US2633094A - Power-operated press device - Google Patents

Description

-J. MULLER POWER-OPERATED PRESS DEVICE March 31, 1953 :Filed Dec.

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ATTORNEYS March 31, 1953 J, MULLER 2,633,094

POWER-OPERATED PRESS DEVICE Filed Dec. 2, 1948 3 Sheets-Sheet 2 FIG: :5.

' INVENTOR.

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Jules Muller, Detroit, Mich, assigntirto EL Bliss. Company; Detroit, Mich'., a corporation of Delaware Application December 2, ieliaserialneecanea GChliins; (Cl. 113-38) This-invention relates to presses for forging, extruding on drawing metals and similar maehines and istparticularly directed to anovel method and apparatusicr operating the drawing,

vextruding or forging slidethrough the Working portion=:of itslstroken V 'Conventionalmechanical presses for. the form- .ing,of.-metals by 'forging, .'extruding or. drawing operate by developing the maximum pressure against the -metal. atuthebottom of the stroke, whereasit is desirable and important to develop the-highest pressureat the initial contact between tlie'forming dieandthe metal to'cause the initial crystal slippage and to maintain the slippage during the working portion of the press, stroke.

The primaryobject of the invention is to provide anovel'method and apparatus for operating the-slide ofi'a forging, extruding. or drawing press bymeans oflwhich energy for the Workingportlonlof'thetstro'ke islderi'ved' in part from an ex- "t'rane'oussource ofpower, andin part from the usual power source that raises and lowers the 'slidethrough' theworkin'gfportion of the stroke, in such a manner that the force aga nst the metal to be worked is raised to substantially the peak pressure at the time of initiallc'onta'ct between the metal and forming die.

Anotherobiect of the invention'isto provide a*' method and apparatus of this" character in which an;'explosivemediumis used to provide the additioria-l power.

Still another obiectofthe invention to'provide'a device of this'character'in which an explosi've medium; is 'used in a powercylinder-having a piston-conne'cted to atogg'le in the slide oper- "atihg* linkage, the-togglebeing adapted to pass oVerPcenter against the actionof a bounce or restoring cylinder;

iwill?become-Japparentfrom th'e following description a preferredembodimenu; reference being the acco'mpanyi'ngv drawings in which:

Fig l is a central vertical section of, a press embodying the'present invention, portions ofthe press being shown'in full lines; Fig. 2 is asection on line 2-2 of Fig; 1 with parts brokenaway;

and Fig.3 is a timing diagram indicating a preferre'd'se'quence' of events in the operation of "the Press t Referring to the drawings, the press structure may take any suitable form "but thepresentinvention is'particula rly applicable to large presses.

'The dies between which the metal is actually formed are omitted but as in norma1 ractice one of the die parts "is to be c'a'rriedby abe'd l0 and disposed'in the path of" movement are mating die member carried by a slide l2, the "slide being gibbed for reciprocation in the press frame and between tie-rods [4' and 1"6. The crown of the press isindicated at l8" and carries'a slide driving motor 2'0' which is connected by" means of a belt ZZand'gear' set" 24'---25 'to a shaftifi. A worm 28 on shaft 26 drives a pinion" 30*disposed on a crank-shaft SZ WhiCIIlS" journalled in a front"'-to-back position'in the press crown in suitable b'ea fingblockst l Eccentricstd'carried by the crank shaft 32 are surr'oundedby connecting rods 38, the rods beihg diametrically divided inthe usual manner forassembly; At their lower ends the" connecting rods '38 are in operating connection Withs'lide l2 through adjustablescr'ew connections 40:

Itsnoum be expressly'understo'od that the parts so rarde'scribed' may'be'varied-intheir construction and formn'o part. ofthe present invention except that they serve to reciprocate the-slide through thenon-working portion of its stroke, that is, advance the slide "to die closing position andre'store it" afterthe drawing operation has been performed; While the sinusoidal movement derivedfrom eccentrics BBYissatisfactQry for certain operations," a slide driving mechanism ineluding a plurality of toggles may serve better inother instances where a dwell i's requirediin the stroke.

