US3193875A - Extrusion press - Google Patents

Description

P. H. TAYLOR EXTRUSION PRESS July 13, 1965 4 Sheets-Sheet 1 Filed OGt. .13. 1961 INVENTOR. Pau H :22j/[07 P. H. TAYLOR ExTRUsIoN PRESS July 13, 1965 4 Sheets-Sheet 2 Filed Opt. 13. 1961 y 0 1% mv H. a www mwN w@ Z 0 NQ uv. M www@ Nv mm\ RB@ MNNN P. H. TAYLOR EXTRUS ION PRES S July 13, -1965 4 Sheecs--Sheei'I 3 Filed oct, 1s. 1961 m. W WIW W3. y@ H uw Z a mm NNK N Q NQN @am Dm W .WQNV QQWN u NKW @Nv QN] N N ZZ/w i i @NN Y. KN .ww/ n|kl%\\\\\\ SNI@ IWW M qui.. |l .1 www@ 1M www@ Fm Mhlwulhwln HM s Lnb/M l///M/A///@ Q [wwf A, .v0 N "//MM//MV/lmrms bk m6 MQ. Q kk MMWR f., @QN

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United States Patent O 3,193,875 EXTRUSEON PRESS Pani H. Taylor, Grand Island, N.Y., assigner to Tayco Developments, Inc., North Tonawanda, N.Y., a corporation of New York Filed ct. 13, 1961, Ser. No. 144,955 9 Claims. (Cl. 18-5) This invention relates to presses and more particularly to presses for forming or compressing materials which utilize liquid compressibility as a motivating force in the energy source for the press ram.

Heretofore, such presses have been of tive categories:

First, there are the hydraulic presses which are characterized by low velocity but in which the velocity can be accurately modulated.

Second, there are the mechanical presses which are motivated by a crank throw or variations thereof and which, in general, generate a sine wave movement with high initial velocity, and high force with low Velocity at the end of the stroke.

Third, there is the drop hammer type of press motivated by a falling weight which may or may not be accelerated by means of air or steam to accomplish the desired impact.

Fourth, there is a class of hydraulic presses in which higher velocities are obtained through the medium of stored energy accumulators in which the compression of a gaseous head provides the stored energy.

Fifth, in recent years presses motivated by explosives have been evolved.

Each of the above presses has its distinct limitations and for a particular manufacturing operation usually only one is suitable so that when there are a range of manufacturing processes, a multiplicity of presses of diiferent types must be utilized.

The primary object of the present invention is to provide a single press which can operate with the high velocity of explosives, the accurate controllability of liquids, and the elasticity of air.

Another important object of the invention is to provide a press in which the force curve can be exactly tailored to requirements.

Another object of the invention is to provide a press having shock absorption capabilities which automatically come into operation in the event of failure of the System to work properly or in the event the operator fails to put work in the press.

Another object is to provide a simple and effective means for hydraulically loading die members against outward deectiou while at the same time permitting of quick die removal. Such hydraulic loading can be controlled either hydraulically or electrically.

Another object is to provide controlled metering of the iiuid to produce precise velocities while still providing rapid acceleration for the ram.

Another object is to provide such a press in which premature operation of the press is avoided, it being necessary to release a latching means or to cock the press before it can be operated.

Another object is to provide simple and rapid means for hydraulically closing the press, that is, bringing the punch up to the workpiece preparatory to the Working stroke.

Another object is to provide such a press in which the working pressure can be built up in a series of pulses to a high value, a liquid having a high degree of compressibility being utilized for this purpose and the liquid being compressed by degrees to obtain the required high work? ing force.

Another object is to provide such a press in which the workpiece can be held under compression for a long period of time, such as for -a week, in the production of 3,193,875 Patented July 13, 1965 ICC man-made gems, and in which the degree of such compression can be held constant thermally.

Another object is to provide such a press in which the main ram is of reduced mass to cut down the flywheel effect thereof, the ram being desirably made of aluminum or titanium for this purpose. Another aim is to provide such a press which can be activated by a medium having both a high initial and also a sustained thrust, such medium being normally in the form of a gas but being used-in the liquid state.

Other objects and advantages of the invention will be apparent from the following description and drawings in which:

FIG. l is a side elevation of a horizontal press embodying the present invention and illustrating the position of the die member for quick removal and replacement.

FIG. 2 is a fragmentary end elevational view, viewed from line 2 2, FIG. 1.

FIG. 3 is a fragmentary, horizontal, longitudinal section taken generally on line 3-3, FIG. 1, and showing on an enlarged scale, the construction of the corresponding end of the press.

FIG. 4 is an enlarged, vertical, longitudinal section through the opposite end of the press from that viewed in FIG. 3.

FIG. 5 is an enlarged, vertical, longitudinal section through an intensifier forming a source of high pressure liquid for the press.

FIG. 6 is a diagram of the hydraulic circuit.

The invention is illustrated as being in the form of a horizontal extrusion press having a horizontal body cylinder 8 mounted on a base or bed 9. The body cylinder is shown as having a Working or extrusion chamber 10 having a top opening 11 through which the workpiece to be formed (not shown) is inserted in the press, and also having a bottom opening 12 through which the extrusion or forging is removed from the press and dropped into a tote pan 13 or the like. The die 14 is shown as being of frusto-conical form and as having a die cavity l15 which receives a punch 16 carried by the main ram indicated generally at 17. To reduce the mass of this ram and hence cut down its flywheel effect it can be made of aluminum or titanium.

