US3735623A

US3735623A - Indirect extrusion die assembly and method of extruding

Info

Publication number: US3735623A
Application number: US00089841A
Authority: US
Inventors: A Mann
Original assignee: TEXAS ALUMINUM CO
Current assignee: TEXAS ALUMINUM CO
Priority date: 1970-11-16
Filing date: 1970-11-16
Publication date: 1973-05-29
Anticipated expiration: 1990-05-29
Also published as: GB1377369A; CA946783A; GB1377370A; DE2156871A1; BE797008Q; FR2131263A5; JPS5214701B1; AU460231B2; AU3575071A; DE2156871C3; IT942847B; DE2156871B2

Abstract

A die assembly as used in an indirect extrusion press, the assembly comprising a die member having an opening therethrough, a plurality of separate support members positioned on one side of the die with openings extending therethrough and aligned with, but larger than, the opening in the die, and a guide tube for containing the support members therein and the die at one end. In extruding material through the die assembly, a billet of material is held in a container and the container with the billet is moved toward the die assembly to force the billet material through the opening in the die and then through the aligned openings in the support members.

Description

nite States Patent 1191 Mann 1 1 May 29, 11973 [5 1 INDIRECT EXTRUSION DIE 2,962,164 11/1960 Scribner ..72/256 ASSEMBLY AND METHOD ()1? 3,150,773 9/1964 Richter ..72/256 EXTRUDING 3,364,707 1/1968 Foerster ..72/253 3,431,825 3/1969 Crawley et al ..72/253 [75] Inventor: Alfred W. Mann, Rockwall, Tex. [73] Assignee: Texas Aluminum Company, Inc., Primary Examiner Richard l Herbst Rockwal], Att0rneyPennie, Edmonds, Morton, Taylor &

Adams [22] Filed: Nov. 16, 1970 [2l] App]. No.: 89,841 ABSTRACT A die assembly as used in an indirect extrusion press, 52 11.5.01 ..72/261, 72/272 the a y Comprising a die member having an [51] Int. Cl ..B2lc 23/20 Opening therethrough, a plurality of Separate Support 58 Field of Search ..72/253, 254, 256, members Positioned on one side of the die with 72/264, 265, 266 272 273 261 openings extending therethrough and aligned with, but larger than, the opening in the die, and a guide tube [56] References Cited for containing the support members therein and the die at one end. In extruding material through the die UNITED STATES PATENTS assembly, a billet of material is held in a container and 3,482,424 12/1969 Bobrowsky ..72/60 the htah1ef with the billet is moved toward the die 2 960,221 11/19 0 Albers at 72 272 assembly to force the billet material through the open- 2,974,791 3/1961 Elkan ...72/272 ing in the die and then through the aligned openings in 2,867,321 1/1959 Swanson... ...72/272 the support members, 3,548,625 12/1970 Fuchs, Jr... ...72/272 3,184,944 5/1965 Sibler ..72/272 13 Claims, 4 Drawing Figures PATENIEU HAY29 I975 SHEET 1 OF 2 INVENTOR m 2m L INDIRECT EXTRUSION DIE ASSELY AND METHOD OF EXTRUDING BACKGROUND OF THE INVENTION With presently available indirect extrusion presses, the billet material is extruded through a die member which, in turn, is mounted at one end of a hollow stem. During the extrusion, the billet material is held in a container on one side of the die assembly. The container is then progressively telescoped over the die assembly and the material thereby extruded through the die opening. Indirect extrusion is sometimes preferred over direct extrusion, because generally lower temperatures and pressures may be used. There is, however, one important drawback to indirect extrusion and that concerns the shapes, both length and cross-sectional size, which may be extruded.

