JPH09225886A - Cutter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To diminish a shock caused by colliding a cutting blade with a side wall so as to prevent such a matter that a sensor switch is damaged and the tip of the cutting blade runs into the tip of a fixed blade, by narrowing the pitches of the spiral of a guide shaft according as it approaches to the end of an axial direction. SOLUTION: This shuttle cutter so formed that a pin extended from a carriage 4 for retaining a cutter blade 5 is loosely fitted to a spline shaft 2 that a spiral groove 21 is formed around the periphery of a cylindrical shaft 20 or a spiral shaft 2 that a linear material is spirally formed around there, thereby, a subject to be cut is cut between the cutting blade and a fixed blade while guiding the axial movement of the carriage 4. In this case, the groove of the spline shaft or the pitches of the spline of the spiral shaft is formed narrower than the pitches in an axial center according as pitches of both ends approach to ends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shuttle cutter mounted in an image forming apparatus such as a copying machine, a printer or a facsimile machine for cutting recording paper, and more particularly to an image forming apparatus using roll paper as recording paper. Regarding the shuttle cutter used.

[0002]

2. Description of the Related Art FIG. 7 is a schematic diagram showing the structure of a conventional shuttle cutter. This shuttle cutter has a spline shaft (a wire rod formed into a spiral shape or a coil shape) rotatably supported by a casing 1. , Spiral shaft (A spiral groove is formed on the outer peripheral surface of the shaft)
By rotating the guide shaft 2 with the motor 3 such as the above, the carriage 4 provided with the guided pin to be loosely fitted in the groove of the guide shaft 2 (in the case of the spline shaft) is moved in the axial direction. A cutting blade 5 is rotatably supported on the carriage 4, and the cutting blade 5 and the fixed blade 6 located below the cutting blade 5 overlap each other by a predetermined amount as shown in the drawing. By moving, the paper sheets passing through the paper passing port 7 between the two blades are cut. By the way, in the above-mentioned conventional shuttle cutter, by arranging the sensor switches 8 such as limit switches at both ends of the movement path of the cutting blade 5 (carriage 4), it is detected that the cutting blade 5 has come to the end. Then, although the motor is braked to stop the carriage 4, the sensor switch 8 is located near the side walls 9 located at both ends of the guide shaft 2 and the carriage does not break even if the brake is applied. Side wall 9
Therefore, the impact at the time of the collision is large, and the sensor switch 8 is damaged, and the cutting edge of the cutting blade 5 rides on the cutting edge of the fixed blade 6 to make cutting impossible.

According to the first aspect of the present invention, the spiral pitch of the guide shaft is made narrower toward the end portion in the axial direction, so that the impact caused by the cutting blade colliding with the side wall is reduced, and the sensor switch is damaged or damaged. , The purpose is to prevent the cutting edge of the cutting blade from riding on the fixed blade. According to the second and third aspects of the present invention, when the cutting blade reaches the end portion of the guide shaft so as not to hit the side wall, the cutting blade collides with the side wall and the above-mentioned problems associated therewith are eliminated. Is intended. In the inventions of claims 4 and 5, when the cutting blade reaches near the end portion of the guide shaft, the cutting blade is caused to reciprocate within a short range by using a spring mechanism so that the cutting blade collides with the side wall. The purpose of this is to eliminate the above problems.

[0004]

