Method and apparatus for producing untrimmed container bodies

Abstract

Exemplary embodiments of the invention relate to an apparatus and method for producing untrimmed container bodies from pre-cut metal blanks. The method involves cupping a metal blank by positioning the blank against an immovable draw punch comprising an annular body having an inner surface adapted to form a redraw die and an outer surface, and drawing a periphery of the blank over the outer surface of the draw punch with an encircling draw die to form a cup having an open end, a closed end and an interior. The cup is then inverted and redrawn by forcing a redraw punch into the closed end of the cup to draw the closed end through the redraw die until the cup is inverted to form an inverted cup with a closed end supported on the punch. The inverted cup while supported on the redraw punch is passed through one or more ironing rings to lengthen the inverted cup to form an untrimmed container body having a closed end. The closed end of the untrimmed container body is shaped by engaging the closed end of the untrimmed container body with one or more end shaping tools while supported on the redraw punch. The apparatus comprises tools, actuators and a solid support structure adapted to carry out the method. The metal blank may be pre-cut and supplied to the apparatus for shaping, or it may be cut from a metal sheet supplied to the equipment just as the shaping operations commence.

1 . Apparatus for making an untrimmed container body from a pre-cut metal blank, comprising:
 shaping tools and actuators for operating said tools with sufficient force for shaping said blank into an untrimmed container body; and   a support structure for supporting said shaping tools and actuators while allowing necessary movements of some of said tools;   wherein said shaping tools include:   a combined draw punch and redraw die comprising an annular body having an inner surface, an outer surface and an end surface defining an opening at an operational end of the annular body that initially contacts said blank, said end surface and said outer surface together functioning in use as said draw punch, and said inner surface functioning in use as said redraw die, said annular body being fixed on said structure against movement relative thereto during use;   a draw die having a die surface dimensioned to encircle said outer surface of said annular body at a spacing effective for cupping of said blank, said draw die being movable in use along said outer surface from said operational end to form a cup from said blank;   a redraw punch comprising a cylinder having an outer surface dimensioned to penetrate said opening at said operational end of said annular body with a spacing from said inner surface effective for redrawing said cup, said redraw punch being movable at a leading end thereof into said opening and through said annular body to invert said cup to thereby form an inverted redrawn cup having an open end and a closed end;   one or more ironing rings aligned with said annular body and positioned to iron an outer surface of said inverted redrawn cup supported on said leading end of said redraw punch after said leading end passes through and emerges from said annular body, to thereby lengthen said inverted redrawn cup to form an untrimmed container body having a closed end; and   a container body end shaper positioned in spaced alignment with said one or more ironing rings to contact said closed end of said untrimmed container body supported on said operational end of said redraw punch, said shaper being profiled to shape said closed end when said closed end is forced thereagainst by said redraw punch.   
     
     
         2 . The apparatus of  claim 1 , wherein said tools further include an annular draw holder confronting said annular draw die and adapted to grip a periphery of said blank between said annular draw holder and said annular draw die with a force that allows said periphery to be withdrawn and guided during drawing of said blank. 
     
     
         3 . The apparatus of  claim 1 , wherein said tools further include an annular redraw holder confronting said operational end of said combined draw punch and redraw die and adapted to grip an outer part of said cup between said holder and said combined draw punch and redraw die with a force that allows said outer part to be withdrawn and guided during redrawing of said cup. 
     
     
         4 . The apparatus of  claim 3 , wherein said annular redraw holder has an inner surface that contacts and provides lateral support for said outer surface of said redraw punch. 
     
     
         5 . The apparatus of  claim 1 , wherein said end shaper is spaced from said one or more ironing rings by a distance that provides only minimal clearance between said untrimmed container body and said one or more ironing rings when said redraw punch is extended fully thereagainst. 
     
     
         6 . The apparatus of  claim 1 , having two or more of said ironing rings, said two or more ironing rings being positioned next to each other with minimal spacing therebetween. 
     
     
         7 . The apparatus of  claim 1 , wherein said redraw punch passes through an aperture in said support structure and is supported at and driven from an end opposite to said operational end. 
     
     
         8 . The apparatus of  claim 7 , wherein said redraw punch has a length no greater than a distance between said aperture and said container body end shaper. 
     
     
         9 . Apparatus for making untrimmed container bodies from pre-cut metal blanks, comprising:
 shaping equipment for said blanks comprising tools, including a draw die, a combined draw punch and redraw die, a draw holder, a redraw punch, a redraw holder, one or more ironing rings, a container body bottom domer and an outer retainer ring, as well as actuators for moving tools with sufficient force for shaping said blanks into container bodies;   a structure for supporting said shaping equipment while allowing movement of some of said tools necessary for making said container bodies; wherein:   said combined draw punch and redraw die comprise a single annular body having an inner surface, an outer surface and an end surface at an open operational end of the annular body that initially contacts said blanks, said end surface and said outer surface together functioning in use as said draw punch, and said inner surface functioning in use as said redraw die, said annular body being fixed on said structure against movement relative thereto during use;   said draw die has a die surface dimensioned to encircle said outer surface of the annular body at a spacing effective for cupping of said blanks, said draw die being movable in use along said outer surface to form cups from said blanks;   said redraw punch comprises a cylinder having an outer surface dimensioned to penetrate said open operational end of said annular body at a spacing from said inner surface effective for redrawing said cups, said redraw punch being movable at a leading end thereof into said open operational end and through said annular body to invert said cups as they are redrawn to thereby form inverted redrawn cups having open ends and closed ends;   said container body end domer and outer retainer ring are positioned in spaced alignment with said annular body to contact said closed ends of said inverted redrawn cups supported on said leading end of said redraw punch, and to shape said closed ends when forced thereagainst by said redraw punch; and   said one or more ironing rings are positioned between said annular body and said bottom domer and are aligned effectively to iron outer surfaces of said inverted redrawn cups supported on said operational end of said redraw punch as said punch moves toward said bottom domer, to thereby lengthen said inverted redrawn cups and form untrimmed container bodies.   
     
     
         10 . A method of making an untrimmed container body from a pre-cut metal blank, comprising:
 cupping a pre-cut metal blank by positioning the blank against an immovable draw punch comprising an annular body having an inner surface adapted to form a redraw die and an outer surface, and drawing a periphery of the blank over said outer surface of the draw punch with an encircling draw die to form a cup having an open end, a closed end and an interior;   inverting and redrawing said cup by forcing a redraw punch into said closed end to draw said closed end through said redraw die until said cup is inverted to form an inverted cup supported on said punch, said inverted cup having a closed end;   passing the inverted cup while supported on said redraw punch through one or more ironing rings to lengthen said inverted cup to form an untrimmed container body having a closed end;   shaping said closed end of said untrimmed container body by engaging said closed end of said untrimmed container body with one or more end shaping tools while supported on said redraw punch; and   withdrawing said punch from said untrimmed container body.   
     
     
         11 . The method of  claim 10 , wherein said closed end of said untrimmed container body is shaped by engaging said closed end with a domer shaped to form an inwardly-extending dome at said closed end, and a support ring to conform a periphery of said closed end to a profile of said redraw punch at a leading end thereof. 
     
     
         12 . The method of  claim 10 , wherein said annular body, said ironing rings and said end shaping tools are positioned relative to each other to minimize distance required to be traveled by said redraw punch when forming said untrimmed container body from said cup. 
     
