JP2002239404A - Rotary cutter for paper shredder, manufacturing method of the rotary cutter and paper shredder provided with the rotary cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary cutter which can easily be manufactured and is inexpensive, a manufacturing method of the rotary cutter and a paper shredder having such rotary cutters. SOLUTION: The paper shredder having these rotary cutters is provided with: two rotary shafts 1 and 2 both of which are placed parallel to each other and rotatable reversely to each other, and two sets of several annular-platelike rotary cutters 3 and 4 and two sets of several spacers 9 and 10, which sets are fitted to the two rotary shafts 1 and 2 respectively and rotatable together with the rotary shafts 1 and 2 respectively, so that the rotary cutters 3 or 4 and the corresponding spacers 9 or 10 are alternately arranged on one of the rotary shafts 1 and 2 and one set of the rotary cutters 3 or 4 on one of the rotary shafts 1 and 2 and the other set of the rotary cutters 4 or 3 on the other of the rotary shafts 1 and 2 are engaged with each other set, wherein the peripheral part of one side face of each of the rotary cutters 3 or 4 on one of the rotary shafts 1 and 2 and the peripheral part of one side face of the corresponding one of the rotary cutters 4 or 3 on the other of the rotary shafts 1 and 2 are allowed to slide on each other, to shred a paper into narrow strips. In the paper shredder, each of the rotary cutters 3 (or 4) has two metal annular-platelike side-face members 31 each for forming the above peripheral part of one side face of the cutter 3 (or 4) and also, an intermediate member 32 which is positioned so as to be interposed between the two side-face members 31 and used for keeping the two side-face members 31 parallel to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cutter for a document shredder, a method for manufacturing the same, and a document shredder.

[0002]

2. Description of the Related Art As shown in FIGS. 5 and 6 of the accompanying drawings, a document shredder usually has two rotating shafts 51 and 52 which are parallel to each other and rotate in opposite directions. The rotary cutters 53 and 54 are mounted so as to rotate together with the rotary shafts 51 and 52 by engaging the key portions 53A and 54A with the key grooves 51A and 52A of the rotary shafts 51 and 52.

The plurality of rotary cutters 53, 54 on the respective rotary shafts 51, 52 are arranged alternately with spacers 61, 62 of annular plates as shown in FIG. That is,
The plurality of rotating cutters 53 on one rotating shaft 51 are alternately arranged with spacers 61 having the same thickness as the rotating cutter 53, and the rotating cutters 54 and the spacers 62 are alternately arranged on the other rotating shaft 52 similarly. The rotating cutter 54 thus inserted enters between the two rotating cutters 53 on the rotating shaft 51 and meshes with each other so that the side surfaces 53B and 54B are in sliding contact with each other as shown in FIG.

Documents supplied to the two rotary cutters 53 and 54 in the direction of arrow A are the two rotary cutters 53 and 5.
4 is cut by receiving the shearing force by the side surfaces 53B and 54B to be meshed with each other and discharged as a strip.

The rotary cutters 53 and 54 are provided at appropriate intervals on the outer circumference thereof with radially outwardly protruding cutting blades 55 and 54.
Some have 56 respectively. The cutting blade 53,
54 cuts into the strip at the above-mentioned interval and breaks the strip into short chips. Usually, the above-mentioned tearing blade 55,
The tip of 56 has straight blade edges 55A and 56A in the plate thickness direction as shown in FIG. 7 (A), but in order to make biting of the strips more reliable and easier, FIG. ), A V-shaped groove is formed, and sharp edges 55A, 5A are formed on both sides thereof.
6A, or as shown in FIG.
56B is formed and sharpened toward the side surfaces 53B and 54B to be brought into sliding contact.

In FIG. 5, protrusions 57, 58 provided between two circumferentially adjacent cutting blades 55, 55 and 56, 56 are formed by fine cutting blades formed by a mating rotary cutter. At the time of biting into the strip, the strip is positioned so as to form a surface close to a right angle to the biting direction so that the bite is easily bitten, and has a substantially trapezoidal shape.

[0007] Each of these conventional rotary cutters,
As shown in FIG. 6 and FIGS. 7A to 7C, one metal plate was formed into a predetermined shape by punching or cutting.

