US2545229A - Billet piercing apparatus - Google Patents

Description

J. F. CRAWFORD BILLET PIERCING APPARATUS March 13, 1951 6 Sheets-Sheet 1 Filed April 28, 1945 BY M 9 y 51% J. F. CRAWFORD BILLET PIERCING A PPARATUS March 13, 1951 6 Sheets-Sheet 2 Filed April, 28, 1945 INVENTOR March 13, 1951 J. F. CRAWFORD 2,545,229

BILLET PIERCING APPARATUS Filed April 28, 1945 6 Sheets-Sheet 3 '7 j a R m r 'm'" .2 ump I I E l l INVENTOR ATTORNEY March 13, 1951 J. F. CRAWFORD BILLET PIERCING APPARATUS Filled April 28, 1945 6 Sheets-Sheet 4 ATTORNEY I I JR I W 7% March 13, 1951 J. F. CRAWFORD BILLET PIERCING APPARATUS 6 Sheets-Sheet 5 Filed April 28, 1945 Mm 2 WW, QM

arch 13, 1951 J, F, CRAWFORD 2,545,229

BILLET PIERCING APPARATUS Filed April 28,- 1945 6 Sheets-Sheet 6 Patented Mar. 13, 1951 BILLET PIERCIN G APPARATUS John F. Crawford, Racine, Wis., assignor to J. I. Case Company, Racine, Wis., a corporation of Wisconsin Application April 28, 1945, Serial No. 590,896

2 Claims. (01. 789) The present invention relates to a forging apparatus, and an object thereof is to generally improve the construction of such mechanism. A further object is to provide an apparatus for forming a round forging from an angular billet. A further object is to avoid the formation of a claw-like appendage at the end of the billet. Further objects are to provide an apparatus for forming a round hollow forging from an angular billet in one heat and for causing an improved flow of metal in such a forging so as to improve the grain structure in the resulting forging. Further objects are to provide expedients for the realization of the above objects.

Other objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawings wherein a satisfactory embodiment of the invention is shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention as herein expressed.

In the drawings,

Figure 1 is a plan view partly diagrammatic in character of an apparatus.

Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1.

Fig. 3 is a horizontal sectional view onthe line 3--3 of Fig. 2 on a somewhat reduced scale.

Fig. 4 is an enlarged detail of a portion of Fig. 1.

Fig. 5 is an elevation of the portion of the machine shown in Fig. 4.

Fig. 6 is an enlarged vertical section substan tially on the line 66 of Fig. 4.

Fig. '7 is a right end elevation (enlarged) of the structure seen in Fig. 5 with parts broken away.

Fig. 8 is an enlarged vertical sectional view substantially on the line 8-8 of Fig. 5.

Fig. 9 is an enlarged vertical sectional view on the line 9-9 of Fig. 4.

Fig. 10 is an enlarged vertical sectional view on the line Ill-l0 of Fig. 8.

Fig. 11 is an enlarged plan view of certain mechanism indicated in Fig. 1.

Fig. 12 is a side elevation of the same.

Fig. 13 is a diagrammatic representation of a billet in the various stages of the operation of forming a hollow object therefrom, the various stages being designated as a to g inclusiveand parts being broken away.

Fig. 14 is an end view of the billet prior to the forming process, as indicated by the line MM in Fig. 13.

Fig. 15 is a view of the billet taken on the line l5l5 of Fig. 13.

Fig. 16 is an enlarged sectional view on the line |6 I6 of Fig. 15.

Fig. 1'7 is a view taken on the line lll 1 of Fig. 13 showing the hollow object nearly completed.

Fig. 18 is a view taken on the line l8-l8 of Fig. 13 showing the completed object.

