US995593A - Pneumatic tool. - Google Patents

Description

UNITED STATES PATENT oEEioE.

GEORGE H. GILMAN, OF CLAREMONT, NEW HAMPSHIRE, .ASSIGNOR TO SULLIVAN MACHINERY COMPANY, OF CLAREMONT; NEV HAMPSHIRE, A CORPORATION OF MAINE.

PNEUMATIC riooL.

Specification of I .etters Patient. Patented June, 20, 1911.

Application led May 14, 1908. Serial No. 432,786.

To all 'whom t mayv concern:

Be it known that I, GEORGE H. GILMAN, a citizen of the United States, residing at Claremont, in the county of Sullivan, State of New Hampshire, have -invented an Improvement in Pneumatic Tools, of which the following description, in connection with theV accompanying drawings, is a specification, like letters on the drawings representing like parts;

My invention relates to pneumatic oi' other pressure-- fluid actuated tools, being more particularly intended to provide a tool having two or more tool-actuated units together with suitable means for controlling l or regulating the operation of said units.

While my invention in its broader aspects may be embodied in constructions other thaii the one herein shown, in the illustrated einbodiment thereof the same is disclosed as applied to a duplex or double tool of the 'pneumatic piston-hammer impact type.

In the form of duplex tool shown, and herein submitted for illustrative purposes, there is provided a main 'controlling valve which controls 'the simultaneous operationployed as a duplex tool, the controllingvalve is operated as a balanced valve, and,

when the tool units are operated singly, as

a differential valve.

My invention will be best understood .by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will bemore particulai-liv pointed out in tlie appended claims.

ln the drawings: Figure 1 is a central sectional elevation, taken throughmtlie workingcylinders and controlling valve, of a duplex hammer tool embodying one form of my invention; Fig. Qis a similar section taken in a Vplane at right-angles to the plane of the section of Fig. l and looking toward the left in Fig. 1, or in the direction of the ar.- row shown on tlie section line 2-'2 in Fig. 7; Fig. 3 is a section in plan, taken on a central plane through the valve block. or head and showing a portion of the bushing and valve in posit-ion. Fig. 4 is a plan of the valve block shown in Fig. 3 looking at the bottom thereof; Fig. 5 is a partial section taken on the line-" in Fig. 1, looking in the dii'ection of the arrow but with the plate reversed from the position there shown; Fig. G is a similar section taken on the line 6-6 in- Fig. el., looking inthe direction of the arrow but with the plate4 reversed from the position there shown; Fig. 7 is a section in plan taken through the working cylinders on the line 7-'7 in Figs. l and 2; Fig. 8 is a central sectional elevation taken through the valve and the valve block on the line 8-8 in Figs. 1 and 3; Fig. 9 is a detail showing the regulating 'valve with .a portion of the valve stem attached; Figs. 10 to 16 inclusive -are sections taken transversely atdifferent points lengthwise the regulating valve, showing the relation of the valve parts to the various registering ports in the head for the position of the' valve corresponding to the simultaneous operation of both tool units: Figs. 17 to 23 inclusive are similar sections showing the relation of the regulating valve ports to the head ports ina different position of thevalve, which position corresponds to the operation of one tool unit only; Figs. Q4 to 30 iii-elusive are similai' sections showing the'port relations in a third position of the valve, which 'position corresponds to the operation of the remaining tool unit; Fig. 31 is a general and partly diagrammatic view showing a development of the pressure passages relatively to the controlling and regulating valves and showthat .shown iii Fig. 31; Fig. l shows the to the position shown in Figs. to 3G; Fig.4

is a partial side elevation ot the duplex tool shown in Fig. l, illustrating the regulating valve handle, and FigL 38 shows a partial. lsection illustratino a modified construction employing a piston directly counected to the tool.

Referring to the drawings, and to the illustrated .embodiment of my invention, l have shown the same as applied to a pneumatic tool ot the piston-hammer type pio v'ded with il" pair ot' working cylinders with i and contained hammer side f side. Any del cnt or construction of 'the pistons may he emigiloyed, but l) the cylinder chain bers 'l and 2 are showny as formed' 'within a single cylinder casting 3, the latter being provided with the upper head It and the intervening head plate 5 closing the upper' or head end the cylinder, and. also provided with. the lower head (5 secured to the lower end thereof.

rl`he pistons 7 and 8, which may be o' vany desired construction, are shown as provided with reduced striking or hammer ends wliicli, las lthey reciprocate, are adapted to strike the ends of the independent or separate tools 9 and l0 loosely held within the bushings ll and l2. In'the construction disclosed the hammer pistons are arranged toreciliirocate in out of step relation so as to reduce the shock and vibration oli'their comjp. A. i) siren arran cylinders and in the dravvings l urated tool being such that they worlr in oppo ition, whereby shock due to the down-- ward ii'ioveincut ol one is largely ,neutralized by the-ui'r-zvard niovcn'icnt or' the other, and vice vey sa, so that the resultant operation 'oit' the duplex tool accompanied vibration and shock than the a single tool.

