US1095848A - Fluid-pressure-actuated tool. - Google Patents

Description

9.11. GILMA-N'l- A FLUID PRESSURE CTUATEDhTOOL.

APPmoATIoN Hup un 19, 1909-.

'llatented May` 5, @91.4.

al. H H1 m@ www f 'enenen H. erm/Inner tirniniii'iroiii`T,l Naw -Haiaisnnn' AssIGNoR, BY mesita Assr'eNian'NTs, r9' si'JLL'ifvAn MAcHiNERY'coiurannj or Boeren, massacnn; sETTs, a coarona'rron or Massnenusnr'r's. f

rLUrD-PnEssURn-aewiimn Toon Y Speciication 'of Letters latent.. Patjlitd lg, Application mea may ia, 1909.. serial No. .496,91s.' t. 7

To all who/i 'ztmayconcerf/t: l

Beit' known that I, GEoRGE lH. GILMAN,

La citizen of the United States, residing at haGlar'emont, in the countyof Sull-ivan and f State yot. New- Hampshire, have invented 'an Improvement in Fluid --Pressure Actuated Tools, .of which the -following description,

` inconnectionwith the accompanying draw- `ings, is al' specification, likeletters on the drawingsrepresenting like parts. i

My inventionrelates to fluid pressureactuated tools and more-particularly to the valve mechanism for'controlling thead-mi'ssion' of the motive'iiuid to and exhaustl from the cylinder. f-f l v My invention will be best understood by Y referencefto the following description when taken in connection-with the accompanying illustration 'of 'one specific embodiment thereof, while its 'scope will be more. par'- ticularly -pointed out/in' the appended claims.

v In the drawings: Figurel 1 is a central,

.l longitudinal section, partially brokenL away,

f of illustration 'bodiment. of my invention, the same cointaken'throiigh the cylinder and valve block, -of apressurefluid percussive to'ol embodying onefforni; 'of myl invention; Fig. 2 i's a similar view showing the valve and the pis'- ton hammerin a dir erentrelation; and Fig. A 3 isa detail in sectional-plan on the-line 3'-3inFi`g.2. Referring'tonthedrawings, foin-the sake I have there shown one emprising a'- pneumatic' hamjmer. 'd-IilL The Ala'tter has thecylinderl, the forward portion of-whichis shown `broken away: vTheeyl-` inder -chamber 2 contains reciprocating blow against any `4,-V which herein is `interposed between. the

which y'is adapted to 'deliver its suitable' receiving mem'- ber, such, for example, as the impact block Ihead offthe piston and' the drill or other y 'tool carried', tis-usual,V inthe foi-wardl endof the cylinder, but not herein shown.' l

The movements, ofthe-.piston are con` -trolledby a'controlling valve .5, .herein '1ny the i v form of a hollow cylindrical shell locateduin avalve chamber' at the rear of the cylinder chamber but inline .chamber beingprovided .herein by "a twotherewith.- such .valve .13, of which there may be .rearward position .(see

l'walls of Athe .cylinder and .f cylinder chamber through 4.its rearv end such passage extendsfthroughm l pai'wtvalve blockpcomposed ofthe forward `section 6 andthe rear'section 7. Both'sectionsfofthe valve block are seated lwithin the walls ofa suitable casing 8 vwliiclipro-.-v

jects fromithehead .block 9,.therear1por- 55 tion of the" latter being .broken away. The.'

headvbloclris Providedwith afsupplyehaniber 10 for the motiveiiuid, to which the l-atter is constantlyY admitted Vfronfiany suitable-J source of supply` throughthe supplyfpas- 60 sa e'11. I v

or. the admission of'fmotive fluid te; the

rear of the lcylinder chamber, .the lvalve chamber is yprovided with an annular vafl-,.1 mission .groove12, whichvhas constant ,come5' municatio'n with the supply chamberl() through the f'rearwardly extending .pass.ages

suitable or desired number.y Wheniiif.its..l

chamber behind the admission .f

thereby. cutting olf the interiouo the vhalve and the rear of the cylinder chamber- ,from. the motive fluid. In' thesfoitvvard position of '7a the valve,-however 5.(see Fig; 1') the .interior of the' vvalve is opened fie'ely to the admission groove 12 so that-the motive fluid .-'lows -freely to .the interior of the valve and. thence to the rear of the cylinder chamber teldrive so ,the piston forwar' The, forward ,end of the cylinder .is supplied with motive vluidwhlen there] ve `is .atfits rearwardposition". (see Fig. 2) by f means of the return pressure.. passage 14,55

which extends. longitudinally through v-the.

