US2669840A - Pulsator operated percussive device - Google Patents

Description

Feb. 23, 1954 J. F. JOY

PULSATOR OPERATED PERCUSSIVE DEVICE 5 Sheets-Sheet 1 Filed March 24, 1948 1270622202 2 JOsepZz f lby. y A; fill/Mm Feb. 23, 1954 J. F. JOY

PULSATOR OPERATED PERCUSSIVE DEVICE Filed March 24, 1948 W Ii 3 I I l twill;

mill II 3 Sheets-Sheet 2 lllll fiiwzzfar; {g assy/2 1 1/09.-

Feb 23, 1954 J. F. JOY 2,669,840

PULSATOR OPERATED PERCUSSIVE DEVICE Filed March 24, 1948 3 Sheets-Sheet 3 Patented Feb. 23, 1954 UNITED STATES PATENT OFFICE PULSATOR OPERATED PERCUSSIVE DEVICE Application March 24, 1948, Serial No. 16,775

5 Claims.

My invention relates to percussive devices, and more particularly, but not exclusively, to rock drills of the percussive type. The usual rock drill of industry requires a source of compressed air generally in the form of a receiver, an air compressor and a driving motor for the compressor. The quantity of air required by an air driven rock drill of substantial size is considerable, and the air is usually supplied by a portable compressor, and accordingly the plant investment for a drilling outfit is substantial and the space required is also considerable.

It is an object of my invention to provide an improved percussive device. Another object is to provide an improved rock drill, a drill per se differing, in external dimension, but little from conventional drills, but having operating mechanism of a different type and which can be caused to function with relatively small auxiliary equipment. Another object of my invention is to provide an improved rock drill having pneumatically efiected striking motions of its hammer, and having hydraulically operated means for effecting the return motions of the hammer. A further object of my invention is to provide an improved self-rotating rock drill having improved rotating means. A further object of my invention is to provide in an apparatus of the character last mentioned an improved cushioning means for preventing injury to the parts of the drill when the piston thereof is operating without the hammer portion thereof coacting with the drill steel. A further object of my invention is to provide an improved percussive apparatus in which an improved and highly compact arrangement is provided for utilizing a liquid and a trapped body of gaseous fluid for effecting a percussive action. Still another object is to provide an improved hammer tool having improved con trol means. A further object is to provide an improved hammer drill having improved means for providing fluid for blowing cuttings from the hole being drilled. Another object is to provide an improved percussive motor having improved cushion means. Still another object is to provide an improved drill having improved rotation mechanism. Still another object is to provide an improved means for holding a working element in desired relation to a striking apparatus. Other objects and advantages of my invention will hereinafter more fully appear.

In the accomplishment of the foregoing re sults in a preferred embodiment of my invention a hammer element desirably has associated with it apiston movingin a chamber in whichair is entrapped at one end of the piston, and with paratus incorporating the invention in a hand rotated form.

Fig. 2 is a central longitudinal vertical section through the drilling implement proper of Fig. 1. Fig. 3 is a horizontal section on the plane of the line 3-3 of Fig. 1, with parts omitted.

Fig. 4 is a vertical section on the plane of the line 4-4 of Fig. 3, with parts omitted.

Fig. 5 is a fragmentary sectional view showing a detail of the air filling valve.

Fig. 6 is a view corresponding generally to Fig. 2, showing an embodiment of my invention in its broader aspects in a self-rotating drill.

Fig. 7 is a section on the plane of the line 'l'l of Fig. 6.

Fig. 8 is a transverse section on the plane of the line 88 of Fig. 6.

Fig. 9 is a corresponding section, partially broken away, on the plane of the line 9-9 of Fig. 6, and 1 Fig. 10 is a section on the plane of the line l0lll of Fig. 6.

Referring first to the embodiment of the indraulic fluid in appropriate volume. The drill l is adapted to operate a drill steel 1 carrying a conventional drill bit. The cylinder 3 comprises a barrel portion 8 and a rear head portion 9 the latter shown as having brackets ll! extending up for connection with the handle 2. Within the cylinder there is a reciprocable piston device II comprising a striking bar portion l2 and a head' 13. The head comprises a spool portion M! and a follower portion l5 threadedly secured together as at E6 and having a highly effective packing H, such for example as is shown in my Patent No. 2,417,828, mounted between the spool and the follower. provided with an enlarged portion 19 which is received ina bore 20 me casing member 21 which cooperates with another casing member 22 to. form a chamber 23 in which there is housed a suitable resilient member .24, which is adapted The forward end of the barrel 8 is slightly raised anvil 29 upon which blows are adapted to be struck by a raisdhammer' portionor nose portion 30 on a plug'3l threadedly 'secured in a bore 32 in the front end of the piston member H. The plug 3| at its; forward end is a close fit for the peripheral wall of the bore 28, which extends upwardly to join a somewhat larger bore 33, in whichithe head of a bushing 3.4 isrreceived, this-bushing being: of. substantial? radial thickness sozthat there isgprovided between. its forward end and the hammer portiontllani annular. chamberfi3'5w whose; volume changes'a as the hammer. piston is reciprocated. Above; the. sleeve 34 there is arranged a seal, Bfirof a typelikewise disclosed in.the p'atenttzab'ovei referred to; and? above thisaa plate; 3.8: supported on: a, The forward fend: oi'e'theportion 1950f the-cylinder 8; presses: the plate 38'1'against the shoulder 39;; and :a I threaded L shoulder 39 in the member 2|.

annular plug or. clamping-gsleeve sil cooperating with threads :41: intthe upper end of themember 2:1 ilclampsithe' parts together;

The drillisteelfla is hollow, as, shown at' l-Z; andi agboren43 extends through'the'member 2'5 Iand-fis provided with a checkevalve' 44: fork permitting downward flow of fluid to land through the drill steelrfromi the chamber 28:, but preventing revers'e' flow. Another check valve' 45: iszarranged': in a;

chamber. 4!rformediinza forwardrend of the striking bar l2 above the threaded plug 3i. Passages 48Fopen through the "walls Ofl themembe'r 2 i into communication with the space,35,'and--this-space isl -lilace'dlinicommunication-with'rth'e check valve 46 through radial'passa'ges 503' andlongitu'dinali grooves 5 [formed in the forward end of-the-strilc'.

ing 'bari- Accordingly, sincethe check valve 46 controls but cannot block a passage 52'communia eating 1 with the chamber 411 it will be: understoodithat as the striking barmoves: upward fluid will begs'upplied'into'; the'chamber 2B: throughthe radial passages 1 48:, the longitudinal grooves 51 thmadialpassages:; pastthecheck valve 46:" and through the;- passage -52 :into, the; chamber; 28;" H ands-on the downwardmovement: ofxthe piston,': the 'check. valve .4 Buthen being closed; the. air will unseat the checklvalve 44; 'andqflowy'through the:

passage ,421-tothe hollow' drill bit:

Within an annular" recess 55.nearxtheforward' of the'iportion. I91 of the cylinder element there is, mounted a split annulus 5 6220f :spring steel" orf-the 'like, 'adapted'ito act as acheck valve in".

co'njunctiomwith it series; of radial: passagesiz51, which passages communicate: with an annular supply passage 59cwhich has azhighen constantly open: 1 communication; as through radial passages 69; withjthe; cylinder'bore below thepisto'n head: The purpose of this 'valve" is to .permitxhy l3: draulic fluid to be 'supplied; as later explained, to 'a-ipointbelow the; head-of, the piston, to lift the same when-.the ports -(ill are covered," and to provide 'adefinite cushion for the forwardlymove ing pistonras-soon assthe ports filltare covered A hydraulic-fluid underpressure is-adapted; i 12C?- The member, 25 contains achamber 28, at whose forward end there is a,

be supplied to the chamber 59 and to be released from this chamber by means shortly to be described, this under the control of an end seating throttle valve 6|, normally seated by a spring 62, and then precluding flow towards the conduit 5 from the annular supply space 55. The throttlevalve1is;adapted3to1:be moved to open positionby-a-rod62 abutting the same and passing through a suitably packed opening 63 in the member 2| and connected by a link 64 with an operatingmeehanism 65 which is rotatable with the handle 2 "or with a part of the latter. The throttle valve obviously acts as a check valve whenv not-positively; held open, but when held open permits" fluid "to surge in either direction past it.

Eonthepurpose; of supplying a liquid under pressure to the space below the piston head l3 to raise the piston, and for effecting a sudden release of the liquid so supplied to permit the air compressed: in the space, in the cylinders above the piston head: to; expand and cause; theistrikr ing-.- of a. blow Ir'have provided; they structure; shown inrelevation in; Fig; 1, and-inj-twoysections z in-Figsz3 and 4:] This:,pulsator pump-includes;,, as shown, an electric drivingmotor 10) connected; by aisuitable'shaft Ikto-oneof anpainofginterrmeshing rotors l2 and-13j'journaled as atr'llr im a housing, 15; having intercommunicating:bores; 16in which the two, rotors :121'and;;' 3': arfiirespfics tively" rotatableia The rotors: are .providedii with; intermeshing teeth H, andzeachof the: rotorssis: provided-also with a:- slot. on roove: 8 0f appropriate size and shape, and the rotors-are so inter:

meshed with each othersthat: thefSlotS. 18-4 are;

adapted to communicate.- with each other;-,.as;1 shown in Fig; 4, ina: predetermined angular res lation of-the rotors and toforma'larger-freew passage between spaces at; the-oppositessidesrfflif the meshline: of the, rotors: Theseslots Hears: butillustrative; of various suitable arrangements; for permitting, back; flaw, of; liquid inpredeterr mined rotor positions; The ;netflow isubjackwardi; when the slotsare, functioning; An openingglcommunicating; withboth r.ot0r.= chambersi at? their point of intersection; is:suitablycconnectedi with the bore; of-a reservoir; 89' whichgiscadaipted to store, an:xadequate; quantity, of oil 1 or; othemhy draulic fluid, and which isradapted-to:bez'placed1 under any desired-initial pneumatidp'ressure by;- meansof a-valved plug 8| :toxwhichgaseous fluid! under pressure may besupplied from ,any suitable; source. Belowtheimesh-line ofthe rotors thereg, is provided another opening 83. which ,communi-r" catestwith the conduit- 5.

The space within the-bore of 3 the: cylinder:- 8; above the piston is adaptedzto; befi-lled, hr-the illustrative embodiment. disclosed, throughnan check valve controlled filler;plug;85, with..gase:- ous fluid" at any desired pressure, a; pressure; sufficient to impart a blow of. the requisite-force adequately to operate the drilling-implement; A pressure from 60to 100 p. s.' i. would Ice-suite"v able, but these values are not to be-taken as: limiting, and the-values will dependon design. features. Other arrangements to exert a yield ing forward pressure may evidently'be em-ployed instead'of this air spring. Before describing the mode -of"operation more in detail, it'shoul-d be'notedthat the'reservoir is desirably equalin capacity to the displacement of the forward side of the headof the hammer piston, and that the flexible conduit*5 is fille'd5 withliquid when theparts are coupled togethen so that; regardless-ofthe length -"('and cubic ans;

1 tents) Ofthis-conduit, 'there wi-ll alwa s iie aa arrangement in Which, when the pulsator pump is running, and if the throttle valve is not manually held open, all of the fluid in the reservoir will be displaced and a corresponding amount of fluid will be forced into the space ahead of the hammer piston head I3, and the throttle valve will act as a check valve to hold the fluid in the cylinder bore. Thus, when the pulsator pump continues to operate, it will not, while the throttle valve is closed, displace fluid, but when the drill runner forces the throttle valve BI open and holds it open, the pressure per square inch exerted on the liquid ahead of the piston head I 3, being greater than the pressure per square inch in the reservoir 80, the liquid will be caused to surge back and forth and cause the drill to operate. I

It will be understood, referring to Fig. 4, that as the rotors turn, the left one in a counterclockwise direction and the right one in a clockwise direction, they will, when direct communication between the openings 19 and 83 is interrupted, take, in the pockets formed between each succeeding pair of teeth 11, a charge of liquid from the reservoir 80, and deliver it to the space 83, and cause liquid to pass from the latter through the conduit 5 and past the throttle valve GI, and through the supply chamber 59 and the radial ports St, and this liquid will raise the hammer through its action in the annular space between the striking bar I2 and the wall of the cylinder 8; and by appropriately designing the displacement of the teeth and the cubic contents of the annular space mentioned the requisite retractive movement of the hammer may be effected, and the entrapped gaseous fluid in the space above the piston will be further compressed so that upon the release of the hydraulic fluid the piston may be moved down and caused to strike a blow of suitable force upon the anvil surface 29 and actuate the drilling implement I. When the rotors 72, 13 have turned through a predetermined angle the transverse grooves 18 move into communication with each other and permit the liquid previously employed to raise the piston II to escape quickly back to- Wards the reservoir 89 which is under a lower pressure than the pressure which prevails in the cylinder above the piston I l.

The mode of operation of this form of the pa;

invention will be clear from what has been said already. The proportions of the parts of the pulsating pump, so to speak, to the rest of the apparatus may be different from those shown, as

a precisely dimensioned drawing is not needed, 1.

since the actual sizes are of simple computa tion. The throttle being manually opened by rotation of the handle 2, and the motor 'lll being in operation and driving the rotors I2, 13 at a high rate of speed, it will be evident that slugs of oil will be periodically forced into the cylinder beneath the piston head to raise the piston, and then be released back through the cooperating slots 18 so that the gaseous fluid above the piston, compressed during upward movement of the piston, may re-expand and force the piston downward to effect the imparting of blows of suitable force and high frequency by the hammer surface 39 on the anvil surface 29. As the piston reciprocates, fluid will be drawn in on its up strokes into the chamber 28 and discharged through the passage 43 on the down strokes of the piston to the bore 42 extending to the lower end of the drilling implement I. In the event that the drilling implement is not against the work, it is undesirable that unduly heavy blows be imparted to the surface 29, and this is prevented by the fact that on a slight overtravel of the piston head below the mouths of the openings there will be a very effective cushioning by reason of the presence of the ring check valve 56, which ring will, however, open freely when fluid is supplied to the space 59 to enable the fluid to lift the piston head, which may then be too low for fluid flowing through the passages 55 alone to cause it to be moved upwardly again.

When it is desired to stop drilling, the pulsator pump may be stopped, if desired, but the preferred-because easiestmethod will be simply to let the valve EI close, and, as the liquid will be trapped in the space ahead of the piston head I3 in such volume that the pulsator pump will cease to reciprocate a column of liquid, the hammer will stop.

Figs. 6 to 10 show a hammer motor of the self-rotating type. This is generally designated 9% and difiers in a number of characteristics from the structure previously described in detail. It is of the automatically rotated type. It is shown as utilizing a solid steel, with the result that no provision for blowing a hole during drilling is provided. Its purely hammer construction, aside from the fact that the striking bar portion I2 of the piston is solid and has no parts associated with it for use in the pumping of air for supply through the drill steel, is essentially the same as the first form of construction described down to the member 2|. This member is connected directly by bolts 9| to a modified chuck housing element 22', which, in a suitable bushing 93, rotatably receives a chuck member 94 having a polygonal opening 95 extending therethrough for receiving the polygonal shank 96 of a suitable tool, for example, an auger element 91. The upper end of the chuck member 94 has a radial shoulder 58 cooperating with the upper end of the sleeve 93 to limit downward movement of the chuck member, while upward movement is substantially prevented by a spring ring 99 sprung into a groove I00 in the inner surface of the chuck housing 22'. Above the shoulder 98 there is fixed, or otherwise suitably secured, a ratchet wheel IflI upon the chuck 94, and this ratchet wheel is adapted to coact with the ring 99 to limit upward chuck movement and to be rotated in steps by mechanism best shown in Fig. 7. In this figure it will be observed that alined cylinder bores I02 and I03 are formed in the opposite extremities of a cylinder block I94 shown as formed integral with the upper portion of the chuck housing 22. The cylinder bore I63 is shown smaller than the cylinder bore I62 and is connected at its outer end, by a conduit I06, with a chamber Iil'I, in which the stem I08 of the throttle valve BI is guided. This stem is longitudinally bored at I69 and has radial passages I it extending through its walls in such position that when hydraulic fluid is admitted into the chamber 59 fluid will also pass into the space 1: I01 and through the conduit I96 to provide an actuating force for a piston arranged in the cylinder I03. The larger bore Ill2 is connected at its outer end by a conduit I I2 with the space above the piston head I3 in the cylinder 8, so that the pressure which is built up in this space is transmitted through the conduit I I 2 to the larger cylinder bore I02. Within the housing I04, a piston structure H3 is reciprocably mounted. This comprises a head H4 suitably packed as at H 5 and movablein the cylinder bore I03, and an 7 otherilargeripiston:portion l1.dsuitablmDackedas atrcH liandimovable 'inthelarger. bore it'll. Suitably-securedtora connecting portion Il8.between theupistons is a pawl memberl l-9 whichaspring mil-normally maintains in engagement with the teeth of the ratchet wheel-1M. The :modeof operation of this arrangement will be obvious from What has been said, if it be borne inmind thata device similar to .the deyice fi is connected with the conduits5, and alternately forcesrslugs ofifluid under high pressure to the space -59,'and releasesthem from that space. Thefluid'admitted tothespace 59 effects reciprocation 10f thehammer piston [Land .also, as-above indicated, pcooperates in effecting reciprocation J of theippawl I t9, since a portion of this fluid passes through the conduit :lllt to act uponthe head HA ;.and cause the, pawl to .move toturn. the ratchet wheel it! a predetermined distance when fluid is forcedrinto thechamber 159,-,the fluid supplieditozthe bore lil3zbeing vented:back, of course, when communication is opened from the chamber 5Q aback :to the reservoir: 80. .Whenthiszcommunication is :opened the pressurein the chamb'er.,:above the :hammer, piston is (at a -maximum, and 'ith-is pressure, -;acting through the conduit M2; ipromptly :causes retractive movement of the pawlpreparatorytothe making of ainewworking movement :by reasonwof .the action of the 'hydraulic .fluidzunder-pressure upon the piston structure-- 113.

:l'Ilhe-roperationof thezzinvention in the second embodimentthereof needs little independent description. It .Wlll be evident thateach time :a surge :ofiliquid passes the throttle valve 6! on its wayito the hammer motor a portion thereof will enter the cylinder Hi3arand cause the drill bit 91 toz m'ake .a fractional turn during the period in which the hammer piston is being forced upwards or 'rearwards in its cylinder. Then Whenthe hammerpistonis-making its working stroke, the gaseous-"pressure in the cylinder [02 will return thexpawl to a positionin which it-will be ready for zanother chuck turning movement.

:It Will bGbVidEIlt that the displacement of the piston"l.l3-is:so small that it will be; practically speaking; without substantial effect on the quantity'iofz'liquid iutilized, abut that'its displacement, plusthevolume ahead of the-head E3 in the rearward position of thelatter, will be substantially the; same as "the cubicmontents of the reservoir associated with the pulsator pump. .It will be apparent that'in both. of the illustrative embodiments ofthe invention: there is provided an emci'entlihigh speed hammer. motor, ithatin the first embodiment I have :disclosed .an improved :and simple supply-meansfor hole blowing 'ifluid, that unimproved drill-rotating means isdisclose'd in the second illustrative embodiment, that in the firstembodiment an improvedsupportfor a chuck is provided,-and that in both forms illustrated a simple, less space consuming and rugged drilling apparatus is provided.

Whilethere are in this application specifically described two forms which my invention may assume in practice, it will "beunderstood that these'forms of the same are. shown for purposes of 'illustration'and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What- I claim as'newand desired to-secure' by lietters'Patent is:

': 1.:'.1In" azrock :jdrill; a cylinder, apiston"reciprocable in said' cylinderand having a striking bar 8. extending-through one end i otasaidtcylindep ssaid cylinder :having at the other :end :thereoftan :energy istoringi.device,:and means for supplying pressure to the-first mentioned end of .saidncylinder to movesaid piston through-1a.- substantial distance to effect the". storing of ener in said energy storing device suflicient tocausesaid striking bar to impart-a blow of rock-cutting force: toa :drill bit and ".Ifor freely venting pressure fromgsaid cylinder. to permit the striking of such a;blo.w,' ineluding for both functions,..asingle intermittent supply, intermediaterelease, rotary liquid pump.

2. In a rock drill for actuating 1a'. drl11..bit,3f31 cylinder, 2. piston re-ciprocablein said -.cylinder and :having .a striking bar :extending through one end of said cylinder, said cylinder having at the other end thereof anamergy storingwdevice, means for .supplying :pressure to therfirst mentioned end of said Jcylinder. and venting pressure therefrom including an intermittent supply, intermediate-release fluid pump foralternately causing surges ofiliquid into said first mentioned endof said cylinderrto move said piston to effect storage of energy in said energy storage device sufficient to-actuatea drill bit and permitting backflow of liquid freely, and means forcontrolling communication-of said pump with said cylinder'including aniendseating throttle valve'opening towardsaid. cylinder, means for resiliently pressingsaid'throttlevalve towards seated position, and means forpositively opening said throttle valve.

3. In a fluid actuatedhammer motor, thecombination comprising relatively reciprocablecylinder and piston elements, one of said elements having a forward strikingportion, a gaseousifluid under pressure confinedin one end of said cylinder element for continuously'urging saidelement with'said striking portion in one direction, and means including a reservoir for a hydraulic fluid under an elevated pressureless than the pressure of saidgaseous fluid under pressure and means forintermittentlydisplacing fluid from said reservoir to. said cylinder element and permitting its return'xthereto for intermittently"supplying hydraulic 'ffiuid to and exhausting hydraulic .fluid from the opposite end of said cylinder element to movesaid element: with said striking portion in the opposite direction against the action-ofesaid gaseous fluid pressure and compress the latter and to'permit its return under the force'exerted by. said gaseous fluid, said gaseousfluid pressure when saidhydraulicfluid is exhausted from'sald cylinder element effecting movement of saidelementwithxsaidstriking portion in said-onedirection to effect the imparting by saidstriking portion .ofa hammer blow.

'4. In a'percussive device, a cylinder, apiston reciprocable'in said cylinder and having'a striking bar extending through one endo'fsaid;cy1in-' der, an energy storing device for yieldingly-pressing said piston towards said endof said; cylinder, means for supplying hydraulic pressure to-said cylinder at said end thereof to effect. the storage of energy in said. device and to permit itsrelease to permit piston actuation in ablow-strikingidirection including an intermittent supply, intermediate release "fluid -pump,- an end seatingithrottle valve seating towards. said :pumpand subjectedon'its back to the pressureisubsistingain said cylinder, means for yieldinglypressingesaid valve in I a seating. direction, andsmeansi fcrxat will opening thesame and holding it open.

5. Ina percussive device, a; cylinder, a piston reciprocable inssaid scylinderirandhavingz asst'rik ing bar, means for yieldingly pressing said piston in a direction to project its striking bar from said cylinder to cause it to impart a blow to an element upon which it impinges, and an intermittent supply, intermediate release pump for delivering liquid to move said piston in the opposite direction, the displacement of said pump and the volume in said cylinder ahead of the piston therein, when the latter is in normal rearward position, being substantially equal.

JOSEPH F. JOY.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Gjuke Nov. 5, 1907 Number Number

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