EP1364712A1 - Cutting tool for a document shredder - Google Patents

Abstract

The cutter for a document shredder has two shredding rollers (12) with cutting discs (13). Spacer rollers (16) are provided to allow removal of cut paper particles from between the cutting discs. The spacer discs are formed by spacer discs (18) with projections (19) with a claw shaper spacer edge (21). The claws grip with the spacer edges in the gap between the cutter discs.

Description

Area of application and state of technology

The invention relates to a cutter for a document shredder according to the preamble of claim 1.

Such cutting units or document shredders have two Cutting rollers on which cutting discs or cutting disc-like and alternately have interlocking sections.

The problem with document shredders is that between Hang cut particles or paper strips from the cutting discs remain and thus inhibit or even block the circulation of the cutting rollers can. So-called scrapers are provided for this, for example, which engage in the cutting rollers in the manner of combs and Remove particles cut in this way. However, there are many cases here Stability problems and in part these breakers can break. Of further it is possible, for example, in on the cutting rollers themselves Attach the clearing ring discs in the circumferential direction. This However, this only works where the cutting rollers are made of one another Cutting disks are built.

Task and solution

The invention is based, an object mentioned To create the cutting unit, with which on any cutting roller Removal of cut particles is guaranteed.

This task is solved by a cutter with the characteristics of claim 1. Advantageous and preferred embodiments of the invention are the subject of further claims and are described below explained in more detail. The wording of the claims is by express Reference made to the content of the description.

According to the invention, the clearing means have projections which reach between the cutting rollers or cutting disks and circulate or rotate. This means that relative to the cutting rollers or Cutting discs not the projections rigid and fixed, but so are trained to move. This has the advantage that Removing the particles not only the movement or rotation of the Cutting rollers, but also used the movement of the projections themselves can be. This is a more efficient way of removing the particles possible. For example, the protrusions can be cut while rotating Particles between the cutting disks, so to speak scratch or tear out.

For the purposes of this application, no distinction is made between individual Cutting discs composed of cutting rollers and massive, cutting rollers having sections like cutting disks. The term cutting disks is used below, including both and thus also cutting disc-like sections of massive Cutting rollers are to be understood.

The clearing means and thus also the projections can be advantageous have a shape corresponding to the cutting disks. This means that the projections in particular can be so wide like the space between two cutting discs. Advantageous it can be provided that a small axial distance or air gap between broaching means or projection and a cutting disc, in particular the side surface of which is present.

So the gaps between two cutting disks are essentially provided with a rectangular profile, that is what engages in it Profile of the protrusions also substantially rectangular.

A similar small distance or air gap can also be in the radial direction be provided. This means that the clearing agents or Protrusions almost to the bottom of the cutting rollers between the Cutting discs can be enough. Direct concern increases in many cases the friction and should be avoided.

Specifically, the clearing means can be round and disk-like, preferably like a cylinder. For the formation of rollers as clearing agents can, similarly as described above for the cutting rollers themselves, several disks can be put together with clearing agents.

Furthermore, the clearing means can have a plurality of projections exhibit. This has the advantage of having a head start a clearing process is initiated.

It can be provided that the clearing means in the direction of circulation each have a plurality of protrusions, for example ten to thirty. The distance between the projections is advantageous in each case equal. The distance between the projections should also be in the circumferential direction not too big for each other, so that on the one hand a sufficiently large one Number of projections can be provided. This is about make sure that the projections are stable enough.

The projections or each projection preferably have a clearing edge on, which is particularly preferred together with the projection in is about claw-like. The clearing edge or the claw formed thereby the projection points in the circumferential direction so that it is in the cutting disks intervenes and accumulates in it like a claw Can tear out particles. The clearing edge is particularly advantageous both the first area of the protrusion when engaging in a Cutting roller as well as the outermost area in circulation or in terms of the circumferential contour of the protrusions or the clearing means. This ensures that the clearing edge in particular accumulates Attacks particles.

To increase the clearing effect or claw effect, the Räumkanten or the entire protrusions jagged or rough be trained. The clearing edges are preferably essentially straight. You can in particular parallel to the longitudinal axis of the cutting rollers run.

It is possible to shape the protrusions so that through cuts in solid, for example disc-like material are formed. The incisions can have a semicircular shape. The incisions can advantageously have a recessed semicircular shape. This means that the incisions start with a certain start constant width and then a rounded or circular End.

In a further embodiment of the invention can advantageously be provided be that the projections or the incisions substantially without Undercut are formed, this in the radial direction see is. Above all, this should be understood to mean that the incisions starting from the outer contour of the broaching means not wider become. This simplifies production, for example by means of radial Directional cutters or the like.

The projections can be made substantially identical to one another his. Furthermore, they can be symmetrical, wherein this is to be understood in and against the direction of rotation. This means, that the clearing means regardless of the direction of circulation reach with similar protrusions between the cutting discs can.

It is possible that the evacuation means due to friction or concerns be moved on the rotating cutting rollers. Advantageous however, the clearing means are powered. Such a drive can particularly advantageous via the same drive as for at least one the cutting rollers as well as gears or a gear. On this way is a more dimensioned for the cutting rollers Provide drive. On the other hand, it can have its own separate drive be saved.

Furthermore, it is possible to project the protrusions at a higher speed to circulate than the cutting rollers. The speed refers to the external speed or the rotational speed. This means that the clearance effect can be reinforced.

The cutting disks and / or the clearing means can be made of metal be made. Steel or tool steel is usually suitable for this on. In particular, the cutting disks can be solid and for example by unscrewing it from a solid roller body are manufactured. The clearing agents can also be produced his. Such clearing agents are particularly advantageous in Cutting units or cutting rollers used for a very narrow cut very small cutting wheel spacings, for example in the range of less than two millimeters.

These and other features go beyond the claims from the description and the drawings, the individual Features individually or in groups in the form of sub-combinations in one embodiment of the invention and others Areas to be realized and advantageous as well as protectable Can represent designs for which protection is claimed here becomes.

Brief description of the drawings

Fig. 1

einen Schnitt durch ein Schneidwerk mit zwei Schneidwalzen, wobei in jede Schneidwalze eine Räumwalze eingreift,

Fig. 2

einen Schnitt durch eine Räumwalze mit verschiedenartigen Ausbildungen von Vorsprüngen und

Fig. 3

einen Längsschnitt durch einen Eingriff einer Räumwalze in eine Schneidwalze.

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. The drawings show:

Fig. 1

2 shows a section through a cutting unit with two cutting rollers, a broaching roller engaging in each cutting roller,

Fig. 2

a section through a clearing roller with different types of projections and

Fig. 3

a longitudinal section through an engagement of a clearing roller in a cutting roller.

Detailed description of the exemplary embodiments

In Fig. 1 is a cutter 11 of a document shredder in section shown. The cutting rollers 12a left and 12b right are as is also clear from Fig. 3, from cutting disks 13a and 13b and one roll core 14a and 14b each. The cutting discs 13a and 13b have projections formed in a known manner. This is familiar to the person skilled in the art and need not be explained in more detail here to become. Are between the cutting disks 13, as shown in FIG is recognizable, there are spaces in between. They reach into these Broaching rollers 16a and 16b with the projections 19a and 19b of the broaching discs 18a and 18b. As in FIG. 1 in conjunction with FIG. 3 can be seen, both the cutting rollers 12 and the clearing rollers 16 designed to correspond to each other. This means she grip, like the cutting rollers 12, alternately with each other into each other.

The projections 19 of the clearing disks 18 or the clearing rollers 16 are, as can be clearly seen from Fig. 1, by incisions 20 in a otherwise a circular disc is formed. The incisions are 20th with a slightly recessed profile that is semicircular on the bottom. This makes it possible, for example, to manufacture them with a round milling cutter.

The projections 19 have clearing edges 21, which on the one hand Rotation of the clearing rollers 16 first in the space between the Engage cutting disks 13. This allows the clearing effect caused by the claw function of the projections 19 with the Räumkanten 21, improve.

Furthermore, it can be seen from FIG. 1 that the clearing edges 21 lie on the circumference of the clearing discs 18 and no point the clearing discs 18 or the projections 19 protrude further outwards.

This also improves the aforementioned claw function and thus the Clearing effect.

Furthermore, it can be seen from FIGS. 1 and 3 that the Projections 19 with the clearing edges 21 to just before the roll cores 14 the cutting rollers 12 are sufficient. So you can almost all between grasp the particles located in the cutting disks 13 and clear them out. A direct concern is due to excessive friction and wear best to avoid.

It can also be seen from FIG. 3 that the lateral or axial Distance between cutting disks 13 and clearing disks 18 or Projections 19 should be such that there is a certain air gap or they rub against each other only marginally. However, the distances should be or air gaps in the axial and radial directions are not too large, so that not too many particles can hold on.

As can be seen from Fig. 1, the cutting rollers 12 each rotate in opposite directions. The associated clearing rollers 16 rotate again in the same direction with the associated cutting roller. This has to Consequence that in the area of engagement between clearing roller 16 and Cutting roller 12 to each other in opposite directions run past and thus clear out the clearing edges 21 cut particles can.

As has been stated previously, the peripheral speeds the broaching rollers 16 may be higher than those of the cutting rollers 12th

Basically, it is also conceivable that the clearing rollers Turn in the same direction with the respective cutting rollers. Then however, the speed of the clearing rollers should be higher, so that the projections 19 in the circumferential direction through the spaces move between the cutting disks 13 for clearing of cut particles.

As can also be seen from FIG. 1, the clearing rollers 16a and 16b are configured such that they have no preferred direction of rotation. The projections 19 offer the same in both directions of rotation Profile. This makes it possible to use a single type of broaching roller 16 get along.

Different designs of projections 19 are shown in FIG remove. For example, the projections 19c are in the circumferential direction pointing claws. These claws open into the clearing edges 21c.

The projections 19d, like the projections 19c, are directly claw-like educated. However, they run from the roll core 17 with approximately the same width and are shown by the dashed lines Circumferential contour of the clearing roller 16 limited. They also flow into a clearing edge 21d.

The projections 19e are essentially triangular, likewise the incisions 20e between them. The top of the triangle will formed by the clearing edges 21g. These types of protrusions show no or very little claw function. Still can with a certain clearing effect can also be achieved. The advantage of such Protrusions 19e can be, for example, particles removed do not get caught on the protrusions and thus the clearing rollers 16 in turn are not clogged.

The projections 19f in turn are in the manner of protruding rectangles or squares and are formed by the orbital contour limited. They have a clearing edge 21f. The bottom of the incisions 20f differs from those incisions 20a and 20b from Fig. 1 differently in that it is just formed is. As can be seen, the projections 19e and 19f Direction of rotation formed according to the projections 19a and 19b.

From the illustration in FIG. 3, on the one hand, it becomes clear that, as on the left in Fig. 3 is shown, the cutting rollers 12 and the clearing rollers 16 from individual disks can be formed. The form between the cutting disks 13 arranged disks the roller core 14 the cutting disc 12. The same applies to the clearing roller 16.

As shown in the right side of Fig. 3, the cutting roller 12 or the clearing roller 16 can be solid. In this case the cutting disks 13 or the clearing disks 18 of projection-like Sections of the massive rolls, which are from the roll cores 14 and 17 stand out.

Whether the cutting rollers 12 or the clearing rollers 16 solid or made individual slices are formed depends on different circumstances from. Especially with particularly narrow cutting disks to perform a particularly fine particle cut is both the provision of the above-mentioned clearing rollers as well as the structure advantageous from individual slices.

Claims (13)

Cutting device (11) for a document shredder with two cutting rollers (12), the cutting rollers having cutting disks (13) or cutting-disk-like sections which alternately interlock to make the cut, the cutting rollers (12) being assigned clearing means (16) for removing cut particles between the cutting disks (13) and for this purpose the broaching means engage between the cutting disks, characterized in that the broaching means have circumferential projections (19) and the projections engage between the cutting disks (13). Cutting device according to claim 1, characterized in that the clearing means (16) and the projections (19) have a shape corresponding to the cutting disks (13) or cutting disk-like sections, the projections in particular being as wide as the space between two cutting disks. Cutting device according to claim 1 or 2, characterized in that the clearing means (16) are round and disk-like, preferably roller-like, with a plurality of projections (19), in particular being formed from a plurality of disks (18). Cutting device according to one of the preceding claims, characterized in that the clearing means (16) each have a multiplicity of projections (19) in the circumferential direction, the projections in particular being arranged at the same distance from one another. Cutting device according to one of the preceding claims, characterized in that the projections (19) have a claw-like clearing edge (21) which points in the circumferential direction, the clearing edge preferably being the outermost point of the projections (19) or the clearing means (16) in the circumferential contour. forms. Cutting device according to claim 5, characterized in that the projections (19), in particular the clearing edges (21), are jagged or rough. Cutting device according to one of the preceding claims, characterized in that the projections (19) are formed by incisions (20) which have a semicircular shape, in particular a recessed semicircular shape. Cutting device according to one of the preceding claims, characterized in that the projections (19) are formed without an undercut. Cutting device according to one of the preceding claims, characterized in that the projections (19) are symmetrical in and against the direction of rotation. Cutting device according to one of the preceding claims, characterized in that the clearing means (16) are driven, wherein they are preferably driven by means of a gear and the same drive as for at least one of the cutting rollers (12). Cutting device according to one of the preceding claims, characterized in that the projections (19) rotate at a higher speed than the cutting rollers (12). Cutting device according to one of the preceding claims, characterized in that the clearing means (16) or projections (19) extend almost to the bottom of the cutting rollers (12) between the cutting disks (13). Cutting device according to one of the preceding claims, characterized in that the clearing means (16) or projections (19) have a small axial distance or air gap to the cutting disks (13).

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