Patent ID: 6558594
Filing Date: 2003-05-06
Classification: B29C,B30B,H01M,Y02P

Abstract:
A powder compression molding method for producing hollow cylindrical pellets comprising the steps of:lowering a lower plunger and a center pin both mounted coaxially in a cylindrical die to a first position; supplying a powder into the cylindrical die; lifting the lower plunger and the center pin to a second position; removing an extra of the powder to cause a given amount of the powder corresponding to one pellet to remain in the die; lowering an upper plunger to close the cylindrical die at a top end thereof with a lower end of the upper plunger; lifting up the center pin to extend through the powder, thereby defining an annular molding space between the center pin and the cylindrical die; compressing the powder in the annular space between the upper plunger and the lower plunger to form the pellet; lifting up the center pin simultaneously with the lower plunger to push the formed pellet upwardly to the outside; and withdrawing the center pin from the pellet after the center pin and the pellet have been transferred from the annular molding space.