     
         13 . Apparatus for making an untrimmed container body from a pre-cut metal blank, comprising:
 shaping tools and actuators for operating said tools with sufficient force for shaping said blank into an untrimmed container body; and   a support structure for supporting said shaping tools and actuators while allowing necessary movements of some of said tools;   wherein said shaping tools include:   a combined draw punch and redraw die comprising an annular body having an inner surface, an outer surface and an end surface defining an opening at an operational end of the annular body that initially contacts said blank, said end surface and said outer surface together functioning in use as said draw punch, and said inner surface functioning in use as said redraw die, said annular body being fixed on said structure against movement relative thereto during use;   a draw die having a die surface dimensioned to encircle said outer surface of said annular body at a spacing effective for cupping of said blank, said draw die being movable in use along said outer surface from said operational end to form a cup from said blank;   a redraw punch comprising a cylinder having an outer surface dimensioned to penetrate said opening at said operational end of said annular body with a spacing from said inner surface effective for redrawing said cup, said redraw punch being movable at a leading end thereof into said opening and through said annular body to invert said cup to thereby form an inverted redrawn cup having an open end and a closed end; and   one or more ironing rings aligned with said annular body and positioned to iron an outer surface of said inverted redrawn cup supported on said leading end of said redraw punch after said leading end passes through and emerges from said annular body, to thereby lengthen said inverted redrawn cup to form an untrimmed container body having a closed end.   
     
     
         14 . The apparatus of  claim 13 , wherein said tools further include an annular redraw holder operationally connected to said draw die such that, when said draw die has completed a drawing operation on said metal blank to form a cup, said redraw holder confronts said operational end of said combined draw punch and redraw die and holds an outer part of said cup against said combined draw punch and redraw die with a force that allows said outer part to be withdrawn and guided during redrawing of said cup. 
     
     
         15 . The apparatus of  claim 14 , wherein said tools further include an annular draw holder confronting said annular draw die and adapted to grip a periphery of said blank between said annular draw holder and said annular draw die with a force that allows said periphery to be withdrawn and guided during drawing of said blank. 
     
     
         16 . The apparatus of  claim 14 , wherein said tools further include a container body end shaper positioned in spaced alignment with said one or more ironing rings to contact said closed end of said untrimmed container body supported on said operational end of said redraw punch, said shaper being profiled to shape said closed end when said closed end is forced thereagainst by said redraw punch. 
     
     
         17 . A method of making an untrimmed container body from a pre-cut metal blank, comprising:
 cupping a pre-cut metal blank by positioning the blank against an immovable draw punch comprising an annular body having an inner surface adapted to form a redraw die and an outer surface, and drawing a periphery of the blank over said outer surface of the draw punch with an encircling draw die to form a cup having an open end, a closed end and an interior;   inverting and redrawing said cup by forcing a redraw punch into said closed end to draw said closed end through said redraw die until said cup is inverted to form an inverted cup supported on said punch, said inverted cup having a closed end;   passing the inverted cup while supported on said redraw punch through one or more ironing rings to lengthen said inverted cup to form an untrimmed container body having a closed end; and   withdrawing said punch from said untrimmed container body.   
     
     
         18 . The method of  claim 17 , further comprising shaping said closed end of said untrimmed container body by engaging said closed end of said untrimmed container body with one or more end shaping tools while supported on said redraw punch. 
     
     
         19 . The method of  claim 17 , wherein, before redrawing said cup, part of said cup is gripped between a redraw holder and said draw punch, said redraw holder being operationally connected to said draw die such that said redraw holder is moved into position to grip said cup as said draw die completes said cupping of said blank. 
     
     
         20 . Apparatus for making an untrimmed container body from metal sheet, comprising:
 shaping tools and actuators for operating said tools with sufficient force for cutting a metal blank from the sheet and shaping the blank into an untrimmed container body; and   a support structure for supporting said shaping tools and actuators while allowing necessary movements of some of said tools;   wherein said shaping tools include:   a combined draw punch and redraw die comprising an annular body having an inner surface, an outer surface and an end surface defining an opening at an operational end of the annular body that initially contacts said metal blank, said end surface and said outer surface together functioning in use as said draw punch, and said inner surface functioning in use as said redraw die, said annular body being fixed on said structure against movement relative thereto during use;   a draw die having a die surface dimensioned to encircle said outer surface of said annular body at a spacing effective for cupping of said blank, said draw die being movable in use along said outer surface from said operational end to form a cup from said blank;   a redraw punch comprising a cylinder having an outer surface dimensioned to penetrate said opening at said operational end of said annular body with a spacing from said inner surface effective for redrawing said cup, said redraw punch being movable at a leading end thereof into said opening and through said annular body to invert said cup to thereby form an inverted redrawn cup having an open end and a closed end; and   one or more ironing rings aligned with said annular body and positioned to iron an outer surface of said inverted redrawn cup supported on said leading end of said redraw punch after said leading end passes through and emerges from said annular body, to thereby lengthen said inverted redrawn cup to form an untrimmed container body having a closed end.   
     
     
         21 . The apparatus of  claim 20 , wherein said tools further include an annular redraw holder operationally connected to said draw die such that, when said draw die has completed a drawing operation on said metal blank to form a cup, said redraw holder confronts said operational end of said combined draw punch and redraw die and holds an outer part of said cup against said combined draw punch and redraw die with a force that allows said outer part to be withdrawn and guided during redrawing of said cup. 
     
     
         22 . The apparatus of  claim 21 , wherein said tools further include an annular draw holder confronting said annular draw die and adapted to grip a periphery of said blank between said annular draw holder and said annular draw die with a force that allows said periphery to be withdrawn and guided during drawing of said blank. 
     
     
         23 . The apparatus of  claim 21 , wherein said tools further include a container body end shaper positioned in spaced alignment with said one or more ironing rings to contact said closed end of said untrimmed container body supported on said operational end of said redraw punch, said shaper being profiled to shape said closed end when said closed end is forced thereagainst by said redraw punch. 
     
     
         24 . The apparatus of  claim 20 , wherein said tools further include an annular cutter fixed to said support structure, said cutter having an annular cutting edge operationally positioned relative to an outer periphery of said draw die to cut said blank from said metal sheet when said draw die is moved relative to said cutting edge with said sheet positioned therebetween. 
     
     
         25 . The apparatus of  claim 24 , further comprising equipment for passing said metal sheet through said apparatus at a position between said cutter and said draw die. 
     
     
         26 . A method of making an untrimmed container body from a metal sheet, comprising:
 cupping a metal blank cut from said sheet by positioning the blank against an immovable draw punch comprising an annular body having an inner surface adapted to form a redraw die and an outer surface, and drawing a periphery of the blank over said outer surface of the draw punch with an encircling draw die to form a cup having an open end, a closed end and an interior;   inverting and redrawing said cup by forcing a redraw punch into said closed end to draw said closed end through said redraw die until said cup is inverted to form an inverted cup supported on said punch, said inverted cup having a closed end;   passing the inverted cup while supported on said redraw punch through one or more ironing rings to lengthen said inverted cup to form an untrimmed container body having a closed end; and   withdrawing said punch from said untrimmed container body.   
     
     
         27 . The method of  claim 26 , further comprising shaping said closed end of said untrimmed container body by engaging said closed end of said untrimmed container body with one or more end shaping tools while supported on said redraw punch. 
     
     
         28 . The method of  claim 26 , wherein, before redrawing said cup, part of said cup is gripped between a redraw holder and said draw punch, said redraw holder being operationally connected to said draw die such that said redraw holder is moved into position to grip said cup as said draw die completes said cupping of said blank. 
     
     
         29 . The method of  claim 26 , wherein said metal blank is cut from said metal sheet just as said blank is positioned against said immovable draw punch. 
     
     
         30 . The method of  claim 29 , wherein said sheet has greater width than a diameter of said metal blank, and residue from said metal sheet is removed after said withdrawal of said punch from said untrimmed container body.