US1781021A - Valve for rock drills - Google Patents

Description

Nov. 11, 1930; E, B, LE 1,781,021

VALVE FOR ROCK DRILLS Filed Aug. 25, 1927 WA T! INVEN TOR.

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v H15 21 ORNIEY Patented Nov. 11, 1930 I UNITED STATES-j ENT. i ops- EARL- n. LEAR; or: PHILLIPSBURG, NEW ERSEY; ASSIGNQR T ,INGERson -nANn'iooM- TrANY, or JERSEY orrmivnwunnsn gn CORPQRATION-OF'NEW JERSEY VAL E FOR noonv DRILLs Ap'p1ication August 25,

This invention relates to 'fluidactuated rock drills; but more particularly to a valve for,'distributing pressure fluid to the per cussiveelement of therol'ck drill.

' The "0101' ectsof the invention are to protect the valve chest against wear and to obtain a quick'and positive action of the valve. v

Oth'er objectswill be in' part obvious and in part" pointed out hereinafter. i

In the drawings illustrating a practical application'of the invention, 9 v

vFigure 1 is'a longitudinal elevation in section of a rockdrill showing the valve in one extreme position, and V 1 Y Figure '2 is 'a-similarwiew showing the valve in the other extreme position;

Referring tothe drawingsy-th'e invention is shownembodied in'a rock drill having a cylinder A provided with a free exhaust port B. Within *the" cylinder 'A- is a 'reciprocatory hammeripiston C having a forward fluted extension or nose D adapted to deliver blows ona drill steel,'only the shank E- of which is indicated inthe-front end'ofthe drill." "a

"A suitable closurefor the front end of the cylinder'A is provided inthe form'of a front cylinder washer F bored to receive slidably the nose D of the piston C! A back cylinder washer G inserted in the rearward end of the cylinder A forms a closure for said rear-f ward end and in this inst-ancealso serves as V anabutment'for one end ofa'rotation ratchet H which is centralizedby the 'cylinder'an encirclesa head *J of the rifle bar K.

=The partsso far described are shown merely' for" illustrative urposes-end; it is" to be understood that the invention which will be hereinafter. described in detail is not limited (iin-itsapplication to any particular" type of In accordance'with the present invention a valve chest-"L 'is'shownformed on the side of the cylinder A and has a straight cylindrical bore Oiextending therethroug'h' to form a valve chamberP. The ends or the-bore O in this" instance are 'sealedjby plu'gs Q, held inoperative position by; bolts R; Pressure""fluid for actuating the drill" may be admitted thereto through arconnection S p i the ends of which projections'the pressure- 192?. sria n 215,368.

in thevalv'echest L; From the connection S- lead a'pair ofsupply passages T and U for introducing pressure fluid at points 7 rearwardly and forwardly respectively of the transverse median line of the valve chamber-P; j 7

r The plugs Q, in this instance also serve as 1 guiding means for a distributing valve V which controls the admission of pressure fluid from the chamber]? to the front and rearwardends of the cylinder through inlet passages Wand Xrespecti'vely, and which inlet passages are of larger cross sectional area than thesup'ply passages T andvUh "Accordin'gl'y; the plugs Q are provided at their 1 inner ends with annular flanges Y having boresfZqa'dap'ted to receive' cylindrical end projections b of the 'valv'el' On the free ends ofthe annular flanges Y are-rib's Y which are spacedwith respect t-oreach other to form slots 0 for admitting pressure fluid from the chamber P into", the inletpass'ag es W and X, said slots cbeing' controlle'dbythe projec tions'b which slide on the ribs Y- and over fluid flowslduring its ofthe'cylinder, I

'Inter'medifte the ends of the valveVhis a flange d which reciprocates between the supply passages T and U -and has fend surfaces 6 andj which cooperate with "the inner ends ofthe-flang esY' for lirnitin gthe'travel V of the valve V; Theend surfaces ean'd are 7 I passage intothe ends alsothe perimeter g oftheflangdwhich, it will be noted, is spacedf'rom the wall of thefvalve chamber P topermitconstant re- 1 stricted communication between the ends of the valve chamber. 7' f The-operation of thedeviceis as follows: Pressure fluid admitted into the connection S will "pass through the supply-passages T and U'int-o thefvalve'chamberlPz With the I valve inzathe position illustrated in'Figure- ,1; such'pressure fluid willflow overthe rea r wardprojection b andthrough the" inlet pas sage X into the rearward'end of the cylinder to actuate the piston C forwardly. b

After the freeexhaustportB isoverrun by; the piston C," the air imm nent end of I the cylinder will be compressed. Such compression flowing through the inlet passage l/V willact against the front end of the valve, tending to throw the valve V rearwardly.

