US3577759A

US3577759A - Method of and apparatus for preparing copper and brass billets for extrusion into hollow shells

Info

Publication number: US3577759A
Application number: US712857A
Authority: US
Inventors: Paul Tandler; Ellis R Blackwell
Original assignee: Cerro Corp
Current assignee: Marmon Group Inc
Priority date: 1968-03-13
Filing date: 1968-03-13
Publication date: 1971-05-04
Anticipated expiration: 1988-05-04
Also published as: GB1205107A; DE1903475A1

Abstract

This invention is concerned with a prepiercing and scalping method, in which the billet is precompressed, pierced and scalped, in a substantially continuous closely controlled operation, in a single press, for the purpose of preparing the billet for subsequent extrusion in an extrusion press. The method is designed to prevent distortion or deflection of the piercing mandrel, prevent the wear and tear encountered in the conventional extrusion cycle, and to save time. Provision is made for removal of the slug or breakout resulting from the prepiercing operation, as well as to sever the scalped material into easily removable segments or parts. The invention is further concerned with a press of novel construction for performing the method.

Description

United States Patent [72] Inventors Paul Tandler Clayton, Mo.; Ellis R. Blackwell, East St. Louis, ll]. [21] Appl. No. 712,857 [22] Filed Mar. 13, 1968 [45] Patented May 4, 1971 [73] Assignee Cerro Corporation New York, N.Y.

[54] METHOD OF AND APPARATUS FOR PREPARING COPPER AND BRASS BILLETS FOR EXTRUSION INTO HOLLOW SHELLS 13 Claims, 30 Drawing Figs.

[52] US. Cl 72/254, 90/24 [51] Int. Cl B2lc 23/01 [50] Field ot'Search 207/1021; 72/253, 254,40, 4]; 90/24.0l

[56] References Cited UNITED STATES PATENTS 2,688,400 9/ 1954 Ansel 72/ 154 3,187,531 6/1965 Cairns 72/254X Primary Examiner-Richard .l. Herbst An0rney-lsler and Ornstein ABSTRACT: This invention is concerned with a prepiercing and scalping method, in which the billet is precompressed, pierced and scalped, in a substantially continuous closely controlled operation, in a single press, for the purpose of preparing the billet for subsequent extrusion in an extrusion press. The method is designed to prevent distortion or deflection of the piercing mandrel, prevent the wear and tear encountered in the conventional extrusion cycle, and to save time. Provision is made for removal of the slug or breakout resulting from the prepiercing operation, as well as to sever the scalped material into easily removable segments or parts. The invention is further concerned with a press of novel construction for performing the method.

INVENTORS PAULITANDLER BY ELLIS R. BLACKWELL ATTORNEYS PATENTEU MAY 41% 3577759 SHiET 02 [IF I 1 INVENTORS PAUL TANDLER y I ELLIS R. BLACKWELL ATTORNEYS INVENTORS PAUL TANDLER ELLIS R. BLAcKwELL Sum; us 'nr v7l h w PATENT-ED am 41911 vm mv ww we R i y mm on s\ v a; im m WM\\\.\ ll H wmvlr I ATTORNEYS PATENTEDNAY 4m: $577,759

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mvemons PAUL TANDLER BY ELLIS R. BLACKWELL ATTORNEYS PATENTEUMAY 4mm 3 577,759

SHEET [17oF 11 I loz o r S 'mvzu'roas PAUL TANDLER Fig". ELLIS R. BLACKWELL ATTORNEYS PATENTEDHAYMBYI $577,759

SHEET near 11 INVENTORS PAUL TANDLER BY ELLIS R. BLACKWELL ATTORNEYS PATENIEDMAY 4mm 3,577,759

SHEET'USUF 11 Fig. /5 Fig. 1

INVBNTGRS PAUL TANDLER BY ELLIS R. BLACKWELL JMLM ATTORNEYS METHOD OF AND APPARATUS FOR PREPARING COPPER AND BRASS BILLETS FOR EXTRUSION INTO HOLLOW SHELLS This invention relates generally toarnethod of and apparatus for preparing-copper or brass billets for extrusion into hollow shells. j In the conventional extrusion process, as shown, for cxample, in Cairns, US. Pat. No. 3,172,536, the billet is placed, in the extrusion press container and is precompressed ,or upset by the main ram of the press, after which the billet is pierced by a piercing mandrel which is so positionedinthe extrusion die as to form an annular space through which metal of the pierced billet flows or extruded, thereby forming a hollow shell or tube. I V I In some cases, the billet is scalped in a separate operation, prior to piercing and extrusion, for the purpose of removing surface impuritiesor defects and/or sizing the billet to a,

desired external diameter.

