US1658330A

US1658330A - Drilling machine

Info

Publication number: US1658330A
Application number: US421748A
Authority: US
Inventors: George H Gilman
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-11-04
Filing date: 1920-11-04
Publication date: 1928-02-07
Anticipated expiration: 1945-02-07

Description

5 Sheets-Sheet 1 Inverr.- 6H 612321109114 Mx *IM-APH Y 8.

lli f gg Feb. 7, 1928.

G. H. GILMAN DRILLING MACHINE w b bm m,

Feb. 7, 1928.

G. H. GILMAN DRILLING MACHINE Filed Nov. 4, 1920 5 Sheets-Sheet 2 G. H. GILMAN DmLLING MACHINE Feb. 7, 1928.

Feb. 7, 1928.

G. H. GILMAN DRILLING MACHINE Patented Feb. 7, 1928.

UNITED STATES GEORGE H. GILHAN, OF BOSTON, MASSACHUSETTS.

DBILLING MACHINE.

Application filed November 4, 192D. Serial No. 421,748.

My invention relates to drilling machines and more particularl but not cxclusivelyto those for drilling roch' and operated by fiuids under pressure.

My invention will be best understood from the following description when read in the light of the accompanying drawings of one specitic embodiment of my invention selected for illustrative purposes, while the scope of my invention will he more particularly pointed out in the appended claims.

In the drawings:

Figure 1 shows a longitudinal section ot the submitted embodiment of my invention, parts heilig broken away;

Fig. 2 is a section on the line of Fig. 1;

Figs. 3 and 4 are sections respectively on the lines 3-3 and 4--4 of Fig. 2:

I `igs. 5, G, 7 and 8 are respectively sections on the lines 5 5, 6 6, 7--7 and 8--9 of Fig. l; l

Figs. 9 and 1() are respectively sections on the lines 9-9 and 10-10 of Fig. 2;

Fig. 11 is a plan view of the carriage for adapting the drilling mechanism to the cradle of the feed mechanism;

Fig. 12 is a section on the line 12M-1; ot` Fig. 11;

Fig. 13 is an end elevation ot Fig. 1l;

Figs. 14 and 15 are diagrams illustrating the operation of the submitted emlmdimcnt of my invention;

Fig. 16 is a diagram showing some of the connections to the throttle valve; and

Figs. 17 and 18 are diagrams respectivel v illustratin{ r the throttle valve in its throttling and off positions.

Referring more iarticularly to Figs. 1 to ltl. the rock drill 1n the submitted embodiment of mv invention comprises a drill steel I and mechanism for operating the same hy imparting percussion thereto and rotating it.

For imparting percussion to the drill steel I have illustrated a piston having a body portion or head 2 of large diameter and projecting therefrom. a hammer bar fl, the front end of the latter being adapted to strike the rear end of the drill steel at the end of the forward stroke of the piston. As shown the piston is further provided with a rearward extension 4 of smaller diameter connected to the body portion Q by means of'- the reduced diameter portion 5. Surrounding Dwi) the piston is -a casing herein comprising a cylinder member 6 having a forward bore 7 of large diameter for the large diameter portion 2 of the piston and a rearward cylinder member having the bore 8 of smaller diameter for the small diameter portion of the piston.

As illustrated the rearward cylinder member comprises a block 9 forming a closure for the larger bore 7 and carried thereby a rearwardly extending member 10. 'The member 10 herein is provided with a flange 11' which abuts the rearward face of the block 9 and at its forward end is provided with a cylindrical portion 12 which enters the bore 13 of the block 9. For maintaining the extension 10 and block 9 in fixed angular relation I have shown the dowel 14, and for maintaining the same in assembled relation I have shown the end of the portion 12 as upset into a counter-sunk portion at the forward end of the bore 13 as indicated at 15. Herein integrallv formed with the extension 10 is a rear cylinder head 16.

The drill Steel is carried by the chuck 16 in any suitable manner sutlicient to cause rotative movement of the chuck to be imparted to the steel. Herein the chuck has an exterior hearing 17 in the chuck casing 18 and at its rearward end an exterior hearing 19 in the front cylinder head 20. On the exterior portion of the chuck intermediate the bearings are illustrated gear teeth Q1 and meshing therewith the internal gear teeth of the yokes Q2. These vokes operate to form a reduction gearing and for driving the same I have shown a rotar)v motor comprising the intermediate gear member Q3 and the side gear members 24. Driven b v the side gear members are the shafts Q5, each of which in the present embodiment of my invention carries a pair of eccentric members 26, which when the shafts are rotated act to gy ate the yokes and thus to rotate the drill awel. For connecting the shaft-s to the rotors I have shown keys 25 carried by the shafts entering suitable ways in the gear members 24. The keys are of such dimensions that the shafts may he drawn together with the keys through the shaft bearing blocks 3Q and 321. In general the details of the chuck rotating motor and gearing 'form no part of the invention to which this application is directed and then`- fore will not be described with more particlll ularity than is necessary to show how they are applied to the invention under consideration.