The invention may be best understood in a preliminary way by a consideration of Fig. 1. The billets which are to be forged are heated in a furnace F, being delivered to a feed plate 25 in any suitable manner forming no part of the invention and not necessary to describe further. A gripping and handling unit generally designated as 26 is used to place the cool billets in furnace F and also to remove heated billets and place them in a pointing and descaling unit generally designated as P. The billets are cleaned of the scale acquired in the furnace, partially pointed and rolled into a substantially round or cylindrical form in the unit P and then delivered into a transferring and inverting unit T by which they are transferred to and placed within a forging die unit generally designated as D where the billet is formed into a hollow object of the desired form, in the present instance a shell blank. The several operations take place in quick succession, the elapsed time from the placing of the billet in the unit P to its removal from the unit D being commonly in the neighborhood of not more than seconds. For this reason, it is possible to perform the several operations which will be described in detail presently, while the billet retains the heat which it had when first removed from furnace F. In other words, it is unnecessary.

to reheat the billet once the cycle of operations is started. This, of course, reduces the loss of metal by oxidation and also greatly reduces the amount of handling as compared with any process in which reheating of the billet is required between the steps of the method. It is commonly more convenient for forged objects of the nature dealt with in the present invention to obtain material of angular formation, in the present instance square, the billets dealt with in this case having approximately the cross section indicated in Fig. 14, namely square with rounded corners- For making a round hollow object, the billet must be brought to a substantially round outer configuration and then pierced. The apparatus which applicant has devised will now be described in the most convenient and efiicacious manner.

The furnace F is of a well-known type having a floor 21 which rotates very slowly in the direction indicated, the temperature within the furnace being maintained at the desired high level by any well-known means not necessary to describe. Handling unit 26 is in the nature of a remote control pair of tongs having handle grips 28 and a long pole-like body 29. Portion 29 is pivotally supported from a trolley 30 freely movable on rails 3| and 32 which are to be understood to be located well above the head of an operator manipulating grips 28. Portion 29 is substantially balanced and pivotallysuspended beneath trolley 35 and has -a claw-like jaw unit 33 which can be opened and closed by suitable con; trol means in the neighborhood of grips 28. A shield 34 protects the operator from the intense radiations from within furnace F. By manipulation of grips 28, cold billets as C may be lifted by jaw 33 and placed within furnace F on floor 21. In the course of time floor 21 will have substantially completed a revolution, whereupon the billets will appear at H in a highly heated condition.

Unit 26 is also manipulated to grip heated billets and remove them from furnace F. It will be understood that suitable controls, not necessary to describe, are associated with unit 25 and that the parts aresuitably cooled by internal circulation of water, etc., so as not to be damaged by the heat of the furnace. Unit 25 is readily moved in and out and swung from side to side so as to keep furnace F charged with billets being heated and to remove heated billets as fast as necessary to supply the forging process.

It will be understood that suitable shields and the like are associated with the mechanism to protect the operators and make working conditions as comfortable as possible, most of these being omitted to avoid obscuring the essential features of the invention.

In operation the unit 26 is manipulated to pick up one of the hot billets H and is then swung to position the billet over a holder 35. Turning to Figs. 4 and 5, holder 35 comprises an upright box like receptacle which is open at both ends. Unit .25 is then manipulated to release the billet which drops into holder 35 and rests on an abutment plate 36. A retainer tongue 31 extends partially beneath the billet and serves to prevent the latter from dropping out of holder 35. Plate 35 is supported in any suitable manner, as from a frame member 38, other frame members as 39, 45, 4|, etc., being united to provide a base for supporting the several operative parts incorrect relation.

Holder 35 is carried on a swinging arm 42 pivoted at 43 on a suitable bearing carried by frame members 39 and 4|. Arm 42 may swing from the full line position of Fig. to the dotted line position therein, thereby carrying holder 35 and billet H into position for a preliminary operation.

The preliminary rounding of the billet is accomplished by forcing it through a roller set generally designated as 44 which as best seen in Fig. 7 comprises rollers 4545, journaled on pins as 45 carried in a yoke, ring or plate member 41, bushings as 48 being introduced, if desired, where the rollers run on the pins. The configuration of rollers 45 is such as to form a substantially round opening therebetween, whereby a billet forced through the space between the rollers will be compressed into substantially round form.