Slide" I 2 is div ided' into upper and lower b sections the lowersection being i'gibbed: in the frame a's pr'eviously stated and the upper section being mounted for slidable reciprocation in the lower section. The upper: slidesection is designated l3 and suitable ounterb-alance"cylinders" are 'provided-fadjacent-the crown: of theipress: to'assist in raising the-weight 'ofthe?slide*parts. 'Ihepisto'ns one ortlieslideparts; preferably 'thehpper term 3; isformedwithopposed power and bounce cylinders, the power cylinder being designated =46 and the bounce cylinder being designated 48. A power piston 58 reciprocates in the power cylinder 46 while a bounce piston 52 reciprocates in the bounce cylinder 48. The two pistons are connected to each other by a link or connecting-rod 54 which is connected at each end to the power and bounce pistons by suitable wrist pin connections and intermediate its ends is connected to a central pivot 56 of a toggle link comprising an upper arm 58 pivotally connected as at 68 to the upper slide art I3 and a lower link 62 pivotally connected as at 64 to the lower slide part I2. It will thus be seen that as the connecting rod 54 moves laterally the toggle, comprising arms 58 and 62, is straightened causing a lowering of the slide part I2 with respect to the slide part I3.

In the normal position, during idle or nonworking movements of the press, the power piston is disposed at the right of its cylinder thus forming one wall of a combustion chamber 66. The power piston is held in a definite position by air pressure in bounce cylinder 48, the pressure being introduced, for example, from a source 68 by means of a pipe Ill and a piston controlled port I2 in the bounce cylinder. The source 68 carries air at a relatively low pressure, in the order of 40 pounds per souare inch. suflicient to hold the pistons in their non-working position and to maintain the lower slide part I2 contracted with respect to the upper slide part I3. In the normal or non-workin osition of the parts, then, the tog le link 58-62 is broken; that is, its arms lie at an angle to each other.

Any suitable motive force may be used to drive the power piston 58 outwardly in the power cvlinder 46. However, it is preferred that the additional energy be derived from the timed explosion of a material such as will decom ose s ontaneously in the power cylinder without the requirement that air at high pressure and tem perature be contained in the power cylinder or without the reouirement of ignition by a spark or otherwise. A fuel of this character may comprise hydrogen peroxide iniected in the presence of an agent capable of causing rapid and spontaneous decomposition such as hydrazine or ethyl alcohol. Both the peroxide and its decomposing agent are liquids capable of being handled separately with complete safety but form a spontaneously explosive mixture when brought together.

The fuel constituents are injected into the power cylinder 46 by means of separate iniection nozzles 80 and BI supplied by separate fuel pumps 82 and 83. The pumps and nozzles follow the known practice of similar pumps and nozbles in the familiar compression engines and it is :only necessary to modify this equipment by changing the material used for the hydrogen peroxide pumps, since this material must be stored and conveyed in suitable metallic containers. Stainless steel, however, is suitable for the pump and nozzle parts and, in fact, is a preferred metal.

A single valve 85 is provided opening into the combustion chamber 66 and the valve serves as a controllable exhaust and venting valve held bustion chamber during that portion of the stroke of piston 50 which would normally be referred to as a compression stroke. The valve is closed slightly before the piston reaches its position of full insertion in the power cylinder 46.

Valve is operated in any suitable manner, as by a cam 81 carried at the end of a reciprocating slide 88 which is connected by means of an arm extension 88 to a pin 51 on central pivot point 56 of the toggle link 58-62. The valve is thus timed in its opening by movement of the toggle link. A lost motion connection comprising pin 5'! extending from the pivot 56 and working in a slot 86 of the arm extension operates to bring cam 81 under the stem of valve 85 when the power piston 58 has completed slightly more than half of its power stroke so that the tog le link 58-62 has been straightened and broken slightly in the opposite direction when the valve 85 begins to be opened by cam 81. The valve 85 is held open by cam 81 during the remainder of the working stroke of piston 58 and the return of this piston through nearly all of its return stroke, being closed only when pin 51 is engaged by the end of slot 96. This occurs when piston 58 is nearly at the extreme inner end of its stroke.

