AS THE HP 500 SH CRUSHER WAS BEING REASSBLED THERE WAS A HYD. CLAMPING CYLINDER LEAKING. THE REMOVED THE CYLINDER THE DUST SHELL WAS TAKEN FROM NORMAL POSITION AND SET ON THE CRUSHER. INJURED EE WAS DISCONNECTING HYD LINE WHEN THREE EES ATTEMPED TO REMOVE DUST SHELL COMPLETELY FROM CRUSHER-IN DOING SO THE DUST SHELL SLID INTO THE ORIGNIAL POSITION HITTING EE IN RIGHT HAND.