Billet H is forced between the rollers in the present instance by a ram 49 so that rollers 45 are rotated by contact with the moving billet. In this type of operation in the past, the rollers have displaced backwardly some of the metal of the corners which would overhang the rear face of the billet and form a pronged claw-like extension which would be objectionable. Furthermore, difficulty might be expected from resistance of the billet to entering between rollers 45." These difficulties are obviated by the use of the pointing operation above referred to.

A set of dies generally designated as 50 is 4 provided and which may be swung into and out of the path of plunger 49, for example by means of a fluid cylinder 5|. Pointing unit P includes the above mentioned dies and a pair oftension rods 52 and 55 which are united with yoke 41 by nuts 54 and 55. Rods 52 and 53 serve to hold some of the operative parts in correct relation with each other, in the present instance die member 55 being mounted on rod 53. A sleeve 55, Figs. 4 and 5 is slidably journaled on rod 53 and has a bracket portion 51 supporting a die 58 which is provided with a cavity 59, as best seen in Fig. 9. A similar die 60 is slidably supported on rods 6| and 52 supported from bracket 51 and die 59 is forced away from die 58 by springs 53 and 64. Dies 58 and 50 are therefore held apart sumciently that holder 35 with billet H therein can be introduced between them by swinging of arm 42. Bracket 51 is urged to the left as seen in Figs. 4 and 5 by a spring 65. In operation, bracket 51 is swung downwardly about rod 53 after which arm 42 is swung to the dotted position indicated in Fig. 5. Holder 35 then being horizontal, billet H will remain therein and tongue 21 will be swung upwardly about a pivot 55 by means of an abutment 56a, suitably supported on the machine. Pivot 55 passes through the horizontal portion of arm 42 and is also supported by a bracket 55b extending from arm 42, and tongue 31 has an arm 650 connected by a spring 55d to a point on arm 42. Spring 55d yieldingly maintains arm 550 against a stop 65c and thus maintains tongue 31 in position to prevent billets from passing through holder 35. When holder 35 takes the dotted position of Fig. 5, finger 31 is pushed out of the way by abutment 65a, so as to clear what was previously the lower end of holder 55. Bracket 51 is then swung upwardly by means of cylinder 51 so as to position dies 58 and 65 at opposite ends of holder 35 and billet H. Ram 45 is then advanced into contact with die 58. The resulting pressure of ram 45' compresses spring 55 and allows bracket 51 to shift into contact with ring 41 which, as above stated, is anchored to above mentioned rods 52 and 55. Pressure of ram 49 also compresses springs 63 and 54 so as to bring die 55 against one end of billet H and also to force the other end of billet H into die '58. Bracket 51 is supported by yoke 41 against further movement and the pressure of ram 4-5 accordingly presses billet H intothe cavity 55 of die 58 and into a corresponding cavity 58a in die 68. This action bevels the ends of the billet and the pressure also upsets the billet or causes it to swell somewhat with a corresponding reduction of its length. This upsetting or swelling causes most or all of the accumulation of scale, which is brittle-to break and fall off the billet. Ram 49 is then retracted whereupon die 55 is forced away from the billet by springs 53. and '54. The billet is unseated from die 58 by means of a fluid pressed cylinder 65a whereupon die set 56 is swung downwardly about rod 53 out of the way of plunger 49, leaving billet H resting in holder 35. Owing to the pointing, beveling or chamfering of the forward end of the billet, it will enter readily between rollers 45 and furthermore, if the material of the corners is forced backwardly somewhat by the rollers, it will merely fill out the corners which were chamfered by the rear die 60 so that the rear face of the billet will be approximately fiat and square after the rolling operation.

Returning to a more detailed description of the construction of the apparatus, ram 49 is actuated 8! whenever a billet is pressed into die 58.

by a plunger 68 reciprocable in a cylinder 89 supported on members 38, 39, 48, etc., and having a flange 18 in which above mentioned rods 52 and 53 are anchored as by means of nuts I! and 12. Therefore, the reaction of the pressure of ram 48 on cylinder 69 is transmitted to and counteracts the reaction in the opposite direction exerted in ring 47 by billet H passing between rollers 45. Plunger 6.8 is actuated in the present instance by hydraulic pressure from any suitable or well-known source not necessary to describe and is retracted when desired by plungers I3 and I4 reciprocable in cylinders I5 and I8. Plungers 73 and I4 connect as by pull rods IT-TI with a cross head I8 engaging plunger 68.

