USRE13882E - Alexander palmbos - Google Patents

Description

A. PALMRUS.

PRESSURE DRIVEN REGIPROCATING TOOL.

APPLICATION FILED SHT. 16, 1910.

. m Y@ M w Reissued Feb. 16

A. .PALMROS- PRESSURE DRIVBN RB'GIPROGATING TOOL..

APPLIOATION FILED SEPT.16, 191'0.

Reissued Feb. 16, 1915, 1 3,882.

' 2 SHEETS-SHEET z.

(claimed a tool comprising a pair of suitably housed pistons connected respectively to the tool related that the driving sTATEs PATENT OFFICE.

LEXA-.Nunn Fuimos, or sYnAcUsn, NEW YORK, assIGfNon To THE rNnUMnLncTRrc incarna COMPANY, or sYnAcUsn, NEW YORK, A coRroaATroNl or NEW YORK.

PRE'SSURE-DRIVEN RECI-PROCATING TOOL.

Tolall rwhom it may concern Be it known that I, ALEXANDERPALMROS,

a citizen of Finland, and resident of Syra' cuse, in the county of Onondaga and State of New York, have invented certain new and useful Improvements 1n Pressure-Driven Reciprocating Tools, of which the following is'a specification. I

This application is a division of my api plication filed `November 25, 1905, Serial No.

289,127, .wherein I have described and fluid pressure driven, percussion carryingv shaft and the connecting rod of an actuating motor; the pistons being so iston has retracting influence over the riven piston during that stroke of the machine in which` the tool draws away `from the work an'd at the same time said driving piston compresses a body of air which, at the end of the retracting stroke of the driven piston, is released and permitted to react upon the driven piston to drive it forward and deliver the working stroke. One of the methods disclosed in my said application-for establishing retracting influence is by arranging for the expulsion of the body of driving air after completion of the working stroke and as the driving piston follows it forward'and to admit 'air `forward ofl the drivenlpiston so that when the driving piston draws rearward, it will so'far reduce the pressure in rear of the driven piston as to permitthe pressure medium in front of it yto drive the`driven piston backward.

The object of my present inventionis to develop a more effective force in front of the driven piston for the purpose of driving it rearward, and to these ends myjpresent Y invention consists in supplying to the space in front of the driven piston, when the compressing piston executes its retracting stroke, a fluid medium under pressure, which `may act against the driven piston to retract it; also in having this delivery of pressure in front of the driven piston to take place during the etracting stroke of the compressing piston, ut independently of said compresslng piston, so that it does not retract from the power which the latter develops and delivers to the driven piston on its working stroke. In the embodiment herein selected Specication of Reissued Letters Patent. Reissued Feb, 16, 1915,

. Original application led November 25, 1905, Serial No. 289,127. Divided and application led April 4,

l 1908,. Serial No. 425,189. Original No. 937,009,`dated October 12, 1999. Applieationjfor reissue led' y September 16, 1910. Serial No. 582,616. L,

piston, so that the pressure mediumy thus employed is a portion of the fluid pressure that was utilized to drive the driven piston forward. By the delivery of a iuid medium under pressure to the forward side of the driven piston, it follows that as soon as a condition' is developed in rear ofthe driven piston which will make the retracting pressure effective, said driven piston will be retracted positively and promptly and be in a position to receive the next forward driving stroke to the best advantage.

According toanother aspect, my present invention consists in trapping or confining a portion of the actuating pressure medium in a pressure driven tool, while said medium is stillat an effective density, and thereafter releasing said pressure medium against the forward face of the piston, after suitable reduction of the pressure on its driving face.

My present invention further consists in certain features of construction whereby the several objects of my invention are attained.

chamber in the plane of their axes, showing 'the pistons and the valve in different relative positions; and Fig. 7 is an axial section of the storage chamber and its valve taken 1n a plane at right angles to the plane'of the sections shown in Figs. 4, 5 and 6.

1 'represents the motor housing and 2 the piston housing or cylinder of an electrol pneumatic coal mining machine of the type selected for illustration of my present invention, which machine is usually mounted upon wheels 3 and is provided-with controlling handles 4 and current controlling switch 5. As these parts have no special conl sections of the working cylinder and storing ne'ction with my present invention, they need not be. further described here.