The intermediate gear member 23 of the chuck rotating motor surrounds and is journalled on that portion of the c linder extension 10 which is rearward o the block 9. For housing the operative parts of this motor I have shown a casing which comprises a lateral portion 27 and an end portion, the latter comprising for a purpose hereinafter to be described a sleeve 33 on the exterior surface of which is mounted the body 28 of the end casing. The sleeve 33 of the end casing is shown as provided with a flange 34 against which the forward portion of the bod abuts, and for holding the parts in assem led relation the end of the sleeve is shown as upset into the counter-sunk portion of a body as is indicated at 35. For holding the motor and its casing in position I have shown a nut having the screw threaded ortion 36 which enters the bore 37 forme in the rear cylinder head 16 and cooperates with screw threads formed on the interior portion of such bore. This nut is shown as provided with a lian e 38 adapted to abut against the rearward ace of the end ortion of the chuck rotating motor casing w en the nut is screwed into position.

As illustrated by Fig. 2 for sup orting the intermediate ortion of each sha t 25 I provide the antiriction bearings 32 and 32a respectively carried in suitable recesses in the block 9 and the front cylinder head 20. For supporting the ends of the shafts I have shown a rearward bearing in the block 32b carried in a suitable recess in the motor casing member 28 and a forward bearing 32 forined in the chuck casing. Herein the

blocks

32 and 32" respectively are formed with

flanges

31 and 31", the flan e 11 of the cylinder extension as illustrate by Fig. 9 bein cut away to receive the flange 31, and the ange 31" as illustrated by Fi 1() being cut away to receive the flange 34 o the sleeve 33 of the motor casing. By this construction are provided smooth surfaces for the end faces of the motor gear members and a shoulder afforded by the ed es of the respective flanges over which I t the motor casing member 2T and thereby dowel the same to ositon it angularly. Further the bearing lock 31 serves to position and doivell the extension 10 in its roper angular relation to the block 9; whi e the block 32h, which carries the automatic lubricator hereinafter to be described, similarly positions and dowels the motor casing parts, 27, 28 and 33 to each other.

For holding the cylinder sections encasing the piston in assembled relation I have shown the side bolts 39. These side bolts preferably are of such number and are so arranged that two of them are located at one side of a plane passing through the longitudinal axis of the machine, the purpose of which will be hereinafter described. These bolts I have shown provided with heads 40 engaging the chuck casing and nuts 41 engaging the rearward face of the chuck rotat'ng iuotor casing. It will be observed that by removing the nuts 41, the sections of the cylinder inay be separated and that the rearward portion of the cylinder together with the chuck rotating motor may be removed as a unit.

I have shown the drilling machine as provided with a suitable feed mechanism which herein comprises the cradle 42 having the ways 43, and the feed screw 44. Carried by the ways in slidable relation thereto is shown the carriage 45 provided with the guide members 4G cooperating with the ways on the cradle. The carriage herein is provided ivitli upstanding members in the form of ears 47 which as shown are four in nunibei'. These ears are perforated as indicated at 48 to receive those side bolts 39 which are adjacent the carriage and herein the casing is recessed as indicated at 49 and 50 to receive such ears. As indicated in Figs. 1, 5, 6, 7 and 8 the adjacent ortions of the carriage and casing are fini ed to provide flat contacting surfaces for better holding the parts in rigid assembled relation. It will ie appreciated that by removing the two side bolts extending through the ears of the carriage the drilling machine niay be removed from the carriage without disassembling the drilling machine.

As hereinbefore described, in the present embodiment of my invention the portion 12 of the cylinder section eiicasing the rear piston extension is provided with a surface which fits the bore 1.3 of the ineniber 9 and likewise the exterior surface 0f the sleeve :lll fits the interiorsurt'aceof the bodyY portion of the end casing and the motor. In these surfaccsas illustrated by Figs. l and :2 are foi-ined

annular grooves

51, 52, 53, 54 and 55. Herciii the groove 51 forms au oil reservoir and the

grooves

52 and 53 respectively forni conduits for distributing the adiuisison motive fluid and exhaust motive fluid to and from the chuck rotating motor while the grooves 54 and 55 forni part of the fluid 'distributv ing passages for reciprocating` the piston. As illustrated by Figs. 1 and 10. the motor is provided at theV intersection of the