With indirect extrusion, the length of the hollow supporting stem must be at least as long as the length of the container or the billet to be extruded. This is so since the container has to fully telescope over the die assembly to extrude the complete billet material, less the butt, through the die member. With present constructions where the hollow stem consists simply of a tubular member, the outside diameter of the stem is limited by the inside diameter of the container. The inside diameter of the stem, in turn, is limited, after the outside diameter has been determined, by the wall thickness necessary to bear the compressive load created during the extrusion processes. With this interrelationship be tween the dimensions of the container and stem, the longer the stem, the greater its wall thickness must be in order to adequately take the compressive and columnar loadings associated with indirect extrusion. This, in turn, places limitations on the cross-sectional shapes and size of the structures which may be extruded. Generally, the greater the length of the extruded structure desired, the smaller the cross-sectional shapes must be.

Even when extruding structures of small crosssectional shape, the length of such structures is limited due to strength limitation of the die assembly. More particularly, the length of conventional hollow stems is limited by the column strength which it possesses. If the stem is too long, even a slight bending under the compressive loading created during extrusion can cause the stem to fracture or shatter. Since a portion of the stem remains exposed to the surrounding area until the extrusion process is completed, this creates a hazardous condition.

In addition to length limitations, conventional indirect die assemblies also have other manufacturing and operating limitations. For example, the longer the stem, the more difficult it is to machine an axial opening therethrough. Similarly, difficulties arise in machining more than one hole which is necessary when extruding more than one structure through a single die. Occasionally, exorbitantly expensive methods have been resorted to in machining the inside of the stem to the configurations required. The unitary elongated configuration of the hollow stem also makes it difficult to clear what is known as plugged tooling." This is a condition in which the material being extruded has become impacted in the tooling due to some malfunction.

Further, with the conventional die assemblies, the stem generally requires heating before the extruding operation. This is so since the materials that are used in manufacturing the stem must be selected from those which will give the required compressive or column strength. These materials, however, are usually those which are rather brittle at ambient temperatures. Also, stem structures as presently made provide little support for the die member; this support being only along the outer border of the die member. With this type of support for the die, the compressive loading created during the extrusion process can cause die deformation or deflection. This is especially true where the die has a die opening of relatively thin cross-sectional dimension. Deformation or deflection of such a die produces structures of non-uniform cross-section.

SUMMARY OF THE INVENTION In accordance with the teachings of the present invention, the hollow support stem of the conventionally constructed die assembly is replaced by a multiple part structure. More particularly, the die assembly includes a die member and a plurality of separate support members. The support members are positioned in a column on one side of the die and held in place by a surrounding guide tube. Each support member has an opening aligned with the opening of the die.

With the improved die assembly of the present invention, the separate construction of the support members essentially eliminates the length limitations on the stem structure and thus permits extrusions of considerably longer structures than previously feasible. Also, the individual support members can be of short axial length and, therefore, the openings through these members can be easily machined to a shape corresponding to the desired shape of the extruded structure and to the shape of the die opening. Accordingly, extrusions of thinner cross-sectional dimensions are possible since deformation of the die during extrusion is no longer a problem.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the die assembly of the present invention;

FIG. 2 is a side elevation, partially in cross section, of the indirect extrusion press of the present invention with the die assembly in place;

FIG. 3 shows a series of circular shapes which can be used as the die assembly of FIG. 1; and

FIG. 4 shows two rectangular shapes for the die assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, the die assembly, generally designated by reference numeral 1, includes a die member 2, a plurality of supporting backup members 3 and a guide tube 4. The guide tube is adapted to contain the individual support members in side-by-side engagement with each other with the die member secured at one end 5 of the tube. The die assembly is shown in FIG. 2 in its assembled condition and mounted in an indirect extrusion press. For mounting purposes, the guide tube is fitted into a holder 6 at the end 7 opposite the location of the die member.

In the particular construction of the assembly shown in FIG. 1, the die member has two die openings 8 and 9 extending through the die from one side to the other. Each of the support members is also provided with two openings 10 and II extending between its opposite sides and aligned with the openings in the die member.

The openings in each of the support members are larger in cross-sectional shape than the openings in the die member so that they produce no extruding function and simply receive the structure extruded through the die openings.

