Device for forming annular articles from powder material

Abstract

The present invention relates to a device for forming tubular articles from powder material including an upper pressing punch, a lower punch, a core pin and a matrix having an inner periphery corresponding to the outer periphery of the upper and lower punch, a molding cavity being defined between the upper and lower punch, the core pin and the matrix, whereby the core pin is movable in relation to the matrix. According to the invention the upper pressing punch is arranged to actuate movement of the core pin or the matrix during compacting of a powder in the molding cavity so that the pressing punch and the core pin or the matrix move together.

What is claimed is:  
     
         1 . A device for forming tubular articles from powder material comprising an upper pressing punch, a lower punch, a core pin and a matrix having an inner periphery corresponding to an outer periphery of the upper and lower punch, a molding cavity being defined between the upper and lower punch, the core pin and the matrix, whereby the core pin is movable in relation to the matrix, wherein the upper pressing punch is arranged to actuate movement of the core pin or the matrix during compacting of a powder in the molding cavity so that the pressing punch and the core pin or the matrix move together.  
     
     
         2 . The device according to  claim 1 , wherein the core pin is an integral part of the upper pressing punch.  
     
     
         3 . The device according to  claim 1 , wherein the core pin is movable between a first position in which the upper end thereof is located in line with or above the upper wall of the matrix and a second position in which the upper wall of the core pin is located below the upper wall of the matrix.  
     
     
         4 . The device according to  claim 3 , wherein the core pin is biased against the first position.  
     
     
         5 . The device according to  claim 3 , wherein the upper pressing punch in the first position has a part of its lower wall in contact with the upper end wall of the core pin so that the pressing punch will force the core pin to follow downwards movement thereof from its first position, and that the upper pressing punch is moveable upwards from its first position in order to open the molding cavity ( 4 ) for insertion of powder material.  
     
     
         6 . The device according to  claim 1 , wherein the lower punch is upwardly moveable in order to eject a compacted article from the molding cavity.