boresl

29 and 30 willi the admission passages 5i' and at the opposite intersection as illustrated by Figs. 5 and 9, with exhaust passages 56. F or convenience of illustration. these passages are shown in Fig. 1 by dotted lines somewhat out of position, the truc positions being indicated by Fins. 5, 9 and 10. llie `n'roovt` 5:2 is connected v means of a conduit 5S with the motive fluid inlet 59 and the groove 53 by means of the conduit 30 till with the atmosphere in a manner hereinafterwards to be described. The purpose of employing the annular roo'.es will he appreciated from the consideration of the conduits admitting motive fluid to the motor. `In this connection it will be observed that the supply conduit 58 is on the top of the machine while the conduits 57 are angularly positioned with reference thereto circumferentially around the axis of the machine. Hereinbefore in such constructions it has been usual to drill intersecting passages in the wall of the cylinder which as understood by those skilled in the art necessitates the use of plues to close the ends of the holes thus drilled and the forming of bosses or thickened portions on the cylinder wall to provide material for drilling the passages. By the construction herein set forth, the manifest disadvantages of the prior construction are avoided.

Referring to Figs. 1, 2, 3, 4 and 6, I have illustrated the groove 55 as connected to a motive fluid supply passage 6l and with the forward portion of the rearward bore by means of oppositely disposed passages G2, while the groove 54 is shown as connected to the forward portion of the reaward bore by means of oppositely disposed passages 63 and to the forward end of the larger bore by means of a plurality of passages 64, one of which is shown in Fig. 1 out of angular position for convenience of illustration but the true position of which is illustrated by Figs. 3 and 6. Extending rearwardly from the passages 62 I have shown longitudinal grooves G formed in the interior surface of the smaller bore and terminating in the plane of the passages (Sil. Bv this construction, when the piston is adjacent the rearward end of the stroke as illustrated by Figs. 1 and 14, the motive fluid admitted to the groove 55 passes into the rearward end of the cylinder bore of large diameter through the passages ($2 and the passage all'orded by the reduced diameter portion 5 of the piston; and when the piston is in its forward position as shown by Figs. 2 and' 15, the motive fluid passes by way of the passages 62 and G5 from the groove 55 into the smaller piston bore. whence it finds its way into the forward end of the larger cylinder bore' through the passages 63, the groove 54 and passages 64. When the piston moves ,forwardly from its rearward position, the snpply to the rearward end of the larger cylinder bore is interrupted and when it moves rearwardly from its forward position the supply into the rearward end of the smaller bore and the forward end of the larger bore is interrupted.

In the present embodiment of my invention the motive fluid admitted at the end of the forward stroke into the rearward portion of the smaller cylinder bore is cut oif when the piston in its rearward movement closes the orts 65 and after this the motive fluid by tie continued rearward movement of the piston is trapped and compressed above its initial pressure. During the forward stroke the pressure of the motive fluid at the rear oi the piston extension l materially increases the energy imparted to the piston and this aids in producing a heavier blow than if motive fluid at initial pressure were utilized in the smaller bore for producing the forward stroke.

In the intermediate portion of the cylinder as illustrated by igs. 1 and 6 I have shown a slot 66, which serves as a piston controlled exhaust port and as will be clearly understood by those skilled in the art. this port permits the lnotive fluid to be alternately exhausted from thc opposite sides of the piston portion 2 when uncovered therebv during its reelproeat|ons. Formed in the wall of the cylinder I have shown a pair of longitudinal passages 6T which intersect the slot 66 and are adapted to be placed in communication with the atmosphere in a manner hereinafter described.

llesides the valveless fluid distributing features so tar described l may also provide additional fluid distributing means in the form ot' a valve. As will be understood by those skilled in the art, the inid distribution directly controlled by the pistou` such usually beingI termed a valveless distribution. has the advantage of quit-lil)Y admit'- ting and exhausting motive fluid, but has the disadvantage that an earl),v point ot' eut-oil' and compression must be provided. ()n the other hand. when the iiuid distribution is controlled .solely b v a valve these advantages and disadvantages are reversed. By properly combining' the two formsl of distribution. the disadvantages of each may be eliminated and the advantages of both re tained, which is to say that b v means ot' the valveless distribution the quick admission and release may be obtained and by means of the valve the mean etleetive pressure may be increased by making the effective point of ent-oli' and con'ipression lute in tbe stroke. The valve. in the submitted embodiment ol my invention controls admission and exhaust of fluid to both sides of the pistou portion for both its strokes. although as will be obvious. the admission or exhaust events controlled by the valve for the fluid used at either side of the piston portion 2. may be omitted. It may, however. be pointed ont. that owing to the compression of the [luid in the chamber 8 on the rearward stroke. either or both a late point of compression for the fluid exhausted at the rear of the piston portion 2 and late point of cut-oli` for that ad mitted in front of this piston portion is desirable. This application is not concerned with the details of the valve and therefore lill only so much of it as necessary for a clear understanding of my present invention will be described.