For purposes of providing good support for the die member during the extrusion operation, the openings and 1 1 in the support member immediately adjacent the die member are of a shape generally corresponding to the openings in the die member and only slightly larger than the die openings. Although one of the support members is shown with this construction, some or all of the remaining members may also be provided with openings of this shape. Also, the configuration of openings in the support members may be progressively enlarged or otherwise changed from one to the other to thereby distribute a more even pressure or load to the structure of the extrusion press which supports the die assembly.

The guide tube 4 surrounding the support members holds the support members and die member in place. The tube is advantageously made of non-brittle material and has the added function of preventing the support members from being projected into the surrounding area in the event of breakage by overloading. Also, the tube can be constructed to either carry or not carry part of the mechanical load. In the construction shown in the drawings, the end 5 of the tube butts against the flanged edge 2' of the die member while its other end 7 seats in the holder 6. Thus, the guide tube will take part of the compressive loading of the extruding operation. If this is not desired, it is simply a matter of shortening the length of the guide tube.

In addition to the construction shown in FIG. 1, die assemblies may be made with die openings of other cross-sectional shapes such as shown at 12, 13 and 14 in FIG. 3. Also, the outer shape of the assembly may be other than cylindrical. FIG. 4 shows die assemblies l5, 16 having rectangular cross-sectional outer shapes. Die assemblies of this shape are particularly suited for simultaneously extruding of a plurality of thin sectioned structures such as shown at 17 in FIG. 4 or for extruding a sheet or plate-like structure 18 having one crosssectional dimension which is a large multiple of a second cross-sectional dimension. Where the die assemblies of the configuration shown in FIG. 4 are used, the billet material will advantageously have a crosssectional shape generally corresponding to the crosssectional shape of the die assembly. Also, where extruding the sheet or plate-like structure 18, the crosssectional shape of the billet will generally correspond to the cross-sectional shape of the extruded structure by being rectangular.

In FIG. 2, the die assembly of FIG. 1 is shown in place in an indirect extrusion press prior to an extrusion operation being performed. The press includes a platen 19 against which the die assembly 1 bears. Bolster or pressure plates 20 are provided for directly taking the load of the tube holder 6 and the last of the support members 3 held in the tube. The press also includes a container 21 mounted for reciprocal movement on suitable guide structure 22. The container has a bore 23 in which a billet of material 24 is positioned. The bore 23 is aligned with the die assembly which is positioned with the die member 22 facing the container. Behind the container is a hydraulic power cylinder 25 having a gag member 26 also aligned with the bore of the container.

In operation, an extrusion of a billet through the die assembly is effected by actuating the hydraulic power cylinder to move the gag 26 over the aligned bore of the container and into contact with the container. The container with the billet is then forced forwardly to progressively telescope the container over the die assembly and to cause the billet material to flow through the openings in the die member of the die assembly. Movement of the container is continued until the entire billet, less the butt, has been extruded through the die member. The butt is then removed and the operation of the press is then reversed to prepare it for another extruding operation.

With the improved construction of the die assembly as described above, the length of the stem structure, including the support members and guide tube, may be much greater than the length of the conventional stem structure presently used in indirect extrusion. Thus, longer lengths may be extruded. At the same time, the cross-sectional size of the structures being extruded may be greater than is possible with conventional indirect extrusion equipment. The increased length and size of the extruded product is possible because of the inclusion of the separate support members in place of the conventional unitary hollow stem structure whereby bending of the assembly under the compressive loading of the extrusion is precluded. With any bending forces that might be created during the extrusion operation, the support members can shift relative to each other to attain proper alignment; and even if the assembly is loaded beyond the compressive strength of any one or more of the support members, the surrounding guide tube will retain the broken pieces and prevent them from being projected into the surrounding areas.

With the use of separate support members in place of the conventional hollow tube, the axial dimension of each support member will be relatively short. This, in turn, facilitates machining of the openings through the support members and makes it possible to cut the opening through any member or all of them to a configuration which conforms generally to the shape of the structure to be extruded. This is of particular advantage for supporting the die member against deformation or deflection to thereby permit the production of extrusions conforming closely to the die opening dimensions. Also, by preventing die deformation, it is possible to produce extrusions of thin cross-sections with close tolerances and minimum variations in cross-sectional dimensions from one end of the extrusion to the other.

