JPH07205089A - Sheet cutting device - Google Patents

Abstract

PURPOSE:To provide a sheet cutting device having stable pressure-contact force by making the shape of a rotary blade and a fixed blade which have a linear blade edge into such a shape that elastic deflection is liable to occur because pressure-contact force increases at a central part of mesh between the rotary and fixed blades. CONSTITUTION:A sheet cutting device consists of a rotary blade 1 and a fixed blade 2 which have a linear blade edge and cut a sheet by crossing the linear edges and bringing them into pressure-contact. A bending section 2e is provided in the vicinity of a connection section between a blade edge section or blade edge sections of either or both of the rotary blade 1 and the fixed blade 2 and a barrel section. Preferably, the bending section 2e is in the shape of U character.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on a device such as a facsimile or a printer, and can be used for roll paper, folding continuous paper,
The present invention relates to a rotary type sheet cutting device for cutting a recording medium such as a film.

[0002]

2. Description of the Related Art Conventionally, a rotary type sheet cutting apparatus has used fixed blades and rotary blades having various sizes and shapes. For example, Japanese Utility Model Publication No. 45-16863 or Japanese Utility Model Publication No. 53-7
As described in Japanese Patent Publication No. 079, the cutting edge of the rotary blade is formed as an intersecting edge of a cylindrical surface and a surface inclined with respect to the axial center surface of the cylinder, and the fixed blade has its straight cutting edge with respect to the rotary blade. It is known that the structure is pressed against the surface.

Further, as described in Japanese Utility Model Laid-Open No. 3-113796, it comprises a movable blade and a fixed blade supported by a frame,
The holder of the fixed blade fixes the blade material to the holder having an L-shaped cross section, and the fixed blade is elastically attached to the frame through an elastic member so that the blade can be tilted with respect to the frame, and the blade edges of the blades are cross-pressed to each other. Structures that cut the material are also shown. Further, the cutting device described in Japanese Utility Model Publication No. 58-26789 discloses a mutual cutting edge line of a rotary blade having a straight cutting edge and a fixed blade, and the cutting edge of the fixed blade at both ends thereof is a locus circle of the cutting edge of the rotary blade. The blade is arranged so that the blade line of the fixed blade interferes with the locus circle of the blade edge of the rotary blade at the central portion, and the blade edges are elastically flexed so that the blade edges are cut while being meshed.

[0004]

In recent years, facsimiles,
There is a strict requirement to equip office equipment such as printers with a low-priced and highly reliable sheet cutting device, and the sheet cutting device having the structure described in JP-B-45-16863 or JP-B-53-70793 is not available. In order to manufacture the rotary blade, an excessively large number of man-hours such as cylindrical grinding are required and the number of parts is increased, so that it is difficult to supply a low-priced product that meets the recent market demand.

Therefore, in order to meet the above requirements, a recent sheet cutting apparatus has a rectangular cross section as described in Japanese Utility Model Publication No. 58-26789. Mutual blade lines of a rotary blade and a fixed blade that have a straight blade fixed to gold are attached at both ends, the blade edge of the fixed blade contacts the trajectory circle of the blade edge of the rotary blade, and the blade edge line of the fixed blade rotates at the center. Widely adopted is a structure in which the blades are arranged so as to interfere with the locus circle of the blade edge, and the blade edges are engaged and cut by the elastic deflection of the fixed blade and the rotary blade that are both blades. Further, in the sheet cutting device having the structure described in Japanese Utility Model Laid-Open No. 3-113796, the fixed blade and the movable blade have a structure in which the cutting edge material is fixed to a holder having an L-shaped cross section, and an elastic member is separately provided. It is difficult to provide low-priced products that meet the requirements of the market because of the large number of parts and the need for frames.

However, in the sheet cutting device having the above-described structure, the fixed blade edge is adjusted and fixed so as to come into contact with the locus circle of the blade edge of the rotary blade at both ends. Due to such slight displacement of position, the pressure contact force between the fixed blade and the rotary blade increases. Along with this, the cutting load is likely to increase, so that the adjustment range of the blades at both ends is significantly narrowed. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and to provide a sheet cutting device having a fixed blade and a movable blade that are likely to cause elastic bending and have stable mutual pressure contact forces.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention variously examines the structure of a sheet cutting device in which the blade edges of a rotary blade fixed blade having a straight blade edge are cross-pressed to each other. It was done as a result. The inventor of the present application has found that a sheet cutting device of this type has a rotary blade and a fixed blade, which have a rectangular or L-shaped cross section, or a thin blade material fixed to a base metal, and have a blade tip of the fixed blade at both ends thereof. Is arranged so that it touches the locus circle of the blade edge of the rotary blade and the blade edge line of the fixed blade interferes with the locus circle of the blade edge of the rotary blade in the central part, and the structure is such that the blade tips are cut by the elastic deflection of both blades. I know that there is. And
In order to solve the above-mentioned problems, it has been found out that it is most economical and reliable to make one or both of the rotary blade and the fixed blade more flexible.

More specifically, the present invention has a straight cutting edge,
A rotary blade for cutting a sheet by cross-pressing the linear blade edges and a fixed blade, and a bent portion is provided in the vicinity of a connecting portion between one or both of the rotary blade and the fixed blade and a body portion. A second aspect of the present invention is a sheet cutting device, which comprises a rotary blade and a fixed blade that have a linear blade edge and cross-contact the linear blade edges to cut a sheet. One or both of the thin blade-shaped material is formed into a substantially L-shaped connecting portion between the blade tip portion and the body portion and a connecting portion between the body portion and the side plate, and either or both of the rotary blade and the fixed blade are formed. The sheet cutting apparatus according to the first aspect of the present invention is characterized in that a bending portion is provided in the vicinity of a connecting portion between the blade edge portion and the body portion. Further, the bending portion has a U-shape provided at the connecting portion of the blade tip portion and the body portion, and is the sheet cutting device according to the first invention, wherein the bending portion is adjusted to adjust the amount of the bending portion. The sheet cutting apparatus according to the first aspect of the invention is characterized in that a mechanism is provided.

[0009]

In the sheet cutting apparatus of the present invention, the rotary blade or the fixed blade is punched out from the material on the thin plate and bent to form the blade tip portion and the body portion, or the body portion and the side plate into a substantially L shape. To do. At the time of this molding, a bent portion is provided at the same time in the vicinity of the connecting portion corresponding to the boundary between the cutting edge portion and the body portion. The bent portion facilitates bending of the cutting edge portion in the pressure contact direction when the rotary blade and the fixed blade are engaged with each other. That is, the rigidity of the fixed blade and the rotary blade is reduced as a whole by providing the bent portion. In addition, the work at the time of assembling is simplified by integrating the cutting edge portion and the body portion, integrating the body portion and the side plate, or integrating the entire body.

When the rotary blade and the fixed blade are engaged with each other, the both ends are assembled so that the locus circle of the blade edge of the rotary blade and the blade edge of the fixed blade coincide with each other.
However, in the vicinity of the center of meshing, the locus circle of the blade edge of the rotary blade and the blade edge position of the fixed blade interfere with each other. At the time of this interference, the rotary blade on which the bent portion is provided, the fixed blade, or both easily bends to relieve the pressure contact force, thereby stabilizing the cutting load over the entire cutting width, and at the same time, cutting edge wear and It also reduces the increase in drive source.

[0011]

Embodiments will now be described in detail with reference to the embodiments and the drawings. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a sectional view of FIG. The rotary blade 1 is formed with an L-shaped rotary blade tip portion 1b and a rotary blade body portion 1c, and a rotary blade side plate 1d is also integrally formed by pressing to provide a straight rotary blade edge 1a. The rotary blade edge 1a and the bent portion of the L-shape are not parallel to each other but are inclined so that the rotary blade edge and the fixed blade edge 2a form a shear angle. On the other hand, the fixed blade 2 is similar to the rotary blade in that the fixed blade tip portion 2b,
The fixed blade body portion 2c and the fixed blade side plate 2d are integrally molded to provide a straight blade edge 2a and a U-shaped fixed blade bent portion 2e.

In this way, the mutual cutting edge lines 1a, 2 of the rotary blade 1 and the fixed blade 2 which are integrally molded and have straight blade edges are formed.
If a is arranged so that the blade edge of the fixed blade contacts the trajectory circle of the blade tip of the rotary blade at both ends and the blade edge line of the fixed blade interferes with the trajectory circle of the blade tip of the rotary blade at both ends, both blade tip portions The sheet cutting device has a structure in which the cutting edges are engaged with each other by the elastic deflection of the blades while being cross-contacted with each other, and the blades are cut together. And
By providing the U-shaped bent portion 1e in the vicinity of the connecting portion of the fixed blade 2, the rigidity of the fixed blade can be reduced over the entire cutting width, and in particular, the increase in the pressure contact force of the blade at both ends can be suppressed, and the entire cutting width can be suppressed. The cutting load can be stabilized over.

FIG. 3 is a perspective view showing another embodiment of the present invention, and FIG. 4 is a side view of FIG. In the embodiment shown in FIGS. 1 and 2, the U-shaped bent portion 2e provided on the fixed blade 2 is provided so as to project in the direction parallel to the sheet passing direction, but in the embodiment shown in FIGS. It is provided so as to project in a direction perpendicular to the sheet passing direction. The U-shaped bent portion 2e of this shape is convenient when it is not desired to increase the width of the cutting device in the sheet passing direction. Further, if the U-shaped bent portion 2e shown in FIGS. 1 and 2 is provided in the opposite direction, that is, provided so as to project toward the rotary blade, the width of the cutting device does not increase, but the bent portion 2e does not correspond to the rotary blade tip 1b. The size and shape of the curve must be taken into account as there is a risk of collision.