In order to achieve the above object, the invention of claim 1 is a spline shaft having a spiral groove formed on the outer circumference of a cylindrical shaft, or a spiral blade formed by spirally forming a wire rod. By loosely fitting a pin extending from a carriage for holding, while guiding the axial movement of the carriage, in the shuttle cutter for cutting the object to be cut between the cutting blade and the fixed blade, the groove of the spiral shaft, Alternatively, it is characterized in that the pitch of the splines of the spline shaft is configured so that the pitch of both end portions becomes narrower toward the ends than the pitch of the central portion in the axial direction. The invention of claim 2 terminates the groove of the spiral shaft or the spline of the spline shaft by endlessly making one round of the groove or the end spline when the cutting blade reaches the end in the moving direction. It is characterized in that it is an endless groove or the like, and the pin is made to idle along the endless groove or the like. According to the invention of claim 3, when the groove of the spiral shaft or the spline of the spline shaft is moved to the terminal end in the moving direction of the spiral shaft, the groove is gradually shallowed toward the terminal end, and finally the shaft is finished. It has the same thickness as the outer circumference, supports the pin provided on the carriage so that it can advance and retreat in the axial direction, and elastically urges it in the protruding direction, and when the pin slides along the groove bottom surface, the groove bottom surface At the shallower position, the tip of the pin should be retracted into the carriage,
When the pin reaches the same thickness as the outer circumference of the shaft,
It is characterized by making it idle. According to the invention of claim 4, a leaf spring is provided at a confluence portion between the groove of the spiral shaft or the endless groove or the like located at each end of the spline of the spline shaft and the groove main body. When the pin moves axially outward, the pin can be circulated in the endless groove or the like, and when the pin moves axially inward, the pin can move from the endless groove or the like to the groove body side. It is characterized by According to a fifth aspect of the present invention, a pressing spring is arranged on a side wall of the cutter, which is located at an axial end portion, so that when the carriage reaches the end portion, the carriage is elastically pushed back to have a predetermined width. The feature is that the carriage is reciprocated inside.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings. FIG. 1A is an overall configuration diagram of a shuttle cutter according to an embodiment of the present invention, FIG. 1B is a configuration diagram of an example of a spline shaft, and FIG. 1C is a configuration diagram of an example of a spiral shaft. This shuttle cutter is a guide shaft such as a spline shaft (a wire formed in a spiral shape) rotatably supported in the casing 1 or a spiral shaft (a spiral groove formed on the outer peripheral surface of the shaft). By rotating 2 by the motor 3, the carriage 4 provided with the guided pin to be loosely fitted in the groove of the guide shaft 2 (in the case of the spline shaft) is moved in the axial direction. A cutting blade 5 is rotatably supported on the carriage 4, and the cutting blade 5 and the fixed blade 6 located below the cutting blade 5 overlap each other by a predetermined amount as shown in the drawing. By moving, the paper sheets passing through the paper passing port 7 between the two blades are cut. Reference numeral 8 is a sensor switch, and 9 is a side wall.

The guide shaft 2 shown in FIGS. 1 (a) and 1 (b) is a spline shaft, which is a coil formed by spirally forming a wire rod. The guide shaft 2 has a space in the center (= spline = winding width a). Is characterized in that the pitch of the splines (winding width a ′) becomes gradually narrower toward both ends, and is characteristic. By rotating the spline shaft 2 with the pin protruding from the carriage 4 protruding into the spiral spline (a space formed between adjacent wire rods and into which the pin fits), Moves along the inside of the spline, so that the carriage 4 (cutting blade 5) can move in the axial direction. In the present invention, since the winding width a'of the axial end portion is narrower than that of the central portion, the moving speed of the cutting blade 5 is slower at both end portions than at the central portion even if the rotation speed of the motor does not change. Become. Therefore, when the pin reaches the end, the carriage 4
The axial movement speed of the shuttle cutter decreases, and the side wall 9 located at the end of the shuttle cutter collides with a strong force, or the sensor switch 8
There is no problem such as damage to. In other words, blur
Since it is possible to mechanically loosen the moving speed of the cutting blade mechanism without applying a force, the impact due to a collision can be reduced.

FIG. 1 (c) shows a structure similar to that of the above embodiment applied to a guide shaft 2 as a spiral shaft, which is a cylindrical shaft 20.
By forming a spiral groove 21 on the outer peripheral surface of the carriage 4 and guiding the pins of the carriage 4 along the groove, the carriage 4 is advanced and retracted in the axial direction when the guide shaft 2 is rotated. In this embodiment, the pitch of the groove 21 is maximized in the central portion and gradually reduced toward both ends, so that the moving speed of the cutting blade 5 is lower than that of the central portion even if the rotation speed of the motor does not change. Both ends are slower.
Therefore, as in the case of FIGS. 1 (a) and 1 (b), when the pin reaches the end, the moving speed of the carriage 4 in the axial direction decreases, and the side wall 9 located at the end of the shuttle cutter collides with a strong force. There is no problem such as damage or damage to the sensor switch 8.

Next, FIGS. 2 (a) and 2 (b) are perspective views of the essential parts showing the structure of the guide shaft of another embodiment of the present invention. (b)
Is a conventional groove structure, and since the end portion 21a of this groove 21 is terminated as shown in the figure, when the groove pitch is the same over the entire axial length as in the conventional case, the carriage 4 is A pin provided on the side wall collides with this end portion, and the carriage moves to the side wall 9
And the carriage, the cutting blade, the sensor switch, and the like are damaged over time. However, in the present invention, as shown in FIG. 2 (a), the spiral groove 21A at the axial end is formed.
Does not end, but is connected endlessly around the outer circumference of the shaft 20 once. Since the cutting blade slides with the pin inside the groove 21A, when the pin reaches the endmost groove 21A, the pin will move into the groove 21A no matter how many motors continue to rotate in the same direction. 1 shaft along
Just go around. Therefore, it does not move outward in the axial direction. By setting the groove 21A that makes one round at the terminal end portion to the front side position where the cutting blade 5 (carriage 4) does not hit the side wall 9, it is possible to prevent collision with the side wall. The structure in which the groove at the end is an endless groove that goes around the shaft in this way can also be applied to the spiral structure of the spline shaft made of a wire rod.

Further, the structure of this embodiment should be applied in combination with the structure of the embodiment shown in FIG. 1, that is, the structure in which the pitch of the groove at the end in the axial direction, the spline (winding width), etc. is made smaller than that at the center. It can also be applied to the end portion of a guide shaft having grooves and splines of a conventional pitch. As a result, similarly to the above-described embodiment, even if the pin reaches the end portion at a high speed, the pin only circulates along the endless groove 21A, so that the carriage 4
The cutting blade 5 supported by does not collide with the side wall 9.
If it is combined with the groove structure of the guide shaft of the embodiment of FIG. 1, the axial movement speed of the carriage 4 is sufficiently reduced at the axial end portion where there are grooves with a short pitch, etc. Although it is unlikely that the side wall 9 located at the end of the shuttle cutter collides with a strong force in the first place, by providing the endless groove, even if the motor continues to rotate in the same direction, the carriage 4 is fixed at the end. Since the carriage can be held at the position, the carriage position is not destabilized, which is convenient.

Next, FIGS. 3 (a), 3 (b) and 3 (c) are a front view showing the structure of a carriage and a cutting blade (cutting blade mechanism) according to another embodiment of the present invention, a sectional view taken along line AA 'and FIG. It is a BB 'sectional view. 4 (a), (b) and (c) are examples of the structure of the guide shaft applied to the cutting blade of FIG. 3, (a) is a general view of an example of the guide shaft, and (b) is the depth of the groove. Of the change state of
FIG. 3C is a configuration diagram of a groove portion that is a main part of the present invention. As shown in FIG. 3, this cutting blade mechanism includes a carriage 4 supported by a casing 1 so as to be movable back and forth in the longitudinal direction, and a cutting blade 5 rotatably supported by a shaft 25 provided on the carriage 4.
And a pin 26 penetratingly arranged in a proper position of the carriage avoiding the cutting blade 5 so as to be able to move forward and backward, a stopper 27 integrated with the pin 26 for defining the limit of the protruding position of the pin 26, and the inside of the carriage. And an elastic body 28 such as a coil spring which is arranged on the outer periphery of the pin 26 and biases the pin 26 in the protruding direction of (a). The pin 26 is fitted into the groove or spline of the guide shaft at the tip portion protruding from the carriage 4, and can be pulled in the (b) side against the elastic body 28 by the pressing force from the groove or the like.

Next, the guide shaft 2 shown in FIG. 4 (a) may be one in which the pitch of the grooves at the axial end portions is made narrower than that at the central portion, as in the embodiment shown in FIG. The pitch may be evenly spaced over the entire length. In any case, the guide shaft 2 of this embodiment is characterized in that the depth of the groove 21 is gradually reduced toward the terminal end at a predetermined inclination as shown in FIG. 4 (b). Target. FIG.
The α- α cross section of the left diagram in (c) is the right diagram, and in this state, the position of the groove bottom surface is inclined and raised toward the axial end. The end of the groove 21 is finally the same as the outer diameter of the shaft 20. This groove 2
When the cutting blade slides with the tip portion of the pin 26 fitted in 1 and reaches the axial end portion, the pin is elastic.
Since it is supported by 8, the pin is pushed by the bottom surface of the groove and retracts in the direction of (b). When the pin gets over the end of the groove, the pin tip is in pressure contact with the outer peripheral surface of the shaft where no groove exists. In this state, the groove ends and there is no spiral groove,
The pin cannot go further axially outwards. The pin runs idle on the outer peripheral surface of the shaft where there is no groove. By setting a position further outside in the axial direction of the end portion of the groove, that is, a position where the thickness of the shaft 20 does not exist in the groove so that the blade does not hit the side wall 9, the carriage 4 and the cutting blade 5 are It is possible to prevent a collision with the side wall 9. In addition, in the spline shaft in which the wire is spirally wound, an obstacle corresponding to the groove bottom is provided in the spline at the axial end portion, and the groove bottom is gradually shallowed to obtain the same as above. May have an effect.

According to this embodiment, like the above embodiment, even if the pin reaches the end portion at a high speed, the pin which is guided by the groove bottom portion and moves to the axial end portion has a shallow groove. When the bottom end portion is further moved in the axial direction, it rides on the shaft outer periphery where there is no groove, and relatively idles there. Therefore, the cutting blade 5 supported by the carriage 4 does not collide with the side wall 9. If this form example is combined with the groove structure of the guide shaft of the form example of FIG. 1, the axial moving speed of the carriage 4 is sufficiently reduced at the axial end portion where the groove having a short pitch exists. Therefore, the side wall 9 located at the end of the shuttle cutter does not collide with a strong force in the first place, but since the carriage idles relatively in the non-groove part, even if the motor continues to rotate in the same direction. Since the carriage 4 can be continuously held at the fixed position at the end, instability of the carriage position is eliminated,
It will be convenient.

5 (a) and 5 (b) show another example of the groove portion of the guide shaft, which is a modification of the example of FIG. In this embodiment, as shown in the enlarged view of (b), an endless groove 21A is provided at the terminal end, while a leaf spring 30 as shown is arranged at the confluence of the groove body 21 and the endless groove. ,
One end of the shaft is fixed at a proper position on the shaft, and the other end is projected into the endless groove 21A as a free end at a predetermined angle. As shown, a notch 31 may be provided to prevent the tip of the leaf spring 30 from interfering with the groove wall. Further, the leaf spring can be moved from the interference position shown by the solid line to the retracted position shown by the dotted line. In any case, the protrusion length and the protrusion angle of the leaf spring 30 are configured so that the pin which relatively circulates in the endless groove 21A always contacts the leaf spring when passing through the leaf spring 30. When the blade moves relatively in the groove 21A in the outward direction shown by the arrow, it pushes the leaf spring 30 to the position of the dotted line and orbits endlessly.
When 6 relatively moves inward in the groove 21A, it abuts against the leaf spring 30 protruding to the interference position, and is guided by this to enter the groove body 21.

In this way, when the leaf spring 30 is projected into the endless groove of the guide shaft as shown in FIG. 5 (b) and the pin moves outward in the axial direction as a result of the guide shaft rotating outward, the groove 21A is formed. Since the pin which has entered inside can be circulated in the outward direction indicated by the arrow, and conversely, when the pin moves in the inward direction indicated by the arrow, it is guided by the leaf spring into the groove main body 21. In addition to being able to obtain the same collision prevention effect as in the above embodiment, when the carriage is desired to be returned inward in the axial direction, it can be returned easily and quickly simply by rotating the guide shaft 2 in the returning direction. . It is also advantageous in terms of cost. Needless to say, the structure of this embodiment can be applied to a spline shaft made of a wire rod.

FIG. 6 is a schematic view of the essential part of a shuttle cutter according to another embodiment of the present invention. In this embodiment, a push spring 40 is attached to the side wall 9 while the depth of the spiral groove 21 is set in the axial direction. The characteristic is that it becomes shallower toward the outside. In this configuration example, when the guide shaft 2 continues to rotate in the direction in which the cutting blade mechanism is directed outward, even if the carriage 4 reaching the end collides with the spring 40, the spring 4 is immediately released.
Since it is pushed back by 0, the carriage has a groove and a spring 40.
You will travel back and forth between. The guide shaft 2
If you rotate the carriage inward in the axial direction,
It is spirally guided by the pushing spring 40. This makes it easy to return. It is needless to say that this form example can be applied to a spline shaft in which a wire rod is formed in a spiral shape. Further, this form example may be combined with the groove structure of FIG. The effects of this embodiment are similar to those of the above embodiments.

[0016]

According to the invention of claim 1, the groove pitch of the spiral shaft or the pitch of the splines (spaces between the wire rods) of the spline shaft is set such that the pitch at both end portions is closer to the end than the pitch at the central portion. By making the shape narrower, the moving speed of the cutting blade mechanism can be mechanically loosened without applying a break,
The impact from a collision can be reduced. In the invention of claim 2,
Since the endless portion of the groove or spline is provided around the end, when the cutting blade reaches both ends, the pin enters the inside of the endless groove or the like and idles, so that collision can be eliminated.

According to the third aspect of the present invention, the groove is gradually shallowed toward the end of the groove, and finally the groove is eliminated so that the shaft has the same thickness as the outer circumference of the shaft and is pressed against the groove bottom. As a result, the pin of the cutting blade is retracted, so that when the pin gets over the end of the groove, it can be idled in the same thickness as the outer circumference of the shaft, so collision can be eliminated. According to the invention of claim 4, by adding a leaf spring for guiding the pin to the structure of claim 2, by inverting the rotation direction of the guide shaft when the cutting blade is at the end position of the groove, the cutting is performed. The blade pin can be guided back and forth in the spiral groove body. According to the invention of claim 5, in addition to the structure of claim 3, by adding a push spring provided on the side wall, when the cutting blade is at the terminal end of the groove, the rotation direction of the shaft is reversed to cut. It can be reciprocated by pushing the blade spirally.

[Brief description of drawings]

1A is an overall configuration diagram of a shuttle cutter according to an embodiment of the present invention, FIG. 1B is a configuration diagram of an example of a spline shaft,
(c) is a block diagram of an example of a spiral shaft.

2 (a) and 2 (b) are perspective views of a main part showing a configuration of a guide shaft according to another embodiment of the present invention.

3 (a), (b) and (c) are front views showing configurations of a carriage and a cutting blade (cutting blade mechanism) according to another embodiment of the present invention,
AA 'sectional drawing and BB' sectional drawing.

4 (a), (b) and (c) are configuration examples of a guide shaft applied to the cutting blade of FIG. 3, (a) is an overall view of an example of the guide shaft, and (b) is a diagram of a groove. Figure showing the changing state of depth,
FIG. 3C is a configuration diagram of a groove portion that is a main part of the present invention.

5A and 5B are a main part configuration diagram and a partially enlarged view of a guide shaft according to another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing the main configuration of a guide shaft according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram of a conventional shuttle cutter.

[Explanation of symbols]

1 casing, 2 guide shaft, 3 motor, 4
Carriage, 5 cutting blades, 6 fixed blades, 7 paper feed openings,
8 sensor switch, 9 side wall, 20 shaft, 21
Groove, 21A endless groove, 21a end portion, 25
Shaft, 26 pin, 27 stopper, 28 elastic body, 30
Leaf spring, 40 push spring.

Claims (5)

[Claims] 1. A pin extending from a carriage for holding a cutting blade is loosely fitted in a groove of a spiral shaft having a spiral groove formed on the outer circumference of a cylindrical shaft, or in a spline of a spline shaft formed by spirally forming a wire rod. Thus, in the shuttle cutter that cuts the object to be cut between the cutting blade and the fixed blade while guiding the axial movement of the carriage, the groove of the spiral shaft or the pitch of the spline of the spline shaft is A cutter device, characterized in that the pitch of both end portions becomes narrower toward the end than the pitch of the central portion in the direction. 2. An endless groove for terminating the groove of the spiral shaft or the spline of the spline shaft by terminating the end groove or the end spline once when the cutting blade reaches the end in the moving direction. The cutter device according to claim 1, wherein the pin is configured to idle around the endless groove or the like. 3. The groove of the spiral shaft or the spline of the spline shaft is gradually shallowed toward the terminal end when the cutting blade reaches the terminal end in the moving direction, and finally the outer periphery of the shaft is formed. They have the same thickness, support the pins provided on the carriage so that they can move forward and backward in the axial direction, and elastically urge them in the protruding direction, so that when the pins slide along the groove bottom, the groove bottom becomes shallow. The cutter device according to claim 1, wherein the tip end portion of the pin is retracted into the carriage at the position where the pin has reached, and when the pin reaches the same thickness as the outer circumference of the shaft, the pin rotates idle. 4. A leaf spring is provided at the confluence of the groove body and the groove of the spiral shaft or the endless groove located at each end of the spline of the spline shaft, and the leaf spring has the pin in the axial direction. When the pin moves outward, it is possible to orbit the pin in the endless groove, and when the pin moves axially inward, the pin can move from the endless groove to the groove body side. The cutter device according to claim 2, which is characterized in that. 5. A pushing spring is arranged on a side wall of the cutter, which is located at an axial end portion, so that when the carriage reaches the end portion, the pushing spring is elastically pushed back so that the carriage has a predetermined width. The cutter device according to claim 3, wherein the carriage is reciprocated.