Tool for forming the bottom of cans

Abstract

A known tool for forming a container bottom, in particular the bottom of a beverage can is provided with an ejector 23 which is of sleeve-like shape and arranged between a downholder 14 and a dome 12. The ejector 23 is biased by a spring means 26 against the activating direction of a punch 3 with a pre-tensioning force which is substantially lower than the counter force of the downholder. The spring means 26 can be formed by compression springs 27, 28 which are arranged in axial cavities formed in the front face of the ejector 23. The ejector force can be changed by changing the compression springs or the number of compression springs.

1 . A deep draw tool ( 2 ) for forming container bottoms ( 17 ) in particular bottoms of two-part beverage cans or aerosol cans, the deep draw tool ( 2 ) having open and closed positions comprising:
 a first tool part ( 3 ) including a punch ( 3 ) having a shape adapted to the desired inner shape of a can,   a second tool part ( 4 ) including a dome ( 12 ) and an annular downholder ( 14 ) arranged concentrically with the dome ( 12 ) and supported movably relative to the dome ( 12 ) and subjected to a downholder ( 14 ) force,   an ejector ( 23 ) which is annular and arranged concentrically around the dome ( 12 ), and   a spring means ( 26 ) resiliently supporting the ejector ( 23 ).   
     
     
         2 . The deep draw tool according to  claim 1 , wherein the ejector ( 23 ) is biased toward the punch ( 3 ) by an ejection force which is lower than the downholder ( 14 ) force. 
     
     
         3 . The deep draw tool according to  claim 1 , wherein the ejector ( 23 ) is supported on the downholder ( 14 ) via the spring means ( 26 ). 
     
     
         4 . The deep draw tool according to  claim 1 , wherein the spring means ( 26 ) is formed by a number of compression springs ( 27 ,  28 ) which are arranged in axial bores of the ejector. 
     
     
         5 . The deep draw tool according to  claim 1 , wherein the downholder ( 14 ) is associated with a pneumatic cylinder ( 20 ) for generating the downholder force. 
     
     
         6 . The deep draw tool according to  claim 1 , wherein the ejector ( 23 ) has an ejector stroke, the downholder ( 14 ) has a downholder ( 14 ) stroke and the ejector ( 23 ) stroke is greater than the downholder ( 14 ) stroke. 
     
     
         7 . The deep draw tool according to  claim 1 , wherein the ejector ( 23 ) has an upper annular surface ( 24 ), the downholder ( 14 ) has an upper shaped surface ( 15 ) and the upper annular surface ( 24 ) is disposed at the upper end ( 29 ) of the shaped surface ( 15 ) when the deep draw tool ( 2 ) is the open position. 
     
     
         8 . The deep draw tool according to  claim 7 , wherein the annular surface ( 24 ) is disposed at the lower edge ( 32 ) of the shaped surface ( 15 ) when the deep-draw tool ( 2 ) is in the closed position. 
     
     
         9 . The deep draw tool according to  claim 1 , wherein the downholder ( 14 ) and the ejector ( 23 ) are in the form of concentric rings which are axially adjustable relative to each other. 
     
     
         10 . The deep draw tool according to  claim 1 , wherein the ejector ( 23 ) is arranged between the downholder ( 14 ) and the dome ( 12 ).