With the construction of the die assembly of the present invention, the increase strength produced by the use of separate support members also permits the use of a greater range of materials in manufacturing the support members than possible with the conventional hollow stem structures. The support members may, for example, be made of hardened steel or equivalent material so that the assembly may be operated cold rather than at an elevated temperature as required with present constructions.

The advantages resulting from the improved construction of the die assembly as described above generally make it possible to now extrude, by the indirect process, structures of considerable length. These extrusions may be produced either singlely or simultaneously. Also, a greater variety of shapes and materials may be extruded.

I claim:

1. An indirect extrusion die assembly comprising:

a. a die member through which a billet of material is adapted to be extruded and moved along a predetermined path by being forced through an opening extending from one side of the die member to the other;

a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predeter mined path;

c. containing means for holding said support members in a column; and

d. each of said support members having an opening therethrough from one side thereof to the other and aligned with the opening in said die member, the openings in the support members being larger than the aligned opening in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material, the support member disposed nearest said die member being supported by said die member and the support member disposed at the other end of the column being exposed for axial support independently of the containing means.

2. An indirect extrusion press comprising:

a. a die assembly having:

l. a die member through which a billet of material is adapted to be extruded and moved along a pre determined path by being forced through an opening extending from one side of the die member to the other, and

2. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, each of said support members having an opening therethrough from one 7 side thereof to the other and aligned with the opening in said die member, the openings in the support members being larger than the aligned opening in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material;

b. a container for holding said billet of material to be extruded through said die member, said container being positioned on said one side of the die member and confining said material against outward movement transversely of the axis of alignment of said billet with said die opening; and

0. means for moving said die assembly and the container holding said billet of material relative to each other to force said billet material through said die member with said container progressively telescoping over said die assembly as the material is extruded therethrough.

3. An extrusion die assembly according to claim 1 wherein:

a. at least the first of said support members nearest said die member has an opening therethrough of a shape generally corresponding to but slightly larger than the opening in said die member.

4. An extrusion die assembly according to claim 1 wherein:

a. said containing means includes a guide tube for containing said support members therein and engaging the periphery of the column formed thereby.

5. An extrusion die assembly according to claim 4 wherein:

a. said die member is mounted at one end of said guide tube.

6. An extrusion die assembly according to claim 5 wherein:

a. at least the first of said support members nearest said die member has an opening therethrough of a shape generally corresponding to but slightly larger than the opening in said die member; and

b. the remainder of said support members have openings therethrough of a simple shape larger than the opening through said die member.

7. An indirect extrusion die assembly comprising:

a. a die member through which a billet of material is adapted to be extruded and moved along a predetermined path by being forced through a plurality of separate openings extending from one side of the die member to the other;

b. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path;

c. containing means for holding said support members in a column; and

d. each of said support members having separate openings therethrough from one side thereof to the other and aligned with the openings in said die member, the openings in the support members being larger than the aligned opening in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material, the support member disposed nearest said die member being supported by said die member and the support member disposed at the other end of the column being exposed for axial support independently of the containing means.

8. An extrusion die assembly according to claim 7 wherein:

a. said die and support members have an outer shape, as measured transversely to their direction of alignment, which is greater in one direction than another; and

b. said tube has an inner cross-sectional shape complementary to the outer shape of said support and die members.

9. An indirect extrusion press according to claim 2 further comprising:

a. a guide tube for containing said support members therein and engaging the periphery of the column formed thereby with said die member mounted at one end of said tube.