The fuel pumps 82 and 83 are driven by any suitable connection to the crank shaft 32 and a small eccentric or pitman connection to this shaft will furnish ample power for the pump drive.

As previously noted, bounce cylinder 48 contains air under relatively low pressure introduced through piston control port I2. When port I2 is covered by the bounce piston 50 the air in cylinder 48 is trapped and is greatly increased in pressure by continued movement of bounce piston 52. This air then is increased in pressure and the energy stored therein may be utilized to return the power piston to its initial position. The action of the bounce cylinder does not take place until after the slide has been withdrawn from the work by movement of the eccentrics 36 and connecting-rods 38.

The operation of the mechanism may best be understood by referring to the timing diagram shown in Fig. 3.

The inner and outer slide parts I2 and I3 move down together by reason of the energy imparted from the driving motor 28 to the eccentric 36 through the gear train and shafting in the press crown. This motion is sinusoidal and is indicated by the sine curve A. As the slide parts near the bottom of the stroke, fuel is injected into power cylinder 45 through the two nozzles 86 and BI if the energy is to be derived from the decomposition of hydrogen peroxide as above stated. Nozzles 88 and 8I act in response to a pressure wave from their respective pumps 82 and 83, the pumps being driven from and thus timed by the shaft 32 which carries the eccentries 36.

Energy expended in the power cylinder 46 drives the power piston 56 outwardly of this cylinder and since the piston is connected to the center pivot of toggle link 58-62 the two slide portions I2 and I3 commence a diiferential movement, slide part I2 moving more rapidly than slide part I3. The motion of slide part I2 alone may be represented by a curve B. The first portion of this curve is relatively steep as it represents the high velocity and rapid straightening of the toggle link. The curve isessentially sinusoidal, but its rate of descent is somewhat more rapid than its later ascending rate, as the ascent is impeded by the action of bounce cyl inder 48. It will be seen that the power applied acped fii'n the power cylinderi aises-goes Theipis on 50 continues tot'drive thetoggle Eli'rik=:to thefleftbeyond center position'and at" aripredetermined'point infthis continued op erac'tfo rdbounce piston52' ciosesport 'ni'and'the bounce"cylinderiftlttcomm'ences-itcrin mewhat l'aterin the stroke): 'at point i E on-the ui'veyexhaust-valve 85 is openedbyj cam 81, the Tcamrbeing :drawm nnder the valve.

by slide 88 connected in turn to actuating arm extension 90. The valve' air'emains open until nearly the end of the cycle as later described.

The retraction"of'thelowerslidepart l2, and thus the openingL orrtne *form'ing dies, is-cau'sed in part by the breaking of the toggle link to "the left in Fig. 1 and in part by the upward move ment of both slide parts I2 and I3 by eccentric 36. Since the two motions are in the same direction, they are added together in curve C which .is only that caused by friction and the weight of the lower slide part. There is no second closing of the die part by the second straightening of the toggle since this action takes place at a time when eccentric 36 has raised the entire slide assembly beyond the point where it is possible for the dies to close.

Expansion of air in the bounce cylinder thus moves the power piston to its initial position. As the toggle link nears its initial position the end of slot 96 contacts pin 51 and moves cam 81 from under the stem of valve 85 so thatthe valve closes. Continued air pressure from'source 68 holds the parts in the initial position, ready for another operating stroke. l

While the invention has been described, in connection with a particular form and disposition of the operating parts and in connection with a specific fuel system it should ;be. appreciated that numerous modifications and changes may be made not only in the press parts themselves but in the method of its operation and fuels or explosive medium used without departing from the invention as defined in the appended claims.

What I claim is:

1. In a metal forming press, a die-carrying slide movable toward and away from work to impart a predetermined shape thereto, power means for imparting said movements to the slide, said slide having upper and lower parts movable toward and away from each other in the plane of movements of the slide, a toggle connection between said slide parts operable when straightened to separate said slide parts, a pair 6 onionposmgicylinderscarried:by'rine ofsaidsfide parts; a: pistoztzirc:eachncylinder; a crossa'zconmotion between saidnpistonsumoving fonet from the othe'r and? connected: to said-toggle connec' "tiento' cause successive straightenmg andbreak mg -movements thereof when the pistons are reciprocatedt means: for creating an "explosion "in", one- 0f "said cylinders at apredetermined point-in sworn-shapingstroke of thesli'de and to imparta sudden straighteningmovementoi said toggle connection to move said slide parts away from each other, said other piston acting during "said" toggle straightening movements to compress abouncecharge inns-cylinder then returns the pistons and toggleeonn'ection to normal positions, and means automatically operable to relievethe'explosive pressure inthe first cylinderwhen=*thepistons hav'e moved a pro-- determined distance undr' the explosing:acti n.-

f2; Ina:pressof-the class described, fll di'ee carrying slidesaid slide*having'upper'anddower parts relatively movable in the planeof the'sl'ide movements, power means operable'to' impart pre determined successive inwardwork-snaping and outward "retracting movements to that oneof said slide parts on which said die is carried,

toggle means connecting said-upper and lower slide sections and operable when straightened to cause a-predetermined relativeseparation of said slide parts, a cylinder carried by one section, a piston in said cylinder connected to said toggle means and movable by explosive action in the cylinder to cause a sudden start of the toggle means to move one slide part outward from the other, means operable at a predetermined point in-the work-shaping stroke of the slide to introduce into said cylinder separate fuel constituents which when combined effect an explosion, and means operable at a predetermined point in a work-shaping cycle to return the toggle to broken position and the piston to initial position.

3. In a press of the class described, a diecarrying slide, said slide having an upper power section and a, lower die-carrying section relatively movable in the plane of the slide movements, power means operable to impart predetermined successive inward work-shaping and outward retracting movements to said upper power slide section, toggle means connecting said slide sections and operable when straightened to cause a predetermined relative separation of the sections, a first power cylinder carried by one slide section, a piston in said cylinder connected to said toggle means and movable by'explosive action in the cylinder to cause a sudden start of the toggle means to move one slide section.

to compress a bounce fluid in its cylinder, and

means to render said bounce fluid active to return the toggle means and the first piston to normal positions after a straightening operation of the toggle means.

4. In a press of the class described, a pair of opposing die-carrying members with one member slidable toward and away from the other, one

of said members including at its work-shaping side a section for carrying the die of suchmemher and movable inward and outward -relative to its carrying member in the plane of relative sliding movements of said members, toggle means connecting said section to its carrying member and being normally broken to hold the connected parts in retracted relation, power means for imparting predetermined inward and outward strokes to said slidable carrying member, a cylinder carried by said member, a piston in said cylinder normally at the inner end of its stroke in the cylinder, a connection between said piston and said toggle, means automatically operable at a predetermined point in a work-drawing cycle of the press to introduce into said cylinder separate fuel constituents which when combined efiect an explosion to actuate the piston and said connection to straighten the toggle and force said section outward from its carrying member to assistin a drawing operation,'and means automatically operable to return the toggle and pistonto normal positions when the drawing opera.- tion is completed.

5. A combination as called for in claim 4, together with means operable at approximately the end of a toggle straightening movement of the first-piston to relieve the pressure in its cylinder. 6. A combination as called for in claim 4, to-

gether with a relief valve in said first cylinder, and means connecting said toggle means and relief valve and automatically operable to open the relief valve when the toggle means reaches its straightened position.

JULES MULLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 887,109 Meyer May 12, 1908 968,608 Smith Aug. 30, 1910 1,035,828 Albree Aug. 20, 1912 1,701,324 Gram Feb. 5, 1929 2,064,129 Temple Dec.- 15,1936

2,088,134 Haessler July 27, 1 937 2,128,152" 'MacMillan Aug. 23, 1938 2,189,497 Pescara Feb. 6, 1940 FOREIGN PATENTS Number Country Date 547,236 Germany of 1932 OTHER REFERENCES Rockets for May, August 1946, p. 7.

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