Die set, machine and method for forming die-pressed cartridge cases

Abstract

Die set for forming cartridge cases ( 1;101 ), comprising at least three support elements, i.e. an upper element ( 1100 ), middle element ( 1200 ) and bottom element ( 1300 ), which are connected together in the longitudinal direction by guide columns ( 1001 ) along which said upper support ( 1100 ) and bottom support ( 1300 ) are actuated displaceably relative to each other in predefined working sequences.

1 . Die set for forming cartridge cases ( 1 ; 101 ), comprising at least three support elements, i.e. an upper element ( 1100 ), middle element ( 1200 ) and bottom element ( 1300 ), characterized in that they are connected together in the longitudinal direction by guide columns ( 1001 ) along which said upper support ( 1100 ) and bottom support ( 1300 ) are actuated displaceably relative to each other in predefined working sequences, in that said upper support element ( 1100 ) and bottom support element ( 1300 ) are movable relative to the fixed middle element ( 1200 ) and in that said middle support element ( 1200 ) comprises means ( 1230 ) for shearing and means ( 1240 ) for forming the case ( 1 ; 100 ) able to co-operate with corresponding locating means ( 1330 , 1340 ) associated with said bottom support element ( 1300 ).  
   
   
       2 . Die set according to  claim 1 , characterized in that said means ( 1230 ) for shearing and means ( 1240 ) for forming the case ( 1 ; 101 ) comprise a sleeve ( 1210 ) extending in the axial direction and constrained to the middle support element; by means of internally threaded elements ( 1211 ) suitable for mating with the threaded opposite ends ( 1210   a ) of the said sleeve.  
   
   
       3 . Die set according to  claim 1 , characterized in that said means ( 1230 ) for shearing and means ( 1240 ) for forming the case ( 1 ; 101 ) comprise a blanking punch ( 1230 ) arranged inside the sleeve ( 1210 ) and coaxially arranged so as to extend outside the side of the middle support element ( 1200 ) directed towards the bottom element ( 1300 ).  
   
   
       4 . Die set according to  claim 3 , characterized in that the opposite ends of said blanking punch ( 1230 ) are respectively locked inside said sleeve ( 1210 ) and axially project towards the outside of the middle support element.  
   
   
       5 . Die set according to  claim 2 , characterized in that said sleeve ( 1210 ) has, arranged coaxially inside it, a containing bush ( 1220 ) housing internally an adjustable-load spring ( 1221 ), the opposite ends of which bear respectively against a closing element ( 1222 ) and against the said blanking punch ( 1230 ).  
   
   
       6 . Die set according to  claim 1 , characterized in that said forming means comprise a drawing punch ( 1240 ) integral with one end of a rod ( 1241 ), the opposite end of which is integrally fixed to the upper support element ( 1100 ) with the arrangement of a spring ( 1243 ) in between.  
   
   
       7 . Die set according to  claim 6 , characterized in that said rod ( 1241 ) has passing through it axially a duct ( 1242 ) for supplying air to the drawing punch ( 1240 ).  
   
   
       8 . Die according to  claim 6 , characterized in that said rod ( 1241 ) passes coaxially through the closing element ( 1222 ) and the spring ( 1221 ).  
   
   
       9 . Die set according to  claim 6 , characterized in that the end part of the drawing punch ( 1240 ) directed towards the top part of the die set has a seat ( 1245   a ) able to contain a shearing ring ( 1245 ).  
   
   
       10 . Die set according to  claim 6 , characterized in that the end part of the blanking punch ( 1240 ) has an axial seat ( 1241 ) able to contain in the boring tip ( 1353 ).  
   
   
       11 . Die set according to  claim 1 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, a shearing die ( 1330 ).  
   
   
       12 . Die set according to  claim 11 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, a drawing die ( 1340 ) coaxial with said shearing die ( 1330 ).  
   
   
       13 . Die set according to  claim 1 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, an extractor ( 1360 ).  
   
   
       14 . Die set according to  claim 1 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, a boring punch ( 1350 ).  
   
   
       15 . Die set according to  claim 11 , characterized in that the shearing die ( 1330 ) is axially fixed to the bottom support element ( 1300 ).  
   
   
       16 . Die set according to  claim 12 , characterized in that the drawing die ( 1340 ) is axially fixed to the bottom support element ( 1300 ).  
   
   
       17 . Die set according to  claim 14 , characterized in that the boring punch ( 1350 ) is axially fixed to the bottom support element ( 1300 ).  
   
   
       18 . Die set according to  claim 13 , characterized in that said extractor ( 1360 ) comprises a cup member ( 1361 ) movable axially against the thrusting action of spring means ( 1362 ).  
   
   
       19 . Die set according to  claim 17 , characterized in that said cup member ( 1361 ) has a coaxial opening ( 1361   a ) able to allow means ( 1350 ) for boring the case ( 1 ; 101 ) to pass through.  
   
   
       20 . Die get according to  claim 14 , characterized in that said boring punch ( 1350 ) comprises a tip ( 1353 ) integral with the top end of a column ( 1352 ).  
   