opens,y into .the theportflgffAt nIn the, rearvs'a-frdv to give asuicieiitly free admission o ffmotYQ; g.

Huid. to the-groove 147 byway. of vthe valve *ice ser providedany v- Fig. `2) ,the-real Bild 7e of the valve enters that portion yOfthievnlve cove 12,\

thevalve block. section- 6. and terminatesfini` 9a? vl'a lateral .portl opening ,into an" annular fvalve. block L groove 17. position of the valvethe groovel.- is'con- .nected with they motive fluid by `means of A gi-153g@ groove 18 to return the piston hammer. From the groove 17 the motive uid passes through the port 16, passageql-ly and port 15 to the forward end ofthe cylinder.

To exhaust the motive iuid from the rear of the cylinder chamber, lateral exhaust passages A2O are provided in the valve block, which passages open into the valve chamber at the annular 'groove or enlargement 21, which latter,l forms an annular chamber to receive the circumferential enlargement near the yforward end of the valve. These lateral exhaust ports communicate with the longitudinal exhaust ports 23 extending through the valve block, the longitudinal ports at their rear communicating with the permanently open exhaust ports 24 formed in the head block. When the valve is in its rearward position (Fig. 2), the prolonged portion 25 of the valve which extends beyond the circumferential enlargement 22, lifts from its seat sufficiently'` to open the rear of the cylinder chamber to the bottom of the valve block chamber 21, thus placing the rear of the cylinder chamber in communication with the exhaust port-s .20. As shown in the gdrawings, the ports 20are only partially uncovered by the valve when in this position, but'such ports may be, and preferably are, of an elongated cross-section, as shown in dotted lines in Fig. 2, so that, by suitably proportioning such ports, the exhaust from the rear of the cylinder chamber" may be made as free or restricted as desired.

To exhaust mot-ive Huid from the forward 4end of the cylinder chamber, the latter is provided with one or more (herein two) exhaust ports 26, adapted to be uncovered by the piston before the completion of the rear ward movement thereof, such ports being connected with the longitudinal exhaust passages 27 and thereby with the atmosphere through the permanently open exhaust passages 23 and 24. In addition to this, the forward end of the cylinder is maintained open for the exhaust of motive fluid during v the forward movement of the piston, and after the closure of the exhaust ports 2G, through the return port 14, the latter being there connected through the valve 'chamber when the valve is positioned as shown in 4ig. 1, with the valve groover 18, the exhaust chamber 21 and the exhaust ports 20.

Referring now more particularly to the provlsion for moving the valve to reverse the piston, the rear end portion 28 of the valve is of slightly `reduced diameter, having a sliding fit in the corresponding reduced portion of the valve chamber beyond the admission groove 12. This forms -a. small circumferential shoulder 29 which constitutes a small pressure area constantly exposed to the motive fluid in the admission groove 12. On the other hand, the lower ace of the noeaa circumferential enlargement 22 constitutes' an. opposing differential pressure area of relatively greater proportions. When the valve is in its forward position (shown in Fig. 1) the valve is maintained in such position during the forward movement of the piston by the pressure on the small area 29 augmented by the pressure on the rear end area of the valve, there being then no substantial pressure against the larger o posingk pressure area in the lower end of t e chamber 21. To insure the absence of substantial pressure against this larger area there may be, and preferably are, provided one or more release ports 30 (herein two in number) connecting the lower end .of such chamber with the exhaust-passage or passages 23, these serving to exhaust any pressure fluid trapped in ythe bottom of said chamber or entering thereinto by leakage from the cylinder chamber. Means are provided, however,l whereby the piston during its forward movement is adapted to admit pressure fluid to the large opposing pressure area to lift the valve to the position shown in Fig. 2 and thereby reverse its own movement. To this end a' port 31 is provided which is adapted to be uncovered by the piston to the motive fluid at the rear thereof, such port conducting the motive Huid through the rearwardly extending passage 32 to the bottom cf the chamber 2l and against the large opposing pressure area.

formed on the under face of the-circumferential enlargement 22. The port 31 may bc located at any suitable point, but preferably so that it-is uncovered just prior to the striking of the blow. Then uncovered, the pressure upon the large opposing differential area exceeds that on the small pressure area 29 and the end area of the valve, and quickly reverses the valve, lifting tothe position shown in Fig. 2. As above described, this admits motive Huid to the forward end of the cylinder chamber and opens the rear end thereof to the exhaust, so that the piston, having delivered its Iblow, moves back on its return stroke.

The piston carries projecting from its rear end a plug portion 33 which, in the illustrated embodiment of my invention, is of lesser diameter than the piston itself. This plug portion is adapted to project out of and beyond the piston or cylinder chamber inthe rearward position of the valve, and

Vthrough an aperture 34 in t-he valve block in which it preferably has av sliding lit, and which constitutes a port leading from the valve chamber to the piston chamber. The valve having been reversed, the piston during its return movement expels the motive fluid at the rear of the cylinder chamber through the exhaust chamber 21 and the exhaust ports 20. During this movement of the piston, the slight pressure maintained by the'disciharguig xhaust fluid inthe exhaust i chamber '21 and against the large opposing pressure area at ythe bottom of the circumferential enlargement 22 predominates over the constant pressure acting against the small pressure area 29, andis suiiicient to maintain the valve reversed in the position shown in Fig. 2, to which position, as above described, it has been thrown by motive iuidadmitted by they piston through the passagei Thisfcondition continues 'and the valve sh'eld reversed by theaction of alle'. exhaust pressure preferably after the .iiilg portioiientersthe aperture 34 and soy fing as there is any` substantialpressureex- .valve block ,section Gfby k.reason ofthe closureof the aperture 34 by the plug'33. This bringsA .theI piston torest and vprevents it from striking the valve' block should the -valve fail torreverse.' About the saine time,

however, thereinainant motive fluid, having been substantiallyexpelled, the lpressurejof 'the discharging exhaust against the larger Vpressure area of the vvalve is reduced to such' a low point that the v Ive is quickly re ,v

versedby the superior pressure-against the small pressure area ,29. As above described,

this admitslive pressureuid from the adward.- At the same time the forward end of -tlie piston -chamber which has been previously opened .tothe exhaust by the uncovering of the exhaust ports 26, is also opened tothe exhaust .through the valve 'chamber by way of the return port 14, this condition holding until the valve is again ref versed.' The valve when reversed, is held securely in its forward position, since the release ports 30 relieve tlielarger pressure. area ofthe pressure of any accumulated motive fluid.

'IWhile the length of the projecting plug portion 33 might be reduced so as not to projecty within the, valve in the rearinost position'j'of the piston, herein, for the sake of reducing-.the clearancey Within the valve cliiniber, it is somewhatprolonged, as shown -in the drawings, so that it not only passes tlirou hand closes the port-'like aperture 34, but a' so enters partl way into vthe valve itself. @The interior' vdiameter y of the valve,

lidwever. .is madeslightlygreater'than the i I claim is:

exteriordianieter voffthe plug, so that a small clearance spaceremains between thevalveandl the enteringportion of the-piug.""' This permits ythe motive fluidtrapped, w1th` its length and separated from each other by @hmmm when 'the ping eaters the visive,

Itwill be observed located in a separate chamber behindvthe mission groove v12, driving the piston for- Such escape, moreover, maybe facilitated,

if desired, by any suitable formation of the plug, such, for. example, as the provision of one o r more longitudinal grooves 35 cut part way on the surface of the plug.

