Shredder

Claim 2

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 about a generally horizontal axis; a set of fingers interdigitated with the flails and mounted on the stationary hopper floor adjacent the inlet, the fingers extending toward the hammer-mill only on the side of the hammer-mill where rotation of the hammer-mill tends to force material downwardly out of the hopper, the balance of the inlet being completely unobstructed; 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 operating along a horizontal axis; and drive means arranged to drive the rotatable hopper, rotary hammer-mill and reciprocating pusher.

Claim 3

A shredder according to claim 1 wherein the receiving hopper further comprises paddle means mounted thereto and rotatable therewith for rotating the material to be shredded.

Claim 4

A shredder according to claim 1 wherein the hammer-mill is located eccentrically of the hopper and to one side of the vertical axis.

Claim 5

A shredder according to claim 1 wherein the hammer-mill rotatable body comprises a plurality of rods to which the flails are loosely attached in a parallel array around a central driven shaft.

Claim 6

A shredder according to claim 1 which further comprises a deflector plate mounted on the stationary floor and closely approaching the hammer-mill at a side opposite the set of fingers, to help prevent shredded material being deposited back into the hopper.

Claim 7

A shredder according to claim 1 wherein there is a clearance between the hammer-mill and the screen, which is greatest adjacent the hopper and least at a lower side of the screen.

Claim 8

A shredder according to claim 1 wherein the pusher means comprises a reciprocating plunger located in the duct, which withdraws to allow shredded material to fall into the space in the duct between the plunger and the non-return flap, and which extends to compact the material and discharge it past the flap.

Claim 9

A shredder according to claim 1 which is further provided with transportation means allowing the shredder to be transported for use on-site.

Claim 10

A shredder according to claim 1 wherein the reciprocating pusher means reciprocates a plurality of cycles per minute during shredding of material.

Claim 11

A shredder according to claim 9 wherein the reciprocating pusher means reciprocates about fifty cycles per minute during shredding of material.

Claim 12

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.

Claim 13

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.

Claim 14

A shredder according to claim 11 wherein the reciprocating pusher means reciprocates about fifty cycles per minute during a shredding operation.