Arm 42 is swung by the action of a ram 19 reciprocable in a cylinder 88 and actuating a rack 8I engaging a sector 82 rotatable about pivot 43 and fixed with arm 42. A guiding device 83 maintains rack 8| in driving relation to sector 82.

Cylinder 5| is pivotally connected at 84 with a bracket 85 fixed in the present instance in relation to yoke 41 and has a bifurcated connection 88 with a portion of bracket 51. Reciprocation of portion 88 caused by cylinder 5| will therefore cause swinging of bracket 51 in a generally up-and-down direction about rod 53.

'It is to be understood that suitable piping and controls are provided for actuating the several rams in proper sequence and they are preferably provided with interlocking means in well-known manner to prevent inadvertent actuation of any one of the rams at the wrong time. These controls being well-known in general and forming no part of the present invention, it is considered unnecessary to unduly complicate the showing by describing them further.

Above mentioned cylinder 85a comprises a caplike member reciprocably fitted in a fluid-tight manner on a stationary piston 8'8 fixed in relation to bracket 51. Piston 81 is hollow and connected by means of a passageway 88 with a source of fluid under pressure, represented by a flexible connection 89. A valve 88 disposed within piston 81 is seated about an outlet port 8! and has a stem 92 fixed with cylinder 85a. Cylinder 85a extends slightlpy beyond a position flush with the face of die 58. As will be seen, pressure in passageway 88 will tend to continuously maintain cylinder 85a as far as possible to the left as seen in Fig. 9, valve 98 closing port 9| and relieving the fluid tight joint between cylinder 65a and piston 81 of pressure except when actually working. It is to be understood that the pressure of billet H into die 59 is substantially in excess of the pressure of cylinder 65a so that cylinder 85a is forced to the right causing opening of port A plurality of perforations 93 extend through cylinder 85a so as to expose the end of billet H to fluid under pressure from the interior of cylinder 650.. This fluid, commonly cold water, immediately disintegrates and washes away scale on the end of billet H. However, the water is so small in amount and the duration of the flow is so short that no material cooling of the billet is effected. The clearing of this end of the billet of scale is important since it is this end which will be exposed to the piercing punch as will appear.

In the retracting movement of arm 42 and holder 35, tongue 3'! is restored by spring 66d to position to prevent a billet from falling out of the holder when the latter is again moved.

Bracket 5! when moved downwardly, as shown in dotted lines in Fig. 6, presents a -V-shaped 6 channel 94 in the path of billet H and which serves to guide the latter between rolls 45 and to insure proper starting of the billet therein. Ram 48 is.

again advanced, this time directly against the rear surface of the billet which is forced over support 94 and between rollers 45. Any remnants of scale remaining on the corners of the billet would be forced into the surface and accordingly a plurality of scraper blades 95 is provided pivoted on plate 96 carried on above mentioned yoke 41. Blades have sharpened inserts 9'I91 which serveto scrape the corners of the billet immediately before they pass between the rollers. In this way the hot metal is substantially entirely clean when it passes between the rollers and no scale is rolled'into the material. Blades 85 are pivoted as at 98 and pulled inwardly by springs 89 so as to insure contact with the billets and allow reasonable variation in size without difficulty. Plunger 48 forces billet H entirely through yoke 41 between rollers 45, the, billet falling into a receptacle I88. It is to be noted that the end of billet H which was cleaned by fluid from perforations 93 is disposed at the bottom of the receptacle I88.