The described form of valve being very near the -close of the rearward piston movedelicatelybalanced, acts quickly to reversev ment 'so that very high'speed and a very' powerful blow can be @secured through its employment. Moreover, theclearance in the cylinder and valve chamber being reduced'to It may be. observed that the pressure exa minimunn a very high efficiency can be obtained. t '9 erted by the escaping exhaust against the larger pressure ar'ea can be' varied, and the action of the valve thereby varied within wide limits, through increasing -or decreasjing the available'cross-sectional area of the l'exln'iust ports 'opened to the exhaust chamber 21'on the vbackward movement ofV the valve by the circumferential enlargement 22. That is to say, .by increasing the area or the number 'ofthe exhaust ports' 20, or by f increasing the extent of exhaust port opening, when the valve is moved to the position l shown in Fig. 2, thevalve-.lifting pressure,

due to the exhaust, is diminished. lConverSely, by decreasing'the area or number of such' `ports tlievalve-lifting pressure is increased and prolonged.

piston chamber and between the latter and 1 the headblocleit is not necessary for the i operation of the tool that any part of the piston enter the valve. Herein the plug 33 carried by the piston is caused to enter the valve chamber to reduce the clearance therein, b ut such is not essential; The clearance within the valve chamber might be reduced by making the valve solid except for a cenL tral axial admission passage through the same, or .with a valve proportioned as shown, a stationary plug might be' employed 'projecting forwardly within the valve from the that the valve, being A foo llO

forni' and relative arrangements of Vthe parts and the application or use herein niad'e of l. A pressure fluid percussive tool 'having fa piston hamnieiga valve having two 'pres'- sure areas at different points, respectively, in

a cylindrical surface, means fitting said cy lindricalsfurlacezin one position, o f the valere,

`tlie invention, without departing from the f means to cause said valve to loe moved into another position bv motive fluid acting.,r against one of said pressure areas, and means to cause thc valve to be held, when so moved, by the pressure of' the discharged exliaust actingl against both of' said areas.

2. A. pressure fluid percussive tool having a piston hammer, an annular valve, means to cause said valve to he moved in opposite directions by pressure tluid, means for closing' the rear end ot' said valve in its rearmost position, a release port and means for causing said valve to he held in its rearniost position h v the pressure of' the exhaust fluid escaping' from the interior of said valve radially outward across the forward end of the valve to said release port.

-l. A pressure fluid percussive tool having;

a piston hammer provided with a plug,` portion, a piston chamber, an annular valve, a valve chamber located at. the rear of the c vlinder chamber, an axially arranged port connecting' the valve chamber and piston chamber into which port the plug portion is adapted to enter, means 'for admitting' pressure fluid to the rear end of the plug poi'- tion and to the rear end of' the piston chamber through the hollow interior of' the valve, and means for exhausting pressure fluid from the rear of the piston about the forward end of the valve.

4. A pressure fluid percussive tool having a piston hammer provided with a rearwardlv projecting' plug` portion, an annular valve. said tool having means including' exhaust ports adjacent the forward end of thc valve .for releasing' the exhaust fluid from the rear end of. the evlinder chamber radiall)1 outward about and across the forward end of the valve. the interior of the valve .heine formedV to permit the escape ot eX- haust fluid radiall)7 outward to said exhaust ports trom the interior of' the valve.

5. .l pressure fluid ptn'cussive tool having' a cjvlinder chandler, a piston hammer provided with :i rarwardly projecting plug,r portion, a valve located behind said cylinder chamber. a port. connecting the valve chainber and cylinder chamber, through which port said projectiirny plug' portiony passes on rearward movement' 01' the piston. said plug' portion beine' also extended to enter the valve` the 4interior of. said valve and said plut' portion beine; formed to permit the es- -ape of exhaust fluid 'from the rear inner end of the valve about the forward end thereof` while also formed closel'v to fit lsaid. port to provide 'o'r theformation of a fluid cushion at the rear of'the. pist-on.

(l. A pressure fluid pereussive tool having' a piston han'nner and an annular valve at the rear thereof: a projecting plug; portion of the hammer adapted to enter the valve and torm- .ing with -said valve a passage permittine' the Yescape oi exhaust motive lluul from one 'ward across one end of the valve to said reend thereof to the other; means to move said valve in one direction b v constantly acting.r pressure' against an area thereof; means tc move said 'alve in the opposite direction b5 pressure intermittentl)v admitted to a la rg'ezpressure area thereof; and means to hold the` .valve in said last named position by the action of the escaping exhaust.

, 7. A. pressure fluid'percussive tool haviln.r a piston hannner and an annular valve, means for closing the rear end of said valve in its rearmost position, means including an exhaust port for releasing the exhaust fluid from the interior of' said valve radially outlease port thereby to hold said valve in 8o position :tp permit such release of the exhaust fluid and means to move said vali l.- to a l'eversefvpositipn solei)v by constantly acting' ressme fluid 'acting' against a pressure area of the valve.

S. A pressure fluid percussive tool having a piston hammer. a piston chamber, an annular controlling` valve open at both ends loated at the rear of, and in line with the piston chamber. said valve heilig interiorly open for the passage of fluid therethrough from one end thereof to the other, means for admitting' live pressure fluid through the said valve to 'drive' said piston forward, and meansI for holding' the valve in one position bv motive fluid and in the opposite position b v exhaust fluid.

9. pressure fluid percussive tool having a piston chamber. an-annular valve which 100 communicatesl interiorlv at one end with the piston chamber. an admission space at the opposite end ol 'the valve` an exhaust space exteriorly of the valve at' its first mentioned end` said valve when iii one position con- 105 'neeting the piston chan'iber with the admission space about tht` end ot' the valve and through its hollow interior. and when in the reverse position connectingr the piston chamber with the exhaust space about the oppo- 119 site end of the v'alve. a pressure area at the admission end of' the valve being' constantly exposed to motive fluid and a larger pressure area al the exhaust end of' the valvc exposed to the exhaust fluid and servingr to hold the -valve open during exhaust.

itl. A pressure fluid percussive tool having' a piston chamber, an annular valve which communicates interiorlv at one end with the piston chamber. an admission space 12u at the tipposite end of the valve. an exhaust space exteriorlv ot the valve at its til-st mentionedend. said valve when in one position connecting ihf1 piston chamber with the admission space about the end of the valve and through its hollow interior. and when in the reverse po,-iio:^= connecting' the piston chain-- 'tier with the exhaust space about the oppi- -ite end nl' she valve. a pressure area at Ilzadmission end ol the valve. beinur constantly so exposed to niotivetluid anda larger pressurearea atth'e exhaust end of the valve exposed to` the exhaust fluidi-and serving to hold the valveopenyduringexhaust, a pis- 5 ton' and a part carried by the end of the -piston'aclapted to .enter the valve on movement' of the listenin one direction and substantially fill the interiorthereof.'5.v l l 11. A.' pressure fluid percussive tool havo i'tion, 'a pistonchamber, an annular'valve, valve chamber located at the rear ofl the adapted to enter and have ay slidingfit, means for .admitting pressure lluid'to the rear end of. the pist-on" chamber through the hollow interior of 'the valve, and means for` eX- haustiiig' pressure-fluid from the rear of the piston about. the Jforward end of the valve.

' -12. Apressure fluid percussive tool having a cylinder chamber, a piston hammer .providedwith a rearwardly projecting plug ;portion, a4 valve located behind said cylin-' der chamber, a port. connect-ing the valve` chamber and c vlinder chamber, through which 'port said projecting plug portion passes on rearward mov-ement of the piston, i0 the interior of said valvel and said plug portion being' formed t-o'permit the escape 4of exhaust fluid from the rear inner end ofthe Lvalve about theforward end thereof, while also formed closely to lit said port-'to provide for the formation of a fluid cushion `at the rear of the piston.

,1%. A pressure fluid percussive tool hav-v ing a piston hammer provided with 'a plug portion,ian annular v-alve at the rear of the 40.' piston hammer@ said .toolhaving a piston chamber and a port forming acommunication between the pistonA chamber and the `interior vof the valve, into' which port the plug portion is adapted to entei-'and closely fit; means to move said valve -in one direction by constantly act-ing pressure against an area thereof; means to move said valve in the opposite direction b v pressure lintermittently admitted to a larger pressure area thereof: and means to hold the valve in the'l last named position bv the action of the escapingA exhaust. I

1l; A pressurefluid percussive tool having a piston hammer, an annular valve having a pressure area, a pistou chamber having communication with the interior of the valve, means to move the valve ina direction opposite to the piston 'by motive fluid 'passing through the valve into the piston chamber and thence to said pressure area of` the valve, and means to hold the valve, when so moved. by the pressure of the exhausting fluid flowing across and acting against said pressure area. l 5,5 .151;A pressnreuid percussive tool havng a piston hammer provided with a plug`4 ft'zyliiideiv chamber, an axially arranged portl lconnecting thevalve chamber and x 5 chamber into which portthe plugrtionis vsure .area at. the exhaust end 'of tlie `valvevterio'r, and when in the reverse posit-ion ooi` nectingthe' piston chamber with the exhaust space about the opposite end of the valve,

a pressure area at the admission end of the valvebeing constantly exposed tomotive fluid and a larger pressure area at the eX- haust'endof the valve exposed` to the lexhaustflud and serving to hold the valve`r open ,during the exhaust. l Y 85 16. A pressure fluid percussive toolhaving `a' piston chamber, an vannular valvel which communicates interiorly lat one'eiidv L with the piston chamber, an admissio'irspace at the opposite end of the valve, 'an exhaust space exteriorly'of the valve at its opposite end, said -valve'ivhen in one position 'con-V necting the piston chamber with the admis' sion space aboutl 4the end ofthe valve'a-nd through its hollow interior, and when in the g reverse position connecting thepi'ston cham-1y ber with the exhaust space about the vopposite. end of the valve, a pressure-area atthe" admission end of the valve being constantly 1 exposed to motive fluid and a larger prese'xposed tothe exhaust vfluid and serving to' hold .the valve open during exhaust, and a piston hammer arranged to reciprocate within said'piston chamber.

17. Apressure fluid percussive tool -hav-Y ing a piston chamber, an annular valve which. communicates inteiiorly at its for- 'Ward end witlithe piston chambery4 an admission space constantly lopen to motive "11o fluid at y'the opposite `end of-the valve, 'an exhaust space exteriorly of the valve at forward end, said -valve wlien'in one position connecting t-h'e piston cliamberwith theadmission spa-ce about the forward end of'115" the valve and through its hollow interior, and when in the reverse position connecting they piston chamber with the exhaust space about. thel opposite end of the valve, a pressurea'i'ea at theadmission end of the'valve 120' being constantly exposed to mot-ive fluid and a larger pressure area at the-exhaust end of the .valve exposed tothe exhaust fluid and serving to hold the valve open during'exciprfocate within vsaid piston chamber.

158. A' pressure.iluidpercussive tool having'- a cylinder chamber, piston hammer y provided with afrearwardly projecting plug haust. and a pils on hammer arranged to re' 125 ,.portonand a hollow valve-.located behindqgo ibi los

said cylinder' chamber, :i port connecting the In testimony whereof, I have signed my fvalve chamber e and cylinder chamber, name to this specification, in the presence of 10 through which port said projecting plug two subscribing Witnesses.

portion passes 'into said valve on rearward ,T movement of the piston, said plug portion GEORGE GILMB' beingformed closely to tsaid port to pro- Witnesses: K

vide for the formaion of a Huid cushion at E. J. BRUOHARD,

the rear of the piston. S. T. CHANDLER.

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