[0008]

The rotary cutter has a thickness corresponding to the width of the document. Therefore, it is obtained by processing a relatively thick metal plate.

In the document shredding machine, a large number of rotary cutters are mounted on the rotary shaft as described above. That is, one document shredder requires a number of rotating cutters. Therefore, preparing such a large number of rotary cutters made of a thick metal plate imposes a great burden on the cutting tool for punching, or increases the man-hour when performing other cutting. I do. Further, in order to facilitate the punching process, a process is performed before the hardening heat treatment, and thereafter, the heat treatment is performed to obtain the hardness as the rotary cutter, and the number of processing steps increases accordingly.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a rotary cutter for a document shredding machine, a manufacturing method thereof, and a document shredding machine, which can be easily manufactured, cost can be reduced, and weight can be reduced. The purpose is to provide.

[0011]

According to the present invention, there is provided a rotary cutter for a document shredder according to the present invention, wherein two rotary shafts which are parallel to each other and rotate in opposite directions are respectively provided with a ring-shaped rotary shaft which rotates together with the rotary shafts. A plurality of rotating cutters and spacers are fitted so as to alternately mesh with each other, and the rotating cutters on both rotating shafts are arranged so that the peripheral side surfaces of the rotating cutters are in sliding contact with each other to shear the document to form a strip. .

In the rotary cutter for a document shredding machine, in the present invention, the rotary cutter is provided with two metal annular plate-shaped side members forming the peripheral side surface, and is sandwiched between these two side members. And an intermediate member positioned so as to maintain the two side members in parallel.

[0013] The rotary cutter of the present invention having the above-described structure is as follows.
The two side members are axially positioned and supported by an intermediate member, and the document is shredded by sliding rotation of the peripheral side surfaces of the side members of the rotary cutter on the two rotating shafts.

In the present invention, the side member and the intermediate member include:
The intermediate member may be formed integrally with the resin at the time of molding with resin, or may be formed separately and assembled by axial mounting on a rotating shaft.

[0015] The side member itself can be made of a thin metal plate, its processing method is free, and there is no limitation on the outer peripheral shape to be made. The intermediate member is not limited in its material, and it is sufficient if the intermediate member is easily processed and has a predetermined strength.
Made of resin or soft metal. Accordingly, the side member can be easily processed (punched or the like) by making it thinner, and the intermediate member does not receive any stress at the time of chopping, so that a lighter member can be used and the weight can be reduced.

Further, in the present invention, it is preferable that the side member is provided with a cutting blade at an appropriate interval on the outer periphery so as to protrude radially outward to cut the small fragment into a short chip shape. At this time, it is desirable that the intermediate member be immersed in the radial direction at least at a portion located at the tearing blade from the outer periphery of the side member. By doing so, the intermediate member does not hinder the biting of the small fragment by the cutting blade, and a sharp biting is performed.

In the method of manufacturing a rotary cutter according to the present invention, when the side member and the intermediate member are formed separately, after forming the side member, the intermediate member is disposed on the rotating shaft between the two side members. In addition, the side member and the intermediate member can be integrated by obtaining a resin between the two side members and integrally molding the intermediate member.

A document shredder of the present invention is obtained by including the above-mentioned rotary cutter.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG.
An embodiment of the present invention will be described based on the above.

In FIG. 1 (A), reference numerals 1 and 2 designate two parallel and oppositely rotating rotary shafts on which rotary cutters 3 and 4 having the same external shape and shape for shredding a document shredder are attached. And shown as a cross-sectional view in a plane perpendicular to the axis. The rotating shafts 1 and 2 have the same outer diameter in this embodiment, and the distance between the shafts (the distance between the shaft centers) is
4 are smaller than the diameters of the outer diameter base circles 3A and 4A. The rotary shafts 1 and 2 have key grooves 1A and 2A formed on their outer peripheral surfaces so as to extend in the axial direction (perpendicular to the paper).

In this embodiment, the rotary cutters 3 and 4 are made by a method described later. These rotating cutters 3, 4
Has key portions 3B and 4B on the inner diameter surface, respectively, engages with the key grooves 1A and 2A of the rotary shafts 1 and 2, and rotates with the rotary shafts 1 and 2 (FIG. 1). (B)).