In such conventional extrusion methods, the method of piercing causes deflection of the piercing mandrel, resulting in an eccentric positioning of the mandrel with respect to the extrusion die, producing an extmded'shellor tube in which the inner and outer surfaces are in eccentric relation to each other.

Moreover, in all'cases where the billets are scalped prior to extrusion, the scalping does not corrector ameliorate the cocentric relationship to which reference been 'made, and this is particularly so because the scalping is not carried out in conjunction with or in a controlled correlationwith the piercing operation, that is to say, no control over or correlation is assured between the scalping and piercing operations.

Finally, in such conventional extrusion methods, the piercing mandrel of the extrusion press is subjected to the considerable wear and tear of normal operations, requiring frequent repair or'replaceme'nt, the overall extrusion cycle is time consuming, and a heavy expenditure or hydraulic power in the operation oft he extrusion press is required. t

The present invention has, as its primary object, the provision of a method of'preparing billets for extrusion, in'which a much closer control over the piercing operation isexercised than in a conventional extrusion cycle, whereby deflection of the piercing mandrel is eliminated, and production of a shellor tube of accurate conformation is assured.

Another object of the invention is to provide a method of the character described, in which the billet is prepierced in a press substantially smaller than a conventional extrusion press, and having easily adjustable alignment of its parts, and wherein no extrusion is accomplished, thereby sparing the mandrel of the extrusion press from the wear and tear of normal extrusion operations. i

A further objectof the invention is to providea method of the character described,- in which the billetis scalped inthe line 7-7 of FIG. 6;

rows ems/tor FIG. 8';

' 9-9 of FIG. 2;

FIG. 3C is a fragmentary topplan view of the rear portion of the mandrel holder, and showing the manner in which .it is connected to the mandrelcrosshead;

, FI G 4 is a vertical cross-sectional view, taken on the line 1" Y; t a v -.FIG. 5 istavertical cross-sectional view, taken on the line 5-5 of.FIG.2;,- I H ,FIGJS isa yerti'cal cross-sectional view, taken on theline FlG.;-7-is a fragmentary cross-sectional view, taken on the FIG. 8 is a vertical cross-sectional view, taken on the line 88ofFIG.2; 2 FIG. 8A is a view taken in the direction indicated by the ar- FIG. 8B is a cross-sectional view, taken on the line 83438 of FIG. 8A; FIG. 8C is a cross-sectional view, taken on the lineSC-SC ofFIGQBA; H

FIG. 9 is a vertical cross-sectional view,- taken on thehne FIG..I0 isa vertical cross sectional view,. taken orI-the line 10-10 of FIG. 2, but with the gate lock in elevated position;;

FIG.. I1 .is-a fragmentary cross-sectional view, taken on the line 11-41! of FIG. I;

trolled correlation with the piercing operation; thereby insur ing that the scalped billet is in proper condition for the extrusion operation.

Other objects and advantages of our inventionwill be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

FIG. I is a fragmentary top plan view of a prepiercing and scalping press embodying the invention;

FIG. 12 is afragmentary front: elevational view, on an enlarged scale, of the scalping die'platen, scalping'die holder and. scalpingdie; 1 t j' 3 j FIG. 13 isra fragmentary. cross-sectional view,;taken on the line 13-13 of-FIG. 12;1: 1:.

FIG. 14 is an end view of. one of the-slitting knives for the scalped material? FIG. His a FIG. 14;

FIG. 16 is FIG. 17 Ba view illustrating'in a more or=lessdiagrammatic manner, the first-step infthe' sequence of operations of the press, and FIGS. 18, 19,20, 21, 22,23 arid 24'il-lust'ratejalso, in a more or less diagrammatic"'mannerjsuccessive subsequent steps'in the sequenceofoperations of the press, constituting a complete cycle of operations. i j

Referring more particularly to FIGS. 1 to 16 inclusive of the drawings, the press which will presently'be'd'escribed in detail is mounted on a support "bas e'of'welded' steel construction generally designated'fby referenc' numeral lfa'ndwhichconk sists of "longitudinally spaced transversely extending pads 2 having transversely extending channelmem'brs 3 mounted thereoh', lohgitudinally extending support channel members 4 secured to the ends "members arid'a longitudinallyic tending m'er'riber' st-scenes. 5,6an d 10 mounted an the members 3 centrally thereof? and having a keyway tithe'rein'. Support plates 7 (FIG. 5 are mounted on the channel members 4, and wear plates 8 (FIG. =5), preferably of a wear-resisting alloy, are secured to the support plates 7.

