US2335154A

US2335154A - Device for applying back pressure to forgings in drawbench passes

Info

Publication number: US2335154A
Application number: US445798A
Authority: US
Inventors: Layton Le Roy
Original assignee: Lansdowne Steel & Iron Co
Current assignee: Lansdowne Steel & Iron Co
Priority date: 1942-06-04
Filing date: 1942-06-04
Publication date: 1943-11-23
Anticipated expiration: 1960-11-23

Description

NOV. 23, 1943. I LE RQY LAYTQN 2,335,154

DEVICE FOR APPLYING BACK PRESSURE T0 FORGINGS IN DRAW BENCH PASSES Filed "June-r4, 1942 5 Sheds-Sheet l NOV. 23, 1943.- LE R Y LAYTQN' I 2,335,154

DEVICE FOR APPLYING BACK PRESSURE TO FORGINGS IN DRAW BENCH PASSES Filed June 4. 1942 5 Sheets-Sheet 5 Nov. 23, 1943. LE ROY LAYTON 2,335,154

DEVICE FOR-APPLYING BACK PRESSURE TO FORGINGS IN DRAW BENCH PASSES Filed June 4, 1942 5 Sheets-Sheet 4 -36 Z}' 7j0 I I 'Fy' -7 V 6 F da 66' I/III/IIII/ 1 I.

I Even/Z 5} lefi lygy 71/ 01 173 J W! Nov. 23, 1943.

LE ROY LAYTON Filed June 4, 1942 DEVICE FOR APPLYING BACK PRESSURE TQ FOEGINGS IN D RAW BENCH PASSES 5 Sheets -Sheet 5 Patented Nov. 23, 1943 DEVICE FOR APPLYING BACK PRESSURE TO FORGINGS IN DRAWBENCH PASSES Le Roy Layton, Lansdowne, Pa., assignor to Lansdowne Steel & Iron Company, Morton, Pa., a corporation of Pennsylvania Application June4, 1942, Serial No.; 445,798

14 Claims.

This invention relates to a method and apparatus for improving the interior surfaces of the bottoms of the powder chambers of explosiveshell forgings.

The method and apparatus of the present :invention are particularly adaptablefor use in conjunction with the method and apparatus forfinishing forgings disclosed in my prior U. S. Letters Patent No. 2,248,002, dated July 1, 1941, andNo. 2,278,325, dated March 31, 1942. The present invention, howevenis also applicable to other forms of the so called draw benches employed in the manufacture of hollow forgings of various kinds.

The external bottom surface of .a shell forging occupies a plane at right angles to the coinciding longitudinal axes of the cylindricallbody of the forging and thev axial cavity which constitutes the powder chamber thereof; and the internal bottom of the powderchamber is usually of a concentric parabolicor other tapering form.

The parabolic bottom of the powder chamber is usually formed over a'mandrel which is forced into the primary piercing of theforging, where-.-

by this piercing eventually constitutes the pew der chamber. 1

By axial movement of the mandrel, the forging is advanced through singleor multiple ring or roll passes having throats of progressively decreasing diameters respectively. The: diameter of each threat is, to some slight degree at least, smaller than the outside diameter of the forging, whereby the metal of the forgin is radially condensed or compacted and stretched or formed over the paraboloidal nose and axially contiguous circular shank of th mandrel, which causes the internal parabolic surfaceof the bottom andthe axially contiguous cylindricalbore of the powder chamber to conform to the external surfaces of said paraba-loidal nose andcorrespondingly axial contiguous circular shank ofthe mandrel, to shape and accurately dimension the interior of the powder chamber.

The piercing tool, which. forms the primary piercing in the forging into which the'mandrelis subsequently projected in normal course'of usage, becomes pocked or grooved by abrasion, and when withdrawn from a piercing leaves small protuberances or ridges projecting from the internal surface of the piercing into the interior cavity thereof.

