JPH05337883A - Sheet cutting device - Google Patents

Abstract

PURPOSE:To prevent the slip-off of a movable blade and guarantee its positive stop in the stand-by position in a device for cutting sheet material between the movable blade and a fixed blade by the oscillation of the movable blade with both end parts thereof rotatably supported at support plates by providing end plates at both ends of the movable blade, and supporting these end plates on the support plates through shafts. CONSTITUTION:A sheet cutting device built in a facsimile or the like is provided with a fixed blade 1 formed of a thin plate blade member by bending and screw-fixed (4) to the bottom plate 31 of body sheet metal 3. The sheet cutting device is also provided with a movable blade 2 formed of thin plate blade material by bending after press punching, and the movable blade 2 is integrally provided on both sides with end plates 22 with fulcrum shaft holes 23 bored therein. The body sheet metal 3 is formed by press punching a plate such as an electrogalvanized steel plate and further machining support plates 32 on both sides by bending, and protrusions (fulcrum shafts) 33 are formed at these support plates 32 by extrusion work. The movable blade 2 is oscillatingly journalled to the fulcrum shafts 33 by inserting these fulcrum shafts 33 into the fulcrum shaft holes 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet cutting apparatus which is installed in office equipment such as a facsimile and a printer and is mainly used for cutting sheets such as paper.

[0002]

2. Description of the Related Art In a conventional sheet cutting apparatus, a movable blade is supported by a movable blade support plate so that the movable blade can rotate or swing. Then, the movable blade is brazed with a shaft long enough to project from the movable blade support plate so that the shaft does not come off from the movable blade support plate due to rocking, impact or deformation during transportation or use. It is fixed to both end surfaces of the movable blade by a method such as adhesion, caulking or the like. And, a movable blade having a shaft having a length sufficient to prevent coming off is a structure in which the shaft is fitted into the support plates at both ends supporting the movable blade from the inside of the support plate toward the outside, Sheet cutting device.

On the other hand, the sheet cutting device can be roughly classified into a structure in which the movable blade rotates once and a structure in which the movable blade swings within a certain angle range. In order to perform the movement, the movable blade must always stop at a fixed position and wait, so it is important to regulate the range in which the movable blade makes one rotation or swings. Various methods are known for restricting the swinging range of the movable blade. One of them is to attach a drive shaft to the end face of the movable blade, and drive this shaft in an elongated hole provided in the movable blade support plate to regulate the swing range of the movable blade, or to cut the sheet. It is well known that a protrusion-like stopper is provided on a support plate or the like of the device by a shaft, a screw or the like, and a part of the movable blade is brought into contact with the stopper. Figure 7
Is an example of a method of restricting the swing range of the movable blade by contacting a part of the drive portion of the movable blade with a rod-shaped protrusion called a locking portion fixed to a support plate or the like. Further, there is also used a method of restricting the drive range by a drive source without providing a member or the like for restricting the movable range in the sheet cutting device.

[0004]

It is necessary to provide a shaft having a sufficient length on the end face of the movable blade so that the movable blade does not come off from the support plate due to rocking, impact or the like. And increase the cost. Therefore, the present inventor manufactures a movable blade from a sheet metal, and forms a protrusion, which is commonly called an emboss or dowel, which is processed by an extrusion press on the plate at the end of the movable blade, and fits the movable blade support plate into a rotary shaft. As a shaft, or conversely, a movable blade supporting plate is provided with a dowel by extrusion and is fitted into the end of the movable blade to be used as a shaft.
No. 65381 filed a cutting device that realized downsizing and cost reduction. However, since the shaft that can be processed by extrusion must be about 80% or less of the plate thickness, the extrusion shaft that can be processed into a 1.6 mm thick sheet metal that is usually used for sheet metal of cutters has a length of about 1.3 mm. Because there is
There is a problem that the shaft may come off the bearing due to vibration or shock.

On the other hand, in a sheet cutting apparatus having a structure in which a movable blade swings within a range of a certain angle, the top dead center or the bottom dead center of the movable range is regulated by some method so as not to go out of the certain range. It is often necessary to provide a stopper on the. For example, even in a device that manually drives and cuts the movable blade, the movable blade is rotated in the cutting direction and then returned to the standby position by a spring, but a stopper is required so as not to exceed the standby position. With such a stopper, the movement of the movable blade is minimized.

In the case of a cutting device driven by a motor, when a paper jam occurs, the motor may be burned out if the motor is continuously energized.
The applicant of the present invention drives the movable blade using the 4-bar linkage, forms one of the links into a clip-like shape, and has a structure in which the drive pin is detached from the link, so that the paper can be moved while sandwiching the paper. A cutting device for returning the blade to the standby position was developed and disclosed as Japanese Patent Laid-Open No. 3-228595. Also in the cutting device having this structure, as shown in FIG. 7, a stopper is provided under the name of a locking portion so that the movable blade does not rotate in a counter-cutting direction beyond a predetermined standby position.

Further, in a cutting device having a structure in which a movable blade rotates, a structure in which the movable blade is stopped at a fixed position and stands by for the next cutting is disclosed in JP-A-61-5969. A cutter stop positioning mechanism is disclosed.
This application has a structure in which a cam is provided on a drive shaft and a roller is fitted into the cam to stop at a fixed position. However, the above-described cutting device provided with these stoppers has a problem in that the number of parts increases and the shape of parts becomes complicated, resulting in an increase in cost due to deterioration in material yield. Also,
Since a relatively large stopper must be attached around the movable blade to stop the movable blade reliably, there is also a problem that the size of the entire apparatus increases.

An object of the present invention is to provide a mechanism capable of solving the above-mentioned two problems while not increasing the number of parts and having a relatively simple structure. That is,
An object of the present invention is to provide a sheet cutting device equipped with a stopper mechanism that prevents the movable blade from coming off when the movable blade moves in the axial direction, and can surely stop the movable blade at the standby position.

[0009]

According to the present invention, as a result of various studies to solve the above-mentioned problems, a phenomenon in which a movable blade using an embossed extrusion shaft comes off from a support plate and falls off is prevented. It was found that this may occur during transportation of the cutting device, and at that time, a shocking force is generated in the direction in which the movable blade comes out, that is, in the direction parallel to the rotation axis of the movable blade. Therefore, when the movable blade is manufactured from sheet metal, the end plate is usually provided by bending, but at the standby position of the cutting device, one surface of the end plate and a part of the frame of the movable blade are provided. The support plate for the movable blade is sandwiched between it and the rear end so that it can be supported even when an impact force is applied in the direction in which the movable blade comes out, that is, in the direction parallel to the rotary shaft core of the movable blade. The plate and the rear end of the blade are now in contact with each other so that the movable blade does not come off even if it moves in the direction parallel to the axis. In addition, in this structure, the movable blade frame rear end portion forming a part of the movable blade frame and the connecting portion of the movable blade end plate are brought into contact with the support plate of the movable blade to move the movable blade in the anti-cutting direction. The present invention has been completed as a structure in which the supporting plate also has a suppressing effect.

With the above-mentioned structure, since the bending end connecting the end plate and the rear end of the blade and the support plate come into contact with each other at the standby position, the movable blade is moved in the direction opposite to the cutting direction. It can be used as a stopper to prevent rotation. With such a structure, the movable blade cannot rotate and only swings. More specifically, the present invention relates to a main body sheet metal having a thin plate-shaped supporting plate that pivotally supports a movable blade in opposition to both ends, and a swingable shaft supported at both ends of the supporting plate, which cooperates with a fixed blade. In a sheet material cutting device including a movable blade that works to cut a sheet material, and a fixed blade, the movable blade has thin plate-shaped end plates at both ends thereof, and the end plates are supporting plates of a body sheet metal facing each other. Is pivotally supported on the outer side surface of the movable blade, and the support plate has a structure in which the movable blade is pivotally held between the end plate of the movable blade and the rear end of the frame of the movable blade. A sheet cutting device characterized by the above.

[0011]

With the structure of the movable blade according to the present invention, even when an impact force is applied in the direction in which the movable blade is disengaged, that is, in the direction parallel to the axis of the swing of the movable blade, a part of the movable blade, usually the rear end Since the portion contacts the support plate, the lateral movement of the movable blade is suppressed, and the movable blade can be prevented from coming off the support plate. Furthermore, since the end plate of the movable blade is pivotally supported on the outside of the support plate, the bending edge of the movable blade and the support plate come into contact with each other. You can prevent it from rotating. That is, a part of the frame of the movable blade and a part of the support plate can also function as stoppers mutually.

[0012]

The present invention will now be described in detail with reference to one embodiment and the drawings. 1 is a perspective view showing an embodiment of a sheet cutting apparatus according to the present invention, FIG. 2 is a top view of FIG. 1, FIG. 3 is a partial sectional view for explaining prevention of detachment of a rotary blade, and FIG. 4 is a movable blade. It is a side view explaining the mechanism of the stopper at the standby position.
The fixed blade 1 was formed by bending a thin blade material and fixed to the bottom plate 31 of the main body sheet metal 3 with the screw 4. In FIG. 1, the fixed blade is fixed to the bottom plate 31 of the main body sheet metal 3 that is integrated with the support plate 32, but the support plate and the bottom plate do not necessarily have to be made of an integral sheet metal, and those that are manufactured separately are joined together. You may. In short, the fixed blade may be attached anywhere as long as it is fixed to an appropriate position where it can be cut with respect to the movable blade 2.

The movable blade 2 has end plates 22 on both sides by bending after punching a thin blade material made of the same material as the fixed blade 1.
And a fulcrum shaft hole 23 is bored in the end plate 22 for molding. In FIG. 1, the movable blade is press-molded as a unit of a thin blade material including the frame and the end plates on both sides. However, other embodiments of the present invention include a structure in which the blade portion of the movable blade is attached to the frame, or a structure in which the end plate 22 is separately formed and joined to the movable blade 2. In particular, if only the blade part of the movable blade is made of high-grade blade material and the other frame parts are joined as ordinary steel plates, it is possible to make a sheet cutting device that is easy to press-form, has high durability, and is inexpensive. it can. Body sheet metal 3
Is a stamped sheet of electrogalvanized steel, and is further bent to form support plates 32 on both sides.
A fulcrum shaft 33 was formed by providing a protrusion by extrusion. The protrusion formed by extrusion is commonly called an emboss or dowel.

In the movable blade 2, fulcrum shaft holes 23 provided on both end faces 22 located on both sides of the movable blade frame are inserted into fulcrum shafts 33 formed on support plates 32 provided on both sides of the main body sheet metal 3, It is pivotally supported in a swingable state. The fixed blade 1 has a screw 4 at a position where its edge line meshes with the edge line of the movable blade 21.
Fixed by FIG. 1 shows a state in which the movable blade 2 is on standby. At this position, the support plate 32 is sandwiched between the frame rear end portion 25, which is a part of the movable blade, and the end surface 22, and is sandwiched. Next, the situation when the movable blade 2 is incorporated into the main body sheet metal 3 will be described. First, in terms of dimensions, the inner length of the end plate 22 of the opposing rotary blade is slightly longer than the outer length of the opposing support plate 32 (a difference of about 0.2 mm is preferable). Then, while bending the entire body sheet metal 3 at a position where the rear end portion 25 of the movable blade and the support plate 32 do not contact as shown in FIG. 3b, the end plate 22 of the movable blade is inserted outside the support plate 32, The fulcrum shaft 33 may be fitted into the fulcrum shaft hole 23 to pivotally support the movable blade 2.

Next, a description will be given of the contents of preventing the movable blade 2 from coming off from the body sheet metal. Figure 2a shows the normal state, Figure 2b.
Shows the state when the impact 5 in the direction in which the movable blade comes off is applied. When the movable blade 2 moves in the direction of the arrow due to the impact 5 (FIG. 2b), the rear end portion 25 of the movable blade moves to the support plate 3
Since it hits 2, it can be prevented from coming off. That is, even if the movable blade moves in the direction of the arrow 5 by the amount of the gap 6, the other supporting plate moves while flexing from the position 32X shown in FIG. 2A to the position 32Y shown in FIG. 2B, so that the movable blade does not come off. Of. Since it is obvious that the fulcrum shaft 33 must be longer than the gap 6 formed by the fulcrum shaft 32 and the end plate 22, if the length of the fulcrum shaft 33 is limited, the gap 6 can be reduced. Good. For example, the support plate 3
It has been confirmed that when the dowel formed by extrusion from 2 is used as the fulcrum shaft 33, it can only extrude up to about 80% of the plate thickness, so if the body sheet metal is 1.6 mm thick, the shaft height is Since it is about 1.3 mm, it is advisable to set the gap 6 to about 0.5 mm.

FIG. 3a is a sectional view showing the movable blade 2 in the standby state, and FIG. 3b is a sectional view showing the state at the end of the cutting operation. The impact direction 5 shown in FIG. 2b is the direction from the opposite side of the paper surface to the front side in FIG. 3a, and it can be seen that the frame rear end portion 25 of the movable blade hits the support plate 32 when an impact force is applied. However, when the movable blade 2 is incorporated in the main body sheet metal 3, the movable blade 2 cannot be incorporated because the rear end portion 25 of the movable blade and the support plate 32 are always overlapped. Therefore,
As shown in FIG. 3, a position where the frame rear end portion 25 of the movable blade 2 and the support plate 32 do not contact when the movable blade is rotated in the cutting direction is provided, and the movable blade 2 is incorporated at this position. To do. However, if an impact force is applied in the state shown in FIG. 3b, the movable blade may come off, but since the operating time of the movable blade is normally about 0.5 seconds, there is almost no risk of impact being applied during this period. In addition, the movable blade 2 does not come off even if a shock is applied. Also,
In most cases, the impact is applied even during transportation, and it is sufficient if the effect of preventing the disengagement is provided at the standby position shown in FIG. 3a.

Next, a description will be given of a stopper mechanism using a support plate for preventing the movable blade 2 from exceeding the standby position and being rotated in the counter-cutting direction when the movable blade 2 returns to the standby position after cutting. 4a is a sectional view showing a standby position, and FIG. 4b is a sectional view showing a state in which the stopper mechanism operates. As shown in FIG. 4a, the movable blade 2 is bent on both sides to provide an end plate 22.
The bent end portion 24 of this bent portion on the side close to the support plate 32.
Depending on the situation, the gap 7 may be provided between the and the support plate 32, or the gap may be set to zero. The cutting device does not always stop at the fixed position due to the dispersion of each component during manufacturing, the difference in the structure on the drive side, etc. It will be impossible. Therefore, depending on the structure of the driving side, at the stop position which is also the standby position, the gap is eliminated between the bent end portion 24 and the support plate 32, or a certain amount of the gap 7 is provided for adjustment.

For example, in the case of a structure in which the movable blade 2 is returned to the standby position by using the restoring force of a spring (not shown) after cutting, even after the bending end 24 and the support plate 32 collide with each other with the gap 7 set to 0 Even if the source rotates in the anti-cutting direction, the elastic force of the spring absorbs the extra rotation, so that the drive source is not forced. However, on the other hand, the movable blade 2 after cutting
In the case of a structure in which the drive force is returned to the standby position only by the driving force, it is possible that the rotational force still remains after the bending end portion 24 and the support plate 32 collide with each other due to variations in parts or the like. Therefore, an extra load may be applied to gears and motors. Therefore, if the gap 7 is provided without causing the bending end portion 24 and the support plate 32 to collide with each other at the return position which is also the standby position of the movable blade, this problem can be avoided. As an example of this, when the present invention is applied to a cutting device having a drive source shown in FIG. 7, if the gap 7 is set to about 0.5 mm, the movable blade bending end portion 24 and the support plate 32 at the standby position during normal operation are Since there is no collision, the drive unit is not forced.

5 and 6 show another embodiment of the present invention. When a substantially L-shaped sandwiching member 26 is fixed to the upper surface of the movable blade frame 21 and the supporting plate 32 is sandwiched by the sandwiching member 26 and the movable blade as shown in FIG.
The same effect as the basic structure shown in can be exhibited. Further, in the present embodiment, the present invention has been described by using the embossing by extrusion as the fulcrum shaft, but the shaft may be fixed by the ordinary embedding, screwing or the like to be used as the fulcrum shaft. Furthermore, the supporting plate was provided with a fulcrum shaft by extrusion processing,
This can also be provided on the end plate of the movable blade.

【The invention's effect】

As described above, according to the present invention, the support plate is sandwiched between the end plate and the rear end of the movable blade by positioning the end plate of the thin plate-shaped movable blade outside the support plate. It is possible to have a structure in which the movable blade is detached when an impact force is applied in a direction parallel to the rotation axis of the movable blade, and at the same time, the stopper mechanism of the movable blade at the standby position is also used. The function can be realized with an extremely simple structure. Further, according to the present invention, since the embossing can be used as the support shaft in addition to mounting another component serving as a stopper, it is possible to reduce the number of components, reduce the size and weight of the device, and reduce the cost and reliability. It is possible to provide a high cutting device.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a sheet material cutting device according to the present invention.

FIG. 2 is a top view illustrating an embodiment of the sheet cutting apparatus according to the present invention, which is for explaining prevention of detachment of the movable blade.

FIG. 3 is a cross-sectional view illustrating an embodiment of the sheet cutting device according to the present invention, which is for explaining the prevention of detachment of the movable blade and the mounting condition.

FIG. 4 is a side view illustrating an embodiment of a sheet cutting device according to the present invention and explaining a stopper mechanism.

FIG. 5 is a perspective view showing another embodiment of the sheet cutting apparatus according to the present invention.

FIG. 6 is a perspective view showing still another embodiment of the sheet cutting device according to the present invention.

FIG. 7 is a perspective view of an example of a conventional sheet cutting device, in which a stopper is provided as a locking portion.

[Explanation of symbols]

1 fixed blade, 2 movable blades, 21 movable blade frame, 22
End plate, 23 Support shaft hole, 24 Bending end, 25 Rear end, 26 Clamping member, 3 Main body sheet metal, 31 Bottom part, 32
Support plate, 33 fulcrum shaft, 4 screws, 5 impact direction, 6
Gap, 7 Gap

Claims (1)

[Claims] 1. A main body sheet metal having a thin plate-shaped support plate that pivotally supports a movable blade opposite to both ends, and a swingable shaft support at both ends of the support plate, and cooperates with a fixed blade. In a sheet material cutting device comprising a movable blade for cutting a sheet material and a fixed blade, the movable blade has thin plate-shaped end plates at both ends thereof, and the end plates are outer surfaces of supporting plates of the main body sheet metal facing each other. Is swingably supported by the support plate, and the support plate has a structure in which the movable blade is sandwiched between the end plate of the movable blade and the frame rear end portion of the movable blade so as to be swingable. Sheet cutting device.