EP0795353B1 - Document shredder - Google Patents

Description

Field of application and state of the art

The invention relates to a document shredder with a Cutting unit, the cutting rollers with interlocking Has cutting discs, in the spaces between wipers engage with wipers that follow one another axially related.

Such a document shredder is known from DE 40 08 654 A1 became known. There are only a small part of the Scrapers comprising one piece with the circumference of the cutting rollers the lower housing part and the upper housing part made of plastic manufactured. Since there is a cutter with a torsion cut acts, i.e. with cutting discs that match their The problem of stripping is to make flanks look like scissors not very big because the cut stripe is a bit twisted like a spiral and thus by itself from the cutting gap is released.

There are also one-piece wipers known as contiguous sheet metal plates are formed in the Longitudinal slots are punched through which the cutting discs protrude through. The webs between them act as wipers (see DE 1 289 404 B and DE 1 511 166 B). To a similar one Training is DE 40 03 222 C, there the plastic webs in one piece with the upper housing or -bottom are made.

From EP 525 491 A, DE-U 93 10 828 and DE 43 42 938 Document shredder became known, their cutting unit Wiper blocks or combs contain, sometimes two each Cutting roller. These are of two almost opposite Pages facing each other, each include a small part of the cutting roller and form on the the side facing away from the cutting gap a relatively large, of Cutting free gap.

A wiper system has become known from DE 36 31 363 A, in the single, disc-shaped and on support rods the wipers are completely lined up. They each consist of two in the circumferential direction contiguous halves. The same goes for the EP 260 636 A and the corresponding DE-U 94 13 845.

For document shredders that are used for particle cutting are trained, but also with strip cutters, is a good stripping or clearing the grooves between the Cutting discs important. This can best be done by wipers happen that are relatively close to the bottom of the grooves between the Cutting discs, i.e. on the knife shaft, run and this reach over a relatively large angle. They have been so far individually punched out of sheet metal and connecting to the chassis Stud bolts, possibly with spacers between them, individually lined up (see DE 27 49 482 A, DE 37 06 862 A, DE 41 09 467 A and DE 44 36 751 A). These wipers work very good, but are very expensive to manufacture and Assembly.

Task and solution

The object of the invention is to destroy a document create with the very effective scraper simple and can be manufactured and assembled inexpensively.

This object is solved by claim 1. The wipers can therefore be separate from the housing, but itself integrally connected over a large part, preferred the entire length of the cutting rollers, go through and thus be designed in the manner of a disc comb. You can So made as a single piece from plastic injection molding be and can be guided by studs that connect two side bolsters supporting the bearings to a chassis. With appropriate training, you can use the stud bolts also replace.

The wipers can cut the cutting roller by more than 180 ° include and two opposed to each other in the circumferential direction directed sharp-edged, especially acute-angled, with the shaft sections between the cutting disks have interacting scraper edges. To still easily inserted into the gaps between the cutting discs To be able to be, there are at least two per cutting roller adjacent stripping units may be provided connect to each other and also to each other lead, the individual wipers with e.g. wedge and groove-shaped engagement elements are centered to each other.

The longitudinal connections can be continuous, in the circumferential direction curved webs, which are in the manner of the cutting rollers partially surrounding elongated shells are. This gives the stripping unit stability. Sequels these longitudinal connections can be made accordingly Shaped protrusions form into corresponding breakthroughs engage in the cross beams in which the cutting roller bearings also are provided. The wipers are so directly to the crossmember belonging to the cutting unit chassis or end shields attached. The wiper units can also be used for document shredders, which are constructed without a chassis with a self-supporting housing. When in connection with this invention of document shredders is spoken, including all crushing Devices of this type are meant for flat materials, ie also for packaging materials made of paper, cardboard or other materials, such as foils, are used can be.

It has proven to be particularly advantageous if the Scraper at least adjacent to the exit side of the shredded written material afterwards provided there Scraper a substantially over the outer circumference of the Section outgoing section and one behind Have free space in which the outer boundary of the wipers preferably set back below the circumference of the cutting disc is. The resulting free space makes it possible Particles e.g. in the tooth gaps of grooved cutting discs got stuck after going between the after outside protruding "horns" on the scraper edges follow, have passed, to expand, so that they then at the end of the free space when the wipers turn Raise over the circumference of the cutting disc, be wiped off can. The scraper not only ensures clearing out of the gaps between the cutting discs, but also for one Keep clear of those intended for particle cutting mostly spiral grooves in the cutting discs formed teeth and the circumference of the cutting disks mostly have a V-shaped depression.

The wiper unit can also hold a sensor serve to control the cutting unit. On the relatively stable Scraper element can thus be protected and secure e.g. a Photodiode arrangement for a control of the cutting unit Photoelectric sensor can be attached.

The cutting unit is put together by the scraper units with the cross members to a rigid and well the substantial Blocked chassis absorbing cutting forces. Especially the crossbeams can preferably hold one Stand made of bar material in the form of a bow exhibit. The forces can thus be absorbed immediately become, without them the outer, because of the outer appearance trained from optically high-quality plastic Affect housing, accordingly, specifically on its Function and trained without special wearing properties can be. Parts of this housing can be on the stripping unit support, especially in the area of the insertion slot. This is narrow and relatively wide. Due to the support on the stripping units a Deformation in this area avoided.

It has been shown that the invention, in particular also the wide embrace of the cutting shaft and the one there close distance from the sharp scraper edges the wiping effect is so good that it is not necessary the wipers very precisely to the cutting wheel width and thus the groove in which they run. This also makes the previous arrangement "floating" in the axial direction of Wipers unnecessary. The thickness of the wipers can therefore considerably, preferably by 20 to 40%, less than that the cutting discs. With that, all problems are caused by different tolerances or strains of the cutting discs and the wiper block could occur avoided. The good adaptation of the wipers to the cutting roller, especially the running of the scraper edges close to or on the bottom of the groove between the cutting discs, is by the self-lubricating properties of plastic injection molding possible without fretting or excessive frictional resistance is to be feared.

So it becomes a document or document shredder created a cutting unit designed as a chassis can have in the cutting rollers driven in opposite directions are stored. They are preferably double-sided cutting discs designed for particle cutting. There are as stripper elements extending over the entire length of the cutting rollers provided, the individual wiper discs via longitudinal connecting elements to form a block are summarized. Since it is more than 180 °, almost 270 °, around reach around the shaft cross-section, there are two per cutting roller Scraper elements match each other in the circumferential direction connected. The wiper elements can be made in one piece Plastic injection molding and are also used Connection of the two side cheeks of the cutting unit.

These and other features go beyond the claims also from the description and the drawings, wherein the individual features individually or separately several in the form of sub-combinations in one embodiment of the invention and in other fields be and advantageous as well as protective designs can represent, for which protection is claimed here.

The division of the application into individual sections as well Inter-headings limit those made under them Statements are not generally applicable.

Brief description of the drawings

Fig. 1

eine teilgeschnittene Seitenansicht eines Schneidwerks für einen Schriftgutvernichter mit einer abgenommenen, einen Querträger bildenden Seitenwange,

Fig. 2

einen Querschnitt durch die Schneidwalzen, die Abstreifereinheiten und die Längsträger (Stehbolzen),

Fig. 3

eine Seitenansicht einer Abstreifereinheit,

Fig. 4

die mit den seitlichen Querträgern (Seitenwangen) verbundenen Abstreifereinheiten in montierter Position (ohne Schneidwalzen und Getriebe),

Fig. 5

die vier zu einem Schneidwerk gehörenden Abstreifereinheiten in Frontansicht und

Fig. 6

ein Detail (in Richtung des Pfeils VI in Fig. 2 gesehen).

An embodiment of the invention is shown in the drawings and is explained in more detail below. The drawings show:

Fig. 1

2 shows a partially sectioned side view of a cutting unit for a document shredder with a removed side cheek forming a cross member,

Fig. 2

a cross section through the cutting rollers, the stripper units and the longitudinal beams (stud bolts),

Fig. 3

a side view of a wiper unit,

Fig. 4

the scraper units connected to the lateral cross members (side cheeks) in the assembled position (without cutting rollers and gear),

Fig. 5

the four wiper units belonging to a cutting unit in front view and

Fig. 6

a detail (seen in the direction of arrow VI in Fig. 2).

Description of the embodiment

The core of a document shredder 11 is the cutter 12, which is designed in a chassis design. It contains two side cheeks or cross members 14, 15 (Fig. 4), of which the cross member 15 simultaneously a gear box 17th contains, in the gear wheels, not shown in Fig. 4 for a reduction of the one not shown Electric motor originating drive speed to the working speed the cutting rollers 16 (Fig. 1 and 2) care.

The cutting rollers 16 are made in one piece from steel and have, based on a continuous wave cross-section 18, outwardly projecting cutting disks 19 with provided in this, 20 leading inclined in the direction of rotation Grooves or tooth gaps 21, the one accordingly form forward-facing cutting tooth 22. Because of the Details of the cutting wheel formation and its effect attention is drawn to DE 22 47 901 B.

Grooves are circumferential between the individual cutting disks 23 formed, the width of which is such that it with a to Cutting between the peripheral edges of the cutting disks 19 suitable fit with the corresponding cutting disc other cutting roller interact. It is particularly out Fig. 2 can be seen that the cutting rollers so one inside the other intervene that each cutting roller with its circumference 24 relatively short distance to the groove bottom 25 of the groove 23 of the opposite cutting roller works together. The Cutting discs are made according to the desired dimensions Dimension particles, i.e. for example 4 mm wide and have on the circumference some, in the present example 4 grooves or Tooth gaps 21. These work together with the extent 24 of the opposite cutting disc for that of the circumferential edges of the strips cut strips torn apart or cut into individual particles become. The cutting discs are synchronized, i.e. with the same Speed, driven in opposite directions in the direction of rotation 20, see above that the material in the area of the entry gap 26th grasp and release the particles at the material outlet 27.

Scraper units 30 are assigned to cutting rollers 16, those for each cutting roller 16 made of two separately Wiper elements 28, 29 exist. They are considered elongated One-piece elements made of plastic injection molding according to Art of a disc comb. Yours as flat segments or discs formed wipers 31 are by a Longitudinal connection running over the entire length of the scraper 32 connected together. This has the shape of a Cutting wheel circumference 24 in the ring shell segment surrounding it at a distance, what good stiffness with little material worries. In extension of this longitudinal connecting web 32 are connecting elements 33 on both sides, which in corresponding crescent-shaped cutouts 34 on the two Cross members 14, 15 are used (Fig. 4). By an as Paragraph trained shoulder 35 (Fig. 3) they put the Cross members 14, 15 also fixed in their distance. By appropriate Connection means, for example clamping connection means or the like., The connecting elements in the cross member also be set against train.

In the present case, however, the longitudinal connection between the two cross members ensured by four longitudinal members 36, which, in the manner of stud bolts, the cross beams in the specified Rigidly connect the distance. In Fig. 1 is too recognize that this is in threaded holes 37 of the side members 36 screws are screwed in by the Are screwed outside of the cross member.

The shape of the wipers 31 is in particular from the figures 2 and 5 to recognize, because of the form expressly Reference is made. Although for every document shredder Two stripper elements 28 and 29 are necessary however, the entry-side elements 28 and the exit-side elements Elements 29 will be the same for both sides. you will be only mounted in mirror image to each other.

Close the two wiper elements 28 on the inlet side between their mutually facing edges 39 the relative narrow entry gap 26. Adjacent to it there is a sharp, acute-angled scraper edge on the groove base 25 or cutting edge 40, to which the shaft cross section 18 adapted arc section 41 connects. At the cutting gap 42 where the overlapping cutting disks 16 work together part of the cutting rollers facing away is a Connection section 43, which in the example shown as a V-shaped rib or spring 43 is shown (Fig. 6).

It works with a corresponding V-shaped recess 44 on the wipers 31 of the outlet-side wiping elements 29 for mutual fixation and centering each individual wiper 31 on that of the adjacent wiper element together.

The wipers 31 of the wiper element 29 near the outlet also have a sharp-edged scraper blade 40 and then an exit gap 27 delimiting edge 39. However, these edges 39 are like this arranged that they are wedge-shaped or funnel-shaped limit opening exit slit 27 during the entry slit 26 is relatively narrow. Then to the edge 39 is a far beyond the circumference 24 of the cutting discs projecting horn 45 is provided on the stripped Particles are pushed along by the cutting discs until they fall down from the cutting gap area.

A space 46 is thereby connected to this horn created that the outer edge of the scraper to within the circumference 24 of the cutting disc 19 is excluded. That then the outer circumference goes back to the big one Distance from the center of the horn back.

The longitudinal connections are in both stripper elements 28, 29 32 arranged so that they connected to each other via the V-connection 43, 44, for example enclose a third circle. The one from the two elements 28, 29 assembled wipers comprise the cutting roller at the bottom of the groove 25 by more than 180 °, preferably close to 270 °.

Both wiper elements have approximately in their wipers semi- to third-circular recesses 47 in which the Longitudinal beams 36 lie, which thus the stripper elements 28, 29 define and manage.

The individual wipers 31 are compared to the thickness of the cutting disc relatively thin. 3 and 4 show that each Cutting roller and thus also every stripper element has thirty side by side wipers in one Graduation of 8 mm to each other are arranged, which results in a cutting disc thickness of a little less than 4 mm results. In contrast, the wipers themselves are only approx. 2.6 mm thick, i.e. about 35% narrower than the cutting discs or the circumferential groove 23 formed between them. Despite the The resulting stripping is the stripping result good because the scraper blades 40 directly on the Nutgrund 25 can run and thus for a good wiping to care.

3 and 4 show that the upper stripping elements 28 shown primarily in these drawings are in the middle of a receptacle 48 for the sensor 49 one Cutting unit motor control, for example a light barrier, Has. It can be snapped in there and is protected and directly at entry gap 26.

Fig. 1 shows that a not shown in detail Housing with the entry gap 26 delimiting Housing sections 50, 51 (shown in phantom) can support the outer boundary of the edge 39, so for a precise alignment of the narrow and wide insertion slot 26 to worry about.

Figures 1 and 4 also show that removed from the cutting rollers End of the cross member mounts 52 for a pedestal 54 are formed. This is as extending downward Bracket formed from rod material, and its upper ends are in the receptacle 52 in the form of a cylindrical Recording added. The chassis of the Cutting unit 12 directly on the feet, and on the document shredder 11 forces acting mainly originate from the cutting unit, are directly from Stand added.

function

The document shredder 11 works as follows: Entry gap 26 becomes documents or other flat material brought into the area of the cutting gap 42. In doing so, after switching on the device, a signal from sensor 49 generates the drive, not shown (motor and Gear) in forward gear. The cutting rollers turn in the opposite direction 20 and take that Documents into the cutting gap. It will be between the cutting edges of the cutting discs in the cutting disc width appropriate strips cut and at the same time through the interaction of the cutting discs with the transverse grooves 23 separated into particles. These fall down the exit gap 27 into one under the document shredder arranged container. If particles in the grooves 23 or am Nutgrund 25 stick, so they are from the wipers 31 and in particular stripped from the stripping edge or edge 40, due to the almost tangential arrangement of the edges 39 also due to the rotation of the cutting disc to the outside transported and thrown down. Should be there Particles adhere to the circumference of the cutting disc or adhering particularly in the grooves 21 of the cutting disks taken between the horns 45, so they can to the side in the area of the adjoining free spaces 46 expand and then become from the subsequent edge 53 the scraper 31 retained and thrown down.

Should a stall occur, either by automatic control or manually the cutting unit in the Reverse direction of rotation and thus promotes the document "lump", that has formed up back. Here become the scraping edges lying on the entry side 26 40 worked to prevent writing particles in this Reverse rotation direction promoted around the cutting rollers become.

Claims (10)

1. Document shredder with a cutting mechanism (12), which has cutting rollers (16) with interengaging cutting disks (19), in whose gaps (23) engage strippers (31), which are connected to axially following strippers, the strippers (31) being constructed on at least one stripper unit (28, 29) in one piece with the strippers (31) and the longitudinal connections (32) connecting them and which is separate from the casing and continuous over a significant part of the axial extension of the particular cutting roller (16) and in which there are two stripper units (28, 29) for each cutting roller (19), characterized in that the stripper units (28, 29) are circumferentially connected in matching manner and the individual strippers (31) of the elements are mutually centred with engagement elements (43, 44).
2. Document shredder according to claim 1, characterized in that the strippers (31) embrace the cutting roller (16) by more than 180° and preferably have two circumferentially oppositely directed, sharp-edged and in particular acute-angled stripping edges (40) cooperating with the slot base (25) between the cutting disks (19).
3. Document shredder according to claim 1 or 2, characterized in that the engagement elements (43, 44) have a wedge-like and slot-like construction.
4. Document shredder according to one of the preceding claims, characterized in that the longitudinal connections (32) are circumferentially curved webs.
5. Document shredder according to one of the preceding claims, characterized in that the strippers (31), at least adjacent to the exit side (27) for the comminuted document and following onto the stripping edge (40), have a portion (horn 45) projecting significantly over the outer circumference (24) of the cutting disk (19) and behind the same a free space (46), in which is set back the outer boundary of the strippers (31), preferably to below the cutting disk circumference (24).
6. Document shredder according to one of the preceding claims, characterized in that the stripping elements have longitudinally directed recesses (47) for the partial reception and support on longitudinal supports (36) of the cutting mechanism chassis and which are preferably constructed as staybolts and/or the stripping elements (28, 29) have projections (33) preferably constructed as an extension of the longitudinal connections (32) and which engage in cutting roller bearing-receiving transverse supports (14, 15) and are optionally fixed there as longitudinal supports connecting the transverse supports and in particular one of the transverse supports (15) forms a gearbox (17), and/or the stripper elements (28, 29) and optionally the transverse supports (14, 15) are one-piece plastic injection mouldings and preferably the transverse supports (14, 15) have receptacles for a bow-shaped standing foot (54), preferably made from bar material.
7. Document shredder according to one of the preceding claims, characterized in that at least one stripper element (28, 29) has on the material entrance side (26) a receptacle (48) for a cutting mechanism control sensor (49).
8. Document shredder according to one of the preceding claims, characterized in that the cutting disks (19) are constructed for particle cutting, preferably by slots (21) in the cutting disk circumference (24).
9. Document shredder according to one of the preceding claims, characterized in that portions (50, 51) of a casing enveloping the cutting mechanism (12) are supported on at least one of the stripper elements (28, 29).
10. Document shredder according to one of the preceding claims, characterized in that the strippers (31) bound between them a narrow material insertion gap (26) and a much wider, preferably wedge-shaped opening exit gap (27) and optionally the thickness of the stripper (31) is considerably, preferably 20 to 40%, smaller than that of the cutting disks (19).

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