While separate valves may he employed tor the two tool units, or any other suitable arrangement -ot valve-ri'onticlling `ineuns operation of utilized, as a simple and cti'ective way of mounted by the end piece 13,;the latter conthere is bincd tool` action, the construction of the T by c ven less taining the pressure-fluid admission passage 14C and the interconnecting exhaust passages l5 (Figs. l. and 2).A l

The valve 16 may be of anypsuitable form,

but herein the same is of the piston type con-- sisting of a hollow cylindrical body hating reduced end portions and alternating spaced grooves and shoulders or lips fthe said grooves being adapted-,according to the pon sition of the valve,

to connect the various desired pressure passages oi the tool. The valve worksv within the suitably apertured valve bushing 717, the two ends of which are closed respectively by threaded cap rpieces 18 and 1.9. The cap pieces' are provided with inwardly facing projections or shoulders 20 and 9,1 acting as spacing members, so that when .the cap pieces are screwed up tight still left, betweentheir inner ends and the outer ends of the bushingspaces which constitute respectively pressure chainbers 2Q and 23. lThese are'ltept in communication with the live pressure'during the 4simultaneous operation o t the'v two toolsv so that the opposite interior endsV ofthe valve 16, which are 'open to the said ,pressure chambers, are lin communication with the live pressure.'V The Vvalve is provided 4with a transverse interior wall or partition 24 which forms two Ychambers 25 and :26 respectively within the valve', "pressure on `opposite sides of the partition, whiohsides are of equal area, being balanced, as above dei scribed, duringthe normal operation of the tool.l The right-hand end of the bushing (as viewed in Fig.- l) is contracted to1`receive the reduced' open end of the valve,'

while the opposite closed by avring or Washer 27,' within which the opposite contracted end.- of vthe 'valve is adapted to slide. Thev shoulders between these contracted' ends of the,V valve and-the adjacentp'ortions of larger diameter present external end" pressure areas' 28 and 29,.re spectiv'ely, preferably et equal areaandneX-f posed to the pressure. in the chambers formed vrespeetively in oppositeends ofthe valve bushingfto 'which pressure is alte!`- nately admitted and exhausted through the movements of the two pistons. As is best shown in Fig. 3, the end pressure area '28 is exposed to the pressure admitted there einst y'through the intermittent pressure passage 3l, and the end area 29 to the pres'-` suie admitted through the pressure passageBO,V the bushing being'cut through laterally, as 'shown in Fig. 3,.to

open these passages to the vexternal end pressure areas 2e and 29. *in one position of the valve pressure' is admitted to the head end oth one cylinder and the torwardend of the l other, while, at the same time, the head end of the second cylinder and the forward end of the first are simultaneously opened to the end of the bushing is intermittent entre@ exhaust and the respective ends of the cylinders are established to reverse the direcl tion of movement of the two pistons.

For the admission of pressure to and its exhaust from the head end of the cylinder, the-cylinder 1 is provided with the passa e 32 leading to its head end and under te control of the valve 16. The cylinder 2 is provided with a like passage 33.' The passage 32 leads to an annular groove 34 (see Figs. 1 and 8) in the valve bushing 17 and the passage 33 to a similar annular groove 35. '.The valve is also provided'with coperating circumferential grooves 36 and 37, through which the said passages 32 and 33 are adapted4 alternately to be placed in com` munication with the pressure admission passage 14l as the valve is alternately moved in its chamber from one position to the other. lNext adjacent the grooves 34 and 35 the valvebushing is provided with grooves 38 and 39 which, as shown in Fig. 1', communicate directly and constantly with the exhaust passage 15, so that, with the4 valve in the position shown in Fig. 1, when pressure is being admitted to the head end of the cylinder 1, through the passage 32, it is being simultaneously exhausted from the head end of the cylinder 2 through the passage 33, valve groove 3T, bushing groove 3.9 and exhaust passage 15. In the reverse position of the valve (Fig. 32) the head end of the cylinder 1 is connected with the exhaust through the passage 32, valve groove 3G and bushing groove 38.