The die 14 is contained in the correspondingly tapered bore 13 in a cylindrical die holder 19, this die holder in turn being fitted in a cylindrical end bore 20 in the smaller cylindrical end 21 of a die block indicated generally at 22. The opposite enlarged end 23 of the die block 22 is mounted in the open end of the bore 24 of the main body cylinder 8 of the press by means of an interrupted thread joint so that the die block 22, together with the die 14, can be quickly removed from the press. For this purpose, the threads 25 of the enlarged end 23 of the die block 22 are in the form of three segmental groups of threads each of 60 extent and separated by unthreaded portions 26 also of 60 extent and the mating segmental groups of threads 28 in thev bore of the main body cylinder S are also of 60 extent and are similarly interrupted by segmental unthreaded portions 29 also of 60 extent. With the segmental groups of threads 25, 28 interengaged, the die 14 is adequately supported in the main body-cylinder 8 of the press against the axial thrust of the punch 16 against the workpiece in the die cavity 15. Upon turning the die block 22 60 so that its threads 25 are disengaged from the threads 28 and its unthreaded portions 26 is registered With the threads 2S, the die block can be pulled axially out of the main body cylinder v8 to the dotted line position shown in FIG. l. In this movement the die block 22 is shown as supported by rails 30 carried by a bed 31, these rails engaging the horizontal downwardly facing ends of the upper two groups of segmental threads 25, as best shown inl-TIG. 2', to slidingly support theY latter. The die blockj .Y

22 is shown as turned by means of a handle 32V although for this purpose is shown as having doors 33 providing' access to its interior. The extrusion can befejectedV fromV Y Y The cylindricalrhigh pressure outlet chamber 76 communicates, via aV p'assager81 containing a check valve 82 the die cavity 'by means of an ejectorV pin 34 which y can be actuated in any suitable manner.

Liquid Yfor actuating the Vpres-s is supplied by a low pressure hydraulic pump 35 capable of primary' pressures to, say, 10,000 p.s.i.g. indicated by a dial 36.V This pump 35 can be supplied with liquid from a tank orV reservoir 38 and its outlet line 39 connects with a two vposition valve 40 kwhich is also connected by a drain .or return line 41 to Vtank 38.v Lines42 and 43 also yconnect-this two position valve to` an' intensifier indicated generally at 44 and shown in enlarged section in FIG.. 5, In one position of the two' position valvefl a port 45 connects the pump outlet line 39with the line 43 leading' to the intensifier while the line 42 from the intensifier is connected by opening kaway from the chamber 76, with a pipe line 83 connectingthe intensifier with the press. The pressure in Ythis line 83 can be indicated by a-high pressure gage 84, thisgage indicatingthe Working pressure lot' the liquid which is compressed to actuate the press.

A line 85, containing a valve 86, also connects with i the passage 81 on the side of the check valve Y82` remote t actuating liquid fromfthe press to the tank 38 for reuse.

An important feature is that the diameter of the enlarged cylindrical outer end 61 of theV through bore 60 is Y greater than the diameterof the inner stepped blind end 53 y of the blind bore 51, this differential determining the effecav port 46 with the drain( line 41 back. to tank. YIn the' other position of the two position valve 40 yit revenses the relation of these pipes, having a port 48- connecting' the pump outletrline 39 with the'pipe 42 and having a a stepped blind bore 51 the large diameter portion 52 tive 'size of the ramY 54 in producing intensified pressure in lthe line 83 in response to the pump pressure applied from the line 43. This pressureis transmitted through the bore 72 in the stud 68'to tl'ie` cylindrical low pressure inlet Ychamber 73V between the piston 65 on this stud and the In this intensifier the applied force is increased in intensity byreason of the stepped ram 54 interposed'betwee'n' the piston 65 and stepped'cylinder of which forms the outer open end ofthe bore andthe small diameter portion 53 of which forms rthe inner blind end of the steppedV blind bore. Thisbore contains a hollow piston or ram, indicatedV generally at 54', having a large diameter end 55 fitting the outer large ldiameter portion `52' of the steppedblind bore 51 and having an opposite small diameter end 56 rfitting theinner small diameter portion 53 of the stepped blindvbore 51.

An annular internal dust sealv ring 58 inthe bore' of '50. Thus delivery from the pump 35 through the line 43 passesthrough theY bore 72 of Vstudr68 into the cylindrical Y. low pressure inlet chamber 73 of the stepped ram 54 and drives this ramY outwardly or to the left as viewed in FIG. 5, This causes ,the piston 65 to reduce the size of the cylindrical chamber 74 andA hence force liquid from this cylindrical chamberthrough the bore 69,`cylindrical high pressure outlet chamber 76, check valve8`2 and passage 81 t'o the line 83 leadingto the extrusion press. At the same Y time the smaller end 56 of the ram 5'4'is withdrawing from the body cylinder 50 is interposed between the largeend 55 of the ram or piston 54 andthe large'vdiameter end 52 of the stepped blind bore 51 in body cylinder 50,'

this dust seal Vring protecting against dust and other foreign matter an external liquid seal ring 59 on'the small 'diam-eter end 56 of the ram or piston54 andv sealing o against the small diameter portion 53 of the stepped the cylindrical high pressure chamber 76 and hence subi tracting from the'liquidrso delivered into this cylindrical,

end head or cap 62 Vscrewed on theouter large end 55 ofV the ram with an external liquid seal ring 63 at theY end f i fixed to' the` cylinder` 44 at the blind end of its stepped M bore 51 by a threaded connection 70,- a liquid seal 71 being provided'at the base of the stud. This tubular stud has a throughV bore 72 which provides communication t between the. lines 43 and the cylindrical chamber 73 between the piston 65 andthe end cap 62 of the ram 54. This chamber 73 is the low pressure inlet chamber of the intensifier.

between and provides communication betweenthe cylindrical chamber 74 on the opposite side of this piston 65 and the cylindrical chamber,V 76 inthe smally diameter. portion* 53 of the stepped blind bore51'. This chamberv 76 is the high pressureV outlet'chamber of the intensifier.V

The open reduced endV 69V of theyV bore 60 surroundsy the'stud68 with substantial clearance therehigh pressure outlet chamber by the piston 65. Accordngly t-he volume of liquid delivered to the line 83 will be proportional to the differential in crossy sectionall area of the cylindrical chambers 74 and 76 and at a corresponding intensified p-ressure. Liq-uid at such intensified p ressure', andi indicated ont the gage y84, is preferably so fed tothe extrusion press through the line4 83 in a series of pulses and return ofth'e stepped ram 54 is effected by moving the two position valve 48 s0 as to connect its Y ports 48 and` 49 with the lines 42 and 43, respectively. lIn this position the delivery from the pump', 35 is to the line 42 past'check valve 79 into the cylindrical high pressure outlet chamber'76 and through the bore 69 into the Y cylindrical chamber 74. Since the cross sectional size of of the stud 68, lineV 60.,

t-he cylindrical chamber V74 is greater than the cross sectional size of the 'cylindrical high pressure outlet charnber 76 the stepped ram 54 will be' moved inwardly or tol Vthe right as viewed in FIG. 5 ,and the liquid displaced from the cylindrical' low' pressure inlet chamber 73 by this movement of the stepped ram escapes through the bore 72 43 and port 49 ofthe two position valve 4f) to tank 38'. y q Y While any compressiblelliquidcan be used as the actuat- Y ing fluid, the use of a normally gaseous fluid, such as This high pressure outlet cylindrical chamber 76 com#y i municates, yviaka passage 78 containing Ya check valve 79 lopening away from, theV chamber line 42.

y The cylindrical' chamber 8f).V the enlarged portionA 52 of the stepped blind `bore51 Vand closedby Vthe piston 54 contains air and istproteoted by the dust seal ring'SS.