When the paraboloidal nose of the mandrel is inserted in the primary piercing, it engages the high spots of the protuberance's and ridges, which prevents the entire area of the internal surface of the bottom of the 1 powder chamber cavity from making complete over-all contact with the whole of the external. surface of the nose of the mandrel.

If .a ring, pass. is, employed inqthe finishing process and the diameter of the throat thereof is sufficiently smaller than the outsidewdiameter of the forging. to apply enough resistance to the advancingof the forging through saidthroatby said mandrel to flatten out the aforesaid protuberances, ridges, etc., the external bottom surface of the forging is frequently bulged fromits normal flat planar condition and in someline stances is actually perforatedby the..nose of the mandrel, under the forcerequired to advancethe forging through the throatof the ringdie.

If a roll pass is employed for finishing the forging, the possibilities of the bulging or perforating of the exterior bottom of the forging are practically eliminated, however, the protuberances remain within the powder chamber and prevent proper contact of the inner surface thereof with the nose of the mandrel.

If the throat of the roll passis excessively, decreased to apply sufficient resistance to the forward motion of the forging to eifect flattening of the protuberances by the nose of the mandrel, the parabolic bottom ofthe' powder chamber is frequently squeezed away from .and elongated-in front of the paraboloidal nose of the mandrel, as the portion of the forging lying in the crosssectional plane of 'or adjacent the extremity of the nose passes-throughthe bite of the rolls of, said pass, leaving a space between the nose of the mandrel and the bottom surface of 'thepowder chamber whichdistorts said chamber.

The principal object of the present invention is to eliminate each and all of'the aforesaid disadvantages of the finishing processesnow being employed. f 1

Another. object of. the invention. is to flatten out all of the. objactionable,protuberances, ridges, etc,- on the, interior surfacesof the powder chambers of the forgings, without bulging or perforating the shell bottoms- V 7 Another object of the inventionis to provide a fiat faced anvilfagainst which the exterior bottom surface of the shell forgings bear as said forgings are forced through the throats of. the

' ringorroll passes during, the finishing of the interior surfaces of, their powder chambers, whereby axial bulging or perforating .ofthe shellbottoms are prevented.

Another object of the inventionisto provide means for applying a predeterminedbackpressure or. resistance against the normally fiat external bottom surface of a forging, through the aforesaid anvil, to the advancing movement of the shell forging through thering orroll pass, in opposition to .the power applied to the mandrel for effecting said advancing of the shell forging.

Anotherobject of the invention is to. provide means. for controlling theback pressure applied by the anvil, and for releasing said" back presthe mandrel has advanced through the ring or roll pass.

' Another object of the invention is to provide means for projecting the back pressure anvil through the throat of a secondary ring or roll pass to the plane of initial contact of the bottom end of the shell forging with the rolls or ring forming the throat of an initial ringor roll pass.

The construction and operation of the mechanism of the present invention, in conjunction with the finishing mechanism disclosed in the aforesaid prior U. S. Letters Patent, willbe fully disclosed hereinafter, reference being had to the accompanying drawings, of which:

Fig. 1 is a side elevation of the apparatus of the present invention coupled, intandem, to the apparatus of the aforesaid Letters Patent;

Fig. 2 is an enlarged longitudinal vertical sectional elevation disclosing the back pressure mechanism in its resistance-affording position;

Fig. 3 is a viewcorresponding to Fig. 2 but showing the resistance-affording mechanism in its effective position;

Fig. 4 is a transverse sectional elevation taken on the line 4-4, Fig. 1;

Fig. 5 is a transverse sectional elevation taken on the line 5-5, Fig. 1;

Fig. 6 is a transverse sectional elevation taken on the line 6--6, Fig. 1;

Fig. '7 is a transverse sectional elevation taken on the line 1-1, Fig. 1;

Fig. 8 is a transverse sectional elevation taken on the line 8-'-8, Fig. 1;

Fig. 9 is a sectional plan view taken on the line 9-9, Fig. 1;

Fig. 10 is an end view as seen from the plane and direction indicated by the arrow-bearing line lD-Ifl, Fig. 1;

Fig. 11 is a longitudinal sectional elevation of a shell forging showingprotuberances in the powder chamber left by a pocked and scored primary piercing tool; and

Fig. 12 is a view similar to Fig. 11, but showing the irregularities in the wall of the powder chamber after being eradicated by use of the method and apparatus of the present invention.