As showm'the cylinder is provided with a longitudinally arranged lateral enlargement 68 which receives the valve cage sections (if) and 70 for housing the tubular valve T1 more fully described. The internal bore ot the valve cage is provided with a conduit 72 adapted in a manner hereinafter described, to be placed in connection with the source of motive fluid supply and is also provided with thc

annular grooves

73, 74, i5. 76 and 77. The exterior surface of the valve is provided with the circumferentially arranged flange 78 and the grooves 79 and 80. The

annular grooves

74 and 76 just referred to are connected by means of passages 8l and 82 with the exhaust passages 67, while the grooves 71.5 and 77 respectively are y connected hv means

ot passages

83 and 84 with the cylinder bore of larger diameter adjacent its opposite ends. The flange 7S of the valve fits in a fluid tight manner the Ainterior surface of the annular groove 75 of the valve casing and extending from op posite ends of the groove 75 to the interior of the enlarged bore of the cylinder are the crossed

kicker passages

85 and 86. As will be understood by those skilled in the art. when the piston reciprocates, motive Huid is alternately admitted and exhausted by means of the

kicker passages

85 and 86 to the annular groove 75 of the valve casing to act upon the Harige 78 of the valve to cause the valve to be thrown to opposite ends of its travel.

The operation of the parts described for controlling the fluid causing the piston to reciprocate is as follows:

lVhen the pistou is in the rearward portion of its stroke as illustrated by Fig. 14, the valve has been moved by the fluid admitted by the kicker port 86 to the forward end of its travel. In this position of the parts, assuming the motive fluid is admitted through the passages 61 and 72 respectively to the groove and to the interior of the valve. motive fluid will How from the groove 55 by way of the pasasges 62 and around the reduced portion 5 of the piston into the rear of the larger cylinder-.bore and when the piston portion 2 uncovers the passage 83 leading from the valve cage, motive fluid will be admitted from the passage 72 by way of the groove 73 and passage 83 into the rearward end of the cylinder portion of large diameter. In this position 'of the parts, the piston has uncovered the exhaust slot 66 which permits the vmotive 61nd in front of thepiston to exhaust throu hV said slot into the passage 67 whence it ds its wav to the atmosphere. Also motive fluid in front of the piston may pass through the passage 84, the groove 77 of the valve cage,

Lesaaso the groove 80 of the valve, the groove 76 of the valve cage, and the passage 82 into the exhaust passages 67.

When the piston reaches the forward end of its stroke as illustrated by Fig. 15, the valve has been thrown to the rearward end of its travel by means of motive lluid admitted through the kicker passage 85. After the piston moves backward owing to its rebound far enough to uncover the forward end of the passages 64 and the passage 84, motive fluid is admitted to the forward end of the cylinder bore ol' large diameter from the groove 55 by way of the passages 62, roove 65, passages (S3, annular groove 54 an passages 64 and likewise from the passage 72 through the interior of the valve, the groove 77 in the valve cage and the passage 84. As the piston moves rearwardly, the motive Huid` in iront of the enlarged piston portion 2 passes through the slot G6, to the passages 6T whence it finds its way to the atmosphere. Motive Huid as the piston moves rearwardly, also exhausts into the passages 67 by way ot' the passage S23, groove 73 in the'valve cage, groove 79 in the valve, groove 74 in the valve cage and passages 8l. At the end of the forward stroke` when the cylinder bore of smaller diameter has been expanded by the iston, the clnunber formed thereby is filled) with live motive fluid which passes from the groove 55 thereto by way of the passages 62 and and when duringthe rearward stroke, the passage 65 is closed, this motive fiuid is trapped between the rearward end of the piston portion of smaller diameter and the rear cylinder head, which compresses the Huid to a high degree of fessure when the iston reaches the rearwar end of its stroke. The energy thus stored u in the compressed motive lluld is available or impartinv to the piston a greater momentum on its tn'ward stroke than if mot-ive Huid at initial pres-l sure were used in the rear piston chamber of smaller diameter.

Motive fluid is led to the machine through a suitable air hose connection shown at 87 which conducts motive fluid to the intake 59. For controlling the motive fluid I may use any suitable valvular mechanism, as for example the valve illustrated by Figs. 1,14, 15, 16, 17 and 18. This valve is in its general aspects of the usual turning-plug type. Formed in the valve is a longitudinal passage 88 and communicating therewith the

radial passages

89, 90 and 91. In the full open operating position of the valve as illustrated by Figs. 1 and 14 the passage 89 is in communication with the motive fluid supply connection 59, which delivers motive u'id to the assage 92 lending to the valve cage conduit 2 and to the assage 61 leading' to the groove 55. Throug the wall of the portion of the block 9 constituting the throttlc valve casing are passages 93 in commuand 18. Fig. 16 shows a p monaco nication with the atmosphere and a pair of passages 94 in communication with the exaust passages 67. In the operating position of the valve,the communication is established between the

passages

94 and 93 by means of the exterior recesses 95, formed in the valve. 0n the exterior portion of the valve in communication with one of the receases 95 is an arcuate slot 96 which in all positions'of the valve is adapted to be in communication with the passa e 60 conducting exhaust motive fluid from t 1e chuck rotating motor. This motor is supplied with motive fluid through the -connectlon 97, which communicates with the intake connection 59 in advance of the throttle valve and in this manner the motive fluid is always admitted to and exhausted from the chuck rotating motor irrespective of the Hosition of the throttle valve. For' contro ing the chuck rotating motor I may provide a suitable throttle valve 98 carried by the chuck rotating motor, casing. y