10. An indirect extrusion press according to claim 9 wherein:

1 l. The method of simultaneously extruding a plurality of substantially identical structures comprising the steps of:

a. positioning a die member having a plurality of openings extending therethrough from one side thereof to the other in a first position and through which a billet of material is adapted to be extended and moved along a predetermined path;

b. positioning a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, each of said support members having separate openings therethrough from one side thereof to the other and aligned with the openings in said die member, the openings in the support members being larger than the aligned openings in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material, the support member disposed nearest said die member being supported by said die member and the support member disposed at the other end of the column being exposed for independent axial support;

0. positioning a billet of said material on one side of said die assembly and in alignment with said openings, said billet having a cross-sectional shape corresponding to but larger than the pattern defined by the plurality of openings in the die member;

d. containing said billet against outward movement transversely of the axis of alignment of said billet and die openings by engaging the outer surface of said billet with a supporting surface; and

e. pressing said billet against said die assembly to force said billet material through each of said openings simultaneously while maintaining the outer surface of said billet stationary relative to said supporting surface until said material is forced through said openings and thereafter passing the material through the aligned openings in the support members and in spaced unsupported relation with the walls of the openings in the support members.

12. An indirect extrusion press comprising:

a. a die assembly having:

1. a die member through which a billet of material is adapted to be extruded and moved along the predetermined path by being forced through a plurality of separate openings extending from one side of the die member to the other, and

2. a columnar support means aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said support means having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, said support means further having separate openings therethrough aligned with and larger than the openings in the die member with the walls thereof spaced from the material extruded through the openings in the die member to provide for unobstructed and unsupported passage of material;

c. means for moving said die assembly and the container holding said billet of material relative to each other to force said billet material through said die member with said container progressively telescoping over said die assembly as the material is extruded therethrough.

13. An indirect extrusion press comprising:

a. a die assembly having:

1. a die member through which a billet of material is adapted to be extruded and moved along a predetermined path by being forced through a plurality of openings extending from one side of the die member to the other, and

2. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, each of said support members having openings therethrough from one side thereof to the other aligned with the openings in said die member, the openings in the support members being larger than the aligned openings in the die member with the walls thereof spaced from the material extruded through the openings in the die member to provide for unobstructed and unsupported passage of the material;

b. a container for holding said billet of material to be extruded through the openings in said die member, said container being positioned on said one side of the die member and confining said material against outward movement transversely of the axis of alignment of said billet with said die openings; and

c. means for moving said die assembly and the container holding said billet of material relative to each other to force said billet material through the openings in said die member with said container progressively telescoping over said die assembly as the material is extruded therethrough.

Claims

1. An indirect extrusion die assembly comprising: a. a die member through which a billet of material is adapted to be extruded and moved along a predetermined path by being forced through an opening extending from one side of the die member to the other; b. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path; c. containing means for holding said support members in a column; and d. each of said support members having an opening therethrough from one side thereof to the other and aligned with the opening in said die member, the openings in the support members being larger than the aligned opening in the die member With the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material, the support member disposed nearest said die member being supported by said die member and the support member disposed at the other end of the column being exposed for axial support independently of the containing means.

2. An indirect extrusion press comprising: a. a die assembly having:

2. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, each of said support members having an opening therethrough from one side thereof to the other and aligned with the opening in said die member, the openings in the support members being larger than the aligned opening in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material; b. a container for holding said billet of material to be extruded through said die member, said container being positioned on said one side of the die member and confining said material against outward movement transversely of the axis of alignment of said billet with said die opening; and c. means for moving said die assembly and the container holding said billet of material relative to each other to force said billet material through said die member with said container progressively telescoping over said die assembly as the material is extruded therethrough.

2. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, each of said support members having openings therethrough from one side thereof to the other aligned with the openings in said die member, the openings in the support members being larger than the aligned openings in the die member with the walls thereof spaced from the material extruded through the openings in the die member to provide for unobstructed and unsupported passage of the material; b. a container for holding said billet of material to be extruded through the openings in said die member, said container being positioned on said one side of the die member and confining said material against outward movement transversely of the axis of alignment of said billet with said die openings; and c. means for moving said die assembly and the container holding said billet of material relative to each other to force said billet material through the openings in said die member with said container progressively telescoping over said die assembly as the material is extruded therethrough.