For the purpose of facilitating the description of the press, the various units or elements'thereof will be described with reference to those views in which they are best illustrated.

" FIXED PLATEN The fixed platen is shown most clearly in FIGS. 2 and 4, and comprises a plate I0 which is located at one end of the base 1, asbykeys II.

The plate 10 is provided with openings 12, through which the reducedends 13 of tie rodsl4 extend,and to which nuts I5 are secured.

The plate 10 is also provided with vertically spaced openings I6 throughwhich cylinders'17 extend, these cylinders having heads I8 which are bolted to the forward face'of theplate 10. The pistons of thesecylinders are indicated by reference numeral}? in FIG. 4.

front elevational viewbf the 'slitting k'nife' of The cylinders", which are utilized for movement of the movable platen to be presently described, are preferably Sheffer hydraulic cylinders Style FF-UH Series, having a lO-inch bore, a 7-inch rod and a 74-inch stroke.

The plate 10 is further provided in its sides with recesses 20, which accommodate the passage therethrough of cylinders 21 having pistons 22. The cylinders 21 are preferably Sheffer" hydraulic cylinders Style FF-UH Series, having a lO-inch bore, a 7-inch rod, and a 28-inch stroke. The function of these cylinders will be presently described.

MOVABLE PLATEN The movable platen of the press is shown most clearly in FIGS. 1, 2, 3, 5, 6 and 7 of the drawings, and is mounted forwardly of the fixed platen, for slidable movement along the base.

This platen comprises a substantially rectangular plate 23, of substantial thickness, having a central bore or passageway 24, which terminates at its forward end in a counterbore 25, for a purpose to be presently described.

The plate 23 is provided centrally thereof adjacent its upper and lower edges with

circular recesses

26 and 27 extending into the rear of the plate, which receive the forward ends of anchor pads 28 (-FIG. 5) which are secured to the plate 23 by means of bolts 29. The forward ends of the piston rods 30 of the cylinders 17 are secured to the anchor pads 28.

The plate 23 is also provided with bores 31 and 32 (FIGS. 6 and 7) which extend through the plate at points spaced equidistantly laterally from the bore 24 and have their axes coplanar with the axis of the bore 24.

The cylinders 21 are secured, as by bolts 33, to the rear face of the plate 23 in alignment with the bores 31 and 32, and the piston rods 34 of these cylinders extend into the bores 31 and 32.

The plate 23 is further provided adjacent its corners with bores or passageways 35 (FIG. 7).

Welded to the plate 23 in axial alignment with the bores 35, at the rear face of the plate, are cylindrical bushings 36, and

, welded to the plate 23 in alignment with the bores 35, at the other face of the plate, are cylindrical bushings 37. The tie rods 14 extend'through the

bushings

36 and 37 and bores 35, as best seen in FIG. 7.

For the purpose of leveling or adjusting the position of the movable platen, the

bushings

36 and 37 are mounted on support pad housings 38 (FIGS. 2, 5, 6 and 7) having inclined lower surfaces 39 (FIGS. 5 and 7) which rest on similarly inclined surfaces .40 of slide locks 41. By moving the blocks 41 longitudinally relatively to the housings 38, the positions of the housings 38 may be adjusted vertically. Any desired means may be employed for moving the blocks 41 and for then locking the parts in adjusted position.

STEM, MANDREL HOLDER, AND MANDREL ASSEMBLY The stem, mandrel holder and mandrel assembly, as well as the manner in which this assembly is mounted on the movable platen, is best seen in FIGS. 1, 2, 3, 3A, 3B, 3C, 6 and 7.

The stem or ram designated by reference numeral 42, comprises an elongated cylindrical member having an axial bore 43 in its forward, portion, which is counterbored, as at 44, to provide a recess which is threaded to receive the stem 45 of a nosepiece 46 for the stem 42, this nosepiece having an axial bore 47, in which is slidably mounted the forward end of a piercing mandrel 48.

Rearwardly of the bore 43, the stem 42 is formed to provide a diametrically extending horizontal slot, defined by upper and

lower walls

49 and 50 respectively.

The stem 42 has secured at its rear end, above the wall 49, a mounting plate 51, and has secured thereto at its rear end, below the wall 50, a second mounting plate 52, the plates being bolted-to the. front face of the plate 23 of the movable platen, whereby to secure the stem to the platen in axial alignment with the counterbore 25. The counterbore 25, to which v reference has previously been made, provides a circular recess to receive extensions 51a and 52a of the mounting

plates

51 and 52 respectively, as well as a tie plate 53 which interconnects the

plates

51 and 52.

A mandrel holder 54 is provided having its forward end slidably mounted in the bore 43 of the stem 42 and has an internally threaded socket 55 at its forward end, in which the rear end of the mandrel 48 is secured, the mandrel having an annular flange 56 which abuts the front end of the socket 55, and which is slidable in the bore 43 0f the stem 42.

The mandrel holder 54 is provided at its rear end with a transversely extending head 57, which is movable along the slot defined by the

walls

49 and 50. The head 57 is secured, as by bolts 58, to a cross head 59, which extends transversely through the aforesaid slot, and is provided on its upper and lower surfaces with wear plates 60 which are slidable along the

walls

49 and 50. The crosshead 59 is provided at its ends with internally threaded sockets 61, which are spaced apart for axial alignment with the bores 31 and 32 of the plate 23, and extend into the latter, as best seen in FIG. 7. The sockets 61 are threadedly secured to the forward ends of the piston rods 34.

For the purpose of cooling the piercing mandrel 48 and its holder 54, the head 57 of the mandrel holder is provided with parallel

horizontal passageways

62 and 63, the passageway 62 communicating with a vertical passageway 64, which is closed at its upper end by a plug 65, and the passageway 63 communicating with a vertical passageway-66, which is closed at its upper end by a plug 67. V

The passageway 64 communicates with a passageway 68 in the holder 54, which, in turn, communicates with a passageway 69 in the piercing mandrel 48; The passageway 69 is closed at its forward end, so that a cooling fluid, such as water, enters the

passageways

64, 68 and 69 and flows through a pipe 70 which extends through the

passageways

64, 68 and 69 and has its rearend threadedly secured to the mandrel holder 54, as at 71. Fluid from the pipe 70 enters a chamber 72 in the mandrel holder which is closed at its rear by a plug 73, and passes from this chamber to the

passageways

66 and 63.

MEANS FOR ACTUATING THE STEM MEANS FOR ACI'UATING THE MANDREL ASSEMBLY The actuation of the mandrel assembly is effected by the cylinders 21, through their piston rods 34, which, as previously described, are connected to the sockets 61 of the crosshead 59 of the mandrel assembly.

BILLET CRADLE The billet cradle is best seen in FIGS. 1, 2, 8, 8A, 8B, and 8C of the drawings, and consistsrof laterally spaced

baseplates

74 and 75 which are mounted on the channel members 3, Iongitudinally spaced uprights 76 and 77, which are welded to the

plates

74 and 75, and

base pads

78 and 79, which are welded to the upper edges of the

plates

74 and 75, and are disposed at an angle of 90 to each other.

The cradle further includes spaced

uprights

80 and 81,

' which interconnect the uprights 76 and 77 and an inverted V- openings 86 in the

base pads

78 and 79, and are secured against displacement from these pads by means of nuts 87 secured to the lower ends of the studs 85. Y

The

pads

83 and 84 are adjustable relatively to the

pads

78 and 79 by means of push bolts 88 which are threadedly secured in the

pads

78 and 79 and which bear against the lower surfaces of the

pads

83 and 84. It will be understood that after this adjustment has been made, the nuts 87 are drawn up against the

pads

78 and 79 to lock the

pads

83 and 84 in adjustcd position. The

pads

83 and 84 are provided attheir ends with guide plates 89 which abut the

pads

78 and 79 and thus act to guide the

pads

83 and 84 during the adjustment.

Angle members 90 ar'e secured to the

pads

78 and 79 in abutment with the

pads

83 and 84, by means of bolts 91,

and serve as dirt deflectors to prevent dirt and scale from accumulating under the

pads

83 and 84.

FORMING PLATEN AND BILLET CONTAINER The press further includes a forming platen and billet container, which is best seen in FIGS. 1, 2, 9 and 11, and cominto flange96, and by means of bolts 106 which pass through unthread 'ed openings in the pad. 101 and are threaded into the wall of the container 94-. Y

The circumferentially spaced. passageways or bores 107 (FIGS. 9 and ll) in the container 94 are adapted to receive heating elements (not shown) which may be installed for preheating the container, if such preheating is desired.