By referring to Fig. 2, it willbe seen that the cylinder 2 contains a driven piston 6 whose rod 7 is designed to receive and carry a suitable bit in a manner well known to4 those skilled in the' alit. In the type of machine selected forillustration of my invena stroke of the piston :8

i to the-space between,v the pistons 8and 6 face olf-piston .e lsimu taneosly with the front o rearward. lBut according to my present 1n- 'the air is being rar'eedbehind it; for which l mlmicates through a port with valved inlet port Q throug purposesfit will be sucient,

` tion, the piston 6l `is'acted upon expansively is compressed byv by a body -of air which the retracting stroke of adriving iston 8 which is housed in the same cylin er with the piston 6, said cylinder bein provided which'a newbody of airis drawn 'bg each forward an f a. by-pass 10 escape throughwhich said b y of air'can after the body of air has'been compressed by the rear-ward". movement of the piston .8

to a position between the ends of said b' piston l8, thel piston-6 is also moved rearmayv term the lsuction of' ward by what we the piston 8, that is to say" by atmospheric or other pressure actin upon the forward rarefaction ofair between the pistons due tothe rearward movement of. piston 8 from the position shown -inv Fig. 6. For some for retracting piston 6 to' simply admit atmospheric air in f said piston as the piston 8 moves vention, I Idesire to;l secure amore positive retractig movement ofthe piston 6 than is attainable by the.mere admission of-atmospheric air in front of said piston atthe time purpose,` I providemeans -such as a' valve housing 11 the two ends of which actas a single storage spaced). .reason of their communication throu' h y-PSSS: v`.11l (see particularly Fig. 7) orreceivin' a portion -of the lpressure medium (see drove the piston 6 forward Figs. 2 and 4) o n it'spreceding stroke, and elivering (Fig. `6) it in front' of' saidpiston 6 at the time when itis desired tol drive said'pi'ston yrearhousin 11 com- 12 wit the cylinder 2 at a point that is' inrear of piston 6 when the (Eig. 5), and. also through a' port pomt forwardlofthe forward limitof-said piston 6, so thatthe driving. pressureme-' 1 dium for the-piston 6 `may pass :into 4thehousing 11. afterthepiston has received ythe necessary forwardl impulse and pass from 4in other wordsfythe housing'forms a by ,said housinginffront ofthe piston 6) ;'t

'-'PSS around the' drive of the cylinder.'

dium from the housing 11 to the front face .said port. vItis also preferable to have tle v '75 which ldischarges into *atmosphere at 19.

itwill move valve 14 in Fig. 5 immediately after the piston 6 l pass. During the retracting stroke of t ,e

. (Fig. 6), ewhich (Fig 4),

9, so as to .avoid resistance tothe forg.. 5) which latter reaches its forward limit lin this'` figure, thereb n vpiston at the forward end y therebyclosing port 12 Totime the delivery of the pressure me- `of the piston 6, -said housing is provided a valve '14 controlled bv avalve stem 15 which is moved" in one direction by 'a spring 16 and in the .constantly rotating cam 17.

Wlth

other direction by a While the piston 6 controls the port. l2 of housing 11, it

is preferable to' have the valve 14 so p'osiv timed that. it will guna the ope-ning of valve 14 control an exhaust port 18 (Fig. 4

The cam 17 may beconveniently mounted 'upon the shaft 20 of the motor l.gear so that it. rotates constantly. It is so designed that to the position shown reaches its forward limit, and hold it there until piston 8 reaches its forward limit 1 I when `the housing 11 will have'been charged with air underl considerable pressure. 'Then cam17 moves valve 14 to close the port 12 andl theexhaust occurs-at the time piston 8 starts rearward.

space in front of the piston 6 and drivesthe port 18 andopen' port 13 This releases .the pressure medium in the forward end of housing 11 through by-pass '11 and port 13 to the latter rearward,.as'a1r 1s exhausted behind i 1t, with much greaterv force thanfif atmosphere alone were as the retraction is nearly complete or has developed sufficiently to insure-completion depended '.upon. As -soon` by the momentum of the .pa-rts,V cam 17 Vj i moves valve 14 at which it opens the exhaust Ward movement of piston 62 The rod 15 is not connected directly with -to an intermediate position the cam, but for convenience is connected to 'a lever 2l, fulcrumedv at 22, which is in turnv brought 'under'theA influence. of the cam.`

throughthe mediumof the push rod 23. As I these'details are not of the essence of my invention, they mayL obviously be modified at will 'and according `to circumstances.

