GB2203966A

GB2203966A - Paper shredding apparatus

Info

Publication number: GB2203966A
Application number: GB08703035A
Authority: GB
Inventors: John Ward
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-02-10
Filing date: 1987-02-10
Publication date: 1988-11-02
Also published as: GB8703035D0

Abstract

The apparatus comprises shredding means comprising at least one metallic rotor and at least one rubber stator, and a housing therefor. A stepped slot for the ejection of metal may be provided in an inclined transit passage between two shredding stages. Thus sabotage by the insertion of a metal bar can be countered. <IMAGE>

Description

PATENT SPECIFICATION THE DEVICE - A PAPER SHREDDING MACHINE This machine is based upon the principle of the heaviest duty pump used in chemical plant, i.e. The Mono Pump.

The mono pump has a flexible rubber stator and a metal rotor and it is this combination that enables this pump to handle a wider range of substances, including powders, than any other pump.

The proposed paper shredding machine utilises this feature by encircling the shredding blades with a corrugated rubber mould which has the effect of returning the inertia to the paper being shredded and re-presenting it to the shredding blades many times during its journey through the machine, prior to ejecting the resulting powder into a hopper or pumping it out of the building.

The machine is at a slight axial angle to ensure that the paper tumbles across at least one blade space on its journey through the machine.

No 1 Type Large, Medium and Small sized machine: Where security demands total destruction of sensitive material, as for instance in a diplomatic embassy in a politically volotile area.

Description:- These machines have a primary shredding stage consisting of blades spaced at h" intervals rotating at 1500rpm which pass on the pulp produced to a second stage with blades spaced at h" intervals rotating at 3000rpm. Between the two stages is a Metal Eject feature, this is a counter to a possible sabotage attempt which could consist of an insider slipping a metal bar into a folder of papers that would be thrown into the shredder prior to an embassy being occupied by intruders, as happened to the American embassy in Iran.

The.metal eject feature consists of a stepped slot over which the pulp from the primary shredding stage would pass but through which the metal bar would drop. The eject feature works because the bar on its travel through the primary stage has the paper surrounding it stripped away, the rubber stator flexing to let it through, its greater inertia ensures that when it is hurled from the primary stage it adopts the lowest level among the pulp climbing an inclined plane to the second stage. Thus ensuring that it drops down the step and falls backwards under gravity through the open space, to be removed from the machine by a spirol brush and deposited into a small container mounted on the side of the machine. Paper clips and lesser metal pieces would also be removed in this way. (not that it would patter if they went through).

cont/....

No 2 Type Junior machine - where security is not of prime importance This is the same as the larger machines but utilises only the primary shredding stages and half of the rubber stator, prior to ejecting the pulp into a hopper.

GENERAL As the paper shredder is pulping rather than shredding as in orthodox shredders, the large shear forces are drastically reduced i.e.

a 40hp motor becomes a 5hp motor or less.

All the machines are entirely modular in construction, hence the big machine is three small ones, the medium sized is two small ones, the junior machine is half of one small machine.

The machines are assembled from parts made by various manufacturers and assembled without welding, hence a very rapid rate of assembly is achieved. i.e. Two unskilled (but trained) personel would assemble two large machines in one day comfortably.

rritten Matter Accompanying Sheet 1 of 2 as originally filed: Section identical for small medium and large machines 'J' box principle Machine at a slight axial incline for fall a/c one blade space Blades spiroled at 10 -every 9th blade has 4 keyways thus avoiding end plates and facilitating modular consN Written Matter Accompanying Sheet 2 of 2 as originally filed: Junior rn/c as small m/c but chopped in half

Claims

CLAIMS 1. The only machine of its type using the principle of the mono pump. ie rubber-stator - metal rotor.

2. The only paper shredding machine with a "metal eject" feature.

3. The only range of machine of its type capable of "modular"construction.

Amendments to the claims have been filed as follows CLAIMS 1. Paper shredding apparatus comprising shredding means in the form of at least one- metallic rotor mounted for rotation relative to a rubber stator.
2. Paper shredding apparatus according to Claim 1, further comprising a housing, and wherein the shredding means is disposed within the housing.
3. Paper shredding apparatus according to Claim 2, wherein the housing includes a paper inlet and a paper outlet.
4. Paper shredding apparatus according to any preceding claim, wherein the or each rotor is provided with a plurality of paper shredding blades.
5. Paper shredding apparatus according to any preceding claim, wherein the shredding means includes first and second rotors, having first and second stators respectively, the arrangement being such that paper to be shredded passes to the first rotor, then subsequently to the second rotor.
6. Paper shredding apparatus according to Claim 5, wherein the rotational speed of the second rotor is greater than the rotational speed of the first rotor.
7. Paper shredding apparatus according to Claim 5 or 6, when dependent upon Claim 4, wherein the second rotor is provided with more paper shredding blades than the first rotor.
8. Paper shredding apparatus according to Claim 5, 6 or 7, further comprising a metal ejector disposed between the first and second rotors.
9. Paper shredding apparatus according to Claim 8, wherein the metal ejector comprises a slot provided in a paper flow channel extending between the first and second rotors.
10. Paper shredding apparatus according to Claim 9, wherein the paper flow channel extends upwardly from the metal ejector to the second rotor.
11. Paper shredding apparatus according to any preceding claim, wherein said apparatus is of modular construction.
12. Paper shredding apparatus according , to Claim 1, substantially as herein described with reference to and as shown in the accompanying drawings.
13. A method of shredding paper comprising feeding said paper to shredding means in the form of at least one metallic rotor and at least one rubber stator.
14. A method according to Claim 13 comprising feeding said. paper to a first of said rotor and stator and subsequently feeding said paper to a second of said rotor and stator.
15. A method of shredding paper according to Claim 13 substantially as herein described with reference to and as shown in the accompanying drawings.