GB2169524A - Document shredding machine - Google Patents

Abstract

A document shredding machine comprises a base assembly (6) in which is located cutting mechanism (8) comprising two sets of intermeshing cutter discs (10a, 10b) which are mounted for rotation in opposite directions. A cover assembly (14) of the machine comprises a document receiving slot (22) and is secured to the base assembly (6) by screws and extends over a majority of the cutting mechanism (8). By removal of the cover assembly (14) access to the cutting mechanism is afforded, enabling the mechanism to unjammed relatively easily. In addition the cover assembly (14) comprises a separable element (25) which defines the slot (22) through which material to be shredded may be fed into the nip. In this manner by changing the separable element for another separable element, the machine may be used for shredding wider paper, or with a feeding mechanism by which paper is fed through the slot from a bulk store. A safety mechanism prevents operation of the machine when element 25 is removed. <IMAGE>

Description

SPECIFICATION Improvements Relating to Shredding Machines This invention is concerned with improvements relating to shredding machines, particularly ofthe kind (hereinafter referred to as being of the kind specified) comprising a housing in which is mounted a shredding mechanism, and a cutting mechanism comprising two sets of intermeshing cutting discs mounted for rotation within the housing in opposite directions. A slot or opening is provided in the top of the housing to enable documentary material to be guided into the nip of the cutting mechanism which pulls the material through the slot, and subjects it to a shredding operation and discharges it through an opening in the base of the housing, conveniently into a bin upon which the machine is placed.

Such a conventional machine suffers from two disadvantages: a) On occasion the cutting mechanism may jam, such as when an unduly thick quantity of material is fed through the slot, or when an item which should not be subjected to a shredding operation by the machine inadvertently enters the nip.

Heretofore overcoming of such a disadvantage has required, in simple cases, the provision of means to reverse the direction of the cutting mechanism, and in complicated cases, a disassemblement of the housing to a significant extent, to allow access to the cutting mechanism as a whole.

b) Certain circumstances require that documentary material be fed into the nip in a particular manner. For example, when large quantities of material are to be shredded, desirably the machine comprises feeding means to feed the material at an appropriate rate into the nip.

Alternatively, when wide paper is to be shredded, such as computer paper, unless a machine is used which comprises a cutting assembly which is sufficiently long (which is expensive), the machine must be provided with a guide means to fold over the paper prior to entry into the nip.

Whilst it is practicable to design a machine capable of carrying out a shredding operation on a number of different types of paper, such machines are unduly expensive and so machines have in general (particularly in the range of smaller machines) been designed for the operation which they are most often required to perform.

According to a first aspect of this invention there is provided a shredding machine of the kind specified, comprising a base assembly on which the cutting mechanism is mounted, and a cover assembly reieasably connected to the base assembly, the cover assembly defining a slot through which, when the cover assembly is in an operative position secured to the base assembly, material may be fed into the nip of the cutting mechanism, the cover assembly extending around the cutting mechanism to an extent sufficient to allow, when at least an element of the cover assembly is moved to an inoperative position, useful access to the cutting mechanism.

By the term "useful access" as used herein we mean access sufficient to permit some maintenance to be carried out on the cutting mechanism, such as freeing the cutting mechanism when jammed, or carrying out most routine servicing.

The cover assembly as a whole may be pivotally mounted on the base assembly, and may be lifted from its operative to its inoperative position, remaining attached to the base assembly, or may be completed separable therefrom. Preferably safety means is provided to prevent normal operation of the cutting mechanism when the cover assembly is other than in its operative position.

The cover assembly may comprise a separable element which may be separated from the remainder of the cover assembly in order to provide useful access to the cutting mechanism, without requiring movement of the whole cover assembly to an inoperative position.

According to a second aspect of this invention there is provided, in combination, a shredding machine of the kind specified, comprising a base assembly on which the cutting mechanism is mounted, and a cover assembly releasably connected to the base assembly, and at least one additional cover assembly, which may be mounted on the base assembly in substitution for the cover assembly thereon, each cover assembly providing a respective slot through which material may be fed into the nip of the machine, the cover assemblies having different slot profiles and/or being adapted to feed different types of documentary material into the nip.