As disclosed in the two aforementioned prior patents, and as shown in Fig. 1 of the present case, a hot primary forging 13 which has been pierced to form the powder chamber thereof, is placed in a horizontally disposed trough 9, with the longitudinal axis of the forging coaxially aligned with the longitudinal axis of the finishing tool or mandrel l0. 7

The pre-formed piercing'C is slightly greater, cross-sectionally, than the mandrel III, at substantially all corresponding cross-sectional planes of the mandrel and the forging. a

The mandrel I is advanced axially into the cavity C of the primary forming B freely and without making any substantial contact with the interior walls of the cavity, until the extreme outer end ll of the mandrel comes into contact with the extreme inner bottom end 0 of the cavity C Continued axial movement of the mandrel If! advances the forging B into the bite of a series of rolls R R having concave peripheral faces which collectively constitute the throat of a first or prelimary pass, concentric to the longi- V tudinal axis of the horizontally movable mandrel Continued axial movement of the mandrel [0 in the direction of the arrow a Fig. 1, forces the forging B through the first rolljpass, formed by the rolls R ,R. into and through the bite of a series of rolls R R which collectively constitute the throat of a second or finishing roll pass, concentric to the axis of the mandrel Ill.

The throat of the first roll pass is of slightly smaller diameter than the outside diameter of the forging B consequently, as the forging is advanced through the first roll pass, its outside diameter is reduced to that of the pass, which effects a radial contraction and compacting of the metal of theforging around the outer surface of the mandrel l0, bringing the interior surface of V the powder chamber or cavity C into close intimate contact with the outer surface of the mandrel.

The diameter of the second roll pass is very slightly smaller than the diameter of the forging after it leaves the first roll pass and acts, primarily, to reduce any fine ridges that may have been formed on the outer surface of the forging by the abutting edges of the rolls of the first pass, it being noted that, as disclosed in the prior patents, the rolls of the second pass are staggered to the extent of 90 degrees about the axis of the mandrel with respect to the rolls of the first pass.

The external normally fiat bottom b of the forging B is formed in a plane x:r at right angles to the longitudinal axis yy of the forging. The bottom I) is provided with a pad b which extends outwardly beyond the plane xr of the bottom I) and is of a smaller diameter than said bottom.

According to the present invention, when the bottom plane :ca: of the forging B advances, in the direction of the arrow a Fig. 1, to the plane XX of the'bite of the rolls R1, R of the first pass, said forging bottom 11 is engaged by a transverse flat face l2 of an anvil l5 which has been converselyadvanced in the direction of the arrow at? through the rolls R, R of the second 40 pass until the plane of the face l2 of the anvil coincides with the plane X-X of the bite of the rolls R R of the first pass;

The end face [2 of the anvil I5 is provided with a recess l3 into which the axial projection b of the forging 13 extends.

The mandrel IE] is advanced in the direction of the arrow oi under a predetermined hydraulic force of, for example, 90 tons per square inch pressure, which is opposed in the direction of the .arrow a by a back pressure of, for example, 40 tons per square inch pressure, applied to the anvil l5. Consequently, as the nose of the mandrel l0 moves into the cavity C of the forging B and engages the high spots of any protuberances, ridges or other irregularities C (Fig. 11) on the inner parabolic bottom surface of the cavity 0, continued advance of the mandrel In in the direction of the arrow a freely advances the forging into the bite of the rolls R R Further advance of the forging B by the mandrel l is then opposed by the mandrel l5.