2. a columnar support means aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said support means having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, said support means further having separate openings therethrough aligned with and larger than the openings in the die member with the walls thereof spaced from the material extruded through the openings in the die member to provide for unobstructed and unsupported passage of material; b. a container for holding said billet of material to be extruded through said die member, said container being positioned on said one side of the die member and confining said material against outward movement transversely of the axis of alignment of said billet with said die opening; and c. means for moving said die assembly and the container holding said billet of material relative to each other to force said billet material through said die member with said container progressively telescoping over said die assembly as the material is extruded therethrough.

3. An extrusion die assembly according to claim 1 wherein: a. at least the first of said support members nearest said die member has an opening therethrough of a shape generally corresponding to but slightly larger than the opening in said die member.

4. An extrusion die assembly according to claim 1 wherein: a. said containing means includes a guide tube for containing said support members therein and engaging the periphery of the column formed thereby.

5. An extrusion die assembly according to claim 4 wherein: a. said die member is mounted at one end of said guide tube.

6. An extrusion die assembly according to claim 5 wherein: a. at least the first of said support members nearest said die member has an opening therethrough of a shape generally corresponding to but slightly larger than the opening in said die member; and b. the remainder of said support members have openings therethrough of a simple shape larger than the opening through said die member.

7. An indirect extrusion die assembly comprising: a. a die member through which a billet of material is adapted to be extruded and moved along a predetermined path by being forced through a plurality of separate openings extending from one side of the die member to the other; b. a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path; c. containing means for holding said support members in a column; and d. each of said support members having separate openings therethrough from one side thereof to the other and aligned with the openings in said die member, the openings in the supporT members being larger than the aligned opening in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material, the support member disposed nearest said die member being supported by said die member and the support member disposed at the other end of the column being exposed for axial support independently of the containing means.

8. An extrusion die assembly according to claim 7 wherein: a. said die and support members have an outer shape, as measured transversely to their direction of alignment, which is greater in one direction than another; and b. said tube has an inner cross-sectional shape complementary to the outer shape of said support and die members.

9. An indirect extrusion press according to claim 2 further comprising: a. a guide tube for containing said support members therein and engaging the periphery of the column formed thereby with said die member mounted at one end of said tube.

10. An indirect extrusion press according to claim 9 wherein: a. at least the first of said support members nearest said die member has an opening therethrough of a shape generally corresponding to but slightly larger than the opening in said die member; and b. the remainder of said support members have openings therethrough of a simple shape larger than the opening through said die member.

11. The method of simultaneously extruding a plurality of substantially identical structures comprising the steps of: a. positioning a die member having a plurality of openings extending therethrough from one side thereof to the other in a first position and through which a billet of material is adapted to be extended and moved along a predetermined path; b. positioning a column of separate support members disposed in side-by-side engagement with each other and aligned with said die member on the other side thereof and forming a support for said die member axially of said predetermined path as material is extruded therethrough, said column having an axial length at least substantially equal to the length of said billet as measured axially of said predetermined path, each of said support members having separate openings therethrough from one side thereof to the other and aligned with the openings in said die member, the openings in the support members being larger than the aligned openings in the die member with the walls thereof spaced from the material extruded through the opening in the die member to provide for unobstructed and unsupported passage of the material, the support member disposed nearest said die member being supported by said die member and the support member disposed at the other end of the column being exposed for independent axial support; c. positioning a billet of said material on one side of said die assembly and in alignment with said openings, said billet having a cross-sectional shape corresponding to but larger than the pattern defined by the plurality of openings in the die member; d. containing said billet against outward movement transversely of the axis of alignment of said billet and die openings by engaging the outer surface of said billet with a supporting surface; and e. pressing said billet against said die assembly to force said billet material through each of said openings simultaneously while maintaining the outer surface of said billet stationary relative to said supporting surface until said material is forced through said openings and thereafter passing the material through the aligned openings in the support members and in spaced unsupported relation with the walls of the openings in the support members.

12. An indirect extrusion press comprising: a. a die assembly having:

13. An indirect extrusion press comprising: a. a die assembly having: