Abstract: A blockage clearance apparatus for a crusher that has a housing and a lid and at least one anvil mounted to the lid for crushing material. The housing contains a rotatable rotor with radial blow bars against which crushable materials are forced during operation. In operation, the materials are fed into the crusher, impacted by at least two blow bars and thrown against at least one anvil for crushing. The blockage clearance apparatus includes means for moving the lid and the anvil relative to the rotor during operation, means for inhibiting the material in the housing from exiting the housing when the lid is spaced from the housing during operation, and means for stopping movement of the lid relative to the rotor.