The opposing force applied by the anvil i5 and distributed uniformly over the entire area of the external bottom surface b momentarily, stops the forging B while the mandrel NJ continues to advance. Thus, any protuberances, ridges, or other irregularities encountered in the bottom 0 of the cavity C are flattened out by the paraboloidal end ll of the mandrel I0.

After flattening of any protuberances ,etc. encountered in the base 0 of thecavity C the pressure exerted in the direction of the arrow (1 by the mandrel l0 overcomes the pressure exerted in the direction of the arrow a? by the an vii I5, and the anvil I5 is caused to recede as a result of the greater advancing force supplied to the forging B by the mandrel l while'the opposing pressure exerted by the anvil is continued until the tapering or paraboloidical end of the mandrel l0, and the correspondingly shaped cavity C of the forging B from the end b to the cross-sectional plane az thereof have passed through the bite of the rolls R R whereupon, the back pressure applied by the anvil |5 is released and nofurther resistance to the normal advance of the forging B through the rolls R R and R R by the mandrel I0 is presented.

The forging B is advanced by the mandrel I8 until the rear or open end b of the forginghas passed through and beyond the housing |6 in which the rolls R R are rotatably mounted, and beyond a stripper plate |8 which is slidably mounted in guides I1, I! on the rear end of the housing l6. After the forging B has passed completely beyond the stripper plate I8, said stripper plate is moved transversely into the path traversed by the forging, to form an abutment forthe end I) of the forging, after which, reversal of the direction of the movement of the mandrel lllcauses'the rear end b of the forging B to engage the stripper plate l8, thereby forcing the forging off the mandrel I8 as said mandrel returns to its normal position beyond the front end trough 9, for the beginning of another cycle.

In the present instance, the anvil I5 is removably mounted onone end of a horizontally operable ram 28. The anvil I5 is provided with a threaded axial extension |5a which is screwed into a threaded cavity formed in one end of the ram 28.

The ram also includes a rearwardly extending cylindrical end 2|, of a diameter suitable for passage through the throat formed by the rolls R R and a rectangular cross-head section 22 which is slidably mounted in a lower guideway 23a and an upper guideway 23b.

The cylindrical section 2| of the ram 28 is interchangeably mounted on one end of the crosshead 22 by an axial threaded projection 21a screwed into a correspondingly threaded bore in the-cross-head 22.

The rear end section 24 of the ram 20, like the anvil I5 is removably connected to said ram'by an axial threaded projection 24a screwed into a correspondingly threaded bore in the rectangular cross-head 22 of the ram2il.

The forward end face iii of the ram 26 is adapted to be engaged by a roller 25, which is rotatably mounted in a forked end of one arm of a triangular or bell crank lever 26. The bell crank lever 26 is pivctaliy mounted on a shaft 21, between a pair of laterally spaced

uprights

28, 28. The second arm of the bell crank lever 26 is'forged and provided with a roller 29 which is'engaged by the lower end of a vertically moving plunger 38. The plunger 36 is slidably mounted in a vertical cylinder 3| having a base 32 which is secured to the upper ends ofthe'uprights 28, 28, as by bolts 33.

Fluid pressure is admitted to the upper end of the cylinder 3| through a pipe 34, from a source capable of producing a force of 40 tons per square inch against the rear end I9 of the ram 28, through the bell crank lever 26.

,Axially aligned with, and superposed on, the cylinder 3| is a return cylinder 35, in which is slidably mounted a vertically movable plunger 36; The upper end of the plunger 36 is provided with .a'- cross-head 31 which (is rigidly-uconnectedto a cross-head38 on the lower end. of theplunger38 by a pair of

tie rods

39,39.

The cylinder 35 is connected to a constant source of uniform pneumatic pressure, by a conduit 48, which at all times admits fluid under pressure to the lower end of the plunger 36;within-cylinder'35, and opposes the downward movement of the plungerfill by fluid pressure admitted to thelcylinder 3| through the conduit 34.

