Circular blade holder

Abstract

To improve the cutting quality of a film while allowing the rotation of a circular blade by applying an appropriate braking force to the circular blade.SOLUTION: A holder 1 holds a circular blade 2 for cutting a film 10 moving in one direction while rotating. The holding part 3 holds the circular blade 2 rotatably. The conductor portion 4 and the magnet portion 5 are disposed to face each other. One of the conductor part 4 and the magnet part 5 is configured to rotate with respect to the other of the conductor part 4 and the magnet part 5 in accordance with the rotation of the circular blade 2, and a braking force against the rotation of the circular blade 2 is generated by magnetic braking against the one by the rotation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a holder for a circular blade. [Background technology]

[0002] The applicant of the present invention has proposed techniques for cutting a film using a fixed circular blade, as described in the following Patent Documents 1 to 4. According to these techniques, the circular blade is periodically rotated by a predetermined angle to change the contact position between the circular blade and the film during cutting, thereby improving the life of the circular blade. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7244149 [Patent Document 2] Patent No. 7244150 [Patent Document 3] Patent No. 7361432 [Patent Document 4] Patent No. 7361433 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in order to rotate the circular blade by a predetermined angle, a mechanism is required to enable the rotation and to hold the circular blade in a predetermined position after rotation.Furthermore, the operation of rotating the circular blade is also required.

[0005] Alternatively, the circular blade may be configured to be freely rotatable, and when cutting the film, the circular blade may be rotated following the movement of the film.

[0006] However, when the circular blade is configured to rotate as the film moves, for example, when cutting a flexible film such as an unstretched film, the film may move downward due to the resistance during cutting, making it impossible to cut. Even if the film is successfully cut, the cut edge may become rough (e.g., frayed). In other words, there is a problem in that the cutting quality is easily degraded.

[0007] The inventors conducted various studies and discovered that even if the circular blade is free to rotate, deterioration of the cutting quality of the film can be suppressed if there is a large difference between the speed of the circular blade and the speed of the film during cutting.

[0008] The present invention was made based on this finding, and a main object of the present invention is to provide a circular blade holder that can apply an appropriate braking force to the circular blade, thereby allowing the circular blade to rotate while improving the cutting quality of the film. [Means for solving the problem]

[0009] The present invention can be expressed as the inventions described in the following items.

[0010] (Item 1) A holder for holding a circular blade for cutting a film moving in one direction while rotating, The device includes a holding portion, a conductor portion, and a magnet portion, the holding portion is configured to rotatably hold the circular blade, whereby the circular blade is rotatable in response to contact with the film moving in one direction; The conductor portion and the magnet portion are disposed opposite to each other, One of the conductor portion and the magnet portion rotates relative to the other of the conductor portion and the magnet portion as the circular blade rotates, and this rotation causes magnetic braking of the one of the conductor portion and the magnet portion, thereby generating a braking force against the rotation of the circular blade. A holder for a circular blade.

[0011] (Item 2) It also has a rotation resistance section, the rotation resistance portion is configured to hold the other of the conductor portion and the magnet portion so as to generate resistance to a rotational force generated by rotation of one of the conductor portion and the magnet portion, Furthermore, the rotation resistance portion is configured to allow rotation of the other of the conductor portion and the magnet portion when the rotational force increases due to an increase in the rotation speed of one of the conductor portion and the magnet portion. Item 1: A holder for a circular blade.

[0012] (Item 3) It also has a rotation resistance section, the rotation resistance portion is configured to hold the other of the conductor portion and the magnet portion so as to generate resistance to a rotational force generated by rotation of one of the conductor portion and the magnet portion, Furthermore, when the rotational force increases due to an increase in the rotation speed of one of the conductor portion and the magnet portion, the rotation resistance portion reduces the resistance, thereby enabling the rotation speed of the other of the conductor portion and the magnet portion to increase. Item 1: A holder for a circular blade.

[0013] (Item 4) The conductive portion is a copper plate, and the magnetic portion is a permanent magnet. Item 1 or 2: A holder for a circular blade.

[0014] (Item 5) A method for cutting a film using the circular blade holder according to item 1, The film is cut by moving the circular blade in the one direction while contacting the film with the circular blade; The movement of the film causes the circular blade to rotate in response to contact with the film; The magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade, thereby suppressing an increase in the rotation speed of the circular blade. Film cutting method.

[0015] (Item 6) A method for cutting a film using the circular blade holder according to item 2, The film is cut by moving the circular blade in the one direction while contacting the film with the circular blade; The movement of the film causes the circular blade to rotate in response to contact with the film; The magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade, suppressing an increase in the rotation speed of the circular blade, and When the rotation speed of one of the conductor portion and the magnet portion increases, the other of the conductor portion and the magnet portion is made rotatable. Film cutting method.

[0016] (Item 7) Item 3. A method for cutting a film using the circular blade holder according to item 3, The film is cut by moving the circular blade in the one direction while contacting the film with the circular blade; The movement of the film causes the circular blade to rotate in response to contact with the film; The magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade, suppressing an increase in the rotation speed of the circular blade, and When the rotation speed of one of the conductor portion and the magnet portion increases, the resistance by the rotation resistance portion is reduced, thereby enabling the rotation speed of the other of the conductor portion and the magnet portion to increase. Film cutting method.

[0017] (Item 8) The film is an unstretched film. Item 7. The film cutting method according to Item 5 or 6. [Effects of the Invention]

[0018] According to the technology of the present invention, by applying an appropriate braking force to the circular blade, it is possible to improve the cutting quality of the film while allowing the circular blade to rotate. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is an exploded perspective view of a circular blade holder according to an embodiment of the present invention. [Figure 2] 2 is an explanatory diagram of the circular blade holder of FIG. 1 as viewed from the left side. FIG. [Figure 3] 2 is a perspective view of the circular blade holder of FIG. 1 as viewed from the right side. FIG. [Figure 4] 2 is a perspective view of the circular blade holder of FIG. 1 as viewed from the left side. FIG. [Figure 5] 2 is a perspective view of a first magnet holder used in the circular blade holder of FIG. 1. FIG. [Figure 6] FIG. 6 is a perspective view of FIG. 5 with a part cut away. [Figure 7] 6 is a perspective view of the first magnet holder of FIG. 5, seen from the opposite direction. [Figure 8] 2 is a perspective view of a second magnet holder used in the circular blade holder of FIG. 1. FIG. [Figure 9] FIG. 9 is a perspective view of FIG. 8 with a part cut away. [Figure 10] FIG. 2 is an exploded perspective view showing a part of the circular blade holder of FIG. 1. [Figure 11] FIG. 10 is an explanatory diagram for explaining a state in which a second magnet holder is attached to a holder. [Figure 12] 12 is an explanatory diagram showing FIG. 11 viewed from the opposite direction. [Figure 13] FIG. 2 is an explanatory diagram for explaining the positional relationship between a first magnet holder and a second magnet holder. [Figure 14] 2 is a partially cutaway perspective view showing a portion of the circular blade holder of FIG. 1. FIG. [Figure 15] 1. FIG. 4 is an explanatory view for explaining a third conductor used in the circular blade holder of FIG. [Figure 16]FIG. 10 is an explanatory diagram for explaining a third conductor. [Figure 17] 2 is an explanatory view for explaining a rotation resistance portion used in the circular blade holder of FIG. 1. FIG. [Figure 18] FIG. 4 is an explanatory diagram for explaining a rotation resistance portion. [Figure 19] FIG. 4 is an explanatory diagram for explaining a rotation resistance portion. [Figure 20] FIG. 4 is a partially cutaway view illustrating a rotation resistance portion. [Figure 21] FIG. 2 is an exploded perspective view showing a part of the circular holder of FIG. 1. [Figure 22] FIG. 22 is a perspective view of the circular holder shown in FIG. 21. [Figure 23] 2 is a perspective view of the circular holder of FIG. 1 with a portion thereof cut away. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] A circular blade holder (hereinafter sometimes simply referred to as "holder") 1 according to one embodiment of the present invention will be described with reference to the accompanying drawings. This holder 1 holds a circular blade 2 for cutting a film 10 (see FIG. 2) moving in one direction while rotating. The film 10 used in this embodiment is strip-shaped and is to be pulled out from a predetermined roll and cut to a predetermined width. In this embodiment, a resin film, particularly an unstretched film, is used as the film 10, but the present invention is not limited to this.

[0021] (Circular blade) The circular blade 2 held by the holder 1 of this embodiment has a circular blade body 21 with a cutting edge on its outer periphery and resin plates 22 attached to both the front and back surfaces of the circular blade body 21. The configuration of the circular blade 2 can be basically the same as the circular blade described in Patent Document 1, and therefore further detailed description will be omitted. However, the circular blade 2 of this embodiment is designed to rotate around a shaft 36 (described below) as the film 10 is cut.

[0022] (Holder configuration) The holder 1 of this embodiment basically comprises a holding portion 3, a conductor portion 4, and a magnet portion 5. The holder 1 further comprises a rotation resistance portion 6 and a blade cover 7 as additional components.

[0023] (holding part) The holding portion 3 is configured to rotatably hold the circular blade 2. This allows the circular blade 2 to rotate following contact with the film 10 moving in one direction.

[0024] More specifically, the holding unit 3 of this embodiment has a mounting plate 31 for attaching the holder 1 to a slitter device (not shown), a main body 32 attached to the mounting plate 31, two blade supports 33 and 34 that sandwich the circular blade 2, a blade setscrew 35, and a shaft 36. The shaft 36 is disposed so as to pass through the main body 32, the blade supports 33 and 34, the circular blade 2, etc., and has one end into which the blade setscrew 35 is screwed so that the circular blade 2, etc. can be held on the shaft 36 (see FIG. 23). The other end of the shaft 36 is fixed to a boss 521 (described below) of the second magnet holder 52 by a pin 361.

[0025] The main body 32 is attached to the mounting plate 31 by screws 311 that are threaded into the main body 32 through elongated holes 312 (see FIG. 2) formed in the mounting plate 31. As a result, in this embodiment, the angle of the main body 32 relative to the mounting plate 31 can be adjusted using the elongated holes 312.

[0026] (Conductor and magnet parts) The conductor portion 4 has a first conductor 41, a second conductor 42, and a third conductor 43.

[0027] In this embodiment, the first conductor 41, the second conductor 42, and the third conductor 43 are all made of a disk-shaped copper plate. The first conductor 41 is fixed to the main body 32 of the holder 3 with a screw 412. A bearing 411 is attached to the center of the first conductor 41, and the shaft 36 is rotatably attached to this bearing 411. Similarly, the second conductor 42 is fixed to the main body 32 of the holder 3 with a screw. A bearing 421 is attached to the center of the second conductor 42, and the shaft 36 is rotatably attached to this bearing 421. Here, the bearings 411 and 421 are, for example, rolling bearings.

[0028] A rotation resistance ring 61 (described later) of the rotation resistance section 6 is attached to the center of the third conductor 43. The rotation resistance ring 61 is attached to a rotation resistance shaft 62 (described later), and thus the third conductor 43 is attached to the rotation resistance shaft 62. An iron disk 431 constituting an iron core is fixed to one side of the third conductor 43 (the left side in FIG. 1) with screws 432.

[0029] The magnet unit 5 has a first magnet holder 51 and a second magnet holder 52. Permanent magnets 51a to 51h (see FIG. 5) are attached to the first magnet holder 51 along its circumference. The permanent magnets 51a to 51h are arranged so that the south poles and north poles appear alternately along the circumference. For example, when viewed from the front as shown in FIG. 5, the magnetic poles appear on the surface in the order NSNS... clockwise.

[0030] Similarly, permanent magnets 52a to 52h (see FIG. 8) are attached along the circumference of the second magnet holder 52. The permanent magnets 52a to 52h are arranged so that the north and south poles appear alternately along the circumference. For example, in the state shown in FIG. 8, the magnetic poles appear on the surface in the order S, N, S, N... in a clockwise direction.

[0031] Both first magnet holder 51 and second magnet holder 52 are fixed to shaft 36 and are coaxial with shaft 36 so as to be able to rotate integrally therewith.

[0032] Furthermore, when the permanent magnets 51a to 51h of the first magnet holder 51 and the permanent magnets 52a to 52h of the second magnet holder 52 are attached to the shaft 36 so as to face each other, they are arranged so that the polarity of one of the opposing magnets is different from the polarity of the other (for example, the north pole faces the south pole), thereby strengthening the magnetic field.

[0033] A boss 511 is provided on the first magnet holder 51 (see FIGS. 6 and 7). A shaft 36 is attached inside the boss 511. The blade support 33, circular blade 2, and blade support 34 are fitted to the outside of the boss 511 so as not to rotate relative to each other. As a result, when a rotational force is applied to the circular blade 2 from the film 10, the shaft 36 can rotate via the circular blade 2, blade support 34, and first magnet holder 51.

[0034] The second magnet holder 52 is provided with a boss 521 for mounting the shaft 36 therein for rotation (see FIGS. 9 and 13).

[0035] The first conductor 41 of the conductor section 4 and the magnets 51a to 51h of the magnet section 5 are arranged facing each other. The second conductor 42 and the third conductor 43 of the conductor section 4 are arranged facing the magnets 52a to 52h of the magnet section 5, with the magnets 52a to 52h sandwiched between them.

[0036] In this embodiment, the first and second magnet holders 51 and 52 of the magnet unit 5 rotate relative to the first to third conductors 41 to 43 of the conductor unit 4 in conjunction with the rotation of the circular blade 2. As will be described later, in this embodiment, the magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade 2.

[0037] (Rotational resistance part) The rotation resistance unit 6 has a rotation resistance ring 61, a rotation resistance shaft 62, and a case 63. As described above, the rotation resistance ring 61 is fitted into the center of the third conductor 43 (see FIGS. 15 and 16). An iron disk 431 is fitted onto the outside of the rotation resistance ring 61. The rotation resistance shaft 62 is attached inside the case 63 (see FIGS. 17 and 18).

[0038] A boss 621 is formed on the rotation resistance shaft 62. The rotation resistance ring 61 is tightly fitted to the outer surface of the boss 621, and the friction between them prevents relative circumferential movement (see FIGS. 19 and 20). Furthermore, as the rotation speed of the second magnet holder 52 increases and the rotational force acting on the third conductor 43 increases, the rotation resistance ring 61 (and therefore the third conductor 43) can rotate while sliding relative to the boss 621 against the frictional force between the boss 621 and the rotation resistance ring 61 (i.e., rotation is enabled). Once the rotation resistance ring 61 begins to slide, the friction coefficient becomes a kinetic friction coefficient, and the frictional force decreases. In other words, although the boss 621 and the rotation resistance ring 61 in this embodiment can rotate relative to each other, the starting torque at the start of rotation is sufficiently large compared to the starting torque at the start of rotation of the bearings 411 and 421.

[0039] As a result, the rotation resistance unit 6 of this embodiment is configured to hold the third conductor 43 of the conductor unit 4 so as to generate resistance to the rotational force generated by the rotation of the magnet unit 5. Furthermore, when the rotational force increases due to an increase in the rotation speed of the magnet unit 5 (specifically, the magnets 52a to 52h), the rotation resistance unit 6 of this embodiment is configured to reduce the resistance to the rotational force, thereby rotating the third conductor 43 of the conductor unit 4 (i.e., to enable the rotation speed to increase). Here, in this embodiment, "reducing the resistance to the rotational force" means that the frictional force decreases as the rotation resistance ring 61 begins to slip.

[0040] The case 63 is attached to the main body 32 (see FIGS. 21 and 23).

[0041] (Blade cover) The blade cover 7 has a first cover body 71 and a second cover body 72. These first and second cover bodies 71 and 72 are attached to the outside of the main body 32 of the holder 3 (see FIGS. 3 and 4). The first and second cover bodies 71 and 72 are slidable relative to the main body 32 by screws 73 and 74, respectively (see FIG. 23). That is, the first and second cover bodies 71 and 72 can be switched between a closed state (see FIGS. 21 and 22) and an open state (see FIGS. 2 to 4) by sliding relative to the screws 73 and 74.

[0042] (Holder operation) The operation of the holder 1 of this embodiment will be described in detail below with reference to the drawings.

[0043] (Initial state) First, assume that the blade cover 7 is in a closed state (see FIG. 22). The mounting plate 31 of the holder 1 in this state is attached to a predetermined slitter device (not shown). In this embodiment, the blade cover 7 can cover the circular blade 2, so that the worker does not come into contact with the circular blade 2 during installation, removal, or other operations, thereby improving work safety.

[0044] Next, the blade cover 7 is opened to expose the circular blade 2 (see FIG. 2). In this state, the film 10 is pulled out and moved in the direction of arrow A in FIG. 2 while being brought into contact with the circular blade 2. The traveling position of the film 10 is indicated by the two-dot chain line in FIG. 2. In this embodiment, the film 10 gradually accelerates from an initial speed of 0 (or a low speed). The acceleration of the film 10 may be constant or may vary as appropriate.

[0045] Circular blade 2 comes into contact with moving film 10, thereby cutting film 10 to a predetermined width. At this time, circular blade 2 receives a force (rotational force) from film 10 and rotates in one direction (i.e., counterclockwise in FIG. 2). As a result, blade supports 33 and 34, first magnet holder 51, shaft 36, and second magnet holder 52 rotate together with circular blade 2. However, first to third conductors 41 to 43 do not rotate (third conductor 43 will be described later).

[0046] This allows the first and second magnet holders 51 and 52 and the first to third conductors 41 to 43 to rotate relative to each other. This generates an induced current in the first to third conductors 41 to 43, and the magnetic force generated by this induced current generates a braking force against the rotation of the first and second magnet holders 51 and 52 (so-called magnetic braking). This also allows braking against the rotation of the circular blade 2. Therefore, according to this embodiment, it is possible to keep the rotation speed of the circular blade 2 low.

[0047] If the rotation speed of the circular blade 2 can be kept low relative to the traveling speed of the film 10, there is an advantage in that cutting quality can be improved even for relatively flexible films such as unstretched films.

[0048] In this embodiment, the third conductor 43 is also fixed regardless of the rotation of the circular blade 2, and therefore a strong braking force can be exerted on the circular blade 2. In particular, it is difficult to obtain a strong braking force by magnetic braking in the early stages of rotation of the circular blade 2 (i.e., before the rotation speed has sufficiently increased), but in this embodiment, the third conductor 43 is also used, which has the advantage of being able to obtain a strong braking force even in the early stages of rotation of the circular blade 2. When the magnets 52a to 52h of the second magnet holder 52 rotate, the force caused by this rotation acts on the third conductor 43 (a so-called Arago disk), but the frictional force between the rotation resistance ring 61 and the rotation resistance shaft 62 prevents the third conductor 43 from rotating.

[0049] As the rotation speed of the circular blade 2 increases with the acceleration of the film 10, the force generated by the rotation of the magnets 52a-52h of the second magnet holder 52 increases, overcoming the frictional force between the rotation resistance ring 61 and the rotation resistance shaft 62 and causing the third conductor 43 to rotate. As the third conductor 43 rotates, the magnetic braking force exerted by the third conductor 43 decreases. During high-speed rotation of the circular blade 2, the relative speed difference between the first and second conductors 41 and 42 and the first and second magnet holders 51 and 52 is large, so a practically sufficient braking force can be applied to the circular blade 2. Allowing the third conductor 43 to rotate also has the advantage of keeping the amount of heat generated by the third conductor 43 low during high-speed rotation of the circular blade 2.

[0050] Furthermore, in this embodiment, when the third conductor 43 starts to rotate, the frictional force (i.e., resistance to rotational force) between the rotation resistance ring 61 and the rotation resistance shaft 62 decreases, and the rotation resistance shaft 62 functions as a so-called sliding bearing. Therefore, when the circular blade 2 rotates at high speed, the braking force caused by the third conductor 43 can be further reduced, which also has the advantage of further reducing the amount of heat generated thereby.

[0051] Furthermore, according to this embodiment, there is no need to provide a mechanism for rotating the circular blade 2 by a predetermined angle, and furthermore, the work of rotating it in this manner is also unnecessary.

[0052] Furthermore, in this embodiment, the film 10 can be cut using the rotating circular blade 2, which has the advantage of producing significantly less chips than when a fixed blade is used.

[0053] Furthermore, compared to cutting in one place like with a fixed blade, using a rotating circular blade 2 can reduce blade wear and chipping, which has the advantage of improving slit quality (cutting quality).

[0054] Furthermore, when a thick stretched film is cut with a fixed plate blade (razor blade), there is a problem that the cut surface is prone to becoming rough (i.e., frayed). However, by using a magnetically controlled circular blade 2 as in this embodiment, it is also possible to suppress the roughness.

[0055] Furthermore, in the past, a plate blade and a rotary blade were used alternately depending on whether the film to be cut was an unstretched film or a stretched film, but according to this embodiment, both unstretched film and stretched film can be cut with good quality using the same circular blade 2. This reduces the frequency with which the production line has to be stopped due to process changes, thereby improving productivity.

[0056] Furthermore, the frequency of blade replacement can be reduced, reducing the risk of cuts or other injuries during blade replacement and improving work safety.

[0057] The above-described embodiment is merely an example and does not represent essential components of the present invention. The configuration of each part is not limited to the above, as long as the gist of the present invention can be achieved.

[0058] For example, in the above-described embodiment, the conductor portion 4 side is basically fixed and the magnet portion 5 side is basically rotating, but conversely, the magnet portion 5 side may be basically fixed and the conductor portion 4 side may be basically rotating. In this case, the first conductor 41 of the conductor portion 4 and the like will rotate as the circular blade 2 rotates. In this case, the rotation resistance portion may be configured to rotate the magnet portion when the rotational force increases due to an increase in the rotation speed of the conductor portion.

[0059] Furthermore, in the above-described embodiment, a resin film, particularly an unstretched film, is exemplified as the film 10, but the present invention is not limited to this and may be a stretched film. Also, the present invention is not limited to a resin film and may be other types of film (for example, a metal film).

[0060] In this embodiment, the rotation resistance ring 61 is tightly fitted onto the outer surface of the boss 621, and the friction between them prevents relative circumferential movement. However, instead of this, for example, the rotation resistance ring 61 and the rotation resistance shaft 62 may be connected via a bearing that has a higher rotation resistance at startup than the bearings 411 and 421. [Explanation of symbols]

[0061] 1 holder 2 circular blades 21 Circular blade body 22 Resin board 3 Holding part 31 Mounting plate 311 Screw 312 long hole 32 Main Unit 33 Blade support 34 Blade support 35 Blade set screw 36 Shaft 361 pins 4 Conductor part 41 First conductor 411 Bearings 412 Screw 42 Second Conductor 421 Bearings 43 Third Conductor 431 Iron Disc 432 Screw 5 Magnet section 51 First magnet holder 51a~h Magnet 511 Boss 52 Second magnet holder 52a~52h Magnet 521 Boss 6 Rotational resistance section 61 Rotational Resistance Ring 62 Rotational resistance shaft 621 Boss 63 cases 7 Blade Cover 71 First cover body 72 Second cover body 73 Screw 74 screws 10 Film A Film running direction

Claims

1. A holder for holding a circular blade for cutting a film moving in one direction while rotating, The device includes a holding portion, a conductor portion, and a magnet portion, the holding portion is configured to rotatably hold the circular blade, whereby the circular blade is rotatable in response to contact with the film moving in one direction; The conductor portion and the magnet portion are disposed opposite to each other, One of the conductor portion and the magnet portion rotates relative to the other of the conductor portion and the magnet portion as the circular blade rotates, and this rotation causes magnetic braking of the one of the conductor portion and the magnet portion, thereby generating a braking force against the rotation of the circular blade. A holder for a circular blade.

2. It also has a rotation resistance section, the rotation resistance portion is configured to hold the other of the conductor portion and the magnet portion so as to generate resistance to a rotational force generated by rotation of one of the conductor portion and the magnet portion, Furthermore, the rotation resistance portion is configured to allow rotation of the other of the conductor portion and the magnet portion when the rotational force increases due to an increase in the rotation speed of one of the conductor portion and the magnet portion.

2. The circular blade holder according to claim 1.

3. It also has a rotation resistance section, the rotation resistance portion is configured to hold the other of the conductor portion and the magnet portion so as to generate resistance to a rotational force generated by rotation of one of the conductor portion and the magnet portion, Furthermore, when the rotational force increases due to an increase in the rotation speed of one of the conductor portion and the magnet portion, the rotation resistance portion reduces the resistance, thereby enabling the rotation speed of the other of the conductor portion and the magnet portion to increase.

2. The circular blade holder according to claim 1.

4. The conductive portion is a copper plate, and the magnetic portion is a permanent magnet.

3. The circular blade holder according to claim 1 or 2.

5. A method for cutting a film using the circular blade holder according to claim 1, The film is cut by moving the circular blade in the one direction while contacting the film with the circular blade; The movement of the film causes the circular blade to rotate in response to contact with the film; The magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade, thereby suppressing an increase in the rotation speed of the circular blade. Film cutting method.

6. A method for cutting a film using the circular blade holder according to claim 2, The film is cut by moving the circular blade in the one direction while contacting the film with the circular blade; The movement of the film causes the circular blade to rotate in response to contact with the film; The magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade, suppressing an increase in the rotation speed of the circular blade, and When the rotation speed of one of the conductor portion and the magnet portion increases, the other of the conductor portion and the magnet portion is made rotatable. Film cutting method.

7. A method for cutting a film using the circular blade holder according to claim 3, The film is cut by moving the circular blade in the one direction while contacting the film with the circular blade; The movement of the film causes the circular blade to rotate in response to contact with the film; The magnetic braking caused by this rotation generates a braking force against the rotation of the circular blade, suppressing an increase in the rotation speed of the circular blade, and When the rotation speed of one of the conductor portion and the magnet portion increases, the resistance by the rotation resistance portion is reduced, thereby enabling the rotation speed of the other of the conductor portion and the magnet portion to increase. Film cutting method.

8. The film is an unstretched film. The film cutting method according to claim 5 or 6.

Images