The rotary cutters 3 and 4 are alternately assembled on the respective rotary shafts 1 and 2 with spacers described later having the same thickness as the rotary cutters 3 and 4. Are slidably engaged with each other on their outer peripheral side surfaces so as to rotate.

Each of the rotary cutters 3 and 4 has on its outer periphery a tearing blade 5, which protrudes radially outward from its outer diameter base circle 3A, 4A.
6 and a plurality of projections 7, 8 at appropriate intervals on the outer circumference. Since the two rotary cutters 3 and 4 have the same configuration, only the one rotary cutter 3 will be described with respect to the cutting blade and the protrusion, and the description of the other rotary cutter 4 will be omitted.

Further, in the present embodiment, the rotary cutter 3 is provided at a position between two adjacent cutting blades 5 in the circumferential direction so as to project radially outward from the outer diameter base circle 3A. 7. The protruding portion 7 has a front edge (inclined edge) 8A rising from the outer diameter base circle 3A at an obtuse angle in the rotation direction, and a rear edge 7B also forming an obtuse angle but having a slightly steeper inclination than the front edge. ing. As shown in FIG. 1 (B), the relationship between the protrusion and the cutting blade is shown in FIG.
The leading edge of the cutting blade 5 of the other rotating cutter 4 intersects the leading edge 8A of the projection 8 of the other rotating cutter 4, and as shown in FIG. Are interlocked with the front edge 7A of the projection 7 of the one rotary cutter 3 so that the two rotary cutters are engaged with each other. This is performed by setting the relative angular positional relationship between the key grooves 1A, 2A of the rotating shafts 1, 2.

In the document shredding apparatus of the present embodiment configured as described above, the document to be shredded is supplied between the two rotating cutters 3 and 4 in the direction of arrow X. The document is provided on the side of the rotary cutters 3 and 4 in sliding contact,
Is subjected to shearing force on the side of the slab and is cut into narrow strips. Further, the strip is cut short by the cutting blade 5 protruding into the strip.

Next, the structure of the rotary cutter and the method of manufacturing the same according to the present invention will be described.

As shown in FIGS. 2 and 3, the rotary cutter 3 (same as the rotary cutter 4) is composed of two side members 31 and an intermediate member 32 located therebetween.

The side member 31 is formed to be thinner than the intermediate member 32, and at least the outer peripheral portion including the cutting blade 5 and the protrusion 7 is made of a metal plate having a hardness required for shredding. The side member 31 itself has the planar shape shown in FIG. 1A (the shape viewed from the direction in which the shaft 1 extends), and is made by punching, cutting out, or the like of a metal plate. A known method is sufficient for the manufacturing method, and there is no limitation.
In the present embodiment, the side surface member 31 has a locking window portion 31A formed at an appropriate position.

In the present embodiment, the rotary cutter 3 is connected by an intermediate member 32 such that the distance between the outer side surfaces of the side members 31 on both sides becomes a predetermined thickness of the rotary cutter 3. The intermediate member 32 is formed by integral molding of resin,
In particular, the engagement with the side member 31 is ensured by the locking window 31A. The intermediate member 32 has a hole 32 </ b> A for penetrating the rotation shaft formed on the inner periphery, and the outer periphery is substantially uniformly sunk in the radial direction from the outer shape of the side member 31. Therefore, the outer periphery of the intermediate member does not reduce the sharpness at which the cutting blade 5 enters the shredded paper at the position of the cutting blade 5. The outer periphery of the intermediate member 32 is uniformly depressed in the radial direction as described above, and
It does not need to be shaped along the circumference of the. For example, the outer circumference may be a circle that is the same as or slightly smaller than the base circle 3A of the side surface member 31. The point is that if the projection 7 or the severing blade 5 (particularly, the tip end thereof) does not hinder the sharp action due to being submerged in the radial direction and does not reduce the supporting force of the side surface member, Immersion form is free. By doing so, the side member becomes as shown in FIG.
Of the conventional cutter (55A, 56A) into the shredded paper with the same sharpness. Thus, as shown in FIG. 3, one rotary cutter 3 is formed and assembled to the rotary shafts 1 and 2 (only the axis is shown in FIG. 3) via the spacers 9 and 10. Then, the rotary cutter 3 slides in contact with the other side of the rotary cutter 4 on the other side, and cuts.