As soon as the-mandrel I8 has moved the forging B through the throat of the roll pass formed by the rolls R R and when the transverse plane z2! of the forging substantially coincideswith the plane XX of the bite of the rolls R R the fluid supply to the cylinder 3| through the conduit 34 is manually or automatically cut off and permitted to exhaust by the reverse movement through the conduit 34, whereupon, the constant-uniform pressure entering the lower end of the cylinder 35 through the conduit 48 returns the plunger 30 to its upper or normal inactive position shown in Fig. .3.

Further advancing movement of the forging 12. by the mandrel m slides the ram in its guideways 23a23b until the rear end IQ of said ram-engages a resilient buffer 4|, which brakes the accelerated forward movement of the forge ing B which takes place whenthe rear end 12 of the forging B leaves the bite of the rolls R R The buffer head 4| is provided with a stem 42 which is slidably mounted in a cross member 43 located at the rear end of the guideway 2311-23?) for the ram 20. The rear end of said stem 42 is-slidably. mounted in a buffer plate 44. The stem'42 of the buffer 4| is provided with an adjustable flanged nut45 between which and the buffer plate 44 is mounted the buffer spring 46.

The anvil I5- is projected through the throat of the pass formed by the rolls R R and into the throat of the pass formed by the rolls R ,.R inthe-present instance, by one or the other of a pair of

dogs

41, 41 which are carried by an endless chain 48. Therear face I9 of the ram 28 isprovided with a recess 43 into which one of the dogs 4! enters and slides the ram 25 and anvil 15 along the guideway 2311-2319, in the direction of the arrow 03, until the roller 25 on the bell crank lever 26, which,.during said sliding of the ram 20 travelsalong the top of the ram 28, rides down and against the rear end l9 of the ram.

Thechain 48 at the

uprights

28,28, is seated in acircumferential groove 58 formed inthe face ofa roller 5|, which is rotatably mounted, between said uprights, on a shaft 52 having its opposite ends journaled in a bearing formed in or carried by a pair of

brackets

56, 56 secured to the

uprights

28, 28.

Between the grooved wheel 5| and the rear end of the guideway 23a23b for the ram 20, the chain 48 rides in a circumferential groove 53 formed ina second wheel 54 which is rotatably mounted on a shaft 55 having its opposite ends journaled in or carried by said pair of

brackets

56, 56 which are secured to the

uprights

28,28.

The outer peripheral surfaces of the grooved wheels. 5| and 54 serve to support the rear end of the cross-head22 which is projected beyond the rear end of the cross-head guide 23a when the cylindrical end 2| and anvil l5 of the ram 20. are projected into and through the throat formed by the rolls R R The uprights 28, 28 are spaced from and rigidlyisecuredtotheframe 6, which houses=the pass rolls R R ,'by.2 a pair .of upper laterally spaced stringers 5'5, 51, and by a lower stringer bolt 58. The rear end of the bolt 58 is anchored in a spacing member 59 supported by and between the uprightsZS, 28 and to which said spacing member is secured by a series of bolts or rivets 60, 60. over-hanging end of the base 32 of the cylinder 3| is supported by means of angular braces 6|, 6| which are secured at their one end to the uprights 28 by

bolts

62, 62, and at their opposite end to the base 32 by bolts or rivets 63, 63. a

The buffer block 43 is supported by a pair of laterally spaced uprights 6 3, 64. The

uprights

64, 64 are secured to and spaced from

theuprights

28, 28 by a pair .of upper horizontally extending tie bolts 66 and a pair of lower horizontally-extending tie bolts 61, 6'5. The buffer plate plate A l is secured to the rear sides of the uprights 64 by the

tie rods

66, 66 and 61, 61.

The upper. guideway 23b, for the ram 28, is provided with transversely extending

arms

68, 68 which are mounted on the

tie bolts

66, 66 and the lower guideway 23a is provided with a pair of transversely extending

arms

66, 69 which are supported by the lower tie bolts 67!, 6'l. The lower guideway 23a. is provided with a longitudinal groove 16, in which the chain 46 travels beneath the ram 26. 1

The end of the chain 48 adjacent the

uprights

64, 64, passes around a sprocket 70 whic is secured to a transverse shaft Ii, intermediate a pair of brackets 12, ;l2, which are respectively secured to the uprights 65, 6*: by bolts 73, 13. The shaft 7! is rotatably mounted in the brackets 12 and is. provided with a hand wheel 15, by which the chain 48 may be operated to move the ram 26 and anvil I5 in the direction of the arrow (2?, and into position to backup a forging advanced into the bite of the rolls R R by the mandrel I0.

As shown in Fig. 4, the bell crank lever 26 is formed of three rigidly connected parts including a pair of

outside members

26a, 26a, and an intermediate member 261), with all three parts rigidly secured together by rivets etc. The intermediate member 2611 is provided with recesses Tl and 18 in which the rollers and 29, respectively, rotate.

'The lower end of the plunger 36 is provided with an interchangeable insert 19 against which the roller 29 of the bell crank lever 26 rides, for replacement in case of excessive wear resulting from the heavy pressure transmitted thereby.

The cylindrical section 2i and anvil l5 are. interchangeably mounted in the ram 26 for changing in accordance with changes in the diameters of the forging being worked by the apparatus and corresponding variations in the diameters of the throats of the passes R R and R R While the shape of the bottom of the cavityC has herein been described as being parabolic and the shape of the nose of the mandrel l0 has herein been described as being paraboloidal, it will be understood that the bottom of the cavity and the nose of the mandrel may be of a frustoconical or tapering shape without departing from The to receive any of the well known explosives com monly employed in high explosive shells.

I claim: a

1. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, means engageable with the exterior bottom surface of the forging for resiliently opposing initial axial movement of the forging through said pass by said mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than'the full length of the forging through said pass.

2. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, means including an anvil engageable with the exterior bottom surface of the forging for resiliently opposing initial axial movement of the forging through said pass by said mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than the full length of the forging through said pass.

3. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, an anvil engageable with the exterior bottom surface of the forging, means for applying a predetermined force to said anvil for resiliently opposing initial axial movement of the forging through said pass by said mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than the full length of the forging through said pass.

4. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, an anvil engageable with the exterior bottom surface of the forging, a ram axially aligned with said mandrel and supporting said anvil, means for applying a predetermined force to said ram for resiliently opposing initial axial movement of the forging through said pass bysaid mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than the full length of the forging through said pass.

5. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface ofa hollow forging to force the forging completely through said pass, an anvil engageable with the exterior bottom surface of the forging, a ram axially aligned with said mandrel and supporting said anvil, means for applying a predetermined force to said ram including a plunger operable in one direction in a cylinder under fluid pressure for resiliently opposing initial axial movement of the forging through said pass by said mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than the full length of the forging through said pass.

6. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, an anvil engageable with the exterior bottom surface of the forging, a ram axially aligned with said mandrel and supporting said anvil, means for applying a predetermined force to said ram including a plunger disposed at an angle to the axis of said ram and operable in one direction in a cylinder under fluid pressure, and a bell crank lever operable between said plunger and said ram for resiliently opposing initial axial movement of the forging through said pass by said mandrel.

7. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, an anvil engageable with the exterior bottom surface of the forging, a ram axially aligned with said mandrel and supporting said anvil, means for applying a predetermined force to said ram including a plunger operable in one direction in a cylinder under fluid pressure for resiliently opposing initial axial movement of the forging through said pass by said mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than the full length of the forging through said pass, and means constantly opposing said movement of said plunger in said one direction resiliently for moving said plunger reversely upon discontinuance of said fluid pressure to said cylinder.

8. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, an anvil engageable with the exterior bottom surface of the forging, a ram axially aligned with said mandrel and supporting said anvil, means for moving said ram in one direction to apply a predetermined force to said ram for resiliently opposing initial axial movement of the forging through said pass by said mandrel, and means for rendering said opposing means ineffective after said mandrel has advanced said forging a distance less than the full length of the forging through said pass, and a buffer engageable by said ram to check movement thereof in the opposite direction when said force is released.

9. A forging apparatus, comprising a pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging through said pass, an anvil engageable with the exterior bottom surface of the forging, a ram axially aligned with said mandrel and supporting said anvil, means including a bell crank lever pivoted adjacent the path of movement of said ram and having one arm engageable with a transversely extending face of said ram for applying a predetermined force to said ram for resiliently opposing initial axial movement of the forging through said pass by said mandrel, said arm being movable out of the path of said ram upon predetermined partial movement of said forging through said pass by said mandrel and means for moving said ram into position for engagement by said bell crank and said forging prior to the application of said of said force to said ram.

10. A forging apparatus, comprising a pass, a guideway beyond one end of said pass, a mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, a ram axially aligned with said mandrel and engageable with the exterior bottom surface of the forging for resiliently opposing initial axial movement of the forging through said pass by said mandrel, said ram including a cross-head slidably mounted in said guideway, and a cylindrical portion movable into said pass to engage said exterior end of said forging.

11. A forging apparatus, comprising a pass, a horizontal guideway beyond one end of said pass, a horizontal mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, a ram slidably mounted in said guideway in axial alignment with said mandrel and engageable with the exterior bottom surface of the forging, a vertically movable plunger operable in one direction in a vertically disposed cylinder under fluid pressure, and a bell crank lever having one arm engageable by said plunger and a second arm engageable with said ram for resiliently opposing initial axial movement of the forging through said pass by said mandrel.

12. A forging apparatus, comprising a horizontal pass, a horizontal guideway, a horizontally movable mandrel engageable with the interior bottom surface of a hollow forging to force the forging completely through said pass, a horizontally movable ram slidably mounted in said guideway in axial alignment with said mandrel and engageable with the exterior bottom surface of the forging, and means for applying a predetermined force to said ram, including a vertically operable plunger operable in one direction in a vertically disposed cylinder under fluid pressure, and a bell crank lever transmitting said force from said plunger to said ram for resiliently opposing initial axial movement of the forging through said pass by said mandrel.

13. A forging apparatus, comprising a horizontal pass, a horizontal guideway, a horizontally movable mandrel engageable with the interior bottom surface of a hollow forging to force the forging through said pass, a horizontally movable ram slidably mounted in said guideway in axial alignment with said mandrel and engageable with the exterior bottom surface of the forging, and means for applying a predetermined force to said ram, including a vertically operable plunger operable in one direction in a vertically disposed cylinder under fluid pressure, a bell crank lever transmitting said force from said plunger to said ram for resiliently opposing initial axial movement of the forging through said pass by said mandrel, a constant pressure cylinder superposed on and axially aligned with said vertically disposed cylinder, a plunger operable in said superposed cylinder in opposition to said vertically operable cylinder, a cross-head on each plunger, and tie rods operably connecting said cross-heads outside said cylinders.

14. The method which comprises inserting a shaping mandrel in a cavity of a hollow forging for engagement with the interior bottom surface of the hollow forging, applying a predetermined force to said mandrel for pushing said forging in one axial direction through the throat of a reducing pass, and applying a lesser counterdirectional force to the exterior bottom surface of said forging for resiliently opposing initial axial movement of the forging through said pass by said mandrel to insure full surface engagement between said mandrel and the surrounding wall of said cavity and discontinuing said counter-directional force after a predetermined partial movement of the forging through said pass has been effected.

LE ROY LAYTON.