76, with theY pipeiv butane,v propane or nitrous oxide in liquid form during initial movementof the ram is contemplated to obtain'the initial thrust energy of high value from the fluid as a compressed liquid andthere'after to obtain sustainedrthrust l from the fluid as a compressed gas.

Referring to FIGS. 3v and 4, the main ram 17 is in the Vform of a tubular body -having itsv end carrying the Apunch 16 closed by an end head 91 screwed therein, an external annular liquid seal ring 92being provided on the Y Vend head 91 and thepunch 16 being removably secured to the end head 91 by means of a suitable holder 93. A

head 91. The tubular body 90 is provided at the end enclosed by the end head 91 with an enlarged piston head 95 working in thebore 24, an external annular seal ring 96 being provided on this piston head between it and the bore 24 and the piston head 95 providing a space or cham- `ber 98 extending along the tubular body 90. At the opposite end of this tubular body the bore 24 is enlarged, as indicated at 99 and the tubular -body is provided with a piston head 100, containing an external annular liquid seal ring 101 working against this enlarged cylindrical section 99 of the bore .24. In this enlarged cylindrical section 99 of the bore 24 is also slidingly iitted a cylindrical follower 102 which can be moved to closethe press and also to bring the punch 16 to a proper distance from the billet to insure impact at the optimum velocity for the particular work involved. This follower has an external annular liquid seal ring 103 working against the bore section 99 and is provided with a cylindrical blind bore y104 at the end opposing the main ram 17. In this cylindrical bore 104 is slidingly iitted a reduced cylindrical end 105 of the cylindrical body 90 of the main ram `17, this reduced cylindrical end having an external annular liquid scad ring 106 in contact with this bore. The follower 102 is backed by a threaded end head 108 screwed into the corresponding end of the main body cylinder 8 and having an external annular liquid seal ring 109 in contact with the enlarged section 99 of the bore 24.

A control liquid line 110 in the end head 108 communicates with the preiill space 111 between this end head 108 and the follower 102, this permitting of hydraulically adjusting the position of the folower 102 so as to close the press, that is, to bring the punch 16 linto contact with the billet in the die cavity preparatory to the working stroke of the press if this type of use is desired. This adjusting the position of the follower 102 also permits of bringing the punch to the correct distance from the billet in the cavity 15 to insure that the punch 16 strikes the billet at the optimum velocity for the work involved. A control liquid line 112, shown as under control of a solenoid Vailve 107, communicates with the space 113 between the follower 102 and the piston head 100, this line being used to initiate or trigger the working stroke of the press. A control liquid line 1:14 communicates with the space 98 surrounding the main ram 17 between its piston heads 95 and 100, this line being used to cock or prevent premature operation of the press. The area 115 of the piston head 100 which forms `an end Wall for the chamber 90 is effective for this purpose.

A stud y116 is connected by a screw joint 1117 with the follower .102, this joint having an annular oil seal ring 11S. This stud projects into the cylindrical bore l119 of the tubular body 90 of the main ram 17 through a coaxial bore `120 through the end head ofthe reduced cylindrical end 105 of the main ram I17, the stud .1.16 being slidingly liitted in this bore 120. Such sliding tit, as compared with the microfit of the sliding surfaces of the body cylinder 8, main ram 17 and piston 65, provides a clearance exaggerated in FIG. 4, which permits the passage of liquid under the very high pressures used in the press, .The tolerance at this point provides a frictional resistance to the passage of liquid during the pressing stroke of the press. At its opposite end the stud 116 has a piston head 121 working in the bore 119 and seating against the gasket ring 94. This piston head `121 is provided with an external annular peripheral liquid seal ring 122 and an important feature of the invention is the provision of holes or passages 123 through the piston head 121 and-terminating againstthe gasket ring 94, The space bounded by the main ram end head 91, gasket 94 and piston head 1-21 is indicated at124. n

A feature of the invention resides in the provision of an enlargement or spool l125 in an intermediate part of the stud `1115, the clearance between the periphery of this spool and the bore 1,19 of the tubular body 90 being limited so as to provide frictional resistance to the passage 6 of liquid thereby during the pressing stroke of the press. The threaded end yof the stud 116 is provided with an axial blind bore 126 having ports 127, 128 communicating respectively, with the interior '119 of the main ram 17 and the cylindrical bore 104 in the follower 102. This blind bore forms a continuation of an axial bore in an integral axial stem 131 projecting from the follower 102 and slidingly iitted in a bore 132 in an axial extension 133 of the end head 108, annular internal liquid seal rings 134,

135 being provided around the stem 131. The bore 130 communicates with the line 83 connecting the press -with the intensifier `44 this line having for this purpose a fitting 136 screwing into an internally `sealed ring l137 fitted around the extension y133 and communicating with the bore 130 through ports 138 and 139 provided respectively in the sides of the extension l133 and the stem 131.

The speed of press operation is adjustably controlled by a restriction valve stem 140 arranged coaxially in the bores 126 and 130 and having a tapered end head 141 between the ports 127 and 1,28. A feature of the invention resides in the closeness of iit of this restriction valve stemf140 in the bore 125, this iit being such as to provide a high degree ofy frictional resistance to the rapid passage of liquid through this bore between the ports 127 and 128. The opposite threaded end 142 is screwed into the outer threaded end of the bore .130 and projects to the exterior of the press for adjustment, being shown as provided with a screw driver slot 143 for this purpose. An annular internal liquid seal ring 144 is provided in the bore 130 around the restriction valve stem 131.

A feature of the invention resides in the ready removability of the die y14 and die holder .19 from the die block 22 while at the same time holding the die against extremely high stress pressures of the expansion force of the billet being extruded. The normal practice with extrusion dies is .to apply a succession of conical shrink rings to the die holder to increase the resistance to deflection of the contained die so that the die will not fail in service. Such shrink rings must be large and render removal of the die and die holder from the press diiiicult and costly.