In the embodiment shown in FIGS. 5 and 6, adjustment screws 3 are provided at both ends of the U-shaped bent portion 2e of the fixed blade 2 as an adjustment mechanism for expanding and contracting the U-shaped opening. By doing so, the fixed blade edge 2a and the rotary blade edge 1a at both ends of the fixed blade 2 in particular.
The amount of interference with can be adjusted freely. Further, since the side plates for supporting the rotary blade 1 and the fixed blade 2 at both ends are integrally formed with the body portion, an error in the precision of the meshing positions of the blade edges of the rotary blade 1 and the fixed blade 2 occurs. It is possible to correct. FIG. 7 shows an embodiment in which a U-shaped bent portion 1e is provided in the vicinity of the connecting portion between the blade edge portion and the body portion of the rotary blade 1, and FIG. 8 shows a U-shaped bent portion 1e of the rotary blade 1. In this embodiment, adjustment screws 3 for expanding and contracting the opening are provided. By doing so, the same effect as the above-described embodiment can be obtained. In the present embodiment, the present invention has been described by assuming that the shape of the bent portion is U-shaped, but other V-shaped, trapezoidal,
The same effect can be obtained with a U-shape. But,
The U shape is the most desirable shape in consideration of press working, spring effect, attachment of adjusting screws, and the like.

Further, in this embodiment, the rotary blade side plate 1d is mounted on the outer side of the fixed blade side plate 2d and assembled so that the rotary blade 1 only swings. Installed inside the fixed blade side plate 2d, the rotary blade 1
You may make it rotate 0 degree. Further, in this embodiment,
The blade tip portion, the body portion, and the side plate were integrally formed, but these were formed into separate parts, and the blade tip portion and the body portion, the body portion and the side plate, or the three members were assembled using a fixing means. May be.

[0016]

As described above, according to the present invention, a simple structure in which a bending portion is provided in the vicinity of the boundary between at least one of the fixed blade and the rotating blade and the body portion to reduce the rigidity in the pressure contact direction. This eliminates the need to perform troublesome work to adjust the position of the cutting edge when cross-welding the rotary blade and fixed blade, and suppresses the increase in the pressure contact force between the rotary blade and fixed blade over the entire cutting width, ensuring stable operation. It is possible to provide a sheet cutting device capable of cutting with the above cutting load. By using one or both of the rotary blade and the fixed blade with such a structure, it is possible to cut the sheet material with a small and light weight with a small cutting torque, and also to cut the blade tip, the body, the side plate, etc. If integrally molded, the number of parts can be reduced, and thus a sheet cutting device can be provided that is inexpensive and facilitates adjustment of meshing.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a sheet cutting device according to the present invention, in which a bending portion provided at a connecting portion between a blade edge portion and a body portion is U-shaped.

FIG. 2 is a cross-sectional view of the embodiment shown in FIG. 1 according to the sheet cutting apparatus of the present invention, in which a bending portion provided at a connecting portion between a blade edge portion and a body portion is U-shaped.

FIG. 3 is a perspective view showing another embodiment of the sheet cutting apparatus of the present invention, in which the U-shaped bent portion is oriented at right angles to the sheet passing direction.

FIG. 4 is a side view of FIG. 3 showing another embodiment of the sheet cutting apparatus of the present invention in which the U-shaped bent portion is oriented at right angles to the sheet passing direction.

FIG. 5 is a perspective view showing still another embodiment of the sheet cutting apparatus of the present invention, in which an adjusting screw is provided in a U-shaped bending portion.

FIG. 6 is a cross-sectional view of FIG. 5 showing still another embodiment of the sheet cutting apparatus of the present invention, in which an adjusting screw is provided on a U-shaped bent portion.

FIG. 7 shows still another embodiment of the present invention, in which the rotary blade has U
It is sectional drawing which provided the character-shaped bending part.

FIG. 8 is a sectional view showing yet another embodiment of the present invention, in which an adjusting screw is attached to a U-shaped bent portion provided on the rotary blade.

[Explanation of symbols]

1 rotary blade, 1a rotary blade edge, 1b rotary blade edge part,
1c Rotary blade body, 1d Rotary blade side plate, 1e Rotary blade bending part, 2 Fixed blade, 2a Fixed blade edge, 2b Fixed blade edge part, 2c Fixed blade body, 2d Fixed blade side plate, 2e Fixed blade bending part, 3 Adjustment screw

Claims (4)

[Claims] 1. A rotary blade having a straight blade edge and cross-pressing the straight blade edges to cut a sheet and a fixed blade, and one or both of the rotary blade and the fixed blade, and a body portion. A sheet cutting device, characterized in that a bending portion is provided in the vicinity of a connecting portion of the sheet. 2. A blade comprising a straight blade, a rotary blade that cross-contacts the straight blade to cut a sheet to cut a sheet, and a fixed blade, and one or both of the rotary blade and the fixed blade are made of a thin plate-shaped material. Near the connecting portion between the cutting edge portion and the body portion of one or both of the rotary blade and the fixed blade, the connecting portion between the body portion and the body portion, and the connecting portion between the body portion and the side plate are formed in a substantially L shape. The sheet cutting device according to claim 1, wherein a bent portion is provided in the sheet. 3. The sheet cutting device according to claim 1, wherein the bent portion has a U-shape provided near a connecting portion between the blade edge portion and the body portion. 4. The sheet cutting device according to claim 1, wherein the bending portion is provided with an adjusting mechanism for adjusting the amount of the bending portion.