Receptacle I88 is partially open at the bottom as seen in Fig. 12 but has a lip I 8I which extends inwardly sufficiently to prevent a billet from dropping entirely through the receptacle. the major portion of the receptacle is open at the bottom as indicated. In this manner, any scale which may still be dropping from the billet is eliminated at this point. Receptacle I88 is fixed at the end of a swinging arm I82 fulcrumed at I83 on a stand I84 of any suitable construction, arm I82 being capable of swinging from the full line to the. dotted line position in Fig. 12. It is to be noted that receptacle I88, in the dotted position, is inverted in relation to its full line position. As arm I82 swings, billet H will be brought first to a horizontal position and then to an inverted position. In the progress of this movement, the billet will shift from contact with lip I8I and rest on a retaining tongue I85. Tongue I85 is swingable on a pivot I86 on receptacle I88 and controlled by,

a hand lever I87. As seen in Fig. 11, tongue I85 has been swung clear of the entrance to receptacle I88. However, when arm I82 approaches a vertical position, tongue I85, due to the preponderence of weight of lever I81 thereover, will swing to the dotted position in Fig. 11, thereby preventing billet H from dropping out of receptacle I88 prematurely. When the billet shifts away from lip I8I, it is caughtand rests against tongue I85 so as to be supported in position above a die unit generally designated as I88, constituting part of above mentioned forging die unit D. By this means, the preliminarily rounded billet is promptly transferred to a convenient position to enter die unit I88 and is inverted so that the cleaned end is uppermost in preparation for the piercing operation.

When it is desired to place the billet in die I88, lever I8! is swung to a position corresponding to that shown in Fig. 11, whereupon the billet drops out of receptacle I88 into die I88 as will be further explained. Arm I82 is then returned to the,

full line position of Fig. 12, ready to receive another. billet. As arm I82 approaches said full line position, lever I81 encounters the inclined face of a cam I88 fixed with a frame member I I8, constituting part of stand I84 and is automatically swung from the dotted to the full line position so as not to interfere with placing of another 75 i let xi. l pta ,I 11., v

However,

Arm I 92 preferably carries a counterbalance weight III tosubstan-tia-lly counteract the very considerable weight-of receptacle I-Iiuand-its-contents and. the. arm is actuated-- in the present instance bya plunger I I2: driven by fluid pressure ina cylinder II3- anchored at I -I-4- to stand H14. Plunger 2'. has aracls Il-5-engaging a gear II-6 fixed with arm I92, a guiding-device- III serving to maintain rack H5 in proper relation to gear Pressure fluid for cylinder I I3 is controlled by well-known means not necessary to: describe as forming nopart of: the present invention. Sufiicient to. say; suitable interlocking elements are provided so: as to make itv impossible for a billet Die H9 comprises a sleeve-like element supported in acasting mil-having an inwardly tapered ring: I 2 I at one end and a shoulderedring I:22 at the other.

Die H8 is supported in a casting I23 and the description-of one will sufiice for the other. ings I and W3 are slidably supported ina die carrier I24 which isoscillatable about apost I25 carried: on the bed I25 of a powerful hydraulic press-of well-known form forming nopart. of. the present-invention. The press has anupper plate on head: I21 which may be driven downwardly with heavy pressure to a predetermined point indicated in. dottedlines in Fig.2..

Thehot. billet dropped into either die. H8 or.

H9 lodges near the bottom of the die in the.

tapered ring IZI'. Die carrier I24 is then oscillated 180 from thepos-ition shown-inFig 1 until oneof dies H8 or I I9 occupies theposition shown for die I19. A ram= I28 is then moved upwardly,

as will appear, and raises billet H to a point substantiallyflush withthe top of ring I22. Head I2? thendescends and a punch I29 enters ring I22 and commences to pierce billet" H which is prevented from descending by rain I28.

The entrance of punch I 29 spreads billet H tothe extent permitted by ring I-22. This is illustrated inF-ig. 13-6. The upper end of billet H is therefore anchored to shouldered ring I22; As

head I21 continues to descend, punch I29-t'hrusts deeper into billet H, spreading the metal against die H9 and stretching the resulting sidewall downwardly between itself and shouldered ring I22. The pressure on punch I29 is resisted byram I28, pressing on the bottom of billet H to a certain point in the travel of punch I29; beyond which ram I28 descends but at a slower rate than punch I29. In this way, the pressure of punch I29 is divided between piercing and spreading the material of billet H against die I I9 and stretching the resulting side wall downwardly from shouldered ring I22. to the limit of movement possible in head I27;

the Various stages of formation of the blank being-indicatedat d, e, f and g in Fig. 13. During the course of the downward stroke of punch I29; the metal is forced intoa recess I30 in' ram I28-to-form-a centering boss on the object; Sub"- stantia-lly any desired configurationofthe object at this end can be obtainedby suitably forming ring l2I and the head I3I of ram I28; The-forg Cast- Punch I29 descends ing process is thus complete in one heating of the billet and in one stroke of the press;

