US1846819A - Rock drill - Google Patents

Description

Feb. 23, 1932.

W. A. SMITH, JR

ROCK DRILL Filed Dec. 8, 1928 INVENTO'R. I/Filha AJmifla Sr.

HIS ATTORNEY NI E STATES Patented Feb- 1932'.

WILLIAM A. smrmlsn or na ro PENNSYLVANIA, Ass eNon roiNeERsoLn-nANn oo raNY, orennsny crry, new JERSEY, A coaroaa'rronor new JERSEY ROCK DRILL Application .filed December 8, 1928.. fieri al No; 324,726;

This invention relates to fluid actuated tools, but more particularly toa fluid actu-' ated rock drill in which the hammer piston reciprocates independentlyof the Working implement which it is adapted to actuate.

One object of the invention is to assure thorough lubrication of the cooperating sur-. faces of the chuck mechanism and the element. whereby it is guided such as thefront head of the rock drill. V

.Another object is to-enable lubricant to be supplied tothesurfaces in a rock drill in which the interior of the chuck mechanism is vented to the atmosphere so thatthe lubricant will have to be conveyed forwardly of the vented portion of the chuck mecha- Other objects will be in part obvious and in part pointed outhereinafter. f V, In the drawings illustrating one form which the invention may assume in practice and in which similar reference characters refer to similar parts, 1

Figure 1 isalongitudinal sectional elevation of a rock drill constructed in accordance with the practice of the invention, 7 Figure 2 is a transverse view taken through Figure 1 on the line 2-2 looking in the direction indicated by the arrows, and.

Figure 3 is a similar-view taken through Figure 1 on the line33 looking in the direc-v tion indicated by the arrows.

Referring more particular y to the drawings, A designates acylinder having a pis-. ton chamber B in whlch 1s disposed a rec 1procatory hammer'piston C. The cylinder A; has a free exhaust port A5 which is controlled by the piston C. A back head D is disposed on the back end of the cylinder A and on' the front-endof the cylinderisa front head E. The cylinder A, the front head E and the back head' D form the casing of the drill and are held operative relationship by side bolts F, disposed on opposite sides of the drill.

-At the rearward end of the piston chain ber B is an enlarged bore G forthereception] of a valve box generally designatedaby Hand comprising in this instance a pair of plates J and K. The valye boxi H forms a closure for the rearward end of the piston chamber B and the plate J is suitably recessed to form avalve chamber .L inwhich is disposed 'a distributingvalve O of the os-' ,cillatory plate type.

In the plate K are formed inlet passa es P and Q, which are controlledby'the va ve O. The inlet passage P opens directly into the rearward endof the piston chamber B and the inlet. passage Q, which is a front inlet passage extends through both the plate K and through the cylinder A tothe front end of the piston chamber B wherewith it.

communicates through a port R. I

T he plates J and K are provided with bores S and T respectivelyfor the reception ofv a rifle bar U.. a The contiguous portions of the bores SandT maybe enlarged to receive a bushing V whichencircles the rifle'bar U at this point and also extends through an aperture W in the valve 0. The bushing Y; thus serves to prevent leakage of pressure fluid from the valve chamber L along the rifle bar into the rearward end of the piston chamber B.

. In the construction showmthe plate J acts as a seat for a ratchet ring X which is disposed in the rearward end of the bore G and encircles a head Y of the rifle bar-U and which head carries spring pressed pawls Z adapted to cooperate with the ratchet ring X in a well known manner for imparting rotary movement to the piston.

Thervalve box H, the ratchet ring X and the rifle bar-Ulare held in the bore G by the back headD and to this-end the back head D is provided with a flange 6 which seats on the ratchet ring --X and. forms'one side of-a' supply reservoir 0 in the back head D.

Pressurefiuid for actuating the piston C the back head through a connection (not shown) but the point at which it'may-be attached to the back head D is indicated by a throttlevalve chamber dinwhich is disposed a throttle valve 6. g p a central bore f into which the pressure fluid maybeintroduced and has a port j in one side which, when the throttle valve 6 is-in its'lopen position; will "register with a passage 7: 10

may be conveyed from a source of supply to 1 The throttlevalve "e' has.

in the back head D and openinginto the supply reservoir 0.

In the ratchet ring X and the plate J are supply passages 0 which aflord communication between the supply reservoir 0 and the valve chamber L. In the present instance however, a supply chamber p is formed in the plate J adjacent the valve L and the supplypassages 0 open into the said supply chamber pfor constantlysupplying pressure fluid thereto. a

The piston C is of the differential type and as shown has a fluted forward extension g" which is guided slidably by a bore 7' in a front;

cylinder washer s which acts as a closure for the front end-of the piston chamber B. The

front cylinder washer s has an annular sleeve or extension at the-front end of which is a lateral flange M which lies between the adjacent ends of the cylinder Av and the front head E and between which element said flange W is clamped to hold the front cylinder washer s securely in position. The interior surface 4) of the extension t acts as a guiding surface for one end of the chuck 'w. The chuck also extends into a bore as in the front head'E whereby it is guided at its forward end. In the rearward end of the chuck w is threaded a chuck nut 3 which may be suitably fluted to interlock slidably with the fluted extension 9 of the piston C.