- Shortly prior to the instant the blow of the hammer piston O is delivered to the drill steel the exhaust port B will befunc'overed,

thus causing an abrupt drop'in pressure in the rearward end of the cylinder. Dueto this' gdropflin' pressure,-.the pre'ssurejin the rearward'i'end ofthe'valve chamber I will of V course also drop somewhat below line pres Y sure; WVit-h thiscondition obtaining,*pres-- sure fluid in the front end of the valve chamber P will flow over the perimeter of 'the' flange and create a suction on said flange wh ch w ll ZISSlStthQ compress on acting against the forward projection 11 to I throws thevalve to its v rearward .e tremep'osi- 20,15,

Y fluid willfiowrj over the forward projection bthroughthe' inlet passage W'intothe front end o f the cylinder and actuate the piston,

50 rearwardly. During the rearward stroke,

, as duripg the forward stroke of the piston C, compression will also *be built up and such compression acting against the 7' reari ward projection b together withthe suction I created by, the pressure 'fluidflowing over the flahge d upon the voccurre'nce ofa drop 'in pressure forwardly of the flange idat the,

a time the pist n CV uncovers the ejxliaust port B, ,will again throw the valve to its initial position, thus vcompleting the cycle, of op-;

erations. P Y

b l rom the foregoing, willthat' alvalve constructed"infaccordancef with the present invention is capable of 5 rapid 'recip- I .rocation. .Thisis in part 'due to the; almost complete absence of friction,;between the -valve and the associated elements and in part to the manner in which the pressure fluid flowing over the valve flange (1 assists in actuating the valve; I i V 1 ;1 .111 a fluid actuated rock drill, the-combination of Va cylinderand piston, a valve chest having a v valve chamber, supply passages conveying pressure fluid into the valve chambeminletpassages, leading from the ,valveichamber to the cylinder and of larger area thanthe supply passages, a distributing valve in the valve chamber comprising cylin- 1 1 drica jlend projections controlling the in'l et I Passa es Said"p nje iens in ii tt V ly exposedto'compression from theoylinder for.- th owing'theyalve, andafiangeouthe valve: e'ciprocableabetween vthe supply assages'and .constantlyexposedat both en s to diameter than thevalve chamberto permit the flow" or pressur fluid overthe perimeter of thelfiange to '7 create a suction thereon to ass e eo pn i nin thrQ -nsf h re t n r sm st Upon reversal of the valvev V pressure" 1 Passages, aid'i'fl n 2. In a fluid actuated rock drill, the combination of a cylinder and piston, a valve chest 7 7 the bores, a distributing valve having end proj ectionsislidabl'ei on lthei l'ribsito control: I the slots,."said projections being intermittently exposed tocompression from the cylinder -for throwing the valve, and a flange on the i valve constantly exposed over its entire area to pressurflu1d',"the perimeter of said flange e to p r t th fiewn livr s i c, the fl ge mmon sideioiit val fecham v. into the OthQi -IO CIGELEQ,aivS uQlilOn on the th eomp i s i throwzthe valve, i a s. 8- 1 flu d actu ed o k d il t e am" t quo a cylind r a ip on;a-.z ree;e '-T haust port in thecylinder ;control led by the; p t la elv flhesthaving aval eicham r,

nt the eyl nd ni up y. pa s ges ep in nto-t le d etl e 'ivalye'l ham er, a n lar flanges in ,the ends ofjnhe valve chamber avi g; b re ommun abl kwithf hyi e 9s Pr su e flu d some va ve shamberj -thel r' w d s r but ng a r in hi valve v 1 9:

mpr s y in r ai i l dp jec ons I 100 iPr0 a 'o1ith bsan wntrolli gthe:1 let .Pas esisaid P j ti esl gaint i mittent y. e pese t cqmpre s en for, t owai i a v ra d a a ge onstan ly expos at both ends to pressure fluid, said flange be- 1 5 v insof s a erd ame erfth nthe val ehamtt perm tt fipw 9f inessure fiuidieven, the p r metertthe flan e t c eateswt m thereon, tqas st .it w thewl eupei i the occurrenceof a {drop in vpressure in the no 7 ds. o t e v l e. q a fi r il t r hau wver ing ofthe free-exhaust portby thepiswul' r afluilectea sdroc kd i ath rcbmbil nation ofa cylinder 'and a piston, a free ,eXF;

haust pe t n. e sylin er ntm e iby theljusf P s on, a alvech t avingwal c m inletpassages leading from thegvalve chamber&

to the y n r,. upp y pa sagesnpen n tda the ends ofthe valve chamber,plugs-forming closuresfontheends of the'valve,chambenan- 1201 nular'flanges on the plugs having bores-in;- Y mm ni a pnv thet e:inl trpa a es; ribs mb r in i -ebQ -fl ifieis ributingak 5 f n t eve Chambe 'ha g; ylimlriaat pr j ti ns slidab e oa r s: a d; c ntr l ling the slotsgsaid projections being exposedi o c mp e ion oa si lti-nthrqn 'gva v n flensepn hgsvalr cnsta tlytlsp edi mf being spaced-iromthe wallofthevalve cha n: 1 i

inlet P a il itromjth va ve-c em V, ,iss yi erib p c idita f Q sl ts,t erebet e nz' r.th passage-o 1 t at both ends to pressure fluid, said flange being of smaller diameter than the Valve chamber to permit the flow of pressure fluid over the perimeter of the flange and thus create a suction thereon to assist the compression in throwing the Valve upon the occurrence of a drop in pressure in the ends of the valve chamber. 1 In testimony whereof I have signed this specification.

EARL B. LEAR.

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