. T he admission of pressure to and exhaust from the forward or tool end of the cylin- 'ders 1 and 2 isV controlled through .the toolend pressure passages 40 and 41 respectively, which, as represented in Figs. 2, 3 and T, extend longitudinally in the walls of the cylinder` casting between the piston chambers and enter their respective cylinders through the ports 42 and 43 at the lower ends thereof. The tool-end pressure passages 40 and 4l extend upward through the cylinder head and valve block (see Figs. 2, 3 andl 3), where they have direct connection with the annular grooves and 34, respectively, hy one or more horizontal passages -14 and 45 (see Figs. 3 and 3), so that, when the passage 32 is opened to the admission passage 14 hy the valve 1G, the tool-end pressure passage 41 tor the tool end of the other cylinder is sinniltaneously opened to the admission. and. whenihe passage 32 is opened` lo the exhaust. pressure fluid is simulialuously exhausted from the tool-end of the opposite cylinder. In other words,

the pressure controlling passage for. the toolendl of each cylinder is so associated with the passage of the head end of the other cylinder that reverseeonditions invariably prevail at the corresponding ends of the two cylinders during operation of the tool, thereby insuring movement of the two hammer pistons in opposed step.

For the control of the actuating or moving pressure for the valve, which is conducted through the reversing or intermittentpressure passages 30 and 31, I have provided constant pressure passages 46 and 47,. for the cylinders 1 and 2, respectively. Each constant pressure passage (see Fig. 2) constantly communicates, through suitably cutaway portions in the bushing 17, lwith the pressure supply passage 14. The passage 14. The passage 46 opens into the cylinder l through the port 43 (see Figs. 2 and 7) and the `passage 47 into the cylinder 2 through the port 49, the ports 43 and 49 being located, respectively, at or about the same position lengthwisev the cylinders as the two ports 50 and 51, which open from the intermittent pressure passages 30 and 31, respectively, into the cylinders 1 and 2.

opened to live pressure through the constant pressure passage 46, whenthe piston 7, approaches the 'limit of its downward movement in the cylinder l, and, on the other hand, the intermittent pressure port 51 is placed in communication with the constant pressure lport 49 when the other piston 3 approaches its limit of downward movement. The'intermittentpressure passages, in addition to the ports 50 and 51, are also provided, respectively, with the ports 54 and 55 (see Fig. 2) opening into their respective cylinders at a 'point or level below or in advance of the ports 50 and 51.

Considering the simultaneous out-o-step operation of lthe two tools under the conditionsreferred to, pressure is admitted through the intermittent pressure port 51 near theclose of the forward movement of the piston 3 (as represented in Fig. 1), thereby admitting pressure to the valve chamber to act against the left-hand (Fig. 1)4 end pressure area 23 of the valve. At

the same time, the forward end of the cylin- 'der 1. being opened to the exhaust (as will be explained) the intermittent p'ressure port 30 is also opened to the exhaust and pressure is thereby exhausted from the opposite end ot' the valve `chamber and contiguous to the opposite end pressure area 29. This occasions the instant reversal of the valve and reverses the movement of the pis: ton in each tool.

On rearward movement of the piston 8 the port 55 in the intermittent pressure passage 31 is soon uncovered and the forward end of 'the cylinder 2 `the valve and a reversal of the piston Inovements.

The forward or tool ends ofthe cylinders maybe exhausted in any suitable ivay, but herein, as is customary in this type of tool, the forward cylinder ends are tir'st opened to the exhaust through the uncovering by their respective pistons of an appropriately located exhaust port or ports.. .The cylinder 1. is provided with a pair of 'exhaust ports 56 (Fig. 7) and the cylinder 2 with'. ports 57, the former connected to exhaust passages 58, and the latter to exhaust passages 59, which passages extend lengthwise the cylinder casting 3 and the valve block and are connected at their upper ends tlirough grooves 61 and 62 of the valve block with the exhaust passages 15. This maintains the exhaust ports 56 and 57 permanently open to the exhaust and each, when uncovered by its respective piston, exhausts the pressurepfrom the for- Ward end of its cylinderand, as above described, also, at the same time, from the corresponding end pressure area of the valve -16 to eiiecta reversal of the same.

