JPH0592391A - Sheet material cutting device incorporating positional stop mechanism - Google Patents

Abstract

PURPOSE:To reduce the number of components of a device mounted to a copying machine or the like, for cutting a sheet material such as a rolled sheet, and to reduce the cost thereof by using only one torsional coil spring which serves as both press contact torsional coil spring and a positionally stopping torsional coil spring. CONSTITUTION:There are provided a rotary blade 1 having rotary shafts 2, 3 at opposite ends thereof which are journalled to side plates 4, 5, a stationary plate 6 having rotary shafts 7, 8 at opposite ends thereof which are journalled to the side plates 4, 5, D-like cams 14 attached to one end part of the rotary blade 1 and a guide ring attached to the other end thereof. A torsional coil spring 11 is rotatably fitted on the shaft 7 of the stationary blade 6, and an L-like bent arm 13 of the spring is hooked to the stationary blade 6 for locking the same so as to make the stationary blade 6 into press contact with the rotary blade. Further, the other arm 12 of the spring is made to abut against the cam 14 which is therefore pressed, and a D-like cut surface 141 of the cam 13 is aligned with the arm 12 of the spring 11 so that the motion of the rotary blade 1 is restrained when the rotary blade 1 comes to a predetermined stop position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material cutting device with a fixed position stopping mechanism which is mounted on office equipment such as a copying machine, a facsimile machine and a printer and cuts sheet materials such as roll paper and film.

[0002]

2. Description of the Related Art A sheet material cutting device composed of a rotary blade and a fixed blade is designed to reduce the time taken until a cutting command is issued and the cutting is completed to improve cutting efficiency. Immediately before meshing, the rotary blade must stop and wait for the next cutting command. As is often seen in devices that drive the rotary blade of a sheet material cutting device via a one-way clutch, when the force that restrains the movement of the rotary blade at a predetermined stop position is weak, vibration or rotation due to the dead weight of the rotary blade occurs. In many cases, a fixed position stop mechanism is provided to prevent the rotary blade from rotating carelessly due to an unbalanced moment around the axis or to stop excessively from a predetermined stop position due to inertia of the rotary blade.

As a structure of the fixed position stopping mechanism, a mechanism in which a cam is provided on the shaft of the rotary blade and a spring is pressed against the cam to restrain the movement of the rotary blade appropriately is generally used.
A typical example thereof is shown in FIG. Furthermore, JP-A-61-1
There is also a well-known structure such as that disclosed in Japanese Patent No. 5969, in which the roller is pressed against the groove of the cam provided on the rotary blade with a spring to restrain the movement of the rotary blade at a predetermined position. Further, the applicant of the present application has developed a cutter having an elastic stopper for stopping the rotary blade at a fixed position, and disclosed in Japanese Patent Laid-Open No. 58-3
Filed as No. 2466.

[0004]

A device for cutting a sheet material by pressing a fixed blade against a rotary blade cuts the sheet material, does not stop and wait immediately before the rotary blade and the fixed blade mesh with each other, and stops considerably ahead of the meshing position. If it does, it takes a long time from the cutting command to the start of cutting, and the rotary blade goes too far, and when the meshing starts behind the meshing position and the meshing starts after stopping, the paper cannot be fed and paper jam occurs. As a result, smooth cutting cannot be performed. Therefore, various cutting devices with fixed position stopping mechanisms have been studied and proposed.

However, as shown in FIG. 2, in the conventional sheet material cutting device with a fixed position stopping mechanism, the drive shaft of the rotary blade is
A structure is generally used in which a cam is attached to the shaft end that protrudes outward from the body of the sheet material cutting device, and the arm part of the dedicated spring is pressed against the cam, and parts such as the shaft and screws that hold this spring are included. Since the number of points is large, and all of these parts are attached to the position projecting from the sheet material cutting device main body to the outside, there is waste in terms of cost and space.
That is, the conventional sheet material cutting device with a fixed position stop mechanism shown in FIG. 2 is provided with a spring 15 dedicated to the fixed position stop mechanism in addition to the spring 11 for pressing the fixed blade 6 against the rotary blade. A cam 14 attached to a portion of the shaft 2 of the shaft 2 projecting outward from the side plate 4, and the spring 15;
The collar 16 for supporting the spring 15 and the screw 17 constitute a fixed-position stop mechanism, which has a problem that the number of parts is large and the space of the entire cutting device is large. Further, since the rotating object (cam) is on the outside, it is dangerous, and it is a device that needs a cover. In addition, JP-A-61
-5969 disclosed by the applicant of the present invention
Both of which have been filed as No. 8-32466 are provided with a spring and a cam dedicated to a fixed position stopping mechanism at a position protruding outward from a side plate of the body of the sheet material cutting device. There is a problem that an extra space is required to mount a fixed position stopping mechanism similar to the attached sheet material cutting device.

By the way, in recent years, sheet material cutting devices have been equipped with
Although there is an increasing tendency to demand a device that is cheaper and has a smaller occupied space, the conventional cutting device with a fixed position stopping mechanism has not sufficiently satisfied this demand.
Therefore, the present invention aims to solve the above-mentioned problems of the conventional cutting device and to provide a sheet material cutting device with a fixed position stop mechanism that can meet the market demand.

[0007]

The inventor of the present application has found out the problems of the conventional cutting device with a fixed position stopping mechanism, and as a result of various studies, the number of parts has been reduced as much as possible to save the space of the cutting device. In order to make it as small as possible, the rotary blade and the fixed blade are pressed into contact with each other, and the coil spring mounted on the shaft portion and the coil spring provided in the part protruding from the side plate to stop the rotary blade at a fixed position. The inventors of the present invention have completed the present invention by finding that the problem can be solved by combining the functions of and.

Specifically, the present invention is rotatably supported by opposed side plates, and has a rotary blade having a D-shaped cam on the rotary shaft, and the side plate is rotatably supported by the rotary blade, and is provided on the outer periphery of the rotary shaft. A torsion coil spring is mounted, and the torsion coil spring is used as a fixed blade that presses the blade edge against the rotary blade.
One arm portion of the torsion coil spring is locked to the fixed blade so that the fixed blade is pressed against the rotary shaft, and the other arm portion is arranged to contact the D-cut surface of the cam at the stop position of the rotary blade. And a cutting device capable of stopping the rotary blade at a predetermined position.

[0009]

According to the present invention, one arm of a torsion coil spring conventionally provided for the purpose of press-contacting a fixed blade to a rotary blade is attached to the rotary blade shaft by a D-shaped cam provided on the rotary blade. By using the contacting structure, the spring for pressure contact and the spring for the fixed position stop mechanism can be used together, and a spring dedicated for the fixed position stop mechanism,
The shaft and screws that hold the spring can be eliminated. Also, since the cam attached to the rotary blade is installed inside the side plate of the sheet material cutting device, the external dimensions are almost the same as those of the sheet material cutting device that does not have the fixed position stopping mechanism. An attached sheet material cutting device can be provided.

[0010]

The present invention will now be described in more detail with reference to an embodiment and the drawings. FIG. 1 is a perspective view showing an embodiment of a sheet material cutting device with a fixed position stopping mechanism according to the present invention. In FIG. 1, a rotary blade 1 is rotatably supported by the side plates 4, 5 via shafts 2, 3, and a fixed blade 6 is rotatably supported by the side plates 4, 5 via shafts 7, 8. The side plates 4 and 5 were supported and fixed to the base 10 by screws 9. The rotary blade 1 was provided with a D-shaped cam 14 at one end and a guide ring at the other end. The torsion coil spring 11 is rotatably fitted on the shaft 7 of the fixed blade 6,
The L-shaped bent arm 13 is locked in a state of being hooked on the fixed blade 6, and the fixed blade 6 is pressed against the rotary blade 1.
The other arm 12 is in contact with the cam 14 so as to press it. Moreover, the torsion coil spring 11 and the cam 14 are attached to the side plate 4
It is located and placed inside. The cam 14 is the rotary blade 1
D-cut surface 1 when the rotation position of D reaches the predetermined stop position
41 was fixedly arranged on the shaft 2 of the rotary blade 1 at a position corresponding to the arm 12 of the spring 11, and the movement of the rotary blade was restrained by the contact force of the spring 11 at a predetermined stop position.

When a sheet material cutting device having the above-described structure was manufactured and a cutting test was conducted to confirm the fixed position stopping mechanism, the inertia of the rotary blade was reliably erased by the torsion coil spring and the cam, and the inertia was always maintained. The rotary blade could be stopped at a fixed position. In the present invention, the position where the cam is moved is a space which is conventionally required only for disposing the torsion coil spring for pressure contact, and is a play space where nothing is installed on the rotary blade side.

[0012]

According to the present invention, in the cutting device with the fixed position stopping mechanism, the torsion coil spring for pressure welding and the torsion coil spring for stopping the fixed position are combined into one torsion coil spring.
Further, by moving the fixed position stopping cam arranged on the outer side of the side plate to the inner side of the side plate, the number of parts can be reduced and the cost can be reduced, and the cutting device can be downsized to reduce the occupied space. Therefore, the cutting device is downsized, and the degree of freedom in arranging the motor is increased. In addition, since rotating objects such as cams disappear from the outside of the side plate, the risk is greatly reduced.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing an example of a conventional sheet material cutting device with a fixed position stopping mechanism.

[Explanation of symbols]

 1 rotary blade 2 rotary shaft 3 rotary shaft 4 side plate 5 side plate 6 fixed blade 7 fixed blade rotary shaft 8 fixed blade rotary shaft 9 screw 10 base 11 torsion coil spring 12 arm portion 13 arm portion 14 cam 141 D cut surface 15 twist Coil spring 16 Color 17 Screw

Claims (1)

[Claims] 1. A rotary blade rotatably supported by opposing side plates, a rotary blade having a D-shaped cam on the rotary shaft, and a rotary blade rotatably supported by the side plates, and a torsion coil spring mounted on the outer periphery of the rotary shaft. A fixed blade that presses the blade tip against the rotary blade by the torsion coil spring, and one arm portion of the torsion coil spring abuts the D-cut surface of the cam at the stop position of the rotary blade. A sheet material cutting device with a fixed position stop mechanism, which has a structure for stopping the rotation of a rotary blade.