US840890A

US840890A - Rock-drill.

Info

Publication number: US840890A
Application number: US16292503A
Authority: US
Inventors: Thomas Edgar Adams
Original assignee: ADAMS DRILL Co
Current assignee: ADAMS DRILL Co
Priority date: 1903-06-24
Filing date: 1903-06-24
Publication date: 1907-01-08
Anticipated expiration: 1924-01-08

Description

No. 840,890. PATENTED JAN. 8, 1907. T. E. ADAMS.

ROCK DRILL.

APPLICATION FILED JUNE 24,1903.

4' SHEETS-$311131 1.

l6 INVENTOR PATENTED JAN. 8, 1907.

T. E. ADAMS. ROCK DRILL.

APPLICATION FILED JUNE 24, 1903.

4 SHEB'I'SSHBBT 2.

VEN Tgle :4lzarney PATENTED JAN. 8, 1907.

T. B. ADAMS.

ROCK DRILL.

APPLIOATION FILED JUNE 24, 1903.

4 SHEETS-SHEET 3.

PATENTED JAN. 8, 1907.

T. B. ADAMS.

ROCK DRILL.

APPLICATION FILED JUNE 24, 1903.

11v VIi/V TOR (ll/army UNITED sTArns PATENT OFFICE.

THOMAS EDGAR ADAMS, OF CLEVELAND, OHIO, ASSIGNOR TO THE ADAMS DRILL COMPANY, OF CLEVELAND, OHlO, A CORPORATION or orno.

ROCK-DRILL.

Specification of Letters Patent.

Patented Jan. 8, 1907.

To all whom it may concern/,

Be it known that I, THOMAS EDGAR ADAMS, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in RockDrills;- and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make ,and use the same.

My invention relates to improvements in rock-drills, one object of the invention being to construct a rock-drill in such manner as to reduce the weight thereof to a minimum and to reduce liability of breakage to a minimum.

A further object is to construct the apparatus in such manner as to trance of grit to the bearing 0 the drill-rod in the nose.

A further object is to rovide means whereby the operator can e informed of the proper position of the drill to cause the drillrod to make the most effective stroke.

A further object is to so attach the drillbody to the guide-shell that great rigidity can be secured and so that the wear can be readily taken up.

A further object is to provide simple and efficient means for securing the removable parts of the drill in place.

A further object is to provide simple and eflicient means for mounting the driving-motor.

A further ob'ect is to construct the drill in such manner t at the bearings of the drillrod can be separated to a maximum extent for the purpose of resisting side strains.

A further object is to improve the general construction and efficiency of a rock-drill of the type to which my invention relates.

A further object is to provide improved means for preventing shock to the motor when the latter is connected with the drilloperating mechanism through the medium of a ri id drivin -rod.

Wit these ohjects in view the invention consists in certain novel features of construction and combinations and arrangements of parts as hereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure 1 is an elevation showing the manner of mountrevent the ena ing the drill and motor on a vertical standard. Fig. 2 is a view in perspective showing the manner of mounting the drill and motor on a horizontal bar with the drill disposed vertically. Fig. 3 is a view illustrating the drill and motor supported by a tripod. Figs. 4 and 5 are detail views of the yielding adjustable motor-support. Fig. 6 is a sectional view of the drill and operating mechanism therefor. Fig. 7 is a cross-section on the line as a: of Fig. 6. Fig. 8 is a sectional view taken at right angles to Fig. 6, showing ortions of the drill-operating mechanism. ig. 9 is a sectional view of the ratchet device. Fig. 10 is a side elevation of the drill. Fig. 11 is arear end view of the same. Fig. 12 is a section on the line y y of Fig. 10. Fig. 13 is a section on the line .2 2 of Fig. 10. Fig. 14 is a detail view of the hand-tightening collar 20. Fig. 15 is enlarged detail view, partly in section, of the rear portion of the apparatus.

1 represents a column or standard adapted at its upper end to engage the roofof a tunnel or other support. A cross-bar 2 is pivotally attached between its ends to the lower end of the column or standard, and at the ends of said cross-bar adjustable feet 3 are provided. The column or standard 1 is provided at a oint between ends with an arm 4, which wil be secured adjustably thereto by means of a suitable clamp, and this arm serves as a su port for the drill, the basebracket 5 of tile latter being secured to a bracket 6, clamped to the arm 4.

The drill-rod is operated by a crank-shaft driven by suitable gearing, (all of which will be hereinafter described in detail,) and said gearing is driven by a motor 7, through the the medium of a rigid driving-rod 8. It is important in order to prevent shock to the motor that the latter shall be flexibly mounted, and it is also desirable that such mounting shall be adjustable and capable of permltting free movements of the motor to accommodate itself and the ri id driving-rod to the varying positions, whic may be given to the drill. To accomplish these results, the devices now to be described are quite efiicient. A clamp 9 is secured at any desired point on the column 1, and this clamp is provided with a-sleeve 10, through which a tubular bar 11 is passed. The sleeve 10 may from slipping through the motor.

be provided with a set-screw12 for holding the tubular bar at any desired adjustment.

The arms 13 of a spring-fork 14 are inserted' into the bar 11 and secured at their rear ends to a block 15, located loosely withinsaid bar.

The block 15 projects beyond the rear end of nions 18' of motor 7, or the ends of the spring-- arms may be bent to enter holes in the motor-casing. It will be observed that the motor-support comprises the sleeve 10, carried by the clamp 9, the tubular bar' 11, and

the spring-tork 14, the motor bein 'pivotally mounted directly in the latter. ithsuch a support and mounting the motor can swing freely on its trunnions, and it can turn freely in a direction at right angles to the axis of said trunnions, the spring-fork being'for 's purpose freely revoluble in the tubular bar 111 The motor can also be adjusted relatively to the standard by moving the tubular bar 11 longitudinally through the sleeve 10. I prefer to employ an electric motor, although other forms of motor be employed. When an electric motor is employed, the rigid drivin -rod will be passed through the armatureo the motor and may have longitudinal movement through the same. The drivingrod (which is angular in cross-section) also passes through the gear 19 of .the -drill-oper- :ating gearing and may have a longitudinal movement through the same. Thus the driving-rod 8 may have a free longitudinal movement through the armature of the motor or the gear-wheel 19; but of course it must be fixed with relation to one or the other. In *1 I'have shown a handtightening collar 20, which serves to prevent.

the dr'ivin -rod from sli; ping through the armature-s aft. This co arcould, however, f

be used to secure the driving-rod from slipping through gear 19 and said drivingrod permitted to have free longitudinal movement through the armature-shaft of the motor. The device 20 may consist of a .series'o'f sections 20, made slightly conical on the exterior and threaded for the reception of nuts 20", to cause the sections 20 to clamp the drill-rod and prevent the latter.

The flexible conductors 21 can be conveniently connected with the motor by means of a plug 22,

inserted into a socket in the motor-casing, the necessary electrical connection with the \coils of the motor being efllected in any suitable manner within said casing. The startbox or rheostat 23 for the motor can be conveniently secured to the column 1, near se ate the upper end thereof, and the conductors electrically connected therewith by. means of removable plugs.

In Fig. 2 I have illustrated the manner of mounting the drill andmotor on a horizontal bar 24 when it is desired to operate the drill vertically, and in Fig. 3 the drill is shown supported in a vertlcal position and supported by a tripod 25, the horizontal bar in -one-case,and the tripod in the other, serving to support thedrill, the motor, and the startingbox. The drill-body comprises a tube or barrel 26, continuous throughout as length,

and a housing 27, in which the crank-shaft 28 is mounted. Thedrill-body is mounted upon a guide-shell 2.9, made of sheet-steel, the latter being supported, through the medium of the base-bracket, by the'column or standard 1 (.or the horizontal bar orthe tripod) in the manner-hereinbefore explained. The housing 27 is made with a-cylindrical extension 30, which enters the rear end of the barrel or body 26. The housing 27 is also made with laterally projectinghollow bosses 31 32, the latter having a much larger internal diameter than the former. A sleeve 33., projecting at right anglesirom a plate 34, is mounted in the larger tubular'boss 32-of the housing, and

said plate 3 1' constitutes one wall of a gearcasing '35. This gear-casing is madewith a peripheral flange 36, projecting beyond the periphery of the plate 34 and having a shoulder 37 bearing against said plate. The flange 36 of the gear-casing ismade in its inner face with a groove-38 forthe reception of a springring 39.,'-whi ch overhangs the face of the plate 34 and serves to connect the gear-casing with said plate in a'manner to permit the former to turn. The sleeve 33 is made internally with a conical bore having its greatest diameter at-the outer end of the sleeve. A slotted gun-metal bushing 40 is also located within the sleeve 33' and provided with an externallyethreacled conical wall tapering toward the outer 'end' ofsaid bushing, the

latter being provided .at its inner end with an annular flange 41, having wrench-holes 42. Between the. sleeve 33 and bushing 40 a split adjusting-sleeve 43 is located. This adjustin sleeve is conical in shape and is prevente from turning in the sleeve .33 by means of a suitably-located spline .or pin 33 fast on sleeve, entering a slot in sleeve 43. The conical adjustihg sleeve43 is threaded internally to mesh with the. threads onthe bushing 40. From this construction and arrangement of parts it will be seen that;

when the-bushing 40 is turned by means of a suitable wrench the-adjusting-sleeve will be .moved longitudinally and being conical and seated in the similarly-shaped bore of the sleeve 33 will cause the bushing to be contracted to compensate for wear. The tubular boss 31 is also made with a conical bore,

and the bushing 44 and adjustable sleeve 45 an adjustable friction slip or drive.

bevel-gear 60.

are arranged therein and cooperate to effect adjustment of the bushing in precisely the same manner as above explained in connection with bushing .40, adjustable sleeve 43, and sleeve 33. Split pins 40 connect wrenchnotches 42 of bushing 40 with sleeve 33, and

similar pins 44 connect holes 44 of bushing 44 with boss 31. The sleeve 45 is slotted, as clearly shown in Fig. '15, and the slotting of the

bushings

40 and 44 is similar'to that of the sleeve 45. i

The journals 4647 of the crank-shaft are mounted in the bushing 40' and 44, the crank 49 of said shaft being located within the chamber formed by the housing 27 .5 The rear end of the housing is closed by a removable head 50, held in place by gibs 51 on the housing, and in order that the head shall be secured oil-tight to the housing wedge-keys 52 are employed and cast integral with the head 50. The journal 46 of the crank-shaft,

is provided witha threaded shank 53 for the reception of a fly-wheel 54, and the journal 47 of said shaft is provided with a threaded shank 55, which projects into the gear-casing 35. A disk 56 is located within the gearcasing and provided with an internallythreaded hub 57 to screw onto the shank 55, and this hub is'threaded externally for the reception of a threaded ring or nut 58. An annular flange 59 on a bevel-gear 60 is disposed between the disk 56 and the rin or nut 58 and between said flange and disk fi erwasher 61 is located. A spring-plate 62is located upon the nut 58 and between said plate and the flange 59 of the gear vulcanized fiber-washer 63 is disposed, all fOllIl ll illg e gear-casing 35 is provided with a lateralenlargement 64, in which the bevel-gear.19 is mounted and arranged to mesh with the The gear 19 is made with an angular bore for the passage of the angular driving-rod 8.

Within the barrel 26 ratchet-casings 65 65, carrying ratchet devices, for a purpose hereinafter explained, are located and spaced from the cylindrical extension 30 of t e housing 27 by a spacing-sleeve or stop 66. Forwardly beyond the ratchet-casings a nose-bushing-67 is located and connected to the ratchet-casings by arms 67*, the space between said bushing and the inner wall of the barrel constituting a lubricant-chamber, the-lubricant from this chamber bein permitted to enter the bushing through sultable ducts 115. The nose-bushing 67'is thus lo-, cated near the forward end of the drill-body and serves as a forward bearing for the drillrod 68. The rear bearing for the drill-rod is. located Within the cylindrical extension. 30 of .the housing 27 and is effected through the.

medium of a cross-head or piston 69, mounted to move in saidcyllndr cal extension 30. The cross-head or plston 69 1s provided with a hub 70 for the reception of the end of the drill-rod. Thev hub 70 and rod 68 are provided with alined slotsfor the passage of a key 71, having a spring locking-finger 72. In connecting the crank 49 with the drill-r'od a draw-bar 73, made in the form of a yoke, is employed. At its rear end this draw-bar is made with an elongated transverse opening or crank-pin slot 74, in which a bushing on the crank-pin 49 slides. The bushing '75 is made in two parts, the meeting faces of which can be filed to compensate for wear. The rear strap 73 'of the draw-bar is made removable and separated from the ends of the draw-bar arms by washers 73 which may be'removed one at a time to compensate for wear'in the crank-pin slot 74. From the crank the draw-bar extends forwardly into barrel 26, the respective members of the draw-bar passing through guide-grooves 76 in the cyllndrical extension 30, as shown in Fi 7. At its forward end the draw-bar or yo e73 isprovided with a cross-head 79,- which embraces the drill-rod 68 some distance from its rear end. A coiled spring 78, embracing the drill-rod, bears at one end against the ring or washer 77 and at the other end against the hub 70 of the piston 69, so that when the draw-bar 73 is moved rearwardly by the crank 49 the drill-rod will be withdrawn. The piston 69 and cylindrical extension not only serve as a rear bearing for the drill-rod, but the piston will also operate to throw lubricant on the crank at all times, but especially when the drill is disposed vertically for sinking.

The end of the draw-bar 73 farthest from the crank forms the cross-head 79, loosely embracing the rod 68, and between said cross- ,head 79 and ring or washer 77 a flexible washer 80, preferablyof leather, is disposed. Spaced forwardly on the drill-rod from the cross-head 79 is a similar but loose collar 81, and adjacent to the latter a recessed ring or washer 82 (the same in construction as the ring or washer 77) is located andbears against a shoulder 82 on thedrill-rod. A yielding washer 83, preferably of leather, is located in the recessed ring, so as to be disposed'between said ring and the collar 81, (thisconstruction being the same as shown in section at 7 7-79 and '80, Fig. 6.) A spring 84 (preferably heavier than the spring 78) is located between the cross-head 79 and collar 81.

The collar 81 prevents contact of IIO the spring 84 with the leather washer 83, and

this protects said washer from injury, which would occur if the s ring 84 were permitted to bear directly against the leather washer. It-is also found in practice that the leather washers serve to prevent deterioration of the spring, which mlght otherwise occur on account of crystallization due to vibration. In sinking the positions of the large and small springs may be reversed.

6o tion of the nose-bushingahd the ratchet- &

, a spiral groove 85 and a straight groove .86.

' the drill-rod.

Within the ratchet-casings the drill-rod is surrounded by two ratchet-wheels 87. One of the ratchet-Wheels 87 is'locked against rotation in one direction by spring-pressed dogs 89, pivotally supported in the casing 65, and the other ratchet-Wheel 87 is locked against rotation in the same direction by similar dogs supported in the casing One of the ratchet-wheels is provided with a lug 90, which engages the spiral groove in v :The other ratchet-wheel (in the ratchet-casing 65*) is provided with a lug to enter the straight groove 86 of the drillrod. Hence as said dl'illrrl'Od. is moved forwardly in theperformance of its functions it moves in a direct line, since the ratchet devices in casing 65 prevent its rotation, and

the lug in the ratchet-wheel in this casing moves in the straight groove in said drill-rod. Durin the'backward stroke the engagement ofthe ug 90 of-the ratchet-wheel in casing 65 vn'th the spiral groove 85 in the drill-rod will 6 which, (asbeforestated, is keyed or otherwise secured to the ratchet casings,) is provided at its forward end with a flange 92,

havin a beveled r tapering peripheral walleripheral wall 93 on the flange of the noseu-shing 67. With such a construction when the drill-rod makes its rearward stroke the movement of the lug 90 'of the ratchetwheel incasing 65 in the spiral groove 85 in the drill-rodwill tend todause: said ratchetwheel to turn and through the engagement of'the dogs carried by the casing 65-cai1se the latter alsoto tend to turn. The nose bushing 67being keyed to the ratchet-casing, said bushing will also turn, and'by friction-a1 contact of/thebeveled wall of the flange 92 with the beveled end of sleeve 94. the latter will be turned andmade to tighten in its threaded connection with the barrel or body 26 -..When the'nose-bushing shall have thus been turned sufficiently to cause the sleeve 94 to have been made perfectlytight within the bed or barrel'26, the perfect ,alinemen t of the ratchet-casings and nose-bushing will he insured. After the sleeve shall have been tightened as above explained further rotacasing will be,prevented, the ratchet-casing ,being eflectually locked against rotation. With this condition, during the further backward movement of the drill-rod, the couse the latter to turn, the nose-bushing waaso operation. of the. lu 90 with the spiral groove in said drill-rod wi cause the latter to turn as the drill-rod, and the drill carried thereby, recedes. Of course a spanner-wrench will be used to tighten the sleeve in the first'instance. g

A drill-chuck 95, having a general conical shape, is secured to the forward end of the drill-rod and is adapted to enter the drillbody 26. The chuck 95 is not out-of the barrel on extreme forward stroke, but fits neatly to exclude dust and is provided with 4 aseries of peripheral ribs96, thefunction of which is to discharge any chippings which may find theirway into the drill-body, and thus prevent them fromentering the bearin of the drill-rod in the nose-bushing.

bufling-spring 97 for the. chuck is located within the sleeve 94 and bears against the flange of the nose-bushing.

The body of the chuck 95 is made; with a conical interior and receives thereiI'La series of jaws 95*, having curvedand inclined outer faces. These jawsare normally pressed outwaiidly by springs-951 and made toclamp the too It is desirable that some means beprovided by means of which the operator can be informed whether or not the drill-rod. is making its maximum stroke. For this purpose I provide an indicator 98. This comprises a spring-arm 99, secured at one end in the forward portion of the barrel 26 and pro -v vided at its forward end with a ball or en-' largement 100, adapted to project through an opening in the .wallof said barrel 26. With such construction when the drill moves to the full end of itsstroke the chuk will strike theball or enlargement 100 and cause it to rise, so as to be viewed ,by the operator and indicate to that the drill-rOdis making its maximum stroke.

thas been hereinbefore stated v drill-body is mounted upon the sheet-steel guide-shell 29. The manner of effecting this mountin' and feeding the drill will now be 'explaine The drill-body, or, more strictly that the speaking, the housing 27, is provided with between the plates 103 and the guide-shell can be readily compensated for by removing said plates and filing. the faces 1 02 and then replacing saidplates. guided at its forward end by means of a strap 107, made to embrace the drill-body and secured at its. ends to theguide-shell. Within The drill-body is c the respective ends of the guide-shell blocks 108 109 are located, and in these blocks a feed-screw 110 is swiveled, the threaded portion of said screw passing through a threaded nut 117 in lug or arm 116, depending from the drill-body. The feed-screw is provided at one end with a suitable crank 114, by means of which to turn it.

A yoke 111 is pivotally attached to the strap. 107 and is constructed at its free end with a cross-head 112, adapted to engage the jaws of the chuck and depress the same for the purpose of permitting the insertion or withdrawal of the tool. Normally the yoke 111 will swing freely, as shown in Fig. 12, or held out of the Way or made detachable.

With the yoke 111 in the position shown in Figs. and 13 the cross-head 112 of said yoke bears against the forward ends of the jaws 95*. Should the drill-barrel 26 be now fed forwardlyby operating the handle 114,

the jaws of the chuck will be prevented from forward movement by the yoke 111, and hence the said chuck-jaws will be caused to move backwardly within the chuck-body against the resistance of the-s rings 95, and

the tool will in this way be re eased, permitting its ready removal.

Variousslight changes might be'made in the details of my invention without departing from the spirit thereof or limiting its scope, and hence I do not wishto limit myself to the precise details herein set forth.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is Y 1. The combination with a drill-guide, a drill-body movable thereon, and drill-operating mechanism carried by the drill-body, of a motor-support, a motor pivotally mounted on said support, means for efl'ecting angular adjustment of said motor-support and a rigid driving-shaft connecting the motor with the drill-o erating mechanism.

2. n a motor-driven tool-opegating machine, a support, a shiftable carrier thereon, and tool-actuating mechanism operatively associated with the carrier including a motor, and means independent of said. carrier for cushioning said motor.

3. The combination with a drill-support and drill mechanism, of a rotary motor,'an elastic supporting device pivotally connected to the motor and connected with said support and a rigid driving-shaft connecting said motor with the gearing of the drill mechamsm.

4. The combination with a drill-support,"

of a motor, a spring secured to said support and pivotally connected to the motor at its free end, a drill in said support anda'rigid driving-shaft connecting the motor and drill.

5. In a drill, the combination with a support and a drill mechanism, of a'motor, a rigid driving-rod connecting the motor with the drill mechanism, a spring-yoke in which said motor is mounted, means for adjusting said spring-yoke, and means for supporting said yoke independently of the drill mechanism.

bar, a motor mounted in said device, and a rigid driving-rod connecting the motor with the drill mechanism.

8. In a drill, the combination with asupport and drill mechanism, of a tubular bar, a

flexible yoke revolubly mounted in said tubular bar, a motor mounted in said flexible yoke and a rigid driving-rod connecting said motor with the drill mechanism.

*9. In a drill, the combination with a support, and drill mechanism, of a tubular bar movable longitudinally through said support, means for adjustably securing said barj to the support, a yoke flexibly mounted in said bar, means for,permitting the removal of said yoke, a motor mounted in said yoke and a rigid driving-rod connecting the motor with the drill mechanism.

10. In a drill, the combination with a support and drill mechanism, of a bracket secured to said; support, a sleeve on said bracket a tubular bar movable longitudinally through said sleeve, means for securing the tubular bar at any desired adjustment in the sleeve, a yoke flexibly carried by the tubular bar, a motor mounted in said yoke and a rigid driving-rod connecting said motor with the drill mechanism.

11. In a drill the combination with a support and drill mechanism including a gear having an opening in its center, of a motor, a support for the motor, a rigid driving-rod passing completely through both the gear and the rotary member of the motor and means for preventing longitudinal movement of the driving-rod, with respect to one of the rotary devices through which it passes and permitting free longitudinal movement of said driving-rod through the other rotary member.

- 12. In a drill, the combination with a support, and drill mechanism, of a motor mechanism, a support therefor, a rigid driving-rod adapted to have longitudinal movement relatively to said motor mechanism and drill mechanism and constructed to transmit motion from the former to the latter, and a thumb-nut or collar for locln'ng the drivingrel, a housing at the rearend thereof and afired againstlongitudinalmovement relatively (to one Pof said mechanisms.

I-3QIn :a drill, the combination with a guide-shell, :a drill-body mounted to move thereon, a housing 'at the rear end of said drill-body, lateral bearing-sleeves on said drill body, and a drill-operating shaft mounted in said lateral bearing-sleeves, of dependingenlargements oneach of said lateral bearin -sleeves, removable plates secured to said -e argements and lips on said removable plates projecting under the upper edges of the guide-shell.

'14. In a drill, the combination with a guide-shell, a drill-body longitudinally movable-thereon, a drill-rod, means for operating the drill-rod andachuck on the end of the drillrod, of a pivoted yoke-connected with the guide-shell and adapted to be made to engage the jaws of the chuck for the purpose of openin the-same for'the insertion or withdrawal-o a tool, when the drill-body is fed forwardly.

15. Ina drill, the combination with a bar-' rel and a drill-rod therein, of a housing, a cylindrical extension on said housing projecting into the barrel, a cross-head on the drill-rod movable in saidcylindrical extension, a crank-shaft in the housing, and a draw-bar connected at oneend with said crank-shaft,

vpassing through said cylindrical extension cesses, a crank-shaft, and a draw-bar connected at one end with said crank-shaft, pass,- ing through the grooves or recesses in the cylinder and connect'edat its forward end with the drill-rod.

.17 In a-drill,'the combination withia barcrank-shaft in said housing, of a drill-rod in the barrel, a cross-head'secured to said drillrod, adraw-bar connected with the-crankshaft andprovided at itsforward end with a 'cross1head embracing t l1e'd'rill-'rod and a 5 head;

spring between "said cross-head and cross- 18. Ina drill, 'the combination with a housing and adjustable bushings in the walls thereof, of a crank-shaft :having itsjournals -:mounted in-said bushings, means for adjusting'said bushings for wear, a drill-rod and a draw-bar. connecting said crank-shaft and drill-rod.

. 19. In aidrill, the-combination with ahous-, ling, acrank-shaft therein, a drill-rod, andva draw-bar #connectin the crank-shaft with the drill-rod, of a ate on said housing, a gear-casing revolu'b y mounted'on said plate,

a gear in said casing secured to the crankshaft, a second gear mounted in said casing and meshing with the first-mentioned gear, a

rigid drive-rod passing through said second gear, and a motor with which said rigid driverod is directly connected.

20. In a drill, the combination with a housing, a crank-shaft therein, and a drill-rod connected with said crank-shaft, of a plate mounted on said housing, a gear-casing, a

spring-ring removably and revolubly connecting said gear-casing with said plate, and gearing in said casing.

21. In a drill, he combination with a drillbody and a drill-rod having a spiral groove, of a sleeve screwed into the forward end of the drill-body, a ratchet device in the drillbody, and having one of its members engaging the spiral groove in the drill-rod, and a nose-bushing for the drill-rod keyed to the other memberof said ratchet device, said nose-bushing'having frictional contact with the rear end of the sleeve in forward end of the drill-body.

22. In a rock-drill, the combination of a barrel, a drill-rod therein and a chuck secured to the forward end of the drill-rod to operate within the forward end of the barrel andexclude dust from thedrill-rod.

23. In a rock-drill, the combination om. barrel, a nose-bushing therein, a drill-rod movable longitudinally through the nosebushing, and a chuck ontheend of the drillrod and movable longitudinally in the forward end of the barrel, said chuck adapted to exclude dust from the portion of the drill-rod which passes through and beyond the nosebushing.

24. In guide-shell, of a drill barrel or body mounted thereon and rovided with means at itssides engaging an movable againstzthe under face of said guide-shell.

'25. .In a rock-drill,'the combination with a drill bodyor barrel havin enlargements at respective sides, of a guide-shell on which said drill body or barrel is mounted and a rock-drill, the combination with a plates secured to said enlargements and movable against the under face ofthe guide-shell.

, 26. In amok-drill, the-combination with a sheet-steel guide-shell and a longitudinallymovable drill body' mounted 'thereon, of

guiding means projectingfrom the sides of thedrill-body, embracing the sides of the guide-shell and movable against the under face of said guide-shelh .In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

THOMAS EDGAR ADAMS. Witnesses:

II. S. JENKINS, -JOHN 11.0mm.