For conducting water to the drill bit, I have shown a water tube 99 which herei n communicates with the boreI 100 of the -bit and is supported at its rearward end in the rear c linder head 16. For securing the water tulie and forming a water ti ht loint at the rear head, I have shown a pac infr 101 of rubber orthe like which is positioned in the cavity- 37 of the rear head and surrounds the rearward end of the `water tube. When the nut 36 is screwed into position the packing 101 is compressed and thus securely clamps and acks the rearward end of the tube. Herein the nut is provided with a passage 102 which at its rearward end is enlarged and provided with securing means for the water hose connection 103.

For supplying the bit with air, I have shown a passage '104, shown in Figs. 1, 7, 14 and 15, in communication with one of the exhaust passages 67 or if desired I may provide two passages 104, each in commun1ca tion with one ofthe passagles 67. For supplying the passage 104 wit air to blow the hole, I have shown the throttle valve as pr vided with a passage 105 in communication with the interior conduit 88 of the valve. Herein this assa e 105 terminates on the exterior of tie va ve in the same lane as one of the passages 67 so that when t e valve is turned to interrupt communication between the exhaust discharge 93 and the exhaust passage (i7, the passage .105 will be brought into communication-with the passage 67 `and therefore fill the interior of the machine with live air which linda its way throu h the passa es 67 and 104 to the interior o the chuck c amber and hence into the boreo the drill steel.A f r Theoperation of my throttle valve will .be best understood from Figs. 14 15, 16, 17

an o the valve corresponding with the section shown in Fig. 1, with some of the connecting passages shown diagrammatically by dotted lines. In Fi s. 14, 15, 17 and 18, the valve is represent by three sections respectively on the lines a-a, 12-6, c-o of Fig. 16. Fig. 14 shows the full open running position, Fig. 15 the hole blowing position, Fig. 18 the throttling position and Fig. 17 the of or inoperative position.

In the position of the parts, illustrated by Fig. 14, the motive Huid is admitted from the intake connection 59 through the throt tlc valve to the passages 92 and 61 to the valve and valveless distributing means of the permissive mechanism, while the exhaust from the same is conducted from the passa 67 through the exterior slots 95 of the va ve to the exhaust discharge 93. In this position the -passaggi 105 is blanked and therefore the hole is not blownand the piston reciprocates. Motive uid is led through the passage 97 from the intake connection 59 and passes, if the valve 98 is open, into the groove 52 whence it is distributed by the passages 57 to the chuck rotating motor. Motive fluid after passing through the chuck rotating motor exhausts through the passages 56 into the groove 57 whence it passes to the atmosphere through the passage 60 and arenal groove 96 on 'the valve plug to -the exhaust discharge 93.

When the hole is to be blown, the valve is moved to the position shown by Fig. 15. Under these conditions, the exhaust discharge 93 is out of communication with the passages 67 and the live air passage 105 of he valve is brought into communication with one of the passages 67 which admits motive iuid thereto and discharges the same, through the passage 104 into the chuck casing whence it finds its way into the bore 100 of the steel. Under these conditions, the passages 90 and 91' are out of communication with the intake conduits leading to the percussive apparatus but obviously with the ordinary form of valve motion it will be suicient if these passages remain in communication with the intake passages; providing the exhaust is closed. It, however, is desirable to control the motor By more or less throttling the intake and for this pur pose the orte and passages are so construct ed that t e intake may be throttled to control the blow before the exhaust is closed. Such a position is shown by Fig. 18 in which it will be noted thatthe exhaust is open and that the admission to the passages 92 and 61 is throttled. Bv turnin the valve slightly from thls position the" egree of throttling can be increased' or diminished.

When the machine is to be placed out of operation, the valve is turned to the position illustrated by Fig. 17, which shows the passage 59 supplying motive fluid closed. From this position the valve is progressively turned in the same direction to the-positions illustrated by F ig. 15. in which the hole is blown, that illustrated by Fig. 18 in which a Small supply ot air is admitted to operate the machine to strike a light blow, and finally that illustrated by Fig. 14, in which a full supply of air is admitted to the hammer. The valve is moved from this last position in a reverse direction to throttle the hammer, blow the hole and finally to sluit olf the air.