It isto be understood that the piston 8 is constantly reciprocated through :its rod 8 by ower received from any suitable source,V as

or instance, the motor housing 1. [I do ing` reciprocation to the piston he following ing the operatlon tion inv Fig. 5, aI 1d 'only a moment thereafter, valve 14 arrives in the position shown while piston 8 is still a nein 'compressing .alf 111170 Chamber .11.5 Vgalve 14 runs rearward into position shown in Fig. 6, and opening port 13; whlle piston 8 1s on the point of reversing,

and piston 6 starting toward the rear.

an electric motor located inl not myself, however, to any specific meansjfor-mpartsteps will be observed durof thel apparatus: I. As soon as'the blowhas been delivered by piston. 6, which is shownV in -its foremost posiopening port 12 CIN .pressure against the rear side of piston 6 sending the latter forward, air escaping ythrough exhaust ports 18 and 19. Piston 8 now reverses; but not until piston 6 has delivered its blow, does valve 14 move for-l ward into the first position-shown in Fig. 5, piston 8 in the meantime going forward. I claim I 1. A percussion implement having a casing, a pressure-driven piston housed therein and receiving the ressure-medium on one face to develop kan impulse therein, a second piston similarly housed in said casingfor compressing said pressure-mediumduring the retraction of the pistons and recompressing said pressure medium in said casing after the driven piston has completed its forward stroke, and mechanically controlled means for conducting a portionvof the pressure-medium which develo ed `the impulse to the opposite face of the riven piston and to trap and to release compressed front of the driven piston.

2. A percussion implement having a air in casing, a pressure driven piston housedtherein and receiving the pressure medium on one face to develop an impulse therein, a second piston similarly housed in said casing for compressing said pressure-medium during the retraction of the pistons and recompressing said ressure medium in said casing after the driven piston has completed its forward stroke, and means including a port for passing a portion of the pressure medium to the opposite face of the driven piston and to trap and to release compressed air in front of the driven piston.

3. A percussion implement having a suitably housed pressure-driven piston receiving a pressure medium on one face to develop an impulse therein, means compressing said pressure medium and means trapping a portion of said medium under pressurezand thereafter releasing it against the forward face of the piston.

4. The combination of suitably housed driving and driven istons having opposed faces; means where yy the driving piston compresses a Huid on its rear face on one stroke, and the fluid under pressure thus developed is delivered between the opposed faces of the `pistons to develop an impulse in the driven piston, and means delivering a portion of said iuid under pressure to the forward face of the driven pistn, and exhausting the same therefrom when expanded. v v

5. In a fluid pressure driven tool the c'o bination of driving and driven pistons, of which the driving piston exerts retracting iniiuence over the driven piston, a common housing for said pistons closed at both ends', said driving piston developing therein the projecting orce :for said drivenpiston at the rear end of said housing, a by-pass'in said housing for controlling said projecting force between said pistons, means for actuatin said driving piston, and means indepen ent of the driven piston for delivering a projectingv force forward lof the driven piston whilethe driving piston is exerting y its retracting influence, and exhausting the same therefrom when expanded, said second projecting force being developed during the atter part of the forward stroke' of said driving piston. A

6. A machineof the class described comprising independently reciprocable tool-operating and fluid-compressing pistons,a cylinder in which said pistons are tted, providing a tight compressing chamber in rear of the compressing piston, and an expansion chamber between the pistons, said cylinder also" having a by-pass adapted to conduct -fiuid from said compression lchamber to said chamber between "the pistons, means -for compressing said Huid and conducting thev same fluid under pressure to the front of the tool operating piston for retracting` said piston, and means for exhausting said. Huid in advance of the tool operating piston, whereby the percussion stroke of the tool operating piston is developed by the expansive action of the pressure Huid medium.

