Compact shredder and compactor

Abstract

A shredder includes a feed screw that pushes the items to be shredded and compacted towards an opening in the shredder via a restrictor that includes a pipe portion leading to the opening in the shredder, the shredder includes a drive motor driving a miller screw which shreds the items to be shredded into acquired size against a cutter plate fastened to a cutter housing to form shredded items, and forces the shredded items into a press chamber.

Claims

1. A shredder comprising a feed screw that pushes items to be shredded and compacted towards an opening in the shredder via a restrictor comprising a pipe portion leading to the opening in the shredder, the shredder comprising a drive motor driving a miller screw within a cutter housing, wherein the miller screw shreds the items to be shredded into acquired size against a cutter plate within the cutter housing to form shredded items, and forces the shredded items into a press chamber, wherein the cutter housing is constructed to be rotated to reject solid slugs, and further comprising a tilt cylinder constructed to rotate the cutter housing about the miller screw.

2. The shredder according to claim 1, wherein the items to be shredded and compacted comprise chips, and the chips are received in the shredder radially and the shredded items are redirected axially and compressed in the press chamber.

3. The shredder according to claim 1, wherein a chip box comprising the restrictor is constructed to be flipped up for easy cleaning access when changing alloys to be pressed.

Description

DESCRIPTION OF EMBODIMENTS

(1) With reference to FIG. 1, a compact shredder and compactor according to the present invention is shown, Metal chips to be compacted into briquettes are dumped in a chip box (A1) by e.g. a CNC machine conveyor or manually by person (not shown). A feed screw (A2) pushes the chips towards an opening in a cutter (see FIG. 2) via a restrictor (A3) comprising a pipe like portion leading to the opening in the cutter. With reference to FIGS. 2-4, the cutter comprises a drive motor (B1) placed on one end of the cutter housing (B2) having internal spiral grooves (C4) and driving a miller screw (B3), i.e. a screw providing both a cutting action and a transporting action for items having been cut, which shreds, or cuts, long chips into acquired size against a cutter plate (B4) fastened to the cutter housing. Chips in the desired size are then forced in the axial direction of the miller screw into a press chamber (C3). Once a desired amount of chips are gathered in the press chamber, the chips are compacted by a piston having a shape corresponding to the press chamber and being powered by e.g. a hydraulic piston (C1) arranged in one end of the press chamber. After the compression, a gate (C2) at an opposite end of the press chamber opens and compacted slugs are pushed out by the piston maneuvered by the hydraulic press piston (C1).

(2) If any solid slug would block the miller screw (B3), a tilt cylinder (B5) will rotate the cutter housing (B2), such that the solid slug will not be engaged by the miller screw and the cutter plate and hence be rejectable, e.g. by the force of gravity once the cutter housing has rotated such that the opening points downwards. After the solid slug has been rejected, the cutter housing will be rotated back to its original position and the process can continue.

(3) One way of determining that a non-shreddable item has been stuck in the miller screw/shredder housing is to monitor the torque applied by the drive motor. This monitoring of the torque could be achieved e.g. by monitoring the drive current to the drive motor. If the applied torque exceeds a certain threshold value, the above sequence for rejecting a stuck item may be implemented.

(4) It is advantageous to be able to tilt, or rotate, the cutter housing if an item has stuck and blocks the miller screw; it is of course possible to reverse the direction of the miller screw in order to release the too large item having been stuck, but if the housing is not rotated, the restrictor (A3) comprising a pipe like portion leading to the opening in the cutter will stop the stuck item from being removed from its blocking position. Moreover, if the housing is rotated such that the opening faces downwards, gravity will help removing the stuck item.

(5) Preferably, the feed screw is shut off prior to the shredder housing being rotated in case of a stuck item requiring removal.

(6) In another embodiment of the invention, there is no tilt cylinder provided for rotating the cutter housing; instead, the rotation of the cutter housing is achieved by providing the housing on bearings allowing for rotation and a locking system enabling the cutter housing to be locked in desired positions. If an object has stuck, the locking system may release the cutter housing, Thereafter, the miller screw is rotated in the cutting direction, bringing the cutter housing with it. Once the cutter housing has reached the desired position, the cutter housing is locked and the miller screw is rotated in the opposite direction, i.e. the direction releasing the stuck item, such that the stuck item may be rejected.

(7) The system disclosed above and in the drawings can handle long or short chips and reject solid slugs that cannot be shredded and are too large for being transported into the press chamber. It is designed from beginning to do this with few parts in a compact package. This covers all possible working conditions and provides one stop shopping at attractive price. The compactness and price gives possibilities for small workshops to own a recycling system. This will give them much more money back per kilo of waste material. Cutting fluids will be fed back to manufacturing machine; this will provide a significant improvement on environmental issues. The fact that chips are compacted directly at the CNC machine will guarantee that no chips are wasted into nature; this is the biggest environmental profit. Every lost kilo of material must in the end be compensated by mining more from the earth. It's much more energy efficient to recycle material. Current system does not provide possibilities for the great mass of workshops to recycle their material in an efficient and economical way.