It will be observed in all positions of the valve the exhaust from the chuck rotating motor is not affected and the same irrespective of the position of the valve may be regulated or put out of operation by means of the throttle valve 98.

As has heretofore been pointed out. iu the present embodiment of the invention the bearing blocks (2b carry automatic lubricators and as the lubricator carried b v each is similar, only one will be described. As illustrated, formed transversely in the block is a cylindrical bore 106 which communi- Cates with the exterior of the motor housing through an opening 107 in the motor housing member 28. Slidably mounted in the bore I have shown a cylindrical plunger 108 which is provided with the intermediate grooves forming chambers 109 and 110. Connect-ing the oil reservoir provided by the groove 51 with an intermediate portion of the bore 106 is a passage 111 and connecting the end of the bore with the groove 52 supplying the/chuck rotating motor with motive fluid is a passage 112. In the [osition shown by Fig. 2, oil is conducted from .the oil reservoir by way ot the passage 111 to the chamber of the lnbricator plunger and when the plunger is moved to the opposite end of its travel, this chamber is placed in communication with the oil distributing passage 113 andthe chamber 109 of the plunger brought into communication with the passage 111 and when the plunger again moves to the position shown b v Fig. 2, the oil which has entered the latter is discharged into the distributing passage 114 and the chamber 110 again filled. Herein the plunger is held inthe position Ishown by Fig. 2 by means of a spring 115 interposed between the end of the plunger and the plug 116 closing the bore 107.. When motive fiuid is admitted to the groove 52, the pressure thereof acting through the passage 112 on the end of the plunger overcomes the force of the spring and moves the plunger to the opposite end of its stroke and when the supply to the groove 52 is interrupted, which results in the .elimination of the pressure of the motive uid on the end of the plunger, the spring moves the plunger to the position shown by Fig. 2.

As illustrated, the passage 113 communicates with the passage 117 extending throughout the length ot' the shafts 25 and oil discharged into said passage is distribut,

ed by means ot radial passages 118 establishin communication between said passage and t e exterior of the shaft to the shaft and eccentric bearings. Oil which is admitted to the passage 114 finds its way through suitable connecting passages to grooves 119 formed on the exterior surface of the cylinder extension 10 and serves to lubricate the bearing for the central rotor of the chuck motor. Some of the oil admitted to the passage 113 tinds its way around the rearward end of the shaft to lubricate the end bearing of the shaft and from this bearing into the interior of the chuck rotating motor and in a like manuel' .some of the oil admitted to the groove 119 finds its way into the interior of the chuck rotating motor. The oil thus admitted into the interior of the chuck rotating motor serves to lubricatc the gear teeth.

As will be understood bv those skilled in the art and as will be obvious a suitable filling orifice in communication with the eX- terior of the machine and provided with a suitable closure will be employed to replenish the oil supply for the groove 51.

The valve and other features herein shown are claimed in applicants co-pcnding applications Serial No. 113,672, tiled June 4. 1920 (which is a division of application Serial No. 386,868, tiled June '5, 1920. on which United States Patent 1,588,407 was granted to applicant June 15, 1926), and Serial No. 76,410, filed December 19, 1925 (which is a division of this application).

It is to be understood that although I have described one specific embodiment of my invention for illustrative purposes extensive deviations from the same may hc made without departing from the spirit ot' the invention.

Claims- 1. In a rock drill, a piston. a sectional casing for said piston. means for securing the sections of said casing in assembled rclation, a chuck, a motor for rotating said chuck, said motor carried by one of the piston casing sections and having a casing separate and removable from said piston casing, and means independent of said means for securing the piston casing sections in assembled relation for securing the motor casing to said piston casing section whereby the last named section can be removed with the motor as a unit.

2; In a rock drill, a piston having a hammer portion of lax' er diameter and an extension of smaller diameter, a casing section for said piston portion of large diameter, a separate casing section for said portion of smaller diameter, a chuck operating moloo lPo

tor com rising a fluid operated member surroun lng said separate casing section, a. separate casing for said motor, means for securing said casing sections for said piston portions in nonrotatable relation, and means for securing said 'motor eosin# to said separate casing section whereby t e latter may be removed with said motor as a unit.

3. In a rock drill, a hammer .piston having an extension, a sectional casing for said piston comprising a se arate section for said extension, said section having anexteriorly reduced portion, a chuck' rotatin motor comprising a rotor surrounding sai portion, a separate casing for said motor surrounding said portion, means for securing said motor casing to said separate section, and separate means for securing in non-rotatable assembled relation the sections of said piston casing whereb1 said separate section or said extension an motor may be removed as a unit.