   
       21 . Die set according to  claim 21 , characterized in that the boring punch ( 1352 ) comprises an annular surface ( 1370 ) arranged coaxially with the said punch and at a suitable axial distance from the boring tip ( 1353 ), the said annular surface being provided with reliefs ( 1371 , 1372 ) for engraving the bottom of the case ( 1 ; 101 ).  
   
   
       22 . Die set according to  claim 21 , characterized in that the forming punch ( 1240 ) envisages a free surface for making contact with the disk ( 10 ), associated with a surface ( 1270 ) on which recesses ( 1271 , 1272 ) corresponding to the reliefs ( 1371 , 1372 ) on the annular engraving surface ( 1370 ) are formed.  
   
   
       23 . Die set according to  claim 1 , characterized in that it comprises an element ( 1310 ) for axially closing the seat housing the said boring means ( 1350 ).  
   
   
       24 . Die set according to  claim 1 , characterized in that said case ( 101 ) has a surface graphically pre-printed in one or more colours.  
   
   
       25 . Machine for forming a case ( 1 ; 101 ), comprising a die set comprising at least three support elements, i.e. upper element ( 1100 ), middle element ( 1200 ) and bottom element ( 1300 ), characterized in that they are connected together in the longitudinal direction by guide columns ( 1001 ) and/or by sliding surfaces along which said upper support element ( 1100 ), middle support element ( 1200 ) and bottom support element ( 1300 ) are actuated displaceably relative to each other in predefined working sequences, in that said middle support element ( 1200 ) is fixed and in that said middle support element ( 1200 ) comprises shearing means ( 1230 ) and means ( 1240 ) for forming the case ( 1 ; 101 ), able to co-operate with corresponding means ( 1330 , 1340 ) associated with said bottom support element ( 1300 ).  
   
   
       26 . Machine according to  claim 25 , characterized in that it is a press.  
   
   
       27 . Machine according to  claim 25 , characterized in that said shearing means ( 1230 ) and means ( 1240 ) for forming the case ( 1 ; 101 ) comprise a sleeve ( 1210 ) extending in the axial direction and constrained to the middle support element by means of internally threaded elements ( 1211 ) suitable for mating with the threaded opposite ends ( 1210   a ) of the said sleeve.  
   
   
       28 . Machine according to  claim 25 , characterized in that said means ( 1230 ) for shearing and means ( 1240 ) for forming the case ( 1 ; 101 ) comprise a blanking punch ( 1230 ) arranged inside the sleeve ( 1210 ) and co-axially arranged so as to extend outside the side of the middle support element ( 1200 ) directed towards the bottom element ( 1300 ).  
   
   
       29 . Machine according to  claim 27 , characterized in that the opposite ends of said blanking punch ( 1230 ) are respectively locked inside said sleeve ( 1210 ) and axially project towards the outside of the middle support element.  
   
   
       30 . Machine according to  claim 26 , characterized in that said sleeve ( 1210 ) has, arranged coaxially inside it, a containing bush ( 1220 ) housing internally an spring ( 1221 ), the opposite ends of which bear respectively against a closing element ( 1222 ) and against said blanking punch ( 1230 ).  
   
   
       31 . Machine according to  claim 25 , characterized in that said forming means comprise a drawing punch ( 1240 ) integral with one end of a rod ( 1241 ), the opposite end of which is integrally joined to the upper support element ( 1100 ) with the arrangement of a spring ( 1243 ) in between.  
   
   
       32 . Machine according to  claim 30 , characterized in that said rod ( 1241 ) has passing through it axially a duct ( 1242 ) for supplying air to the drawing punch ( 1240 ).  
   
   
       33 . Machine according to  claim 30 , characterized in that said rod ( 1241 ) passes coaxially through the closing element ( 1222 ) and the spring ( 1221 ).  
   
   
       34 . Machine according to  claim 30 , characterized in that the end part of the drawing punch ( 1240 ) directed towards the inside of the riddle support element ( 1200 ) has a seat ( 1245   a ) able to contain a shearing ring ( 1245 ).  
   
   
       35 . Machine according to  claim 30 , characterized in that the end part of the drawing punch ( 1240 ) directed towards the upper support of the die set has a seat ( 1241 ) able to contain the tip ( 1353 ) of the boring punch ( 1352 ).  
   
   
       36 . Machine according to  claim 25 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, a shearing die ( 1330 ).  
   
   
       37 . Machine according to  claim 25 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, a drawing die ( 1340 ) coaxial with said shearing die ( 1330 ).  
   
   
       38 . Machine according to  claim 25 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, an extractor.  
   
   
       39 . Machine according to  claim 25 , characterized in that the bottom support element ( 1300 ) has, inserted inside it, a boring punch ( 1350 ).  
   
   
       40 . Machine according to  claim 35 , characterized in that the shearing die ( 1330 ) is axially fixed to the bottom support element ( 1300 ).  
   
   
       41 . Machine according to  claim 36 , characterized in that the drawing die ( 1340 ) is axially fixed to the bottom support element ( 1300 ).  
   