Since the arrangement of the various pressure passages relative to the valve chamber and the clyinders, for obvious' -construc-- tional reasons?, are notv shown in any of the' constructinnab views, there is shown (Figs.

iagrammatic arrangement of these y of, ivithout attempting to portray accurately the mechanical construction. The Aarrangement shown in Fig. 31, showing the valve in one position, and in Fig.. 32, showing the valve in its reverse position, illustratesthe arrangement or pressure passages when the tool is operated, as above described, vvit-h both units having simultaneous, but opposed, reciprocating movement.

In order to convert the duplex tool into a single yacting .tool a -regulating valve 63 is employed located in thc valve block transversely the controlling valve 16 and between the latter and the head plate This regulating val-ve is so constructed and arranged with reference to suitable passages in the head that it may be turned to cut out of operation either cylinder at will, this being accompanied, at the same time inthe illus trated form of my invention, by the conversion of the balanced pressure-actuated valve into a differential pressure-actuated valve lcont-rolling the movements of the particular cylinder and piston then in operation. The head end admission passages 32 and'33, thetool-end admission passages 40'and 41, the

constant pressure-passages 46'and 47 and the intermittent pressurepassages 30 and 31 are allintercepted and controlled by the regulatin valve 63. Before describing thev construction of the regulating valve it may be stated that, in the form shovvn,V When the valve is turned in a direction to cut oli one 'of the cylinders, forexa-mple, the left-hand cylinder l, it leaves` the passages connecting with the right-hand cylinder unchanged from-the relation shown in Fig. 31. At the same time, hovvever, it acts not'only to close the admission passage for the head end of the left-hand cylinder, the tool-end admis `sion passage 40 and the left-hand intermittent pressure passage 30, but causes it to cut ott live pressure from the left-hand interior valve chamber 25 -at one side of the partition 24, opening the said chamber to With the opposite exterior end area 28 connected With the right-hand intermittent pressure passage 31 and. exposed to the ressure intermittently conducted therethrough. The end area 28 is greater in extent than the area of the interior partition 24, and the valve is accordingly moved to the right at each forvvardstrolrel of the piston.2, when the latter opens the intermittent pressure port 51to the' constant pressure port 49, but'-is moved in the opposite direction as soon as the said intermittent pressure port. is opened to the exhaust. When the regulating valve is turned to a position to peut out the right-hand cylinder 2 reverse pressure conditions 'are caused to prevail, that is to say, the left-hand exterior end area 28 of the valve and the-right-hand interior valve chamber 26 are open to the exhaust, thereby convert-ing the valve into a differential valve. controlled through the movement of the piston 1.

The valve chambers 22 and 23, into which the interior valve chambers 25 and 26 open, are placed in communicationlvvith theconstant pressure passages 46 and 47 by passages or conduits 64 and v65 (Figs. 1, 3 and 4) Which extends downward from the said chambers through theV valve block to the bottom face thereof, Where they are connect-` I Aplressure and placed in communication with the exhaust through the regulating valve, whereby the end chamber 22 or 23 is also opened to the exhaust.

Referring now to the regulating valve 63,

the latter may be of any suitable construction and located in any selected position on the tool, .but herein the same is constructed as represented 1n Figs. 9 to 30 and arranged I' transversely the tool 'beneath'the valve 16,

as represented in Figs. 1 and 2. The valve, as shown, is provided with two piston -or barrel portions connected by an intermediate substantially flat portion 70. The latter lies adjacent the passages 32 and 33 in the valve block, as best shown in Figs. 1, 13, 20 and 27, so that in one position (Fig. 13) the said passages are both lett tree and open; in another position (Fig. 20) the passage 32 maintained closed, with th'e passage 33 open, and, in the third position 4 (Fig. 27 the passage 33 closed and the passage 32 open. The barrel portion 68'is provided with apertures or ports 71, 72 and 73 which, with the valve in position, aline with' the- passages 30, 41 and 47, respectively. The barrel portion 69 likewise is provided with apertures or ports 74, 75 and 76 which, with the valve in position, aline with the passages 31, l 40 and 46, respectively.- The end of the-barrel portion 69 ot' the valve is provided with Ia projection 77 (Figs. 2 and 9) which is embraced by the forked end ot the valve stein 7S, the latter passing through an aperture in -the threaded cap 79l (Figs.

and 35), and n 'ovi led with the external regulatinglever S0. The lever is provided w1th a thumb or linger piece 81 cari-jung a sliding spring-pressed. pin S2 adapted t0 engage with any one ot three notches formed inthe exterior tace ot the valve block (Fig. 85), whereby it may be moved to a central position, as represented in Figs. 2, 31 and 35, or to a position against the stop S3' to throw out ot' operation the cylinder 1 (Fig or. against the opposltely disposed stop S4 to throw out of operation the cylinder 2 (Fig. 34), the spring-pressed pin acting at all times to retain it in its assigned position.