4. In a rock drill, a liain'mer piston having an extension, a sectional casing for said piston comprising a separa te section for said `extension, said 'section having au exteriorly reduced portion, a chuclrl rotating motor comprising a rtor surrounding said portion, means carried by said'reduced rtion for securing said motor casing to sai separate section, and separate means for secnr. ing in nonrotatable assembled relation the sections ofv said piston casing whereby said4 separate section and motor 'may be removed as Va unit.

Vli. In a rock drill, a hammer piston, u cylinder for said hammer piston having a main body iortion, an end section for said cylinder forming a closure -for said cylinder body portion and having a member projecting therefrom. u chuck rotating motor comprising a rotor jouriuilvd on said member, a casing for said motor surrounding said member and carried thereby, and nicnns carried b v said ineiiilicr for securing the motor casing thereto.

(i. ln n rock drill, a hammer piston, a cylinder for said hammer piston having a main body portion, un end section for said c linilw' forming a closure for said cylinder indy rmi-tion and lhs-refrain, a chuck rotating motor comprising: a rotor iouriialcd on said member, a casing for said motor surrounding isaid member and carried thereby, und said inein ber having a screw threaded portion currying :i nut for securing the motor casing to said member.

7. In a rock drill, a hammer pistou, a cylinder for said hammer piston havin a main body portion, an end section for said c linder forming n closure for said cylinder ody portion and having a member projecting therefrom, a chuck rotating motor compris- 'ing u rotor journaled on said member, a

having a nicml'ier projecting casing rfor said motor surrounding said member andcarrled thereby, said member having a screw threaded portion carrying'a nut for securing said mot-or casing tosaid iuember, and a cleansing lluid tube connected to said nut.

8. I n a rock drill, a hammer piston, a cylinder for said hammer iston having a main bod "portion, anen section for said cylinder ornii a closure for said cylinder body portion an having a member project- ,ing therefroima chuck rotating motor comprising a rotor y a casingforsaid motor surrounding said ii'icmber and carried thereby, a cleansing 'luid conducting means, and said member having a screw' threaded portion carrying a nut surrounding said conducting means for securing raidcasing to said member.

9. In a rock drill, a- -c rearward extension of uced diameter, a motor surrounding said extension, means for .holdi said motor and cylinder in assembled re tion, feeding means for said cylinder, said feeding means comprising ears received in recesses infsaid c linder; side bolts passing throu li said cylinder, said motor and ears: an vsaid side bolts having their nuts at their rearward ends whereby'said motor may be disassembled without removing said cylinder from said feeding mechanism. A A 1 10. AJdrilling machine having, in combination, a hammer cylinder comprising separute sections, at least three side bolts for securing said sections to ether. a member for supporting said cylin er, pairs of perforated ears on said member, und a. mir only of said side bolts pussin through tie erforations of said ears, w iereby said cy inde-r may be detached from said member while securing the sections of said cylinder to-4 gether.

11. A rock drill, having in combination, u ercussivc motor comprising a sectional 'cy indcr, u carriage for supporting said cyliiider, a support slidably supporting said carriage, means for securing t e sections of said cylinder together comprising a pair of side bolts at the side of said linder adjacent said carriage, longitudinal y and transs vorsely aced ears on said carriage thi-on li which' said side bolts extend, and other si e bolts for securiii said sections together.

12. A rock drill havin in combination. a sectional hammer cylin er having a lurality of side bolts for securing the sections thereof in assembled relation, a feeding mechanism including a carriage in side to side relation with said cylinder, and means securin to part only of said said carriage side bo ts, wliereb said cylinder may be detached from sai' carriage while securing said sections together.

18. A rock drill, having in combination,

ournaled on said member,`

linder having a' lil) llKl

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a chuck, a hammer pistou havin a rearward extension, a cylinder for sai hammer piston having a body and a separate rearward section, the latter forming a cylinder portion for said extension, said rearward section having a reduced. exterior portion, a motor for driving said chuck having a rotor journalled on said reduced exterior portion and surrounding said'rearward exten-Y wardV section, the latter forming a cylinder` portion for said extension, said rearward section having a reduced exterior portion, a motor for driving said chuck having a rotor journalled on said reduced exterior portieri and surrounding said rearward extensin of said piston, a casing for said motor surrounding said reduced portion, means for securing said casing to said rearward section, a feeding device for said cylinder having a slidably supported carriage, and common means independent of said means for securing said casing to said separate section for securing said separate section to the body of said cylinder and said cylinder to said carriage.