The present invention is not limited to the embodiments shown in FIGS. 2 and 3, the side member and the intermediate member form a single rotary cutter by integral molding of the intermediate member. However, in another embodiment shown in FIG. The intermediate member 32 is formed separately.
Therefore, the locking window as in the previous embodiment need not be formed on the side member. The side member 31 and the intermediate member 32 are separated from each other before assembly to the shaft body 1. At the time of assembling to the shaft 1, the side member 31, the intermediate member 32, the side member 31, and the spacers 9 are repeated in this order, and mounting to the shaft 1 is performed so that a predetermined number of rotary cutters are provided. The same applies to the assembly to the shaft body 2. At this time, if the side member 31 is formed by punching and the outer peripheral edge is punched and drooped, as shown in FIG. 4, the roundness of the corner due to the drooping is directed to the inside of the rotary cutter. And it is preferable that shredding by sliding contact with the counterpart rotary cutter be good.

The intermediate member 32 and the spacer have the same shape and can be formed simply as two members having different thicknesses.
Both can be formed by resin or by punching a soft metal plate.

[0032]

As described above, according to the present invention, the rotating cutter forms a peripheral side surface effective for shredding of a document by a metal side member, and is provided between two parallel side portions. Since the intermediate member is positioned at the lower end, the side member contributing to the shredding can be made thin even with a metal plate having a high hardness which does not require heat treatment, and processing becomes extremely simple. Also, the intermediate member that does not contribute to shredding does not require strength or hardness, even though it is thicker than the side members, so it can be made of a lightweight or easily processable material. The overall weight and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a rotary cutter for a document shredding machine according to the present invention as viewed from the axial direction, where (A) is a view at one time and (B) is a view at a time when rotation has progressed.

FIG. 2 is a perspective view showing a part of a rotary cutter as one embodiment employed in the apparatus of FIG. 1;

FIG. 3 is a sectional view taken along line III-III of the rotary cutter shown in FIG. 2;

FIG. 4 is a cross-sectional view of a rotary cutter as another embodiment of the present invention in a plane including an axis.

FIG. 5 is a front view of a conventional rotary cutter viewed from an axial direction.

FIG. 6 is a sectional view taken along a plane including an axis when the rotary cutter of FIG. 5 is assembled.

7 (A), (B) and (C) are cross-sectional views of a cutting blade cut along a plane including an axis of various conventional rotary cutters.

[Explanation of symbols]

 1, 2 rotating shaft 3, 4 rotating cutter 5, 6 tearing blade 9, 10 spacer 31 side member 32 intermediate member

Claims (9)

[Claims] 1. A plurality of annular plate-shaped rotary cutters and spacers, which rotate with the rotation shafts, are fitted to each of two rotation shafts which are parallel to each other and rotate in opposite directions so as to alternately mesh with each other. A rotary cutter for a document shredding machine in which a rotary cutter on an axis is arranged so that the peripheral side surfaces of the rotary cutter slide in contact with each other to shear the document to form a strip. Having two side members in the form of a metal ring plate, and an intermediate member positioned so as to be sandwiched between these two side members to maintain the two side members in parallel. Characterized rotary cutter for document shredders. 2. The rotary cutter for a document shredding machine according to claim 1, wherein the side member and the intermediate member are integrally formed at the time of molding the intermediate member with a resin. 3. The rotary cutter for a document shredder according to claim 1, wherein the side member and the intermediate member are formed separately and assembled by axial mounting on a rotary shaft. 4. The side member is provided with a cutting blade at an appropriate interval on the outer periphery to protrude radially outward to cut the small fragment into a short chip shape. A rotary cutter for a document shredder according to claim 3. 5. The intermediate member according to claim 1, wherein the intermediate member is at least at a portion located at the tearing blade, and is sunk in a radial direction from an outer periphery of the side member. Rotary cutter for document shredder. 6. A rotary cutter for a document shredder according to claim 1, wherein the side member is made by punching. 7. The method for manufacturing a rotary cutter according to claim 1, wherein an intermediate member is disposed between the two side members after the side member is formed. Manufacturing method of rotary cutter. 8. The production of a rotary cutter for a document shredding machine according to claim 2, wherein the intermediate member is provided by filling a resin between two side members and integrally molding the resin. Method. 9. A document shredder comprising a rotary cutter according to claim 1. Description: