INSTALLATION OF OUR IMPACT HAMMER IS INCOMPLETE RESULTING IN EE USING A PRY BAR TO LOOSEN STUCK/JAMMED ROCK AT OR NEAR THE CRUSHER OPENING. INJURED EE WAS INGAGED IN THIS VERY ACT WHEN HE SMAS ED HIS FINGER BETWEEN THE BAR AND THE SIDE WALL OF THE CRUSHER BODY. THIS RESULTED IN A LACERATION REQUIRING 5 FIVE SUTURES. EE RETURNED TO REGULAR DUTIES THAT MORNING.