15. A rock drill, having in combination, a chuck, a hammer iston having a rearward extension, a cylinder for said hammer piston having a body and a separate rearward section, the latter formir:J a cylinder portion for said extension, "said rearward section having a reduced exterior portion, a motor for driving said chuckhaving a rotor journalled on said reduced exterior portion and surrounding said rearward extension of said piston, a casing for said motor surrounding said reduced portion, means for securing said easing to said rearward section, a feeding device comprising relatively ymovable parts, side bolts independent of said meansfor's'ecuring said casing to V'said separate'sectionfor securn said sepversely Vspacedears` at `each end of said carriage, recesses in said c linder for receiving one armere of-sai pair of ears, said y side bolts intersecting said recesses, and the portions of saidearsreceived by saidv recesses having perforations through which said side `bolts extend. t

17. A rock drill, having in combination, a cradle having a pairrof longitudinally disposed ways, a. cradle slidahly supported in said Ways, a ercussive hammer having a sectional cylin er supported on said. carringe, means for holding the sections of said cyhnder in assembled relation com-prisng a air of side bolts at the side of said cyl in er adjacent said carriage, a pair: of transversely spaced ears at each end of said earriage, recesses in said cylinder for receiving one or more of said pair of ears, said side bolts intersecting said recesses, and the portions of said ears received by said recesses having means for locking` said ears to said side bolts.

InA testimony whereof, I have signed my name to this specification.

GEORGE H. GILMAN.

ill)

a chuck, a hammer piston havin a rearward extension, a cylinder for sai hammer piston having a body and a separate rearward section, the latter forminer a cylinder portion for said extension, said rearward section having a reduced exterior portion, a motor for driving said chuck having a rotor journalled on said reduced exterior' portion and surrounding said rearward extension of said piston, a casing for said motor surrounding said reduced portion, means for securino said casing to said rearward section, and-'means independent of said first named means for securing said separate section to said cylinder.

14. A rock drill, having in "combination, a chuck, a hammer piston having a rearward extension, a cylinder for said hammer piston having a body and a separate rearward section, the latter forming a cylinder portion for said extension, said rearward section having a reduced exterior portion, a motor for driving said chuck having a rotor journalled on said reduced exterior portion and surrounding said rearward extension of said piston, a casing for said motor surrounding said reduced portion, means for securing'said casing to said rearward section, a feeding device for said cylinder having a. slidably supported carriage, and common means independent of said means for securing said casing to said separate section for securing said separate section to the body of said cylinder and said cylinder to said carriage.

15. A rock drill, having in combination, a chuck, a hammer piston having a rearward extension, a cylinder for said hammer piston having a body and a separate rearward section, the latter termin, a cylinder portion for said extension, said rearward section having a reduced exterior portion, a motor for driving said chuck having a rotor journalled on said reduced exterior portion and surrounding said rearward extension of said piston, a casing for said motor surrounding said reduced portion, means for securing said casing to said rearward section, a. feeding device comprising relatively movable parts, side bolts independent of said means for securing said casing to said separate section for securing said scparate section to the body of said cylinder, and spaced ears on one of said parts of said feeding device having openings through which said side bolts extend for securing said part to said cylinder.

16. A rock drill, having in combination, a cradle having a pair of longitudinally disposed Ways, a cradle slidably supported in said ways, a ercussive hammer having a sectional cylin er supported on said carriage, means for holding the sections of said cylinder in assembled relation comprising a pair of side bolts at the side of said cylinder adjacent said carriage, a pair of transversely spaced ears at each end of said carriage, recesses in said cylinder for rcceiving one or more of said pair of ears, said side bolts intersecting said recesses, and the portions of said earsreceived by said recesses having perforations through which said side bolts extend.

17. A rock drill, having in combination, a cradle having a pair of longitudinally disposed Ways, a cradle slidably supported in said Ways, a percussive hammer having a sectional cylinder supported on said. carringe, means for holding the sections of said cylinder in assembled relation comprisng a pair of side bolts at the side of said cylin er adjacent said carriage, a pair of transversely spaced ears at each end of said carringe, recesses in said cylinder for receiving one or more of said pair of ears, said side bolts intersecting said recesses, and the portions of said ears received by said recesses having means for locking said ears to said side bolts.

In testimony whereof, I have signed my name to this specification.

GEORGE H. GILMAN.

Patent No. l, 658, 330.

Granted February 7, 1928, to

GEORGE H. GILMAN.

ll is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6, lines 125 and 126, claim 2, strike out the word "hammer" and insert the same before the word piston in line 12S; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the ease in the Patent Office.

Signed and sealed this 3rd day of April, A. D. 1928.

M. J. Moore,

Acting nmmiginnnr nf Darn lll) CERTIFICATE OF CORRECTION.

Patent No. 1,658,330. Granted February 7, 1918, to

GEORGE H. GILMAN.

lt is hereby certified that error appears in the printed specification of the above numbered patent requiring Correction as follows: Page 6, lines 125 and 26, claim 2, strike out the wurd "hammer" and insert the same before the word piston in line 125; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 3rd day of April, A. D. 1928.

M. J. Moore, Acting Commissioner of Paten