As shown in FIGSI9 and 11, the plate 92 is provided adjacent its corners with openings 108 through which pass threaded portions of the tie rods 14, the tie rods being secured to-the plate 92 by means of

nuts

109 and 110 which are mounted on these threaded portions of the tie rods.

'SCALPING DIE PLATEN AND DIE the gate lock to be presentlydescribed, but which is posiprises a plate 92 of generallyrectangularconfiguration and substantial thickness.

- The plate 92 has a circular opening 93 therein through which a billet container 94 extends, which container has a cylindrical outer surface and a conical inner wall 95,- that is to say, this wall 95 decreases slightly in diameter from its right end, as viewed in FIG. 11, to its left end. This taper of the wall 95 is to facilitate insertion, as by a press fit, into the container of a removable alloy steel liner (94a), having an outer 'wall of a taper corresponding to that of the wall 95, and an inner wall of a diameter corresponding to the diameter of the billet, e.g.,

about 1 H4 inches to 12 inches, to be received in the liner.

' The container 94 is provided with an annular collar or flange 96, which may be formed integrally with the container or welded thereto, this flange being in abutment with the plate 92, and secured to the plate by means of bolts 97.

The billet container 94 does not have a slide fit in the opening 93, but, instead, has an outside diameter slightly smaller than the diameter of the opening 93, so that the billet container can be adjusted, by means to be now described,.for-the purpose of aligning the alloy steel liner therein axially with the mandrel assembly.

For this purpose, the front wall of the plate 92 is provided at points spaced circumferentially thereabout with a center adjusting pad 98 and angular adjusting pads 99, which pads are welded to the Iate'Adjusting screws or bolts (not shown) are mounted in threaded openings 100 in these pads, with their stems bearing against the periphery of the flange 96, whereby adjustment of these screws or bolts in the pads enables the position of the billet container to be adjusted.

Similarly, the rear wall of the plate 92 is provided at points spaced circumferentially thereabout with a

center adjusting pads

98 and 99, enables the position of the billet container to be adjusted;

It may be noted that the openings 104 in the flange 96 through which the bolts 97 pass are of slightly larger diameter than the diameter of the bolts 97, so that the adjustment'which .has been described may be made without removal of the bolts from the plate 92. After the adjustment has been made, the

bolts 97 may be tightened.

After the adjustment has been made, the container is fixed in position or stabilized by means of bolts 105 which pass through unthreaded openings in the pad 98 and are threaded tioned between the forming. platen 92and the scalping die platen. v

' The scalping die platen and die is best seen in FIGS. 1, 2, 10, 11,12, 13,14, 15and l6. v I I It comprises a plate 111 of substantially rectangular configuration, and is mounted on the base between pads 112 and 113, constitutingstops, and which are-welded to the base. Adjustable'leveling blocks 111a (FIGS. 10 and 11) are used to ,level or adjust the position of the plate 111 vertically. Adjustment of the plate 111 transversely is accomplished by screws Illb (FIG. 10') mounted in an adjustment bracket lllc secured to the plate 111. These screws are providedwith buttons 111d which bear against a key ll-le mounted in the keyway 6'. T I 1 The plate 111 is provided adjacent its corners with openings through which pass threaded portions of the tie rods 14, the tie rods being secured to the plate between'washers 114 and nuts 115 secured to the ends of the tie'rods; t a

The plate Illispro'vided with a bore 116, which is axially aligned with the mandrel assembly, andis counterbored as at disposed a scalping die 126 having an annular scalping or cutting edge 127,'formed"b y the intersection of the internal surface 128 of the die and a conical surface 129 of the die. The surface 128 is of the same diameter as theinner diameter of the bushing 12,0 and the opening 123 of the dieholder 122. The die 126 is secured to. the holder 122 by means of bolts (not shown) which extend, through circumferentially spaced holes 130 which extend through the plate 1 11 and holes 131 in the die holder 122, and are threaded into the rear of the die.

The die 126 is provided at three circumferentially spaced points, apart, withknives 132, ofa construction clearly depicted in FIGS. 14,15'and l6, and having cutting edges 133 which are perpendicular to thecutting edge 127 of the scalping die 126. The cutting edges 133 are preferably tipped with a cutting alloy, such, for example, as Stellitej.

. GATE rock bored to provide a recess 140.

. The bracket 137 is also provided with spaced guide blocks 141 and 142 having vertical bores therein which are in axial alignment with the ores of the guide blocks 134 and 135 respectively.

Mounted in the bores of the

blocks

134, 135, 141 and 142 are the reduced end portions of gate lock guide rods 143 which serve to guide a gate lock 144 in its vertical movements.

The gate lock 144 has secured to its upper edge a cylinder mount adapter 145, which, when the gate lock is in its uppermost position, extends into the recess 140 of the plate 138.

Stop plates 146 are secured to the upper edge of. the gate lock 144-and come into abutment with the lower ends of the guide blocks 141 and 142 to stop upward movement of the gate lock.

Mounted on the plate 138 of the bracket 137 is a hydraulic cylinder 147 for actuating the gate lock. The cylinder 147 is preferably a Sheffer Style FFXqSeries I-II-I cylinder, having an 8-inch bore and a Bic-inch rod 148 having a stroke of 24 inches, this rod being threadedly secured to the adapter 145.

The gate lock 144 is provided with a bore l49, which is counterbored as at 150 to provide a recess in which is secured,

as by bolts 151, a trimmer 152 having a circular cutting or or the plate 111. This knockout or rod is adapted to be moved into the bore 149 and through the trimmer 152 when the gate lock is in raised position, for the aforesaid purpose.

The rod 155 is actuated by a pneumatic cylinder 157 which is mounted on the plate 111. The cylinder 157 is preferably a Sheffer" cylinder Style FFX-I-IH Series, having a 3A-inch bore and a [56-inch rod having a 10-inch stroke, the rod of the cylinder being threadedly secured, as at 158, to the rod 155.

METHOD OF OPERATION A hydraulic system for actuating the various cylinders,.and an electrical system for actuating these in a predetermined sequence, so that operation of the press is virtually automatic, isprovided, but a description of these systems, and the circuitry involved, is not deemed to be necessary or essential for the purposes of this invention.

The method of operation and the sequence of operations will be understood, through reference to the constructional features which have been described, taken in conjunction with FIGS. 17 to 24inclusive, which illustrate, in a somewhat diagrammatic manner, the sequence of operations.

A heated billet, designated 3 in FIG. 17, is rolled onto the 1

pads

83 and 84 ,of the billet cradle, which has been described,

with the stem 42, piercing mandrel 48, billet container 94, lowered gate lock 144, plate 111 and scalping die 126 in the relative positions shown in this FIG.

' The stem 42, sometimes referred to as the ram, is, through movement of the movable platen, effected by the cylinders 17, moved forwardly to the position shown in FIG. 18, pushing the billet B into the container 94, or rather, into the liner 94a of the container, and just before the billet bottoms against the gate lock 144, the ram or stem slows to a pressing speed and upsets or compresses the billet, at a pressure of 200 tons.

The pressure on the stem is then relieved, and the stem is backed away from the billet approximately 2 inches, as indicated'in FIG. 19, where the stem is stopped and locked in position hydraulically, preparatory to the piercing operation.

The stem is then moved to the position shown in FIG. 20, to

lock the billet against rearward movement, and the piercing mandrel 48 is then moved to the position shown in this FIG., causing the billet to be pierced. This piercing operation involves movement of the mandrel at piercing speed by the billet, a slug or breakout of copper or brass from the billet is cylinders 21, and the mandrel is moved through its full stroke, so that its forward end extends into the opening 149 of the gate lock, 144. As a result of this pier'cer' breakthrough of the forced into this opening. This slug or breakout of copper or brass is sheared off the billet and subsequently disposed of in a manner to be presently described.

At the end of its stroke, the piercing mandrel 48 is returned or withdrawn to the position shown in FIG. 21, while the ram or stem 42 maintains some pressure against the billet, thus stripping the billet off the mandrel.

With the billet and parts in the position shown in FIG. 21, the gate lock 144 is elevated by the cylinder 147 to the position shown in FIG. 10, and denoted, in FIG. 22, by the absence of a showing of the gate lock. This movement of the gate lock causes the trimmer 152 to shear off the slug or breakout on the end of the billet, and which, as stated above, has been forced into the opening 149. This slug or breakout is then knocked out or removed from the gate lock by movement of the rod 155 through the opening 149, which movement is effected by the cylinder 157, after which the rod 155 is retracted to the position shown in FIG. 11.

With the gate lock 144 in its fully elevated position, the ram or stem 42 moves forwardly, as indicated by FIG. 23, and at pressing speed, to push the billet out of the container 94 and through the scalping die 126, the cutting edge 127 of which scalps" or removes a thin outer layer or skin of a depth of from 0.050 inch to 0.060 inch from the billet, in the manner indicated in FIG. 23, to thereby remove surface impurities or defects and/or size the billet to a desired external diameter for subsequent extrusion of the billet.

In order to facilitate removal of thisouter skin or scalped layer, as the scalping operation proceeds, the knives 132 cut the scalped layer into segments, which fall off the billet, and thus cause no. interference with the scalping operation.

The ram or stem 42 then pushes the billet through the platen 111 and to the discharge position indicated in FIG. 24, from which position the billet rolls into an extrusion press loader (not shown). The ram is then retracted to its fully retracted position, as shown in FIG. 17.

With the ram in fully retracted position, the gate lock is lowered to the position shown in FIGS. 2 and 11,,pushing off any scalped material which has clung to the scalping die, and the gate lock is then in position for the next cycle of operations. 1 1

It is thus seen that we have provided a method of preparing billets for extrusion in which a close control over the piercing operationis exercised, and wherein deflection of the piercing mandrel is virtually eliminated, and production of a shell or tube of accurate conformation is assured.

It is also seen that we have provided a method of the character described, in which the billet is prepierced in a press which is substantially smaller than'a conventional extrusion press, which press has easily adjustable alignment of its parts, and wherein no extrusion is accomplished, thereby sparing the mandrel of the extrusion press from the wear and tear of normal extrusion operations. In this connection, it should be noted that the prepiercing operation enables the extrusion of an open tube in the extrusion press in which such tube is subsequently extruded, and without the usual formation of a piercing slug" during the conventional piercing stroke of such extrusion press, with the attendant problem of removing the piercing slug. In other words, the piercing slug is removed in the press of the present invention, and the extrusion operation on the prepierced billet in the extrusion press is greatly facilitated.

It is also seen that we have provided a method of the character described, in which a time savings in the overall extrusion cycle is effected, as well as a substantial saving in the hydraulic power required for operation of the extrusion press.

It is furtherseen that we have provided a method and press in which the billet is scalped in the same press in which the prepiercing is accomplished, that is to say, the scalping is carried out in conjunction with or in a controlled correlation with the piercing operation, thereby insuring that the scalped billet is in proper condition for the extrusion operation.

It is to be understood that the form of our invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes may be made in the shape, size and arrangement of parts thereof, without departing from the spirit of the invention or the scope of the subjoined claims.

We claim:

1. In a method of prepiercing and scalping billets for subsequent extrusion into hollow shells, the steps which comprise compressing a billet to a predetermined size by releasably confining said billet against movement of a ram thereagainst, piercing the confined billet by means of a piercing mandrel moving in the same direction as said ram, retracting the piercing mandrel from the confined billet, thereafter releasing the confined and pierced billet and moving the released billet by movement of said ram in the same direction as said initial movement of the ram through a scalping die to remove a thin outer skin from the released billet, and then continuing movement of the billet beyond the scalping die by continued movement of the ram in said direction.

2. The method, as recited in claim 1, wherein the billet is confined against a removable means comprising a gate lock, which is withdrawn from operative position prior to the scalping of the pierced billet.

3. The method, as recited in claim 2, wherein the slug or breakout produced incidental to the piercing operation is removed from the pierced billet simultaneously with the withdrawal of said gate lock.

4. The method, as recited in claim 1, wherein said scalped material is severed into segments during the scalping operation.

5. In a method of prepiercing and scalping an unpierced billet for subsequent extrusion into hollow shells, the steps which comrpise pushing a billet into a container by movement of a ram in a predetermined direction, whereby to compress or upset the billet in the container, retracting the ram from the billet, piercing the billet axially by piercing means moving in the same direction as said ram movement, retracting the piercing means from the pierced billet, shearing off the slug or breakout on the end of the billet caused by the breakthrough of the piercer through the billet, and causing the pierced billet to move in the same direction as said initial movement of the ram and pass through a scalping die, to remove a skin portion of the billet.

6. The method, as recited in claim 5, including the step of cutting said skin portion into segments incidental to said scalping operation.

7. In a press of the character described, a container having a cylindrical inner wall, means independentot' said container disposed at one end of said container and comprising a vertically movable gate, one wall of which provides an abutment, means for supporting a billet to be pierced and scalped, a ram for forcing said billet from said supporting means into said container and against said abutment, whereby to compress said billet to a predetermined external diameter, means movable independently of said ram for piercing said billet while in said container, and means disposed at that side of said gate remote from said container and comprising a scalping die having an annular cutting edge for removing a thin outer skin from said billet.

8. A press, as defined in claim 7, wherein said gate is provided with an opening having a circular cutter therein for shearing off the slug or breakout produced by the piercing of the billet.

9. A press, as defined in claim 8, including a series of circumferentially spaced knives mounted on said scalping die and adapted to sever said skin into segments during removal of said skin.

N). A press, as defined in claim 9, wherein said means for supporting the billet comprises angularly disposed plates, and means for ad usting said plates in a direction normal to their said stationary platen for moving said movable platen relatively to said stationary platen, a ram mounted on said movable platen, a piercing mandrel disposed within said ram, hydraulically actuated means mounted on said movable platen for moving said piercing mandrel independently of said ram, billet-supporting means disposed at that end of said ram remote from said movable platen, a container disposed at that end of said supporting means remote from said ram and adapted to receive a billet from said supporting means, a gate disposed at that end of said container remote from said supporting means and having a wall providing an abutment for the front of said container, and an opening adapted to receive the slug or breakout resulting from piercing of the billet by said mandrel, means for hydraulically moving said gate vertically upward out of the path of movement of said billet, a second stationary platen disposed at that side of said gate remote from said container and having an opening therein for passage of said billet when said gate has been elevated, said second stationary platen having means for guiding said gate during movement of the latter, and a scalping die mounted at one end of the opening in said second stationary platen for removing a thin outer skin from the billet as it passes through said opening.

12. A press, as defined in claim 11, including hydraulically driven means for removing said slug or breakout from the opening in said gate after the gate has been elevated.

13. In a method of prepiercing and scalping billets for subsequent extrusion into hollow shells, the steps which comprise pushing a billet into a container by movement of a ram in a predetermined direction, whereby to compress or upset the billet in the container and against a movable abutment, retracting the ram from the billet, piercing the billet axially by piercing means moving in the same direction as said ram movement, retracting the piercing means from the pierced billet, removing said abutment to permit continued movement of the pierced billet out of the container, causing said rarn to push said pierced billet out of said container, and by continued movement of the ram, pushing said pierced billet through a scalping die having an annular cutting edge for removing a skin portion of the pierced billet.

Claims

7. In a press of the character described, a container having a cylindrical inner wall, means independent of said container disposed at one end of said container and comprising a vertically movable gate, one wall of which provides an abutment, means for supporting a billet to be pierced and scalped, a ram for forcing said billet from said supporting means inTo said container and against said abutment, whereby to compress said billet to a predetermined external diameter, means movable independently of said ram for piercing said billet while in said container, and means disposed at that side of said gate remote from said container and comprising a scalping die having an annular cutting edge for removing a thin outer skin from said billet.

10. A press, as defined in claim 9, wherein said means for supporting the billet comprises angularly disposed plates, and means for adjusting said plates in a direction normal to their planes.

11. In a press of the character described, a stationary platen, a movable platen, hydraulically actuated means mounted on said stationary platen for moving said movable platen relatively to said stationary platen, a ram mounted on said movable platen, a piercing mandrel disposed within said ram, hydraulically actuated means mounted on said movable platen for moving said piercing mandrel independently of said ram, billet-supporting means disposed at that end of said ram remote from said movable platen, a container disposed at that end of said supporting means remote from said ram and adapted to receive a billet from said supporting means, a gate disposed at that end of said container remote from said supporting means and having a wall providing an abutment for the front of said container, and an opening adapted to receive the slug or breakout resulting from piercing of the billet by said mandrel, means for hydraulically moving said gate vertically upward out of the path of movement of said billet, a second stationary platen disposed at that side of said gate remote from said container and having an opening therein for passage of said billet when said gate has been elevated, said second stationary platen having means for guiding said gate during movement of the latter, and a scalping die mounted at one end of the opening in said second stationary platen for removing a thin outer skin from the billet as it passes through said opening.

13. In a method of prepiercing and scalping billets for subsequent extrusion into hollow shells, the steps which comprise pushing a billet into a container by movement of a ram in a predetermined direction, whereby to compress or upset the billet in the container and against a movable abutment, retracting the ram from the billet, piercing the billet axially by piercing means moving in the same direction as said ram movement, retracting the piercing means from the pierced billet, removing said abutment to permit continued movement of the pierced billet out of the container, causing said ram to push said pierced billet out of said container, and by continued movement of the ram, pushing said pierced billet through a scalping die having an annular cutting edge for removing a skin portion of the pierced billet.