Considering the die holder 19, and die blocks l22 as a heavy ywalled vessel, it is well known that with a heavy Walled vessel the stress levels in the Wall rapidly diminish as thedistance from the axis of the vessel. Thus if. at the core of the die '14 the stress level is, say, 200,000 p.s.i.g., to withstand extrusion pressures of 100,000 p.s.i.g., the stress level at the exterior of the die would be in the `order of 100,000 p.s.i.g., the stress level at the exterior of the die holder 19 would be in the order of 50,000 p.s.i.g., and the stress level at the exterior of the die block 22 would be in the order of 20,000 p,s.i.g.

In accordance with the present invention liquid under such assumed pressure of 20,000 p.s.i.g. is applied to the exterior `of the die block `r22 around the die holder and die `to provide resistance to the Ioutward yield or deiiection of the die, while at the same time providing normal sllding clearances between the die, die holder and block wltle pressure is relieved so that they can be readily separa e Preferably the structure for accomplishing this also expands into engagement with the` bore of the horizontal body cylinder 8 so that the body cylinder also resists the outward yield or deiiection of the die and liquid under pressure is also shown as applied to the exterior of the body cylinder 8 around the die further to relieve such expansion stress against the body cylinder and permit of using a less bulky body cylinder.

To this end an annular pressure ring 145 is shown as having its bore fitted, with normal sliding clearance, around the periphery of the cylindrical end 21 of the die block 22 and as having this bore provided with a broad central annular channel 146 and this bore also provided with internal liquid seal rings 148 on opposite sides of this channel. The periphery of this pressure ring 145 is similarly fitted, with normal sliding clearance, in the bore 24 of the horizontal body cylinder 8 and external liquid t taljbody cylinder', `pressureof the liquid supplied from the line 154, one or sealfrings 143 `are provided in this periphery near its V0pposite ends. 1 Liquid underV pressure is supplied through registering ports 150 and i151 through the pressure ring" 145,'` and body `cylinder 18 respectively, and liquid under pressure canbe supplied to these ports bya pressure ring 152'tted to the exterior of the main-body cylinder` 3 and having abroad central annular channel 153in itsV bore which is in register 'with the portr151 and'is Vsupplied with v S reduced resistance to passage through small orifices and behaving as liquids in storing the energy required to compress'theY liquid, Such liquid-gases canY be controlled fluid lunder pressure .from a supply line- 154. Internal liquid seal rings 155 around the ends of' the'boreof this pressure ring 152 prevent leakage of this liquid from between this pressure ring. and the periphery of the horizon- In placejofor in addition-to the more electric resistance immersion heaters .15d-can be contained in,` the liquid Vin the channel .153 Vto head andV expand the -body Vof liquid 'therein vand thereby elevate its VVpressure to the value required to'resist outward yield of the die .14 and the parts surrounding thedie. sure of the liquid gage 158.

The Vpresin this system 'can be'indicated by1ay with great accuracy through smaller orifices than will pass equivalent amount of pure liquids due to transition to the gas phase-on release from the orifices. This functionprovides liquid.Y flow control through rsmaller orilices which can be of importance in achievingY compactness of Such liquid having ahigh degree ofr compressibility is contained in the tank 38 or as a liquid gas in a pressurized tank and is withdrawn therefrom and delivered at low pressure, say at 10,000 pls.i.g.fto the intensier *Pressure can kbe i further intensified or held constant v behind'the main rarn17 of the.V extrusion press by heat,V

this being shown as accomplished by circulating a high temperatureL liquid'in the annular space '9,8 'surrounding the press ram, this being for/the'purpose of getting higher Y peak `performance out of a press of a given pump, capacf ity or to obtain constant operating pressures for ay long', Vperiod of time such as in producing man made gems,

such' as diamonds, Sapphires and the like, which are,

grown under high pressure for periodsl of asl long as a 44 and thence behind theram' vr1*'7v of the press;

In `preparation-for the cold extrusion operation, a dieA V1 4 mustbe installed in the press. and tothis ,end the die blockv 22 is rotated in its vinterrupted thread joint 60 or a sixth of a Vrevolution so as to disengage its thread segments 25 from the thread segments 28 in the end of y the bodyj cylinderS andfbring the thread'segments 28 into line with the unthreaded portions 26 of the die block V22 so that the die blockcan be' withdrawn axiallyy from the bore 2,4 in the horizontal body cylinder 8. yIn being f so withdawn, the rdownwardly'facing ends of the two top.,groupsroi,threadl segments on the die block l22 lie in Va commonlhoriz'ontal plane intersecting the `major v axis of the press, as best" shown in` FIG; 2, and these l downwardly facing ends rideV on the side rails 30 of the week. `With the press of the present inventionV main# Y tenance of a constantA high` pressure on theV gems' could quite easily be accomplished .byl thermal means rather than the pulsation of thel press ysystem through the intensifier 44 `and low-pressure pump 35. -f

For this purpose, liquid yof the desired temperature can be recirculated through a branch line 160 Vof the liquid control line 114 leading ytoone end of .the'space 98 around the main ram and aline 161 connecting with Y 'oi'itstwov upper groups of thread segments 25 riding on the other end'of this space. These lines 160, 161 arefV shown as connecting with a heat exchanger 162 the heating medium for which can be heated in a heater 163.' If required the yWorking liquid'behind the main ram could,

1 thef'rails 30 during suchlinsertion so as to support the die block and guide it in its movement to operativeV posivrtion.l When the die block v22 has, been fully inserted it be cooledY before beingrintroduced to the press and also e Y.

a coolant could be supplied to theheat exchanger 162 ,during the period of mechanical build up by pulses ofthe working pressure behind the main rani by the `intensier Operation The principal feature` of the press ofathe present invention resides in the utilization of liquid `compressibility as the motivating force inthe energy lsource for the press room to obtain the required Working pressuresV andl explosive action of the vpressi if required.V ToV this-,end it is desirable to use a liquid having a lrelatively high de-v gree of compressibility. v

VSuch liquid can be a silicone having a high degree of compressibility, but theV use of atliquid-gas, thatY is, a fluid normally gaseous but-ccnnpressedl into a liquid is especially contemplated. i Examples ,of such 'gases are butane,V propane and nitrous oxide.V Considering liquid propane, for example, this gasgin yliquid form has a s ubstantially greater degree ofcornpressibility than liquid silicone V of the highest compressibility known toV provide istv given a '60?V turn, as by 1means of its handle 32, to reengageits .thread Vsegments 25 with thel thread segments 28 'of thev horizontal body cylinder 8 and to lat'chthese two'pa'rts togetherin operative relation.

v Fluid of any. suitable characterunder suitable presl sure, say l0,000'p.s.i.g., isthen applied to the line 154 into `the pressure ring V152 .surrounding the horizontal body cylinder 8 and this Huid pressure is'trans'mitted through the ports 151 and `150 into the internal chan- ,nel 146 ofthe pressure ring 145 interposed between the periphery of the' cylindrical part 2,1 of the die block 22 and thebore `24 of the horizontal body cylinder 8; Leakage of this uid beyondthe opposite ends of these pressure rings isY prevented by the pairs lof annular liquid seal rings 148,. 149 and 155-and the pressure in the broad internal yannulafrichannels 146 and 153 thereby resist outward yield or Ydeflectionof the die 1.4, die holder19, die

pressures subsequently applied. L The billet (not shown). is then inserted into'the die i 'block 22 and mainlbody cylinder under the extrusion Y cavity '1 5 and `the press closedA to bring the punchA into,

proper spatial relation to this inserted billet. This adjustment of the starting position ofthe punch can" be such a greater movement of v the ram 17 asa function'of the compression of the liquidiv VIn addition, by'conversion `to its gaseous phase on continued movement ofthe ram, ay sustained thrust is maintainedV which could not be ob-i tained from mere decompression of a liquid. Thus such liquidgases have the energy storage characteristics of low pressure gases multiplied by highfpressures when inrliquid phase to Vstore as much as twice the energy fora given volume Vas compared with purek liquids but behaving, by transition to their gaseous phase, as gases in providing 'billetinto the iextrusion. y

that thepun'chvis spaced from the billet a distanceftor acqulre an' optimum velocity for forming the billet, this 'capability being a feature of thefinvention. This adjustment also adjusts theV travel of the punch in forming the YTo accomplish this, fluid of any suitable character is Vintroduced under pressureV through theline 110into the space lllgbetween its end head 108 and the cylindrical follower 15052 tothe left `as viewed in FIG. 4 thereby to move the maint-'ramV 17 along'the bor'e24 so as to bring its punch 16 towardthe die cavity 154 and into the optimum spatial relation with the billet (not shown) therein. When this is done, the liquid so admitted through the line 110 is held trapped within the space 111 between the follower 102 and main body cylinder end head 163 to serve as a backing for the follower against the subsequently applied extrusion pressures. lt is unnecessary, therefore, that the liquid so admitted through the line 110 be of a cornpressible character.

The speed of forming the extrusion is then adjusted by turning the restriction valve stern 1411 as by its exposed screw driver slot 143, FIG. 4.

The first phase of the pressing operation is to establish a seal at the gasket 94 between the main ram 17 and the piston 121 at the end of the stud 116. For this purpose liquid of any suitable character is introduced under pressure through the line 114 into the space 9S and is thereby impressed against the face 115 of the piston head 1GO. This moves the main ram 17 to the right as viewed in FIGS. 3 and 4 and thereby compresses the gasket 94 between the end head 91 of the main ram 17 and the piston head 121 of the stud 116, thereby to establish a seal around the ends ofthe passages 123 of the latter. At this time the valve 86 is open to permit the escape of liquid from behind the main ram. While this seal is subsequently additionally maintained by the working pressure introduced into the main ram bore 119 behind the stud piston head 121, during the build up of this working pressure, the pressure in the chamber 98 is preferably maintained at a high enough valve to insure the maintenance of the seal at the gasket 94 to provide against premature operation of the press. As long as the effective area of the face 115 of the piston head 169, in relation to the liquid pressure in the chamber 98, is greater than the effective total area of the bores 123 in the stud piston head 121 against the gasket 94, in relation to the working pressure in the bore 119 of the main ram, the main ram is held sealed, via the gasket 94, against the stud piston head 121. The areas and pressures involved can be readily calculated to achieve this.

The next phase of the pressing operation involves'closing the valve 86 and introducing, in pulses, a compressible liquid into the bore or chamber 119 in the main ram 17 to build its pressure up to the working levels in which the liquid in this bore or chamber is compressed to a high degree to have a high degree of stored explosive-like energy. As this pressure is built up to working values in pulses, this increasing pressure also serves to maintain the seal of the gasket 94 against the stud piston head 121 so that even in the event of failure of pressure in the chamber 9S to maintain this seal, premature operation of the press will nevertheless be prevented. In this function the increasing pressure in the bore 119 of the main ram 17 is impressed against that'internal portion of the piston head 100 and its cylindrical extension 195 equal to the difference in diameter between the bore 119 of the body cylinder of the main ram and the chamber 104 in the follower 102. Since this differential area always exceeds the effective total cross sectional areav of the passages 123 against the gasket 94, this rising working pressure increases the sealing value of this gasket.

The compressible actuating liquid is supplied by the pump 35 and is built up to working value and delivered in pulses to the bore 119 of the main ram 17 by the intensifier 44. For each pulse, the two position valve 4) is -moved to the position shown in FIG. 6. In this position the compressible liquid is delivered by the pump 35 from the tank 3S via line 39, valve port 45, line 43 and bore 72 of stud 68 to the low pressure inlet chamber 73 between the piston head 65 at the end of this stud and the end head 62 of the ram 54. This moves this ram 54 to the left as viewed in FIG. 5 thereby to force the cornpressible liquid from the chamber 74 through the bore 69 of the rarn into the high pressure outlet 76 of the cylinder 50 and thence past the check valve 82 through the line 83 to the press. The pressure of the compressible 1'@ liquid so leaving through the line 83 is intensified as conipared with the pressure of the liquid admitted to the intensilier 44 in the low pressure inlet chamber 73 in accordance with the differential in cross sectional area of the larger bore 61 forming this low pressure inlet chamber 73 and the smaller bore 53 forming the high pressure outlet chamber 76. Obviously this differential can be designed to any value, an increase in pressure being accompanied, however, by a reduction in volume of liquid transmitted by the intensifier.

Itis desirable to build up the required volume and pressure of the compressible liquid in the bore 119 of the main rarn 17 of the press in a series of pulses obtained by moving the two position valve 40 back and forth between its two positions. Thus after each filling impulse as above described, this two position valve 40 can be moved to bring its ports 48, 49 into service. When this is done, the build up of working pressure in the press is maintained by the check valve 82 in the outlet 8183 from the intensifier 44, FIG. 5, but the pump 35, outlet line 39 is connected via port 48, high pressure outlet chamber 76 and oversize bore 69 into the chamber 74in the ram 54. This drives the ram 54 to the right as viewed in FIG. 5, this movement again being due to the differential in cross sectional areas of the bore 61 forming the low pressure inlet chamber 73 and the bore 53 forming the high pressure outlet chamber 76, this differential area being effective as the' wall surface forming the chamber 74 to move the ram to the right as viewed in FIG. 5. This compresses and purges the liquid in the low pressure inlet chamber 73 of the intensifier, this liquid flowing out through the bore 72 of the stud 68 and thence through line 43, valve port 49 and line 41 back to the tank.

The compressible liquid so supplied in pulses by the intensifier 44 via line -83 to the press fiows around the stem 149 of the restriction valve in the bore 126 of the stud'116 and thence through port 127 into the chamber formed within the main ram 17. of the press by its bore 119. In this movement, while the cylindrical diameter of thestem 140 of this restriction valve is closely fitted vto the bore 126 to have a high degree of frictional resistance to the high speed passage of compressed liquid from the interior of the ram 17 during the extrusion or working phase of the press, this close fit does not materially impede the feed `of liquid from the intensifier in pulses to be compressed in the main ram 17 due Ito the fact that the build up is at a slower rate and in a succession of pulses. If objectionable resistance during buildup of pressure were encountered it is obvious that there is no necessity for introducing the feed liquid through this bore and that a separate inlet passage could be provided from the line 83 into the bore 119 of the main ram 17.

After the pressure of the compressible liquid in the bore 119 of the ram has been builtup to the value necessary to compress it and reduce its volume to have the required high amount of stored energy for the extrusion operation, the press is first cocked or readied for operation by relieving the'pressure maintained via line 114 in the chamber 98 and preferably also by draining or purging the liquid out of this chamber. At this time this has no effect except to release the pressure against the face of Athe piston head 100 which pressure initially set up the seal of the gasket 94 and during the period of working pressure buildup maintained this pressure to insure against premature operation of the press.

The working stroke of the press is then initiated by energizing the solenoid valve 107 to introduce liquid under pressure through the line 112 into the chamber 113. Such introduction builds up pressure at the external end of the main ram 17 opposing the follower 162 and reverses the condition of unbalance of the ram theretofore maintained bythe total area of the passages 123 against the sealing gasket 94 as opposed to the dif- -ferentialY internal piston area atvthe other end oftheV Y 'Aram 17 represented by the difference in cross sec-tional Varea .between the'bores 119.. and 104 of the main ram 17 'and follower 102, respectively.

With such introduction vof liquid. under pressure'into the chamber 113 the main ram 17: is immediately moved*A to the left as viewed in FIGS. 3 and 4 aY suiiicient `distance to break Ithe seal'of the gasket 94 against the ends of the passages. 123 through the piston head 121 of the stud 116. Accordingly theliquid inthe ram bore 1.19:

behindrthe stud vpistonhead 121 andunder a state'of high compression with accompanying storedY energy l passes throughv the passages 123 into the chamber 124 and `against the ful'l'internal areaof the end head 91 of the mainjramY As ya .result the, ramcanfbe driven with. explosive force to the left asfvie'wedin FIGS. 3 and 4 to Vdrive'the pu'nchqlV into the billet (not shown) contained .in the die cavity 15. and to extrude lor forge -this billet Yto the required shape. Y

With a. given setting of the follower 102 and agiven operatingpressure the speed lof movement of the main ram 17l during this working stroke of the press is controlled by la number of elements.

the spool l125V restricts the movement of liquid from the trailing end of the main ram 17 to the forward end thereof. .'AlsoV liquid can escape' past the `'surface 120 from the chamber 119 to the chamber 104 and this can be rcalculated to be', of any Vdesiredvalue and provided by leaving a kcorresponding Yclearance at this. surface. Also the sliding fit of the bore 120 provides a clearance in bypass-relation to the adjustable restriction valve 140,

this clearance being'exaggerated in FIG. 4.

'In addition, moreover, this speed. of movement of the ram Vis adjustably controlled bythe setting of thev valve stem 140 as bypits screw driverslot .143. If an'V Thus the passages v 123 restrict the flow of liquid as above described.4 -AlsoV Y ia The extrusion is then removed from 'the die cavity 15 by. the VactionA of the kejector pin 34 which" forces the 'extrusion from the die cavity 15 into .the working chamber tovfall by gravity vthrough the bottom opening 12 `into the tote lpanV 13a. The press is then readyffor Yanother sequence of operations.

To remove or replace .thedie 14, pressure applied by the l line 154 is relieved therebyv to relieve pressures exerted Aradially inwardly 'against the cylindrical die "holding end '21 of the die block 22 and the surrounding. portion of vthe main horizontal body cylinder S'by the' channels in the peripheries ofY tliepresvsure rings 145 andV 152, respectively. Y This reestablishesthe original normal 4sliding toli erances between the .die l1-4 and die holder 2021s well as between this die'holder 'andi the dieblock 22-,Vsov that by Y turningthe die'block 60 to bring the segments of the threadZS of the main `horizontal body cylinder Sinto line with the unthreaded'portions -26' of the die block'22,

' thevr latter canV be withdrawn axially on the rails 30 to expose the die and die holder and permit them ready removal from the die block. Y

Asrpreviously described, `instead of fluidpressure from the line 1S4vto so holdV the die 14 against outward deection j under extrusion pressures, thel liquid can be trapped inthe vconnected channels, 146 and`153 of the pressure rings 145 and 152, respectively, and then heated,

.through energizingrthe Yelectrical Vresistance immersion v heating units 156'to expand the iiuid'andsupply the required compressive pressure on the `die block 22 and main body cylinder Y8, respectively. Y j 4 Likewise,Y liquid pressure can be intensified within the bore 119 by the recirculation'of high temperature liquid in the space 9S between the4 main ram 17 and the sur- Y explosive speedY is desired, thisvalve stern s backedgci v so that its pointed end 141 is beyond the'port..128 to Y the bore or chamber VV-104 in the follower 102. VIn this position the Valve stem 140 offers practically no resistance i into Vthe bore 104 of the follower 102. Lacking `such resistance the main ram can perform its working strokeV with explosive violence. .Y

To slow down the working stroke, the valve stem 140 is progressively advanced to rst move its pointed end 141 across the port128 and thenV to bringits full cylindrical cross sectional diameter into that section. of the bore 126 between the ports 127 and 128. This full cross sectional 'diameter of the valve stem 140 has a suficiently `close t in this'bore 126 to provide a capii- V lary action and hence a high ydegree of resistance to the flow. of liquid at pressing .speedsand this high degree of resistance can be increasedV by progressing the j to the ow of liquid from the bore 119 of the main ram-17 through Vport 127, passage 126 and port 128- the heater 163.

rounding 'main body cylinder 8. This liquid is recircuf. late`d` via theV linesr160,Y 161 'through the heat exchanger 162 Which can'be vsupplied with a heating nmedium from Suchmaintenance of constant pressure bylheat could be particularly useful for a long period pressing operation, as of a week,in producing man made gems. A cooling medium'V can also be passed through theheat exchanger162. l

From the foregoing it will be seen thatthe press of the present invention is essentially motivated by the forces valve stem further into the bore126 toward theV port 127. The adjustment of such a valve can slow tsworking stroke from one of explosive ,action to one equalling the slowestcommercial hydraulic press Von the market.

.After the working .stroke the lpunch V16 canbe with-y drawn Afromthe extrusion: in .the die cavity 15 by opening the valve S6, FIG. 6, and'relieving the: pressure in the chamber-140, via line-112 and solenoid valve 107 so k that the liquid will exhausty therefromand by reintroduc-y ing liquid under pressure via line 114 into the chamber `98, the pistonV head 100 acting. as a pullback piston t0 withdraw the main ram 17 and its punch 176. from the extrusion.' VIn such pullback movement of vthe punch,V

the compressible liquid in the chamber 124 between the end head 91 of the main ram 17 and the stud piston lhead` 121 flows back'through the passages 123 inthis 'l stud piston head into the'bore 119 -of the main Vram 17 andjthence through the port'127, passages 1261a'nd line 85.

130, line 83, passage 81 in intensifier 44 and past vopen valve VS6 back to tank 38. v

stored within liquids capable of compression and which can operate with the velocities of explosives, the controllability of liquids and the elasticity of air. l It will further Vbe seen'that the press is ycapable of very heavy duty and Wide variety of purposes, especially for pressing voperations running into days of time. Further, the die can be quickly and easily changed even when in use it is subjected torheavy expansive pressures. Also a Vnovel intensifier is provided for building up thenecessary high pressure from arelatively low pressure source.

"I claim: f'

VVV1. In a press motivated by the expansiveA force of a .compressible liquid under compression, atubular main ram having an end head at one end and beingqprovided with an opening at its other end, a main cylinder slidingly. containing said main'ram and Vforming aclosed chamber with said` end of said main ram provided with said opening and said closed chamber containing said compressible liquid, Vmeans compressing saidV liquid in Y.said chamberV to a required'working value, a head fixed tov said main cylinder and arranged iin said mainram against said end head and isolating said end head from saidliquid infsaidl chamber while being so'compressd,v

13 chamber with said end of said main ram provided with said opening and said closed chamber containing said compressible liquid, means compressing said liquid in said chamber and main ram to a required working value, a stud xed with reference to said main cylinder and projecting through said opening at said other end of said main ram, a piston fixed to the outboard end of said stud and slidingly fitted in said main ram and isolating said end head of said main ram from said liquid in said chamber while being so compressed, and means conducting said liquid from said chamber to between said piston and end head when said compressible liquid in said chamber had been compressed to said required working value.

3. In a press motivated by the expansive force of a compressible liquid under compression, a tubular main ram having an end head at one end and being provided with an opening at its other end, a main cylinder slidingly containing said main ram and forming a closed chamber with said end of said main ram provided with said opening and said closed chamber containing said compressible liquid, means compressing said liquid in said chamber and main ram to a required working value, a stud fixed to said main cylinder and projecting through said opening at said other end of said ram, a piston xed to the outboard end of said stud and slidingly fitted in said main ram and isolating said end head of said main ram from'said liquid in said chamber while being so compressed, means providing a valve seat on said end head opposing said piston, said piston being provided with a passage therethrough having one end seating against and closed by said Valve seat, and means moving said main ram relative to said piston to unseat said one end of said passage from said valve seat when said compressible liquid in said chamber has been compressed to said required working value.

4. In a press motivated by the expansive force of a compressible liquid under compression, a main ram having an end head, a main cylinder slidingly containing said main ram, a head fixed to said main cylinder and arranged against said end head of said main ram, said main cylinder and its fixed head forming a closed chamber on the side of said fixed head remote from said end head, means compressing said liquid in said chamber to a required working value, said fixed head isolating said end head from said liquid in said chamber while being so compressed, means providing a valve seat on said end head opposing said fixed head, said fixed head being provided with a passage therethrough having one end seating against and closed by said valve seat, and means moving said main ram relative to said fixed head to unseat said face of said one end of said passage from said valve seat when said compressible liquid in said chamber has been compressed to said required working value, comprising a piston fixed to said main ram and working in a bore formed in said main cylinder, and means arranged to introduce fiuid under pressure into said bore on the side of said piston to force said end head away from said fixed head.

In a press motivated by the expansive force of a compressible liquid under compression, a tubular main ram having an end head at one end and being provided with an opening at its other end, said other end being of less external diameter than the end of said main ram at said end head, a main cylinder with a blind bore having a larger diameter part slidingly fitting said end of said main ram at said end head and having a smaller diameter part slidingly fitting said other end of said ram, a stud fixed to said main cylinder and projecting into the open end of said main ram, a piston xed to the outboard end of said stud and slidingly fitted in said main ram, said piston, main ram and blind bore forming a closed chamber, means compressing said liquid in said chamber to a required working value, means providing a valve seat on said end head opposing said piston, said piston being provided with a passage therethrough having one end seating 14 against and closed by said valve seat, said passage terminating in a face held seated by the preponderating pressure of said compressible liquid in said chamber against said main ram, as a function of the differential in diameters between said large and small diameter parts of said bore, in the direction to hold said end head and piston together, and means moving said main ram relative to said piston to unseat said one end of said passage from said valve seat when said compressible liquid in said chamber has been compressed to said required working value.

6. In a press motivated by the expansive force of a compressible liquid under compression, a main ram having a chamber therein, a main cylinder having a blind bore slidingly containing said main ram and forming a closed chamber behind said main ram, a stem extending lengthwise of the line of movement of said main ram through both of said chambers and slidingly fitting a bore in the wall of said ram separating said chambers, a passage in said stem having a port communicating with each of said chambers and communicating with the exterior of said main cylinder, means exterior of said main cylinder supplying said compressible liquid to said passage at a pressure sufficient to compress the liquid in said chambers to the required working value, and valve means in said passage adjustable from the exterior of said main cylinder and controlling the fiow of said liquid through said passage between said ports from said chamber in said ram to said chamber behind said ram, thereby to control the speed of operation of the press.

'7. In a press motivated by the expansive force of a compressible liquid under compression, a main ram, a main cylinder having a blind bore slidingly containing said main ram and forming a closed chamber behind said main ram, a follower slidingly fitted in said blind bore in said closed chamber and dividing said closed chamber into two separate compartments, means introducing a liquid into the compartment between the blind end of said bore and said follower to position said follower and main ram with reference to said main cylinder, means introducing and compressing to the required working value said compressible liquid into the compartment between said follower and said main ram, means holding said ram against movement while said compressible liquid is so being introduced and compressed, and means releasing said holding means when said compressible liquid has been so compressed to said required working value.

8. In a press motivated by the expansive force of a .compressible liquid under compression, a main ram havlng a chamber therein, a main cylinder having a blind bore slidingly containing said main ram and forming a closed chamber behind said main ram, a follower slidingly fitted in said blind bore in said closed chamber and dividing said closed chamber into two compartments, a stem projecting from said follower lengthwise of the line of movement of said main ram into the chamber in said main ram and slidingly fitted in an opening in the wall of said main ram separating said chambers, a second stem in line with said first stem projecting from said follower to the exterior of said main cylinder and slidingly fitted in an opening in said main cylinder, a bore through said stems connected by a port with said chamber in said main ram and by a second port with the compartment between said main ram and follower, means introducing a liquid into the compartment between the blind end of said first mentioned bore and said follower to position said follower and main ram with reference to said main cylinder, means introducing and compressing to the required working value said compressible liquid into said second mentioned bore to enter said chamber Within said ram and said compartment between said ram and follower, means holding said ram against movement while so being introduced and compressed, and means releasing said holding means when said compressible liquid has been so compressed to said required working value.

9.1nfa` press motivated by theV expansive force of a 'said main ram, a follower slidingly tted in Vsaid blind Y bore in said yclosed chamber and dividing saidy closed chamber into two compartments, a stud projecting axially'v from said follower in closely tted relation to saidV slide-Y way opening 4into said main ram, a stemlin line with said stud projecting from said follower to the exterior of Vsaid main cylinder and slidingly fitted inV an opening in said main cylinder, arbore through said stem and stud connected by a port with the interior of said main ram and by` a second port with the compartment between said main "ram when said compressible liquid inthe interior main ram and follower, means introducing a liquidV into the compartment between the blind end of said rst mentioned bore and said follower to positionfsaid follower and mainram with reference tov said main cylinder, means introducing and compressing to the required working value said compressible liquid into said bore `in said stem andY stud to enter the v interiorrof saidr main ram andsaid compartment between saidV main ram andy follower, a

.piston in said main ram fixed to the endfof saidstud against said end head and substantially isolating said end 565,014 t 8/96 Morgan 60-54.6 584,712 6/97 ShemY A.. 60-54.6 11,230,486 y6/17 Jacominir- 18-16 1,625,751 '4/27 S0lberg` 60-54.6 '1,955,002 4/34l Irwin 18-16 2,572,953 10/51 Saari 18-16 l 2,600,775 6/52 Hurry etal. 18-34 2,620,631 12/52 Denton v92- 13 v 2,834,048 5/58 Wright 18-7-16 l 2,836,848 6/58' YZink et al. 18--5 A'2,851,725 9/58 Bauer 18-4-5 2,915,043 12:/59 Neimer 92-12l Y2,942,298 6/ 60 Loeddiug 18--34 3,003,190A 10/61 Macks 18-34 q 3,036,538 745/62 'Ottestad 113--45 3,044,113 V7/62Y Gerrard et al. 18--5 main ram to betweenV said piston and end head of said of said main ramy has beenjcompressed to said required working Value, and avalve stem arranged in said bore in said Vstem and stud'in` closely fitted relationto the walls thereof and moved axially toV occupy varyingy amounts of space between said ports, thereby to control the speed of operation of thezp'ress.

y "References Cited by the V{Ebramilrler UNITED STATES PATENTS WILLIAM J. v-STEPI-IENSON,Primary Examiner.

Claims (1)

1. IN A PRESS MOTIVATED BY THE EXPANSIVE FORCE OF A COMPRESSIBLE LIQUID UNDER COMPRESSION, A TUBULAR MAIN RAM HAVING AN END HEAD AT ONE END AND BEING PROVIDED WITH AN OPENING AT ITS OTHER END, A MAIN CYLINDER SLIDINGLY CONTAINING SAID MAIN RAM AND FORMING A CLOSED CHAMBER WITH SAID END OF SAID MAIN RAM PROVIDED WITH SAID OPENING AND SAID CLOSED CHAMBER CONTAINING SAID COMPRESSIBLE LIQUID, MEANS COMPRESSING SAID LIQUID IN SAID CHAMBER TO A REQUIRED WORKING VALUE, A HEAD FIXED TO SAID MAIN CYLINDER AND ARRANGED IN SAID MAIN RAM AGAINST SAID END HEAD AND ISOLATING SAID END HEAD FROM SAID LIQUID IN SAID CHAMBER WHILE BEING SO COMPRESSED, AND MEANS CONDUCTING SAID LIQUID FROM SAID CHAMBER TO BETWEEN SAID FIXED HEAD AND SAID END HEAD WHEN SAID COMPRESSIBLE LIQUID IN SAID CHAMBER HAS BEEN COMPRESSED TO SAID REQUIRED WORKING VALUE.

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