Method of and a device for sorting pellets upon their molding in a preforming press

Claim 1

In a preforming press having a rotary die disk, a punching station having punching means cooperating with said disk to mold pellets in said die disk within a predetermined range of compressing forces, and a device for sorting the completed pellets, said sorting device comprising means for measuring the compressing force exerted by said punching means during the molding process; pellet ejecting means arranged in the range of said disk downstream of said punching station, said pellet ejecting means including a solenoid and a guide partition operatively connected thereto; an electronic measuring circuit for evaluating the applied compressing force to measure the quality of the resulting pellet; a first proximity switch cooperating with said punching means for activating said measuring circuit at the moment of maximum compressing force; and an electronic control circuit for actuating said ejecting means, said control circuit including a time-setting circuit cooperating with said measuring circuit, a second proximity switch cooperating with said punching means to generate a signal the duration of which is a function of the speed of travel of said punching means and of the rotational speed of said die disk, said signal being applied to said time-setting circuit to determine the beginning of the activation of said control circuit in response to the speed of said die disk, said solenoid being activated by said time-setting circuit to thereby move said guide partition between a lower pellet ejecting position and an upper pellet passing position in response to said signal.