI there is mounted the inner race of bearing I4I, the race being held in place by a spacing collar and bottom nut I63.

At the upper end of the drill head housing I20, there is provided a recess I which contains a bearing retainer Ill. The bearing retainer carries a pair of ball bearing races I12, which are held downwardly in place by the bearing retainers I13, which in turn are held by means of an upper cap I14 bolted to the housing I20 by a plurality of bolts I15.

The bearings I72 serve rotatably to support an internally threaded feed nut generally designated I which is provided with a lower shoulder I SI against which the inner races of bearings I12 are tightly seated. Above the bearings, there is provided a spacing collar I8I and above these a pair of drive gears I82 and I83. Above the drive gears, there is provided a hand wheel I84; all of these are held in place upon the feed nut by a nut and lock nut I85.

Within the hollow drill shaft generally designated I50 and the co-axially aligned feed nut generally designated I80, there is a threaded hollow drill spindle generally designated 200, which is threaded throughout its length (as shown at 20!) so as to cooperate with the internally threaded feed nut I80. The hollow drill spindle is also provided with one or more longitudinal key ways 202, which cooperate with internal keys on the hollow drill shaft I60. As a result, the hollow drill shaft I69 serves to rotate the spindle whereas the spindle is advanced or retracted by relative rotation with respect to the feed nut I80.

At the left side of the drill head housing as shown at Figure 2, and as shown in the broken away part of the housing Figure 4, there is provided a feed nut drive arrangement having a shaft generally designated 22%. The shaft 220 is rotatably mounted in its lower end in an antifriction bearing, preferably a needle roller bearing 22!, and at the lower end of the shaft there is mounted a gear 222 for rotation with the shaft. The gear 222 meshes with gear I62 as shown in the dotted lines in Figure 2 and serves to rotate the shaft 220 as the hollow drill shaft rotates.

The upper end of the feed nut shaft 220 is likewise mounted in an anti-friction roller bearing 224 which is held in place by a spacing collar 225. Above the spacing collar, there are mounted

gears

226 and 221 which are of slightly different diameter, and rotatably mounted with reference to the shaft 220, being held in place upon the shaft by means of a nut and lock nut 228.

The upper half of the shaft 220 is hollow as shown at 230, the hollow portion extending down-' wardly to 23!. Near the lower portion 23!, the shaft 220 is provided with oppositely disposed side slots 232, one of which is shown, and at the upper end there is provided a pair of similarly disposed and shown slots 233.

Within the opening 230 of shaft 220, there is mounted a shift rod 240, which is provided with a cross pin 24! near its lower end and with another cross pin 242 at its upper end. The pin 2M serves to attach the shift rod 240 to an external circular rack 243, which is slidably mounted upon shaft 220, the rack 243 being provided with circular teeth 244 which mesh with a shift gear, not illustrated, on shift rod 245. This shift rod 245 is mounted in an external pillow block 245, which is attached to the drill head housing by means of a plurality of bolts 241. At the outer end of the shift rod 245 there is provided a shift handle 268 by which the rod may be rotated with the result that the circular rack 243 is moved upwardly or downwardly on the shaft 220. This shifting of the circular rack 243 and the attached internal shift rod 240 may be accomplished while the apparatus is in rotation or while it is stationary.

The spring detent generally designated 245a is provided between the inner surface of circular rack 243 and the shaft 220. It has a neutral position in which 242 is out of mesh with

gears

225 and 221, an upper position in which pin 2 52 is in mesh with inner notches on ear 221, and a lower position in which pin 242 is in mesh with gear 225.

The

gears

226 and 221 are continuously in mesh w h ears I82 and H33, respectively. on the feed at H89. The gear ratio of the gear pa r 22$ 2. is slightly different than the gear ratio of the gear pair 221|83, and with either pair of gears the feed nut 6 is driven at a slightly lesser rate than the spindle.

While only two pairs of feed gearsare illustrated, it is obvious that where rock hardness conditions vary widely, require a greater ratio than is possible with two gears, additional gears and shifting box may easily be added.

The threading upon the drill spindle 200 is right-hand and the feed nut I is driven at two speeds, depending upon whether

gear

226 or 221 is the driving gear. Each of the feed nut drive speeds is less than the spindle speed and as a result, the spindle is accordingly advanced downwardly as it is rotated in the right hand direction. Thus when the spindle is rotated thru 1000 turns, the feed nut may be rotated 994 or 940 turns, which represents one and ten inch feed where the pitch of the spindle thread is six per inch.

At the lower end of spindle 220, there is provided a hexagonal wrench portion 250, which is formed integrally with the drill spindle 200. Be-

neath the wrench portion 250, there is provideda certain drill rod coupling which has a. standard drill rod coupling thread of six threads per inch. In the present apparatus, the threads 20! on the drill spindle are made of the same pitch as the threads 25! for a purpose which will be described below.

Extending downwardly from the rotation plate 8| there are a pair of legs 260, which converge downwardly and are joined together by web 26! at a distance from 30 to 40 inches below the drill rod. At the lower connected ends of the legs 260, there is provided a mechanism for selectively engaging and holding the portion of the drill rod which remains in the hole, all for a purpose to be described.

The mechanism for engaging and holding the drill rod is preferably formed integrally with the downwardly extending legs 26!], although in some instances it may be desirable to use separate elements which are attached to the leg portions.

In the illustrated embodiment of this mechanism the two legs 260 are joined together at their lower ends by a unitary casting having

cylindrical end portions

262 and 263. Between the cylindrical end portions there is a displaced section having an upper surface 264 and. a lower surface 265, (Figure 2), which extends from the plane 266 to the plane 251 as shown in Figure 2.

Each

cylindrical end portion

262 and 263 is bored to form cylinders 2113 and 21!, the cylindrical bores being continued to the lines 212 and 213 respectively. The bore 215 of smaller diameter is continued from the plane 212 directly thru to the plane 213 and thus intersects the outer surfaces of the casting represented by

planes

264 and 265 thus leaving an opening 3 through the casting, which is bounded by the lines 28l282 and 265251. Within the cylinders 210 and 21!, there are placed

plates

232 and 283, which have square central openings as shown at 235 in Figure 4, each of the plates being attached to its cylinder by means of a bolt 286 each plate is thus preventedfrom rotation'within'the cylinder. V

Within cylinder 21!], there is provided a piston 288 which is preferably made from a cut leather washer. The piston 288 is supported on the reverse side by a metal washer 289 behind which there is a spring 29!], which is provided for the purpose of retracting the piston in the direction of the arrow 29L The piston rod 292 is square and thus slides neatly through the square opening 285 of plate 282. The piston is thus prevented from rotating with reference to the cylinder although it is free to move longitudinally. 7

At the outer end of the piston rod 292, there is provided a cylindrical head 294, which is of the same diameter as bore 215, and at the free end of the head, there is provided a transverse semi-circular notch 295, having teeth 296. Both the notch 295 and teeth 2% are aligned with the drill spindle. The diameter of the semicircular portion 295 is the same as that of the drill rod being used.

Cylinder 2' is provided with a similar piston rod and outer cylindrical head for gripping the drill rod, all as described with reference to cylinder 210.

On the side of the cylinders toward legs 25!), there is provided a transverse bore 238, which intersects with a. bore 297 of cylinder 2'") and a bore 299 of cylinder 2H. Tothe bore 291, there is attached an air feed line 305 having a control valve 3M by which air to the cylinders may be turned on and off. The valve 30I is preferably provided with a bleed part to exhaust the air or other motive fluid from the cylinders when the air supply to them is interrupted. The bore 299 is stoppered by means of screw plug 302 and the bore 298 is likewise stoppered by means of plug 303. The outer ends of the cylinders 210 and 21! are provided with cylinder heads 355 and 336 respectively, which are attached to the cylinders by means of a plurality of cylinder bolts 38?. A gasket 388 is preferably provided between the cylinder head and the cylinder body.

At the upper end of the drill spindle 2Il'0,there is provided a swivel water connection generally designated 320, to which there is attached a water hose 3ZI. This swivel connection may be of any acceptable variety capable of delivering water to the spindle while the spindle is rotated at high speeds.

In Figures 2 and 4, the portion of the drill rod which extends into the hole being bored is illustrated at 330, the surface of the rock or earth being shown at 332.

Operation In the operation described below, it will be assumed that the drill is mounted over a surface being bored and that the drill spindle coupling portion 259 is closely adjacent the drill head housing I20, that the drill rod is coupled to the drill spindle at threads 25I, and that the drill is not rotating, but is ready for the drilling operation. It is assumed further that water is being supplied tothe swivel joint 320-and therethrough to the diamond bit, not illustrated, at the lower end of the drill rod.

1. In order to initiate the operation, the operator shifts the gear box handle 1B into the forward drive position in which gear 51 is located to the right as shown in Figure 1 into engagement withgear 40. The handle 248 is then moved to one or the other of its extreme positions which shifts the pin 242 into engag ment with one or the other of the feed' drive gears 226 or 221 thereby providing a feed drive through gears I 82 and I83 to the feed nut I 80.

The valve 33! of the drill rod assembly is moved to the off position and springs 290 within cylinders 27!! and 2' move their respective pistons to the retracted position with the result that the cylindrical drill rod engaging and holding heads 294 are moved out of en age ment with the drill rod.

The throttle valve I2 of engine II! is then opened and the drill begins to rotate and is fed downwardly, the drilling being continued until the spindle has approached the limit of its downward travel. at which time the hexagonal end 250 of the spindle will be closely adjacent the cylinders 210 and 2'.

2. The air supply to motor I0 is then discontinued, and air valve 35I is moved to the on position with the result that pistons 288 are moved to their operated position. This forces the heads 294'into engagement with the portion 330 of the drill rod in the hole and prevents any rotation or longitudinal movement of the part of the drill rod within the hole. The shaft handle I0 is then moved to the reverse position, the feed shaft 245 is mo'ved to the neutral position by means of handle 248 and the motor II) started by opening valve I2. At the same time, the operator firmly grips hand wheel I84 so as to prevent the feed nut I83 from rotating. The spindle 2GB is accordingly rotated towards the machine, and since the threads 251 of the coupling to the drill and the threads 2! of the feed screw are of the same pitch, the spindle 200 is screwed upwardly and out of connection with the drill rod 330 without longitudinally disturbing the drill rod. This is important inasmuch as it is undesirable on the one hand to force the diamond bit into engagement with the end of the hole and likewise undesirable to retract the drill rod and attached diamond bit from engagement into the bottom of the hole. When the threaded coupling 25I is disconnected, the drill rod is rapidly withdrawn due to the fact that at the time the operator is holding the feed nut I89 stationary. With the feed nut stationary the upward movement of the spindle is very rapid as compared with the down feed of the spindle during drilling operations since the differential of speed between spindle and feed nut is at this time equal to the spindle speed. By way of comparison it maybe noted that when the feed nut is rotated during drilling there is only a slight differential of speed between the spindle and feed nut.

3. As soon as the spindle 20B is fully retracted, a fresh section of drill rod is screwed on to the drill rod 330, which is .at the time held tightly in place due to the action of cylinders 21B and 2' which are in the operated condition. The fresh section of drill rod may have a short space between its upper end and the then retracted screw coupling 25I, and in order to bring down the spindle into engagement with the upper end of the fresh section of drill rod, the operator may merely turn the hand wheel I84 if the distance is small and thus bring the threads of the spindle into alignment with the threads of the newly added section of drill rod. Preferably, however, the operator shifts handle 70 into the forward drive position and the throttle I2 of motor I0 is slightly opened so as slowly to rotate the motor with the result that the spindle is brought downwardly into engagement with the newly added drill rod section. During this running down, as in the retracting operation previ ously described, the operator holds wheel I84 of the feed nut. In this mode of operation the threads 25I may run directly into the threads of the newly added section of drill rod since by holding the feed nut I stationary the downward movement of the spindle 203 through each turn is equal to the pitch of threads 25I in the then stationary drill rod. Due to this correspondence in pitch, there is no tendency to displace the drill rod 330 in the hole either to lift the same from the end of the hole nor is there a tendency to force the drill rod against the bottom of the hole with excessive pressure.

At this juncture it may be explained that excessive pressure on the drill rod may ruin the diamond bit and may even lift th drilling apparatus due to the pressure on the bit. When the latter occurs the alignment of the drilling apparatus with the hole is changed, all with undesirable consequences. Likewise, lifting the bit oi the bottom of the hole is undesirable since it must then be run down into contact with the hole before drilling can be resumed.

4, After the threaded coupling 253 has been screwed into the fresh section of drill rod as previously described, the shift handle 248 of the feed screw drive is moved into one or the other of its operated positions and with the gear box lever Hi already in the forward drive position and valve Bill and cylinders 210 and 2' moved to the off position drilling may be resumed by opening the throttle valve 12 of motor l5.