7. The combination with a driving compression piston and a driven pistonhof a cylinder casing wherein both of said pistons ai'e suitably housed, and a` by-passage forming communication between the controlling face of the driven pistonand the compres- Asion space of the driving piston, through which a medium compressed during such retraction is communicated Ato the driven piston, said cylinder casing providing means through which Huid under pressure is` conducted to the forward side -of the driven piston whereby the driven. piston is retracted during the Icompression strokeof the driving. piston, and means having intercommunication with said first means through whicha the fluid medium is .displaced after the advance of the driven piston. t'

, 8. A machine of the class lprising a casing provided with a cylinder,

tool operating and fluid-compressing pistons independently reciprocable therein, the

casing being provided with a by-pass lhaving ports for conducting compressed flu-id from one side of the compressing piston to a described coinspace between the latter piston and the tool operating piston, and means for recompressing and conducting said Huid to the forward l side of the tool operating piston for retracting the latter. l

In a fluid pressure driven tool the combination of a driving piston and a" driven Aio piston, asuitable housing for said pistons closed at both ends, said driving piston exerting r/etracting influence over the driven piston, and compressing a pressure medium at the rear, end of 'the housing, means for actuating said driving piston, and a by-pass in said housing for delivering` said pressure medium between the pistons, said driving piston compressing `said pressure medium on its forward stroke, means for trapping said pressure medium after the forward stroke of the driving piston and delivering 1t under pressure forward of the driven piston, while said drivingpiston is exerting its retractin influence and exhausting said" pressure me ium whenexpanded. i

l0. In a 'fluid' pressure driven tool th combination of a driving piston and a -driven piston, a suitable 'housing for said pistons closed at both ends said driving piston exerting retracting infiuence over the driven piston and compressing a pressure medium at the rear end of the housing,4 means for actuating said driving piston and l a by-pass in said housing for delivering said pressure medium between the pistons,

' ber into which said fluid drivin is forced by theforward stroke oI the driv.

les

lng influence on said driven piston, and exhausting said iiuid` therefrom when `eX- said driving piston compressing said pressure medium on its vforward stroke, means for trapping a portion of said pressure medium after the forward stroke of the. driving""pi`ston and delivering said pressure medium forward of the driven -piston while said driving piston is exerting its retracting influence and exhausting said pressure medium therefrom when expanded. v

11. In a fluid pressure vdriven tool thel j combination of a driving piston and.. a

driven piston of which the driving piston develops pressure ina iuid'on its rearward stroke, a commonhousing for both pistons, means delivering said luidunder pressure.

to the rear face ofthe driven piston to develop a forward impulse therein, a chain- `ing piston,

fluid .front of othe driven pion to exert 'retracta trap and means delivering said panded.

12,'Inx`aqf1'uid pressure driven tool.. the

driven piston of whichy the riving vpiston medium 1 from said chamber to the Vspace inV combination of a driving. iston and f aing said driving piston, means delivering to the rear face of said`driven piston a Huid under pressure developed by said driving piston, and means independent of the drivcomprising a pressure chamber for receiving a portion of the pressure medium previously delivered to the rear face ofl said driven piston and now recompre'ssed by said driving piston, and communicating the same pressuremedium to the forward face of sald driven piston for driving it rearward, and means for exhausting vsaid me- .dium therefrom when expanded.v

14. In a fluid pressure driven tool the `combination of a driving piston, a driven piston receiving a fluidv under pressure on its rear face to drive it forward, a common housing for botli pistons, and means coinprising a pressure chamber for-receiving a portion of the pressure medium which is being recompressed by said Ydriving piston asl said driven piston approachesits forward limit, and communicating the same pressure medium to e forward face of said driven piston for driving it rearward, and means for nally exhausting said medium therefrom when expanded.

. y 15. The combination of a drivingpiston, a driven piston, a housing forsaid pistons, a chamber in said housing to the rear of said drivingv piston wherein driving pressure medium isv compressed by said driving piston, a by-pass from said chamber tothe i pressure side of said driven piston and an inlet valve in said by-pass; a valve. chamber communicatingwith the housing of said pistons at. a point in rearfof the forward position of the driven piston and also at a 'tion of saiddriving pressure medium 1n said chamber, as well as the delivery of said pressure' medium to the `cylinder forward of said .piston and an exhaustport fr the expanded' pressure medium'.

-16 The combination of a.

ven piston,

l a housing for said piston, ga viii-ye chamber communicating .with the.'houing vof said piston at. aj point :in f 'ofgthe forward izo lii'ri'tof thepistonland-"ilso at a, point forchambefreceives aportion of,y fthe. driving cylinder forward of said piston, said valve also controlling said communication in rear of said limit and closin the same till the driven piston has passedg.

17. In a fluid pressure driven tool, the combination of a cylinder, a driven piston therein, a valve chamber having communication with the cylinder at a point in rear of the forward limit of the piston and also at a point forward of the said limit, and having-an exhaust port; and a valve controlling said communications and exhaust port; ,said valve opening the cylinder to exhaust durin the forward stroke of the piston, admittmg driving' pressure fluid to the chambercfrom the cylinder in rear of the driven piston, and then delivering said pressure fluid to the cylinderforward of said piston.

18.` In a fluid pressure driven tool, the combination of compressing and driven pistons, a suitable housing for said pistons, a passage in the rear end'of said housing, a valve mechanism 'to trap the compressed fluid medium and a chamber for said valve communicating with the housing both forward and rearward of the forward position of the driven piston, said compressing piston during its rearward stroke both exhausting the air behind the driven piston and compressin a fluid medium at the rear end of sai housing while at the forward stroke of the compressing piston the drivenl piston receives through saidpassage l the medium thus compressed and is driven forward by the same, said chamber receiving a portion of the pressure medium used to drive the driven piston forward, when the compressing piston moves forward, and delivering said pressure medium forward of the driven pistom to drive thelatter rearwardwhen the air is exhausted fromv nection betsween said valve and a shaft of theA 20. In a fluid-'pressure driven tool, a working piston, a cylinder in which said piston works and in which it issubjected to fluid pressure on its rear face to develop its working stroke, means for compressing said fluid,

a valve mechanism to trap the fluid pressure mediflm, and a, chamber for said valve mechanism having a`-port through which it pressure.

communicates with the cylinder and receives said fluid under 'pressure therefrom upon being recompressed by said fluid compressing means, and having an outlet port for exhausting the air in front of the piston on its forward stroke and a port cornmunicating with and transmittingsaid fluid under pressure to the forward face of said piston to drive it rearward.

21. In a fluid-pressure ldriven tool, i a working piston, a cylinder in which said piston works and in which it is subjected to fluid pressure on its rear face to drive it forward and develop its working stroke, and a chamber having suitably controlled ports through which it communicates with said cylinder, both in rear and forward of the said piston, and through which it receives therefrom, under pressure, a part of the fluid that drives the piston forward and returns said fluid under pressure to the forward face of said piston to drive it rearward.

22. In a fluid-pressure driven tool, a working piston, a cylinder in which said piston works and in which it is subjected to fluid pressure on its rear face to drive it forward and develop its working stroke, and a chamber having suitably controlled ports communicating with said cylinder, both in front and in rear of the forward limit of said piston, and receiving fluid under pressure from said cylinder in rear of said piston, and returning said fluid urfder pressure to said cylinder forward of said piston, to drive thepiston rearward; means being provided to time the opening of such communications.

23. In a fluid-pressure driven tool, a fluidpressure driven working piston, a cylinder in which said piston works and in which it is subjected 'on its rear face to the expansive action of the fluid pressure medium, to drive it forward and develop its working stroke, a chamber for storing the fluid medium under pressure, having suitably controlled ports communicating with said cylinder,v through which it receives fluid medium under pressure therefrom, and returns said fluid under pressure to the forward face of said .working piston to drive it rearward, means to exhaust the fluid pressure medium from the front side of the driven piston, and a suitably housed pressure-developing piston, supplying said fluid-medium under 24. In ai fluid-pressure driven tool, a fluid pressure driven working piston, a cylinder in which said `piston works and in which it is subjected. on its rear face to the expansive action of a fluid pressure medium, to drive it forward and develop its working stroke, a chamber for storing the fluid medium under pressure, having suitably controlled ports communicating with said cylinder, through which iti receives fluid medium ward, a motor-driven compressing piston under pressure' therefrom, and returns said fluid under pressure to the forward end of said Working piston to drive it rearward, and a suitably housed pressure-developing piston, supplying means to exhaust the fluid pressure medium from the front side of the \driven piston, said Huid-medium under pressure compressing the pressure-medium on one stroke and on the other stroke forcing said medium, under pressure, into the storage\\chamber.- y

25. In a fluid-pressure driven tool, a {inidpressure driven working piston, a cylinder in' which said piston works and in which it is subjected on its rear face to the expansive action of a fluid pressure medium, to drive.

it forward and .develop its workingstroke, a chamber for storing the fluid medium under pressure, having suitably controlled ports communicating with said cylinder, through which it receives Huid -medium under pressure from said cylinder, and returns said fluid Aunder pressure to the forward end of saidr working piston to drive it rearward, means to exhaust the fluid pressure medium from the front side of the working piston, a passage way for the pressure medium and a pressure-developing' piston also in said cylinder supplying said iuid-mediumA under pressure compressing thel pressure medium and releasing it by means of said passageway into the space between` the pistons on one stroke and on the other stroke forcing a portion of said meber.

26. In a fluid-pressure driven tool, a fluidpressure driven working piston, a cylinder in which said piston works and in which it is subjected to fluid pressure on its rear face to drive it forward and develop its working stroke, a chamber communicating with said cylinder, receiving Huid under pressure therefrom, a valve mechanism to trap said com- `returning said fluid Aunder pressure to the forward face of said piston to drive it rearalso working in said cylinder, compressing a charge of fluid on its rearward stroke, there being means for, delivering saidchargeunder pressure thus developed, to the space between the pistons, whereby it ,drives the v front of the driven piston being simultaneously exhausted and said compressing piston thereafter following the pressure-driven piston forward, to introduce a new charge in rear of said compressing piston and'displace pressure medium from between the pistons into the chamber.

27. .In apparatus of the class described, the combination with a reciprocatory gasdriven member carrying a tool,- of a recipdium, under pressure, into the storage cham-- pressed fluid medium in said chamber, and

pressure-driven piston forward by its expansion, the expanded pressure medium in rocatory gas compressor associated therewith, and means for delivering the vcompressed gas to actuate said tool member, a cylinder in which\ said member and said gas compressor work, a port in said 'cylinder driven tool member.

28. In apparatus of theV class described,`

the combinationl with a reeiprocatory gasdriven member carrying a tool, of `a yreciprocatory gas compressor associated therewith, a cylinder closed at both ends wherein said member and said compressor work, a by-pass in said cylinder for transmitting the compressed gas from the pressure side of said gas compressor to the space between said compressor fand said gas driven member for the purpose of acting on the'latter, a port in said cylinder adapted to communicate with the atmosphere, and a positively driven associated valve-mechanism with a chamber therefor, adapted intermittently to open to the atmosphere, by means of said port, the space in advance of the driven member and close such space during the retracting thereof to permit reciprocation of the driven lmember, a receiving port transmitting the compressed gas into said chamber and a delivering port transmitting gas from said chamber to the front of said member for retracting it, said receiving and delivering ports being controlled -by said valve mechanism and said gas being recompressed by said compressor before entering the chamber.

29. A machine of the class described com-- prising a cylinder closed at both ends, tooloperating and fluid-compressing pistonsreciprocable in said cylinder, and port-s for conducting compressed Huid from one side of one of said pistons to a space between .said pistons, said fluid compressing piston piston, and said machine also having a valve controlled Huid exhaust port.

30. A machine of the class described comprising a cylinder closed at both ends and tool operating 'luid pressure driven piston,

and a fluid compressing piston adapted to.

actua-te said driven piston by means of the fluid, and reciprocable in said cylinder, .said machine also having ports controlled by said fluid compressin (piston for conducting compressed iuid om the compressing side jeo said pistons; sai machine being provided with ra valve controlled chamber perma nently closed to the atmosphere and having means for conducting fluid recompressed by said compressing piston from the space between the pistons to the space forward of the fluid pressure driven piston.

31. A machine of the class described comL prising a cylinder closed at both ends, tool operating and fluid compressing pistons reciprocable in said cylinder, saidI machine having ports for conducting compressed fluid from the 'pressure side of the fluid compressing piston to the space between said pistons to actuate said tool o erating piston, means permanently close to the atmosphere for 4conducting fluid to the tool operating piston for retracting the'latter, anpexhaust port for the expanded fluid, and positively driven valve mechanism controlling said fluid conducting means and said exhaust port.

32. A machine of the class described comprising a casing provided with a cylinder closed at both ends, tool operating and fluid compressing pistons reciprocablel therein, said machine having ports for conducting compressed fluid from the pressure side of the compressing piston to the space between.

the latter piston and the tool operating pis- `ton to actuate said tool operating piston, -means permanently closed to the atmosphere forconducting fluid to the tool operating piston for retracting the latter, an'exhaust port for the expanded fluid, and positively driven valve mechanism controlling said flul conducting means and said exhaust po L 33. A machine of the class described comprising a cylinder closed at both ends air compressing and tool operating pistons reciprocable in said cylinder, ahy-pass at one end of said cylinder, having ports controlled by s aidcompressing piston, said compressing piston adapted to actuate said tooli operating piston byrmeans of air compressed by said compressing piston at said end of the cylinder and tnsferred tothe interpiston space; and a valve controlled chamber with ports for transmitting air recompressed by said compressing piston from the inter-piston space to the outer face of the tool operating piston.

34. A machine of the class described comprising a cylinder, air compressing and tooloperatingn pistons' reciprocable in said cylinder, a by-pass' at the rear end of the cylinder, by means of which by-pass the air compressed at said rear end bythe compressing iston is respectively communicated to the inter-piston space from the outer face of said compressing ypiston thereby actuating said tool-operating piston, said by-pass being controlled by saidcompressing piston, a chamber with ports atthe forward end of s aid cylinder and a valve in said chamber for controlling said ports, said cylinder also having at its respective ends controlled ports communicating with theJ atmosphere. 35. A machine of the class described comprising a cylinder, air compressing and tool operating pistons reciprocable in said cylinder, a by-pass at the rear end of said cylinder by means of which by-pass the air compressed at said rear end by the compressing piston is respectively communicated to the inter-piston space fromV the outer face of said compressing pistons, said tool operating piston, and from said inter-piston space to the outer face of said tool operating piston, said bypass being controlled by said compressing piston, a chamber with ports at the forward end of said cylinder and a valve in said chamber for controlling said ports, said cylinder havports at its respective ends.

r3.6. A maching of the class described comprisinga cylinder, a tool'operating fluid pressure driven piston and a fluid compress- .ing piston independently reciprocable in said cylinder, and means being provided for conducting compressed fluid from the compressing side of the compressing piston to a spacebetween said pistons, a valve housing secured to the cylinder, and provided with a by-pass and 'exhaust port, independently driven means located within the housing and adapted to regulate communication through the by-pass and exhaust port, the said bypass being adapted to conduct fluid com pressed in the` space between the pistons and deliver it to lthe-space.. `forward of the fluid pressure-driven piston.

37. In a device of the character described, the combination of a pressure cylinder, a tool piston, means for supplying atmospheric air to the rear end of said cylinder, means for compressing the same for effectin? the working strokel of the piston and carrying the effective pressure o f said compressed airto the tool end of said cylinder, means -for trapping air compressed by said compressing means at the tool lend of s aid cylinder and releasing said aii for assisting in retracting said piston during the major portion of the return stroke of the tool piston.

The foregoing specification signed at Syracuse, N. Y. this 19th day of August l ALEXANDER PALMROS. In presence o C. GRACE KENTNER, EVA CinfrwiLL.

thereby actuating llO

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