To lumlerstand'the changes which the regulating valve ettects in connections between the various ports and passages in the conversion ot' the balanced jn'essure valve into a differential pressure valve, attention is directed particularly to F 3 tio 7 inclusive. Fronl this it `will be observed that in the saine plane with the intermittent pressure passages (see Fig. 5) there. are also provided 'valve chambers 25 or 26.

supplemental passages '85 and 8 6 opening' into the regulating valve chamber (the former in line with the intermittent pressure passage 30 and the latter with the passage 31),Which supplemental passages are permanently connected, as by the grooves 87 and 88, respettively, in the bottom of the valve block, each with an adjacent one of the exhaust passages 58 or 59. This makes it possible, by means of the regulating valve, to open up either intermittent pressure passage to the exhaust and thereby o-pen up the corresponding 'exterior end pressure area tothe exhaust. Furthermore, there is also provided (Fig. 6) in the planes ot' the constant pressure passages 46 and 47 respectively, additional supplemental ,pas-

sages S9 and 90 which lead from the bottom ot' the valve block and enter the regulating valve chamber' on an incline, the' said passages being also .permanently connected each with an adjacent oneot the exhaust passages 59 or 58 by means-ofthe grooves 91 and 92, respectively, in the bottom of the valve block. This makes it possible by means of the regulating valve to shut ott' either one of the constant pressure passages from live pressure and open the same to the exhaust, thereby permanently exhausting .pressure from the corresponding interior T-he'various connections made by the regulating valve will be best understood from an inspection of Figs. 31 to 84 inclusive in conjunction with the sections shown in Figs. 1.() to 30 inclusive, the latter being-taken transversely the regulating valve, and ,lookingin the direction ot the arrow in Fig. t), 'a'. c., in the direction of the section of Fig. 1. When the regulating valve is set to the in id position-the connect-ions of the various ports areas shown in Figs. 10 to 16, both tools being simultaneously in operation. In this position all the cylinder passages for both cylinders' are open, the supplementary exhaust passages 85, 86, 89 and 90 leading into the regulating valve chamber and adjacent to the pprts 2:50, 31,46 and 47, respectively, being closed, as will be seen from Figs. 10, 16, 14 and 12, respectively. In this position of the regulating valve the tool operates in the manner previously described, the valve 16 acting as a balanced pressure valve with pressure constantly admitted against the smaller ett'eetive areas thereot which are presented by the interior partition 24, and alternately admitted to and exhausted Jfrom the largerA opposite and vequal end pressure areas 2S and 2S). This condition is represented by thediagrammatic viewin Fig. 31. lVhen the regulating valve handle 80 is turned to the right against the stop 84 it cut-s out of ope 'ation the lett-hand cylinder, changing thc connections of the various passages, as represented in Figs. 17 to 23. In

- time, the regulating valve has connected the exhaust passage with the external end pres.

24; in thev chamber 2G, pref' through the head end admission passage 33.