Thus, one cover assembly may be adapted to feed standard width (e.g. A4) paper into the nip, and another may be adapted to feed larger width paper (e.g. computer paper) into the nip subsequent to subjecting the paper to a folding operation. A further cover assembly may comprise a feeding mechanism to feed the paper into the nip from a bulk store, and a further cover assembly may be afforded by an element of a machine adapted to subject the material to a pre-shredding operation prior to feeding into the nip of the machine.

Preferably the means by which the cover assemblies are mounted on the base assembly are identical over all the cover assemblies.

Preferably the cover assembly itself comprises a separable element which defines at least one edge of the slot, whereby, by selection of the shape of the separable element, a variety of slot shapes may be produced while utilising the same modular form for the remainder of the cover assembly.

A number of such separable elements may be provided, which may be interchangable with each other so as to be suited to the respective functions hereinbefore described in relation to the cover assemblies in their entireties.

Thus, according to a third aspect of the invention, there is provided, in combination, a shredding machine of the kind specified, comprising a base assembly on which the cutting mechanism is mounted and a cover assembly secured to the base assembly, the cover assembly comprising a separable element which may be separated from the remainder of the cover assembly, and at least one additional separable element which may be received by the remainder of the cover assembly in substitution for the separable element thereon, each separable element providing at least part of a respective slot through which material may be fed into the nip of the machine, the separable elements having different slot profiles and/or being adapted to feed different types of documentary material into the nip.

Preferably the machine in accordance with the third aspect of this invention is also in accordance with the second aspect of this invention.

Thus, a user of machines may purchase a basic machine and a number of interchangable cover assemblies and/or interchangable separable elements, and at any given time may use the machine with the cover assembly and/or separable element which is/are most appropriate to the use to which the machine is being put.

Alternatively a manufacturer of machines may build one standard base module and sell the base modules with any particular cover assembly and/or separable element, in accordance with the wishes of a purchaserofthe machine.

Preferably the machine according to the second aspect and/orthird aspect of this invention is also in accordance with the first aspect of this invention.

There will now be given detailed description, to be read with reference to the accompanying drawings, of a document shredding machine which is a preferred embodiment ofthis invention, having been selected for the purposes of illustrating the invention by way of example.

In the accompanying drawings: Figure lisa perspective view of the machine; and Figure 2 is a vertical sectional view of the machine.

The machine which is the preferred embodiment of this invention comprises a base assembly 6 which supports a generally conventional cutting mechanism 8, comprising two sets of intermeshing cutter discs 10a, 10b mounted for rotation in opposite directions, such that portions of the discs which are uppermost at any given time move rotatativelytowards each other and towards an upwardly-accessible nip N.

A cover assembly 14 comprises a documentreceiving slot 22 and is secured to the base assembly 6 by screws 11 (not all shown), and extends over a majority of the cutting mechanism 8.

Thus, by removal of the cover assembly 14 (by pivoting or lift-off movement, following removal of the screws 11) a considerable degree of access to the cutting mechanism 8 is afforded, enabling the mechanism 8 to be unjammed when necessary and enabling maintenance to be carried out. Such removal of the assembly 14 operates switch means which interrupts supply of power to the mechanism 8, for safety.

The cover assembly 14 comprises a separable element 25, secured to the remainder of the assembly 14, via interfitting of an edge 26a of the element 25 with a recess 27 in the remainder of the cover assembly, and by two screws 12 (only one of which is visible in Figure 2) which extend through a rear portion of the assembly 14 and engage the element 25 to prevent lifting thereof. The element 25 extends over a majority of the cutting mechanism 8.

Thus by removal of the element 25, which may easily be achieved by removing the screws 12, grasping one side of the slot 22 and manually pivoting the element 25 about the edge 26a, and then lifting the element 25 out of engagement with the recess 27, a considerable degree of access to the cutting mechanism 8 is afforded, enabling the mechanism 8 to be unjammed when necessary and enabling limited maintenance to be carried out.

The screws 12 are normally concealed by respective removable plugs 1 2a which must be removed in orderto gain access to the screws 12.

Such plugs 12a may be omitted if desired.

The separable element 25 defines the slot 22 through which material to be shredded may be fed into the nip N. Respective longer sides ofthe slot are defined in part by portions 24 and 26 of the elements 25. In the embodiment illustrated, the portions 25 and 26 are integrally formed with each other, but could alternatively be separable parts so as to allow a manufacturer readily to vary the shape of the slot, and the presentation thereof (e.g. forwardlyextending or rearwardly-extending), using alternative interchangable such parts, whilst retaining the same general design of cover assembly.

The machine which is the preferred embodiment of this invention is associated with a number of similar, interchangable cover assemblies and/or interchangable separable elements therefor, each cover assembly or separable element being capable of being received in place of the cover assembly 14 or separable element 25, as the case may be, shown in Figures 1 and 2. Specifically, the other cover assemblies and/or separable elements are suitable for use: a) with a the feeding and shredding of wide paper; b) with a feeding mechanism by which paper is fed through a slot from a bulk store; c) with a primary shredding machine adapted to subject the material to a pre-shredding operation.

Thus a user of the machine may select the cover assembly or separable element so as to be in accordance with the material intended to be shredded.

Claims (1)

1. A shredding machine of the kind specified comprising a base assembly on which the cutting mechanism is mounted, and a cover assembly releasably connected to the base assembly, the cover assembly defining a slot th rough which, when the cover assembly is in an operative position secured to the base assembly, material may be fed into the nip of the cutting mechanism, the cover assembly extending around the cutting mechanism to an extent sufficient to allow, when at least an element ofthe cover assembly is moved to an inoperative position, useful access to the cutting mechanism.

2: A shredding machine according to Claim 1 wherein on movement of the cover assembly from its operative to its inoperative position, the cover assembly remains attached to the base assembly.

3. A shredding machine according to Claim 2 wherein the cover assembly is mounted on the base assembly for pivotal movement between its operative and inoperative positions.

4. A shredding machine according to Claim 1 wherein movement of the cover assembly from its operative to its inoperative position involves a complete separation from the base assembly.

5. A shredding machine according to any one of the preceding claims comprising safety means to prevent normal operation of the cutting mechanism when the whole cover assembly is other than in its operative position.

6. A shredding machine according to any one of the preceding claims wherein the cover assembly comprises a separable element which may be separated from the remainder of the cover assembly to provide useful access to the cutting mechanism, with requiring movement of the cover assembly into an inoperative position.

7. In combination a shredding machine of the kind specified, comprising a base assembly on which the cutting mechanism is mounted, and a cover assembly releasably connected tithe base assembly, and at least one additional cover assembly, which may be mounted on the base assembly in substitution for the cover assembly thereon, each cover assembly providing a respective slot through which material may be fed into the nip of the machine, the cover assemblies having different slot profiles and/or being adapted to feed different types of documentary material into the nip.

8. A shredding machine according to Claim 7 wherein the means by which the cover assemblies are mounted on the base assembly are identical over all the cover assemblies.

9. A shredding machine according to one of Claims 7 and 8 wherein the cover assembly comprises a separable element which defines at least one edge of the slot.

10. In combination, a shredding machine of the kind specified, comprising a base assembly on which the cutting mechanism is mounted and a cover assembly secured to the base assembly, the cover assembly comprising a separable element which may be separated from the remainder of the cover assembly, and at least one additional separable element which may be received by the remainder of the cover assembly in substitution for the separable element thereon, each separable element providing at least part of a respective slot through which material may be fed into the nip of the machine, the separable elements having different slot profiles and/or being adapted to feed different types of documentary material into the nip.

11.The combination of Claim 10, being in accordance also with any one of Claims 7,8 and 9.

12. A shredding machine according to any one of Claims 1 to 6, being in accordance also with any one of Claims 7 to 10.

13. A document shredding machine constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

15. Any novel feature of novel combination of features hereinbefore described and/or shown in the accompanying drawings.