The forward end of the chuck 'w is provided with clutch members 2 adapted to lock with similar-clutch members 2 of a chuck driver3-disposed in the frontend of the bore 00'. The chuck driver 3 may be provided with the usual ribs 4 tointerlock with wings 5 carried by a working implement 6 which extends into cavity 7 in the chuck w to receive the blows of I the hammer piston O- The rearward end or shank 8 of the working implement 6 extends into 'and is guided by a chuck bushing 9 fitted into the forward end of'the chuck w. In orderto prevent the passage of any pressure fluid which may leakpast the piston extension into the working implement and thence through the working implement into the drill hole which, as is well known, is objectionable in certain localities where, because of the peculiar nature of the rock being drilled, the dust resulting from drilling when inhaled has been found to be injurious to the health of the operators; the front cylinder washers is provided with an internal annular recess 10 which encircles the fluted portion of may. leak past the pistonextension Q will be the piston O and communicates with the atmosphere through a port 11 in the front cylinderfwas her and the cylinder'A. Due to this arrangement any pressure fluid which intercepted by the recess '10 and will then be exhausted to the atmosphere 7 Similarly the chuck cavity 7 is'vented to the atmosphere through'a port 12 leading from the chuck cavity to the atmosphere to provide an avenue of escape for any pressure fluid which may flow from the rearward end of the piston chamber B through the piston and into the chuck cavity 7.

As. is well known, in modern drilling practice it is customary to constantly supply lubricant to the various surfaces of the relative- 1y movable parts of arock drill by conveying the lubricant thereto through the medium'of the pressure fluid utilized for actuating the drill. Lubricant may be introduced into the pressure fluid in various manners. One method which has met with considerable favor is to dispose an air line oiler in the pressure fluid supply line and introduce the lubricant into the main pressure stream in suitable form andquantitiesto supply the require ments of the rock drill. Another method frequently employed for accomplishing this purpose. is to provide the drill with means embodied in itself to supply such lubricant as may be required for the best operation of the drill. One of the latter devices is incorporated in the drill illustrated and comprises a reservoir 13, for lubricant such as oil, formed in the periphery of the front cylinder washer s and for which the wall of the cylinderA forms an outer bounding surface. The lubricant may be introduced into the reservoir 13 through'a 'fllling opening '14: in the cylinder A normally sealed by a filler plug'15. 1 i

For the sake of simplicity of illustration; the lubricating system shown is intended to supply lubricant to the various portions of the rock drill only immediately prior to the starting of eachperiod of operation of the drill. To this end the cylinder A is provided with a passage 16 which communicates at its front end with the reservoir through passages'li in the cylinder A andthe front cylinderwasher s. The passage 16 extends municates in this instance with a supply, passage 0 through a port 18 in the cylinder A. and the rotation ratchet X so that when the throttle valve e is opened to supply pressure fluid-tothe drill pressure fluid will at the same time be admitted into the reservoir 13 to exert a pressure on the oil therein.

Owing to the fact that the'reservoir l3is vremotely located from the point, such as'the port 18 through which pressure fluid is admitted into the reservoir, there will be no oil conveyed from the reservoir into themain pressure fluid stream-during thenormal operation of "the drill; However Vwhen the throttle valve 6 is closed to cutoff the supply of pressure fluid to the valve chamber L the pressure fluid which has previously been entrapped in the reservoir and the passage leading thereto will also be exhausted into the valvechamber L and will carry with it a portion'of oilsuflicient to lubricate-the movable parts of the drill such as the piston and the valve preparatory tothe subsequent drilling operation. Obviously, a considerable portion of oil will then remain in the valve chamber L and when the drill is again set in operation, such oil will be blown from the valve chamber and will pass through the inlet passages P and Q, to the ends of the piston chamber B.

In order to assure an adequate quantity of lubricant to the cooperating surfaces of the chuck mechanism such as the chuck w and the chuck jaw 3 and the elements whereby they are guided as the bore w of the front head and the surface 0 of the extension t, the cylinder, the flange u and the front head E are provided with a passage 19 which leads from the forward extremity of the inlet passage Q, to a point near the front end of the front head E. In the front head E are a pair of ports 20 and 21 which branch from the passage 19 and ,open into the bore w. Similarly in the front portion of the cylinder A is apassage 22 which leads from the passage 19 through the extension't to 111- bricate the surface of the rearward portion of the chuck w. 7

To insure a proper distribution of the oil flowing through. the inlet passage Q, between the front end of the piston chamber B and the chuck mechanism a restrictedport 23 is formed between the passage 19 and the inlet passage Q, to avoid an excess of oil to the chuck mechanism and a reduction in the supply of the oil to the front endof the piston chamber B.

As explained, the connecting port 23 between the inlet passage Q, and the passage 19 will serve to supply oil to the chuck mechanism through these channels only immediately prior to each drilling operation. It may however be desirable that oil in suitable quantities be constantly supplied to the chuck mechanism and in order to secure this result the front cylinder washer s is provided with annular groove 24.

The groove 24 is preferably located slightly in advance of the forward passage 17 so that the pulsations occurring in the reservoir 13 will force oil from the forward passage 17 between the cooperating surfaces of the front cylinder Washer s and the cylinder A into the groove 24 from whence it will flow into the passage 19 through a connecting passage 25. The amount of oil thus conveyed rom the reservoir into the groove 24 may be readily controlled by the degree of clearance between the front cylinder washer and the supporting surface of the piston A or by the spacing of the groove 24: and the passage 17.

The present invention has been found to be well adapted for supplying lubricant to the chuck mechanism of rock drills, particularly in drills where, as in the present instance, the chuck'fc'avity andlvother interior portions ofthedrill are VBDtQdztOffhBfitIIlOS- phereolHeretoforeyit has been foundto bean" exceedinglyadiflicult matterlto lubricate V the element forwardly ofv the vented portions 2 of thei'drill. In fact the life of. these parts in drills as formerly constructed has invariably been short; This vwas due tov the'fact that anylub-ricantWhich was conveyedwby' the pressure fluidfiowingpast the fluted err-* tension of; the piston was immediately fexhausted to the atmosphere withoutanyap; 3

preciableamount of it being deposited-won the relativelyfmovable surfaces of the. chuck mechanism and the stationary :parts of the drill. :The present inventionilf'orms 'a-convenient means of providing adequ'ate 'lubri cant to'the chuck mechanismrand hasbeen foundtto greatly prolongthewlife ofzthese parts both in rock drillsfof' the vented type orthose which are unvcnted.

- The following is'a briefdescript-ion 5f the operation. of'thedevice: Afterthert-hrottle' valve 6 has been openedto set the percussiveelement of the drillin operation,rpressure fluid will-flow through the port 18, through thepassage 16 and the ports 17 into the reser voir 13 tolcreatexa pressure therein'on the.

foil; Duringzthe subsequent operation ofthe drillzthe pulsations occurring in .the1reser-.

voir due to the admission and cutofii ofpres- I and through the passages 22, 21-and 20 and will be delivered to thesurfaces-of the chuck w and the chuck jaw 3. Due to the pressure acting against these surfaces the oil will, be

suitably distributed longitudinally of the chuck mechanism. Any pressure fluid which may leak past the rearward end of thechuck w will find its way into the recess 10 and will then escape to the atmosphere through the ios port 11. V Likewisesuch pressure" fluid that r flows from the ports .20 and 21 into'the bore and which may find-its wayinto-the interior of the chuck mechanism will escape; either through theforwardend of the chuckjaw 3 or will flow rearwardlyinto the chuck cavity 7 from whence it will escape to the atmosphere through the port 12. I

VVlienthe throttle'valve e is closedto stop the drill and the pressure fluid existing-be tween the throttle valve .andthe' valve chamher will be exhausted therefrom the pressure fluid in the reservoir-13 will then escape through the passage 16 and the port 18 and through the supply passage wherew'ithit is connected into the the valve chamber-L. v

This pressure fluid will carry with it oil which will be deposited in the valve chamber 1 9 to the cylinder, a chuck in the bore, and a and when the drill is again setin operation the inrushing, vpressure fluid will blow the oil from the valve chamber through the inlet passages both intoithe piston chamber and through the passages connecting the front inlet passage with the chuck mechanism. 1

LI claim:

. 1. In a fluid actuated rock drill, the combination of a cylinder and afront head having a bore, a valve chamber, a distributing v I valve in the valve chamber, means for supspecification.

plying lubricant to-the valve. chamber, a chuck in the bore, and a passage in the cylinder and the front head leading from the valvechamber for conveying-lubricant from the valve chamber to the cooperating surfaces of the chuckand the; bore, said passage being controlled by the valve.

2. In a fluid'actuated rock drill, the combination of a cylinder and a front head havv ing a bore, a valve chamber, a distributing valve in the valvechamber, means for supplying lubricant to the valve chamber, inlet passages leading from the valve chamber to the cylinder to convey pressure fluid and en trained lubricant to the cylinder, a chuck in the bore, and a passage in the cylinder and the front head associated with one inlet passage for conveying lubricant to the cooperating surfaces-of the bore and the chuck. 3. In a fluid actuated rock drill, the combination of a cylinder and a front head having a bore, a valve chamber, a distributing valve in the valve chamber, means for supplying lubricant to the valve chamber, a front inlet passage'and a rearward inlet passage leading from the valve chamber to the cylinder to convey pressure fluid and entrained lubricant from'the valve chamber passage'leading from the front inlet passage to the boreto convey lubricant to the cooperating surfaces of the bore and the chuck. v

4. In a fluid actuated rock drill, thecombination of a cylinder and a front head having a bore, a chuck in the bore, a valve chamher, a valve in the chamber, means forsintroducing lubricant into the valve chamber,

and a passage leading from the valve to the bore and controlled by the valve for intermittently conveying pressure fluid and entrained lubricant from the valve chamber to the cooperating surfaces; of the chuck and the bore. v 1 y In testimony whereof I have signed this WILLIAM A. SMITH, SR.-

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