Drilling is then continued as described under paragraph 1 above.

The aforementioned operation may be carried out with equal facility regardless of whether the drill is being operated in a vertical position or at some angle other than vertical since in any position the drill rod engaging and holding arrangeent is accurately positioned and aligned with respect to the spindle and drill rod by means of legs 28%].

Many obvious variations may be made in the apparatus herein described without departing from the spirit of the invention. Thus, in some instances, it is desirable to use a hydraulic feed mechanism in place of the mechanical feed screw mechanism here described, and in some instances it is desirable to use a reversible electric, or pneumatic motor in place of the engine M and reverse gear box G here described. Likewise, the illustrated mounting of the drill head D may be widely varied to meet the exigencies of particular installations and the method of mounting the drill rod engaging and holding arrangements (cylinders 210 and 21!) may be changed to suit any particular design. Thus cylinders 210 and 2'Il need not be pneumatic but may be a hydraulic mechanism operated, for example by a foot pressure on a master cylinder, or a mechanical device for accomplishing the desired result of holding the drill rod while the fresh section of drill rod is being added, may be used.

These and many other obvious variations will be apparent to those familiar with the art and may be made without departing from the broad scope of the invention claimed.

What I claim is:

1. A drilling device comprising drill spindle means having a feed screw means thereon, motor means for driving the spindle means in either direction, feed nut means, hand means connected with the feed nut for rotating the feed nut by hand and disconnectable drive means for rotating the feed nut means from the spindle means during drilling.

2. A drilling machine comprising a spindle, means including screw threads on said spindle and cooperating feed nut means for advancing said spindle through a predetermined distance, a drill rod axially aligned with said spindle, and means including a screw threaded connection having threads of the same pitch as those on the spindle for connecting the drill rod and spindle.

3. A drilling machine comprising a spindle,

means including screw threads on said spindle and cooperating feed nut means for advancing said spindle through a predetermined distance, a drill rod axially aligned with said spindle, means including a screw threaded connection having threads of the same pitch as those on the spindle for connecting the drill rod and spindle and means on said machine for engaging and holding the drill rod.

4. A drilling machine comprising a spindle, means for rotating the spindle in either direction, means including threads on said spindle and a cooperating nut means for axially moving the spindle through a predetermined distance in either direction as it is rotated, a drill rod arranged in line with said spindle and a screw threaded joint for connecting the drill rod and spindle end to end, the threads of said joint being of the same pitch as the threads on said spindle, disconnectable means for rotating the feed nut means as the spindle rotates to axially move the spindle, and hand means for controlling the rotation of the feed nut means when said disconnectable means for rotating is disconnected.

5. A drilling machine comprising a spindle,

, means for mounting said spindle for movement through a complete circle of radial positions, said movement being about an axis at right angles to the axis of said spindle and through said spindle, means for rotating said spindle about its own axis, means for moving said spindle axially through a predetermined distance as it rotates about its own axis, a clamp means mounted on said means for mounting said spindle, said clamp means being positioned axially with respect to said spindle beyond the limit of axial movement of the spindle.

6. A drilling machine comprising a frame, a spindle mounted for rotation and for axial movement with respect to said frame, means for rotating the spindle, means for axially moving the spindle including threads on said spindle and a cooperating feed nut, means for rotatably mounting said feed nut, mechanical drive means for rotating the feed nut at a slightly different speed than the speed of said spindle, means for interrupting said mechanical drive means, and hand wheel means connected to said feed nut for rotating the same.

'7. A drilling apparatus comprising a spindle, a drill head mounting the spindle for rotation and for advancing and retracting axial movement through a limited path, power means for rotating and axially moving the spindle, means mounting the drill head for free turning movement about a drill head axis which is through the spindle and at right angles thereto, said drill head having a frame extension thereon and a plurality of clutch jaws mounted on the frame for movement toward and from the drill spindle axis, said jaws being positioned beyond the limit of advancing movement of the spindle, whereby the jaws may grip a drill rod attached to the spindle, in any radial working position of the drill head.

8. A drilling device comprising drill spindle means having a feed screw means thereon, motor means for driving the spindle, feed nut means, hand wheel means connected with the said nut for rotating the feed nut by hand, and disconnectable drive means for rotating the feed nut means from the spindle means during driving.

OLOF B. ANDERSON.