Assoon as stage g, Fig. 13-, i reached, head IT! is raised. The forged object, tending to follow punch I29 encounters a ring: I32 in a stripper plate I33 anchored to bed [26. therefore forcibly withdrawn from the forging which-remains in the die. Ram I28- being in its lowered position, die carrier I24 is again oscillated until the die carrying the object is returned-- to the'loadingpoint, seen in Fig. 2". Herea ram I34 is pressed upwardly intothe die and raises the forged object substantially into the position shown in dotted lines. Any suitable means is employed to transmit the object to asuitable place to be cooled and further processed.

It will be understood that while the above=de-- scribed operations aretaking place in one die as H 8, 2; corresponding series ofoperations is taking place in die H9, one die being unloadedand again loaded during the period that ablank is'being formed in the" other die.

Punch I29 receives considerable heat from the metal being processed and cannot be used repeatedly without proper treatment. Accordingly, a plurality of additional punches I35; I36, I31, I39 and I59 is provided depending from arotat able plate I iil journaled on a' stem I4I' rigidly attached to plate I2l". The whole assembly descend 'with head I2? and after each operation,

plate I49 is rotated sufficiently to bring a new punch in line with ring I32 in stripper plate I33. In the situation shown, punch- I29 is about to perform a forging operation; Punch #35; which 1 ha just been used and is heated will descend a-t oneside of die carrier I24 into a tank or vat. I42 in which is retained a body of cooling and lubricating fluid I43. I21 immerses several of the punches in fluid I43' preparatory to a subsequent punching operation. By the time any one punch comes into positionto forge a blank, it has been thoroughly cooled and coated with the necessary lubricating material;

Plate I 38 is rotatedasbest' seen in Fig. 1 by a hydraulic cylinder I44 pivoted to. a portion of head E21; Cylinder I44 hasa ram I'45'having a pawl I48. engaging a series of notches as I41. Cylinder I44 is swung towards plate I by a spring I48.

At the conclusion of each. turning movement of plate I49, a detent I49 engages one of the several punches, being yieldably pressed there against by a spring. I59 and resting against a stop I5 I. Inthis manner, it is assured that plate I46 will. be held in the proper position for its working stroke. Detent I49 is swung outwardly by suitable or well-known mechanism to clear plate Hillin its downward movement.

Plate I 49 has a stem I5Ia reciprocable in a.

guide I52- which. is fastened to a registering plate I53. Guide I52 rests on a plate I54 supported by a. carrier I55 from stem I5'I'.. Thus. upon downward movement of head I251, plate I53 also descends to the extent permitted by stripper plate It'd Plate I53 carries a series ofpins I56 in. the presentinstance spaced equally between punches I29. I35, etc; Pins I56 shortly prior to entering of any punch into any billet H pass through registering holesas I 57 in stripper plate I33 and enter locating holes I58 in die carrier I 24. In'this manner; the dies'are accurately registered with the punches before. the punches enter the billets.

Punch I29 is Repeated'strokes of head.

Die carrier I24 is oscillated by a gear I59 engaged by a rack I60 driven by a fluid pressure cylinder I6I of well-known type not necessary to further describe.

The pressure of punch I29 both downward and upward when being removed from the forging, is very substantial. For this reason, bearings I6Ia and I62 of die carrier I24 are protected from these forces. The weight of the die carrier is supported by pressure fluid in a cylinder I63 having a piston I64 which rests on post I25. The fluid, in the present instance air, raises'die carrier I24 against stop nuts I65. Downward pressure of punch I29 overcomes the pressure in cylinder I63 until casting I20 rests on a collar I66 solidly supported on bed I26 and forming part of the mechanism of ram I3I. Thus, bearings I6I and I62 are relieved of downward pressure. When punch I29 is being pulled out of the forged object, carrier I24 is again raised by the fluid pressure against stop nuts I 55 but casting I20 is further raised until ring I22 rests against stripper plate I33 so that the upward pressure is taken by plate I33 and not by carrier I24.