`stant pressure port 4G are shu valve 16 being .the )assao'e 33 and adn'iitied to the l s vend of the cylinder through the passab assess this position of the valve the head and adposition showninfig. 32, through the memission passage 32 (Fir: :20) tor der l is closed.r While passage the cylinder 2 remains open. The pressure port .il (Fig. 18) for the rignt hand cylinder2`reina-ius open, while the corresponding port L t0 Fig. 22) for the lefthand cylinder lis closed. 'lhe constant pressure passage e7 for the right-hand cylinder 2 Fig. y19) remains open, While the cni stant pressure passage Al@ (lt-ig` 2l) for the .leftshand cylinder l is cut oil from coinmunication With the pressure above and connected through the regulating valve port 76 with thel supplementary exhaust passage 89, thereby exhausting` vfrom the interior valve chamber 25. The intermittent pressure passage 3l (Fig. 23) for the right-hand cylinder yremains in communication with the 'externalendl pressure valve area 28, as before, while the intermittent pressure port 30 (Fig. 17) klor .the leftvhand cylinder l is closed by the 'regulating valve and the upper portion of .the passage which leads to the end pressure valve area. 29 is'placed in communication with the supplemental exhaust port 85 by" means of the regulating valve port 71. This condition of aiiairs is represented diagraniniatically in Fig. 33. i In this position ol' the valve it will be seen that all the cylinder ports for the cylinder l except the leont oil", while the constant pressure port is opened to the exhaust, thus exhausting pressure from the interior valve chamber 25.I At the saine sure area 29 of the valve. The piston 2 Will then-operate in thefollloiving manner. The constant-ly pressed toward the left, as represented in Fig'. 32, by pressure acting against one side ,of the partition ure is admitted to drive the piston toi-ward. it the saine time, pressure is exhausted from the forward end of the cylinder through the tool end pressure passage dl. lVhen the piston nears the lorward end of its travel, it un-l covers the intermittent pressure port 5l to the constant pressure port i9, thereby admitting' pressure against the exterior end Apressure area 28' of the valve. The area 28 being greater than the area ofthe partition 252th@ valve is moved to the right, or to the position shoivn in Fig. 3l. ln the` position shown in Fig. 3l pressure is exhausted from the head end of the cylinder through this condition obtaining until the liistoii uncovers the exhaust port 5T andfthe intermit tent'pressure port 55, whereupon the exhaustion of pressure from the end pressure area 2S permits the reversal of the valve to the Ahammer tine itis -of course i v 7 i e valve handle 80 .hand op S3, effecting' connections between the saine with reference to. the left-hand c vliinler as are those just described with reterence to the `right-hand cylinder. Such connections are represented in the sectional view shown in Figs. 24 to 30'and in the diegranunatic View shown in Fig. 34, which Will be suliciently clear Without the need of further explanation, it being understood that under. such conditions the left-hand cylinder operates while the right-hand cylinder is inoperative and the controlling valve 16 operates as adilerential valve but with its etlective areas reversed, that is to say, the larger area is now the external end aree 2Q, and the smaller area the transverse Wall 2e facing the chainber, pressure under these conditions being exhausted from the chamber 26 and the end area 28.

Wllhile I'have described my invention as applied to a tool of the pneumatic impactapplicable also todirect connected' tnols, which, for

seine purposes, it may he'advantageous tol employ.' In Fig. 3G l have sh-o'vvnsuch an application of the tool previously described,

`Win-)rein the piston ineinhersl and 2 have their reduced ends tixedly attached to. chuck or tool holders cutting'bits tools 9 and 10, respectively. It therefore fellows that the cate back andforth in alternation With the pistons, instead. of receiving at each pistou stroke the impact orjblow thereof.

fWhile I have shown `for illustra-tive purposes one embodiment of my invention, it is to he understood that the saine is not liznitedto the particular torni herein disclosed er to' the details of construction, which. tor vthe salie of eitplicitness, are herein `fully describecand illustrated, but that extensive 1n odiications-and deviations from the illustrated construction may be made without departing `from the truespirit of the invention.

l claun is:

l. il. pressure liuid tool having i' "on, a balanced v el for controlling the saine. and niea'l i ionverting 'the said halaureil valve n .i a dillerential valve.

.l pressure fluid tool having a piston, a valve rontrelling the ,saine and presenting pairs oit' equal opposed pressure areas. means for adaiitting pressure' constantlyv to one pair ot' areas, ar. l means for a rious ports and passages, substantiallv tools recipro Having-.thus described my invention, what lteruatvlv ad ico 93 and 94, which latter, inturn, have removably secured thereto 'the mi'tting pressure to one member of the other pair of pressure areas while exhausting pressure from the remaining one.

3. A pressure fluid tool having a controlling valve for controlling the admission ot pressure to itscylinder, said valve present-A pairs of equal opposed pressure areas, means for constantly admitting pressure against one pair'of pressure areas, means for alternately admitting pressure to one member of.

'the remaining pair of pressure areas while exhausting the same from the remammg one of sald pa1r, thereby to operate said valveas a balanced valve and means to with draw pressure from an area of one pair and the opposed area of the other pair, thereby to permit said valve'to operate as a differential valve. u

A4,' A pressure fluid tool having a valve provided with differential areas, to the smaller of whichpressure maybe constantly admitted to move the valvein one direction, and ,to the larger area of which pressure may be intermittently admitted to move the valve inthe opposite direction, means for adnntting at will constant pressure to an- 4other area, acting to balance said first-inenl first-mentioned direction by intermittently acting pressure fluid.

6. A pressure fluid tool having a pair ofpistons and cylinders, a single controlling valve for controlling the movements of' said pistons, said` controlling valve operating as a balanced pressure-actuated valve, and means foi-,converting said valve into aditferential pressure-actuated valve.

't'.l A pressure fluid tool having a p airof cylinders each with .its contained piston, a single controllingr valve for controlling the movements of the. pistons, means for causing said -valve tooperate as a balanced pressure-actuated valve during the simultaneous action of the two pistons, and means for cutting out of operation one of sail cylinderswhile, at the saine time, converting the said controlling valve into a differential pressureactuated valve.

8. A pressure fluid tool having a plurality of cylinders, cach with its contained piston, and a balanced pressure-actlultcd controlling. valve for alternately admitting live pressure fluid Afrom the valve chamber to opposite ends of each cylinder. A9. A pressure fluid toolhaving a urality of cylinders, each with its containe piston,

a balanced pressure-actuated valve, with its valve chamber controlling the movements of said pistons, each cylinder being provided with a passage leading to its forward end through which passage is alternately opened to the live pressurefluid and the atmosphere through the movements of said valve.

410. A pressure fluid tool having a pair ofv cylinders, each with its contained piston, a balanced pressure-actuated valve passage connecting the opposite ends of each cylinder with the valve chamber, said valve being adapted on movement in one direction to place the rear end of one cylinder, and the 'forward end of the opposite cylinder, in communication with the live 'pressure fluid, and the forward end of the first cylinder and the rear end of the second incommunication with the atmosphere.

11, A pressure fluid tool having a pair of cylinders, each `witl1 its contained piston, a controlling valve presenting equal opposed pressure areas, passages controlled by said valve for admitting live pressure fluid to opposite ends of each cylinder, pressure being admitted to the forward endof .one cylinder simultaneously with its' admission to the rear end of the other cylinder, means for admitting pressure to one of said ressure areas on the forward movement o one piston and for exhausting pressure therefrom 011 the rearward movementthereof, and means alsofor admitting pressure to said other area on the forward movement of the remaining piston and for exhausting pressure therefrom on the rearward* move.

ment thereof.

12. A pressure fluid tool h'avmg a plurall ity1 of cylinders, each with its contained piston, valve controlling means for causing the simultaneous operation of said pistons', and

a regulating. valve for throwing any one of said pistons out of o eration.

13. A pressure flni tool having a plurality of cylinders, each with its contained pistons, means for operating the same simultaneously, a single controlling valve, and a regulating valve for throwing one or another of said pistons out of operation.

14. A pressure fluid tool having a pair of cylinders, each lwith its conta-ined piston, means for causing the same toV operate siniultaneously in opposed step, and a. regul piston, a single controlling valve for causing the operation of the same simultaneously, and 'a regulating valve for throwing either one of said pistons out of operation.

35. A pressure-fluid tool having a -plurality of cylinders, each with its contained piston, pressure-actuated controlling valve vpiston controlled ports for causing the operation of the said pistons simultaneously, and a regulating valve for throwing either one of said pistons out of operation.

37. A lpressure-fluid tool having a plurality ofy cylinders, each with its contained piston, pressureactuated controlling valve means controlled by ports actuated through piston controlled ports for causing the operation of the said pistons in out of step relation, and means for throwing either one of said pistons out of operation.

38. A pressure-Huid tool having a plurality of cylinders, each with its contained piston, pressure-actuated controlling valve means controlled by ports actuated through piston controlled ports for causing the operation of the said pistons in out of step relation, and a regulating valve for throwing either one of said pistons out of operation.

39. A pressure-fluid tool having a plurality of cylinders, each with its contained piston, valve means for operating the same simultaneously, and a regulating valve located to control passages between the main valve and said cylinders for throwing either one of said pistons out of operation.

40. A pressure-fluid tool having a plu- -rality of cylinders, each with its contained piston, valve means for operating the same in opposed step, and a regulating valve located to control passages between the main valve and said cylinders for throwing either one of said pistons out of operation.

In testimony whereof, Ihave signed my name to this specification, in the presence of two subscribingwitnesses.

GEORGE H. GILMAN.

lfVitiiesses E. J. BURGHARD, J. BRUCE.

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