Shredder

A shredder for shredding bulk waster paper cardboard, packaging material, microfilm, microfiche and other sheet material, comprising

• a receiving hopper for receiving material to be shredded which is rotatably mounted for rotation about a vertical axis, and having a stationary floor;
• a rotary hammer-mill disposed below the hopper floor and protruding through a hammer-mill inlet into the hopper for shredding material contained in the hopper, the hammer-mill comprising a plurality of flails loosely mounted to the circumference of a body rotatably mounted on a generally horizontal axis, the inlet of the hammer-mill being substantially completely unobstructed to facilitate receiving material form the hopper;
• a set of fingers interdigitated with the flails and mounted on the stationary hopper floor, the fingers extending toward the hammer-mill only adjacent the side of the hammer-mill where rotation of the hammer-mill tends to force material downwardly out of the hopper;
• a perforated screen partially enclosing the hammer-mill below the hopper floor and through which the shredded material passes when it has reached a chosen level of comminution;
• reciprocating pusher means disposed in a horizontally extending duct arranged to receive the shredded material from the screen and to compact the shredded material, before discharging it from the duct past a non-return flap hingedly mounted at an outlet from the duct, said pusher means reciprocating a plurality of cycles per minute along a horizontal axis at least during shredding of material;
• and
• drive means arranged to drive the rotatable hopper, rotary hammer-mill and reciprocating pusher.