   
       42 . Machine according to  claim 39 , characterized in that the boring punch ( 1350 ) is axially fixed to the bottom support element ( 1300 ).  
   
   
       43 . Machine according to  claim 37 , characterized in that said extractor ( 1360 ) is formed by a cup member ( 1361 ) movable axially against the thrusting action of spring means ( 1362 ).  
   
   
       44 . Machine according to  claim 42 , characterized in that said cup member ( 1361 ) has an opening ( 1361   a ) allowing means for boring the bottom of the case ( 1 ; 01 ) to pass through.  
   
   
       45 . Machine according to  claim 28 , characterized in that said boring punch ( 1350 ) comprises a tip ( 1353 ) integral with the top end of a column ( 1352 ).  
   
   
       46 . Machine according to  claim 38 , characterized in that said boring punch ( 1352 ) comprises an annular surface ( 1370 ) arranged coaxially with the said punch and at a suitable axial distance from the boring tip ( 1353 ), the said annular surface being provided with reliefs ( 1371 , 1372 ) for engraving the bottom of the case ( 1 ; 101 ).  
   
   
       47 . Machine according to  claim 45 , characterized in that the forming punch ( 1240 ) envisages a free surface associated with a surface ( 1270 ) on which recesses ( 1271 , 1272 ) corresponding to reliefs on the annular engraving surface are formed.  
   
   
       48 . Machine according to  claim 25 , characterized in that it comprises an element ( 1310 ) for axially closing the seat housing the said boring means ( 1350 ).  
   
   
       49 . Machine according to  claim 25 , characterized in that said case ( 101 ) has a pre-printed surface.  
   
   
       50 . Method for forming a cartridge case ( 1 ;  101 ), characterized in that it comprises the following-steps: 
 e) supplying a sheet of metal ( 10 ) to a forming machine ( 20 );    f) forming and boring the case ( 1 ; 101 ) in a single stage by three coaxial movements of a forming die set;    g) extraction of the formed and bored case ( 1 ; 101 ).    
   
   
       51 . Method according to  claim 50 , characterized in that said metal sheet ( 10 ) is cut to a predefined size.  
   
   
       52 . Method according to  claim 50 , characterized in that said forming operation is a drawing operation.  
   
   
       53 . Method according to  claim 50 , characterized in that said forming and boring operations are performed.  
   
   
       54 . Method according to  claim 50 , characterized in that the case obtained ( 1 ; 101 ) has a substantially constant thickness along the side surface and bottom.  
   
   
       55 . Method according to  claim 50 , characterized in that it comprises a further step for widening the bottom ( 1   b ) of the case ( 1 ; 101 ).  
   
   
       56 . Method according to  claim 50 , characterized in that it comprises a further step for printing the bottom ( 1   b ) and/or the external side surface of the case ( 1 ; 101 ).  
   
   
       57 . Method according to  claim 56 , characterized in that said further printing step is performed in-line.  
   
   
       58 . Method according to  claim 56 , characterized in that said further printing step consists in tampography, serigraphy or printing with an electronic pen.  
   
   
       59 . Method according to claim  90 , characterized in that the material used for forming the case is steel.  
   
   
       60 . Method according to  claim 59 , characterized in that the said material is preferably steel lined electrolytically and/or suitable for combination with a film of metal such as brass, stainless steel, zinc, aluminium, titanium, copper and/or plastic.  
   
   
       61 . Method according to  claim 59 , characterized in that said material is preferably steel lined with tin.  
   
   
       62 . Method according to  claim 59 , characterized in that the case ( 1 ; 101 ) comprises a further step for painting the cut edges.  
   
   
       63 . Method according to  claim 61 , characterized in that said painting is performed by means of electrophoresis.  
   
   
       64 . Method according to  claim 50 , characterized in that said material is preferably aluminium and alloys thereof.  
   
   
       65 . Method according to  claim 50 , characterized in that it comprises the following steps) downstream of the step for cutting the sheet ( 10 ) and upstream of the step for forming the case ( 1 ; 101 ): 
 b) lithographic printing of a surface of the sheet ( 10 ;    c) varnishing the printed sheet ( 10 ) with a layer of protective varnish;    d) polymerization of the print and the varnish.    
   
   
       66 . Method according to  claim 65 , characterized in that the protective varnish applied to the print is of the polyester, epoxy ureic, polyurethane, epoxide type containing zirconium or water.  
   
   
       67 . Method according to  claim 65 , characterized in that polymerization of the print and the varnish is performed using hot air.  
   
   
       68 . Method according to  claim 67 , characterized in that the temperature of the hot-air oven is kept between 180° and 220° C.  
   
   
       69 . Method according to  claim 68 , characterized in that the temperature of the hot-air oven is preferably kept between 195° and 205° C.  
   
   
       70 . Method according to  claim 65 , characterized in that polymerization of the print and the varnish is performed using UV rays.  
   
   
       71 . Method according to  claim 50  or  65 , characterized in that it envisages a step involving engraving of the bottom of the case during boring thereof.