Patent ID: 8734712

Claim:
A method for manufacturing a green body ( 10 ) comprising the steps of: (i) providing a tool set ( 40 ) having a central axis (A) defining axial and radial directions, and comprising: a base body ( 42 ) having a base through hole ( 50 ), a plurality of radially directed punch channels ( 52 ) and a plurality of radially directed die channels ( 54 ); a cover plate ( 44 ) mountable on the base body ( 42 ), the cover plate ( 44 ) having a plate through hole ( 46 ), the central axis (A) passing through the base and plate through holes ( 50 , 46 ) when the cover plate ( 44 ) is mounted on the base body ( 42 ); an upper punch ( 56 ) and an opposing lower punch ( 58 ), the upper punch ( 56 ) being axially moveable through the plate through hole ( 46 ), the lower punch ( 58 ) being axially moveable through the base through hole ( 50 ); a plurality of side punches ( 60 ) arranged in opposing pairs, the side punches being radially moveable in the punch channels ( 52 ); and a plurality of die rods ( 74 ) radially moveable in the die channels ( 54 ), each die rod ( 74 ) being common to and located between two adjacent side punches ( 60 ), each die rod ( 74 ) having a forward die shaping surface ( 78 ) and two die guiding surfaces ( 82 ) diverging rearwardly therefrom; wherein the two adjacent side punches ( 60 ) are slidably moveable on the die guiding surfaces ( 82 ) of the common die rod ( 74 ); (ii) establishing an initial closed cavity (ICC) between the upper and lower punches ( 56 , 58 ), the side punches ( 60 ) and the die rods ( 74 ), with a predetermined amount of sinterable powder located in the initial closed cavity (ICC); (iii) deriving a final closed cavity (FCC) from the initial closed cavity (ICC) by urging the upper and lower punches ( 56 , 58 ) towards each other and by urging the side punches ( 60 ) of opposing pairs of side punches ( 60 ) towards each other with each two adjacent side punches ( 60 ) moving slidably on the die guiding surfaces ( 82 ) of a common die rod ( 74 ) whilst maintaining the die rods ( 74 ) stationary with respect to the side punches ( 60 ) thereby compacting the sinterable powder to form the green body ( 10 ); and (iv) bringing the tool set ( 40 ) to a removal configuration by removing the upper punch ( 56 ) and the cover plate ( 44 ) from the base body ( 42 ), withdrawing the die rods ( 74 ) and the side punches ( 60 ) to a position remote from the green body ( 10 ) and bringing the lower punch ( 58 ) to a lower punch removal position wherein the lower punch ( 58 ) protrudes from the base through hole ( 50 ) thereby enabling removal of the green body ( 10 ).