Forming of materials

Claim 5

Apparatus for producing from a workpiece a product of reduced cross section comprising a workpiece, an orifice defining the reduced product cross-section, means for applying an initial bulk compressive stress to the whole of the workpiece to influence the workpiece to extrude through said orifice, a tool having a working face of smaller cross section than the workpiece, the tool being mounted for application to a localized region of the bulk-stressed workpiece adjacent said orifice and so as to be movable in a repetitive closed cyclic path with the working face of the tool maintained in pressure contact with the workpiece during at least part of the cyclic path, and means for effecting relative movement between the tool and the workpiece to apply an additional compressive stress at said localized region to influence the localized region to extrude through said orifice, whereby the material of the workpiece in the localized region forward of the working face of the tool is subjected to an additional compressive stress and is thereby formed through the orifice defining the product cross section under the influence of the bulk compressive stress acting in combination with the additional compressive stress in the material of the workpiece in the localized region forward of the working face of the tool.

Claim 6

Apparatus for producing from a workpiece a product of reduced cross section comprising a workpiece, an orifice defining the reduced product cross-section, means for applying an initial bulk compressive stress to the whole of the workpiece to influence the workpiece to extrude through said orifice, a tool having a working face of smaller cross section than the workpiece, the tool being mounted for application to a localized region of the bulk-stressed workpiece adjacent said orifice and so as to be movable in a repetitive closed cyclic path with the working face of the tool maintained in pressure contact with the workpiece during at least part of the cyclic path, and means for effecting relative movement between the tool and the workpiece to apply an additional compressive stress at said localized region to influence the localized region to extrude through said orifice, whereby the material of the workpiece in the localized region forward of the working face of the tool is subjected to an additional compressive stress and is thereby formed through the orifice defining the product cross section under the influence of the bulk compressive stress acting in combination with the additional compressive stress in the material of the workpiece in the localized region forward of the working face of the tool.

Claim 7

Apparatus for producing from a workpiece a product of reduced cross section comprising a container having a region of smaller cross section than the workpiece, means for applying pressure to the workpiece in the container so as to set up an initial bulk compressive stress in the whole of the workpiece and so as to force a part of the workpiece into the region of smaller cross section of the container, an orifice opening into said region and defining the reduced product cross-section, a tool having a working face and mounted for application of the working face to the part of the bulk-stressed workpiece in said region of smaller cross section of the container, and Means for moving the tool in a repetitive closed cyclic path with the working face of the tool maintained in pressure contact with the workpiece during at least part of the cyclic path so that the material of the workpiece in the region of smaller cross section of the container forward of the working face of the tool is subjected to an additional compressive stress and is thereby formed through the orifice defining the product cross section under the influence of the bulk compressive stress acting in combination with the additional compressive stress in the material of the workpiece in the region of small cross section of the container forward of the working face of the tool.

Claim 8

Apparatus for producing from a workpiece a product of reduced cross section comprising a container having a region of smaller cross section than the workpiece, means for applying pressure to the workpiece in the container so as to set up an initial bulk compressive stress in the whole of the workpiece and so as to force a part of the workpiece into the region of smaller cross section of the container, an orifice opening into said region and defining the reduced product cross-section, a tool having a working face and mounted for application of the working face to the part of the bulk-stressed workpiece in said region of smaller cross section of the container, and Means for moving the tool in a repetitive closed cyclic path with the working face of the tool maintained in pressure contact with the workpiece during at least part of the cyclic path so that the material of the workpiece in the region of smaller cross section of the container forward of the working face of the tool is subjected to an additional compressive stress and is thereby formed through the orifice defining the product cross section under the influence of the bulk compressive stress acting in combination with the additional compressive stress in the material of the workpiece in the region of small cross section of the container forward of the working face of the tool.

Claim 9

Apparatus as claimed in claim 3 wherein said means for applying a bulk compressive stress comprises a container, and pressure means for applying a compressive stress to the bulk of the workpiece within the container, said tool comprising a reciprocable punch, and means for reciprocating the punch between limits, the apparatus being constructed and arranged such that on the forward stroke of the punch the face of the punch is forced under pressure into the bulk-stressed workpiece, so that the material of the workpiece in the localized region forward of the face of the punch is subjected to an additional compressive stress and is formed through the orifice leading from the container, and whereby on the backward stroke of the punch the compressive stress applied to the bulk of the workpiece feeds the material of the workpiece to replace the material formed during the previous forward stroke of the punch.

Claim 10

Apparatus as claimed in claim 4 wherein the bore of the container has a tapered end reducing to said smaller cross section, and said means for applying pressure to the workpiece in the container sets up a compressive stress in the bulk of the workpiece so as to force the corresponding end of the workpiece into the tapered end of the bore of the container, said tool comprising a reciprocable punch, and said means for moving the tool comprising means for reciprocating the punch between limits such that on the forward stroke of the punch the face of the punch is forced under pressure into the material of the workpiece in the tapered end of the bore of the container so that the material of the workpiece in the localized region forward of the face of the punch is subjected to an additional compressive stress and is formed through the orifice leading from the tapered end of the container, and such that on the backward stroke of the punch the compressive stress acting in the bulk of the workpiece feeds further material into the tapered end of the bore of the container to replace the material formed during the previous forward stroke of the punch.

Claim 11

Apparatus as claimed in claim 4 wherein the bore of the container has a tapered end leading to a secondary chamber of smaller cross section, and said means for applying pressure to the workpiece in the container sets up a compressive stress in the bulk of the workpiece so as to force the corresponding end of the workpiece through the tapered end of the bore of the container into the secondary chamber, said tool comprising a reciprocable punch, and said means for moving the tool comprising means for reciprocating the punch between limits such that on the forward stroke of the punch the face of the punch is forced under pressure into the material of the workpiece in the secondary chamber so that the material of the workpiece in the secondary chamber is subjected to an additional compressive stress and is formed through the orifice leading from the secondary chamber and defining the product cross section, and such that on the backward stroke of the punch the compressive stress acting in the bulk of the workpiece feeds further material from the workpiece into the secondary chamber through the tapered end of the bore of the container.

Claim 12

Apparatus as claimed in claim 6 wherein the punch is entered axially along the container axis into the said correspondiNg end of the work piece at the forward part of the tapered end of the bore of the container.

Claim 13

Apparatus as claimed in claim 7 wherein the punch is entered axially along the container axis into the said corresponding end of the material of the workpiece in the secondary chamber.

Claim 14

Apparatus as claimed in claim 6 wherein the punch is entered through the side wall of the tapered end generally normal to the bore axis of the container.

Claim 15

Apparatus as claimed in claim 5 wherein the orifice defining the product cross section is provided in the reciprocable punch leading from the face of the punch.

Claim 16

Apparatus as claimed in claim 8 wherein the orifice defining the product cross section is provided in the side wall of the tapered end of the bore of the container.

Claim 17

Apparatus as claimed in claim 10 wherein the orifice defining the product cross section is provided leading axially from the forward end of the tapered end of the bore of the container.

Claim 18

Apparatus as claimed in claim 9 wherein the punch is of smaller diameter than the internal diameter of the secondary chamber and the orifice defining the product cross section is provided by the annular space defined between the punch and the wall of the secondary chamber.

Claim 19

Apparatus as claimed in claim 10 wherein the punch is entered into the tapered end of the bore of the container through a passageway in the wall of the container and the punch is of smaller diameter than the internal diameter of said passageway, the orifice defining the product cross section being provided by the annular space defined between the punch and the wall of the passage way.

Claim 20

Apparatus as claimed in claim 4 wherein said tool comprises a reciprocable punch, and said means for moving the tool comprises means for reciprocating the punch between limits, the apparatus being constructed and arranged such that on the forward stroke of the punch the face of the punch is forced under pressure into the workpiece, so that the material of the workpiece in the localized region forward of the face of the punch is subjected to an additional compressive stress and is formed through the orifice leading from the container, and whereby on the backward stroke of the punch the compressive stress applied to the bulk of the workpiece feeds the material of the workpiece to replace the material formed during the previous forward stroke of the punch.