Ram I28 is raised by a piston generally designated as I61 operating in a cylinder I68. Pressure fluid is supplied through a pipe I69, a continuation I10 of which extends to within a short distance of cap I3I. Pipe I10 clears a bore 11! so that pressure fluid supplied through extension I10 passes through cap I3I and returns through bore "I to the underside of piston 561. A considerable volume of fluid thus passes immediatel beneath cap I3I during rising and falling movement of ram I28. In this manner, cap I3I is prevented from overheating. Casting I is provided with grooves as I 12 to which cooling fluid, in the present instance water is supplied as for example by a hose connection I13. The fluid is confined in grooves I12 by means of a jacket I14 and passes from one groove to another, being finally exhausted through a pipe I 15. Dies II 8 and H9 are thereby prevented from being overheated and destroyed by the heat of the billet being forged.

Ram I34 has a claw-like lifting element I16 which engages the bottom of the forged object. Since the engagement with the hot forging is momentary only, element I16 is adequately cooled by the surrounding air. A slotted opening I11 is provided for connection I13 to provide freedom for raising and lowering of casting I20.

I18 is a circulating pump which keeps the fluid I43 sufiiciently agitated for effective cooling of punches I35, etc.

The operation of the mechanism is thought to be adequately clear from the foregoing description, the billet being pointed and upset in mechanism P where most of the scale drops off. It is then pressed through roller set 44, the corners being scraped by blades 95 immediately before being acted upon by the rollers. The billet is immediately inverted, by transfer unit T and placed in a forging die where it is pierced while being supported partly from beneath and partly from above by shouldered ring I22. In

this manner the complete hollow object is forged a billet and form it into a substantially cylindrical hollow object, the combination of a bed, a rotatable die element mounted on the bed, a punch, means for supporting the punch and advancing it toward the bed for piercing a billet, a plurality of dies supported by said die element and movable selectively by rotation thereof from a position registering with said punch, to a position removed from said punch, a stripper member rigid with the bed, and disposed adjacent said die element, and a locating pin movable with said punch and engageable with said stripper member and with said die element for accurately locating said die in registration with said punch preparatory to a piercing operation.

2. In a forging machine adapted to receive a billet and form it into a substantially cylindrical hollow object the combination, of a bed, a rotatable die element mounted on the bed, a punch, means for supporting the punch and advancing it toward the bed for piercing a billet, a plurality of dies supported by said die element and movable selectively by rotation thereof from a position registering with said punch to a position removed from said punch, a stripper member rigid with the bed and disposed adjacent said die element, and a plurality of spaced locating pins movable with said punch, a plurality of said pins engaging at spaced points with said stripper member and with said die element for accurately locating said die in registration with said punch preparatory to a piercing operation.

JOHN F. CRAWFORD.

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

UNITED STATES PATENTS Number Name Date 437,866 Muncaster Oct. 7, 1890 724,270 Ehrhardt Mar. 31, 1903 946,584 Smith Jan. 18, 1910 1,244,741 Johnson Oct. 30, 1917 1,244,803 Walp et a1. Oct. 30, 1917 1,604,755 Peterson Oct. 26, 1926 1,910,384 Eksergian et al. May 23, 1933 1,929,802 Brauchler Oct. 10, 1933 2,001,902 Engelbertz May 21, 1935 2,215,943 Traut Sept. 24, 1940 2,298,077 Witter Oct. 6, 1942 2,299,105 Muir Oct. 20, 1942 2,342,021 Swanson Feb. 15, 1944 2,350,425 Spalding et a1 June 6, 1944 2,368,603 Welssford et a1. Jan. 30, 1945 2,392,925 Kelleher Jan. 15, 1946

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