Cutting blade safety system for a roller cutter

Abstract

The invention relates to a handle (1) for picking up, holding, and releasing a round blade (2) from a blade receptacle (6), wherein the handle (1) comprises a holding device (8), wherein the handle (1) comprises a centering mechanism (7) designed to center the blade (2) in the holding device (8), and wherein the handle (1) comprises a key device (10) designed to open a related locking device (11) of a blade coupling (3), and wherein the handle (1) comprises a magnet (9) whose action can be switched, wherein the magnet (9) is designed to releasably fix the blade (2) in the holding device (8). Furthermore, the invention relates to a blade coupling (6) and optionally a transport cassette (4) and a cutting device (5) which are connected to the handle (1).

Description

[0001] The invention relates to a handle for picking up, securely holding, and releasing a round blade. The blade has a diameter of 140 mm to 400 mm and is designed to cut a paper web in a cutting device of a slitter-winder in a paper mill. The handle comprises a holding device. Furthermore, the invention relates to a blade coupling, a transport cassette for transporting the blades, and a cutting device, which are designed for blade replacement by means of the handle.

[0002] In a winder on a paper machine, a paper web is cut along the production direction using cutting devices and then rewound onto smaller rolls. The cutting devices comprise round blades that must be replaced when worn. Changing the blades in the winder is a challenge for occupational safety due to the accessibility and the weight of the blades. In the current technology, blades are usually removed from the cutting device using tools and transported out of the winder area using personal protective equipment such as chain-link gloves. Accessibility in the winder is usually limited, so ergonomic handling of a handle or changing tool is important. A handle that can be operated with one hand is particularly advantageous, so that the other hand is available for holding on to ladders.

[0003] EP3500409 A1 is known from the prior art, which shows a blade housing for a rotating knife, wherein the housing can be used to support an annular blade for rotation about a central axis. A device for safely exchanging blades is not disclosed.

[0004] The object of the invention is to provide technical means that improve occupational safety during a blade change in a winder of a paper machine. Furthermore, the object of the invention is to enable safe holding, safe transfer during blade change, and safe transport of the sharp blades.

[0005] The object is achieved according to the invention by an embodiment according to the independent claim. Further advantageous embodiments of the present invention can be found in the subclaims.

[0006] The object is achieved according to the invention by a handle, wherein the holding device comprises a centering mechanism, a magnet and a blade coupling, wherein the centering mechanism is designed to center the blade in the holding device, and wherein the magnet and blade coupling are designed to releasably fix the blade in the holding device, wherein the handle comprises at least one lever, designed to switch the fixing effect of the magnet and / or the blade coupling, and wherein the handle comprises a key device which is designed to open or close a locking device of a cutting device or a transport cassette which is related to it and thereby to release or fix a blade in the cutting device or transport cassette.

[0007] A blade coupling is advantageously designed to releasably fix a round blade with a diameter of 140 mm to 400 mm and a weight of 300 - 3000 g in one position, whereby the blade coupling holds the blade in the closed state and releases it for removal in the open state.

[0008] The object is further advantageously achieved, wherein the handle comprises a centering mechanism which is designed to center the blade in the holding device, and wherein the handle comprises a key device which is designed to open a locking device of a blade coupling which is related to it, and wherein the handle comprises a magnet whose effect can be switched, wherein the magnet is designed to releasably fix the blade in the holding device.

[0009] When the blade is taken from the handle, it can be positioned in the holding device by the centering mechanism. For this purpose, the centering device advantageously comprises an inclined surface or phase that allows the blade to be centered when positioned in a round opening. In the context of this application, a blade receptacle is the more general description of a device that accommodates a blade, while a blade coupling holds a blade in a defined position with sufficient holding force for its intended use. A detachable connection in the holding device is achieved, for example, by the blade being held in a defined position and / or by an activated magnet. The detachable connection can be opened easily and reversibly for removal.

[0010] A switchable magnet can be switched by changing the distance from the object being held. When switched on, for example, the magnet rests advantageously against the ferromagnetic blade and remains connected to the handle in a single structural unit. If the magnet is removed from the blade using a lever, the magnetic effect decreases with the distance, and the blade can be picked up by a blade coupling connected to the handle.

[0011] The magnet can optionally and advantageously also be fixedly mounted in the handle, whereby the magnetic effect can be switched by changing the magnetic polarity using a lever in such a way that the effect is switched on or off externally. The lever can directly change the position of a part of the switchable magnet via a rotating movement, or can be switched indirectly via another lever or a pull device from an ergonomically favorable position.

[0012] The blade sizes, ranging from 140 mm to 400 mm, pose a particular danger to handling, as the blades initially appear easy to grasp, but are surprisingly sharp due to their weight and rounded blade. Even though personal protective equipment, such as chainmail gloves, is usually required for blade changes, cuts still occur from time to time.

[0013] Switchable magnets can also optionally and advantageously be designed as electromagnets, whereby switching on supplies a magnetic coil with electrical current, thus activating the magnetic effect. In this embodiment, a lever and / or safety lever for switching the magnetic effect is designed as an electrical switch.

[0014] Also advantageous is a handle which comprises a protective device designed to shield the cutting area of ​​the blade from the environment.

[0015] The shielding makes a significant contribution to occupational safety when handling the blade. Shielding is particularly important in the area of ​​the handle, as this is where the handle comes into contact with the person changing the blade. A plate-shaped protective plate has proven particularly advantageous, with the edge protruding 1 mm to 10 mm beyond the edge of the blade. The protective plate advantageously has a rounded edge. In another embodiment, the protective device is advantageously constructed using a cage made of metal wire. The transport cassette can be constructed similarly to a protective cover for a compact disc (CD). The transport cassette can advantageously protect the surrounding area from the sharp blade and at the same time protect the blade from damage or impact.

[0016] Also advantageous is a handle which comprises at least one lever, wherein the lever is designed to switch the magnetic effect of the switchable magnet.

[0017] The lever is advantageous because it can activate the magnetic effect independently of the grip, increasing safety when holding the blade. The lever can also activate the magnet indirectly via a rod or pull mechanism, and the lever can be positioned at an ergonomically favorable location.

[0018] A handle comprising at least one safety lever that secures the switching position of the first lever is also advantageous. A safety lever is an additional lever or switch designed to prevent accidental switching of another lever or to prevent unintentional opening of a blade clutch.

[0019] A handle is also advantageous, wherein the magnet of the holding device is designed to be switchable in its magnetic effect by a blade coupling connected to the handle.

[0020] A blade can be safely transferred from a cutting device or transport cassette to or from a handle using appropriate security features based on a key / lock principle. For example, the magnetic effect during the transfer of the blade to the handle can also be switched by a blade coupling in such a way that the blade is securely held either in the blade coupling or in the handle at all times.

[0021] A handle is also advantageous, wherein the handle comprises a tool for closing or opening a blade coupling in a cutting device. In the prior art, blades are usually screwed into the cutting device. Here, a corresponding wrench can be integrated into the handle to loosen the screw, while the blade is simultaneously held securely by the handle, allowing it to be removed from the cutting device without exposing the user of the handle to any risk.

[0022] A handle comprising at least one permanent magnet, preferably a neodymium magnet, is also advantageous. In practice, it has proven particularly advantageous for the blade to be held in the holding device of the handle by at least one permanent magnet. The holding device can also include additional locking latches to enable the blade to be held in place. A permanent magnet can also advantageously assist in centering or positioning the blade through magnetic forces.

[0023] Also advantageous is a blade coupling for picking up, holding and releasing a round blade, wherein the blade has a diameter of 120 mm to 400 mm, and wherein the blade coupling is designed to pick up the blade from a handle from one of the preceding claims, or to release the blade to the handle, wherein the blade coupling comprises a locking device which is designed to be lockable by a key device of a handle which is related to it.

[0024] A blade coupling according to the invention can advantageously be used in a transport device, a cutting device, and / or in a machine tool. A transport cassette comprising a blade coupling is particularly advantageous. A cutting device of a rotary cutter comprising a blade coupling is also advantageous. A machine tool, in particular a device for sharpening a blade, can also advantageously comprise a blade coupling.

[0025] The blade coupling is advantageously connected to a handle for transferring a blade from the blade coupling to the handle or receiving a, preferably new, blade from a handle. The blade coupling can also hold a blade for its intended use. In a transport cassette, for example, the blade coupling is advantageously used to securely hold the blade. In a cutting device, the blade coupling can advantageously be used to rotate the blade during cutting.

[0026] Another advantage is a blade coupling that can be opened using a safety lever, releasing the blade. In addition to transferring the blade to and from a handle, it may be necessary and advantageous to remove the blade from the blade coupling without removing the handle. This can be accomplished using a separate, additional safety lever. The use of a detachable screw connection can also allow the blade coupling to be opened manually in an emergency.

[0027] Also advantageous is a transport cassette for the safe transport of at least one round blade, the blade having a diameter of 120 mm to 400 mm, the transport cassette comprising a blade coupling, the transport cassette being designed to at least partially shield the circumference of the blade from the environment.

[0028] A shield improves work safety because the sharp blade does not come into cutting contact with the surroundings. Even partial shielding in the area of ​​the handle that is in direct contact with the operator is advantageous. The shield is advantageously rounded so that it does not catch on objects in the vicinity of the rotary cutter. A plate-shaped protective plate has proven particularly advantageous, with the edge protruding 1 mm to 10 mm beyond the edge of the blade. The protective plate advantageously has a rounded edge. In another embodiment, the protective device was advantageously constructed using a cage made of metal wire.

[0029] A transport cassette that can accommodate two blades is also advantageous. The ability to accommodate two blades is particularly advantageous because when replacing a blade, the old (blunt) blade is first removed from the cutting device, which can then be safely placed in the transport cassette. In the second step, the new (sharpened) blade is then safely removed from the transport cassette and installed in the cutting device.

[0030] A transport cassette which comprises an additional locking device is also advantageous, designed to securely arrange the transport cassette on a guide rail. To enable safe working when changing the blade, it is advantageous if the transport cassette is securely positioned. A further locking device with which the blade can be arranged on the guide rail of the cutting device is particularly advantageous. In practice, clamping it on the guide rail or screwing it to the guide rail has proven particularly effective. This leaves the technician with both hands free to enable safe blade changing. State-of-the-art roller cutters often include guide rails on which the position of the cutting devices is adjusted. These guide rails are usually also suitable for arranging a transport cassette.

[0031] Also advantageous is a transport cassette which comprises a display device, wherein the display device indicates whether one or more blades are located in the transport cassette.

[0032] To improve handling of the transport cassettes, it is advantageous if it is clearly visible whether the transport cassette contains a blade. It is particularly advantageous if the transport cassette can be seen from the outside whether a new or used (or sharpened or blunt) blade is located inside. The indicator device can comprise an indicator light which indicates the contents, for example using an LED, in particular a colored LED. However, a flag or color-coded switchable part on the transport cassette can also make the contents visible from the outside. In practice, it is particularly advantageous to use a small flag which is foldably attached to a viewing window to indicate when a blade is inside the transport cassette. In a particularly advantageous embodiment, the indicator shows a new blade in green and a blunt / used blade in red.Instead of a color marking, a pictogram or text can be used to indicate a sharp or blunt blade in the transport cassette.

[0033] A transport cassette comprising a wear scale is also advantageous, wherein the wear scale is designed to indicate the wear of the blade. The wear scale is advantageously integrated directly into the transport cassette, whereby the circumference of the blade centered in the blade coupling can be read in the transport cassette. In a particularly advantageous embodiment, the wear scale comprises a size scale on which the blade radius and / or the blade diameter is displayed, for example, in millimeters.

[0034] Also advantageous is a transport cassette which comprises a flexible fall protection device on at least one corner, which is designed to absorb kinetic energy in the event of an impact. Due to the weight of the blade, which is in a range of approximately 150 g to 1500 g, the transport cassette can be damaged if it falls or bumps into the rotary cutter, or the blade can be unintentionally released. It is therefore advantageous if the transport cassette is designed to absorb kinetic energy in the event of an impact by means of an elastic or plastically deformable, flexible fall protection device. It is particularly advantageous if all four corners each comprise a flexible fall protection device. The fall protection device can, for example, comprise a flexible, elastic polyurethane material.

[0035] Also advantageous is a cutting device for cutting a paper, cardboard or fiber web in a roll cutter of a paper machine, wherein the cutting device comprises a blade coupling.

[0036] The cutting device of a rotary cutter advantageously comprises a blade coupling connected to a handle, enabling blade changes to be advantageously and safely facilitated. The cutting device can optionally and advantageously comprise a key device that can open a locking device in a handle. Also optional and advantageous is a cutting device whose blade coupling is designed to be opened by a handle such that a blade is picked up or released from the blade coupling.

[0037] The invention is explained below with reference to the figures. The figures show in detail: Fig. 1: A handle according to the invention Fig. 2: A transport cassette with a blade coupling Fig. 3: Another handle Fig. 4: Another transport cassette Fig. 5: A cutting device with transport cassette Fig. 6: A transport cassette for two blades

[0038] Figure 1shows an isometric, not to scale, schematic representation of a handle 1 according to the invention. The handle 1 is designed to receive a blade 2, which is then visible through an opening in the handle. The handle 1 comprises a magnet 9, the effect of which can be switched by a lever 13. When switched on, the magnet 9 holds the blade 2 in a holding device 8 of the handle 1. The holding device 8 comprises a centering device 7, which is designed to center the blade 8 in the holding device. The illustration shows an optional embodiment with two magnets, each arranged in the housing of the handle 1. The position of the magnets 9 can be moved towards or away from the blade 2 by means of the lever 13. The magnetic effect is thus switched by changing the distance of the magnets 9 from the blade 2.The handle 1 further comprises a safety lever 14 which is designed to fix the lever 13 in one position. This prevents accidental opening of the holding device 8, and the blade 2 is held in the handle 1 in a controlled and secure manner. The handle 1 further comprises a centering mechanism 7 which is designed, for example, to center the blade 2 in the holding device 2 by means of an oblique phase (not shown). The centering device is moved into a round opening of the blade 2 so that the blade is centered in the holding device 8. Through the centering, a key device 10 can also engage and open a locking device 11 of a blade coupling 3 so that the handle 1 can receive the blade 2.

[0039] Figure 2shows a schematic, not to scale, view of a transport cassette 4 with a blade coupling 3. The transport cassette 4 comprises a round blade coupling 3 in its center, which forms a locking device 11 by means of three latches, which is designed to hold a blade 2 (not shown in the illustration) stationary in the transport cassette 4. The locking device 11 of the blade coupling 3 can be opened by a handle 1 connected to it. Alternatively, the locking device 11 can also be opened manually via a safety lever 14. In the open state, the blade coupling 3 releases the blade for removal or can accommodate it. The blade coupling 3 forms a blade receptacle 6 in the transport cassette 4. The edge of the transport cassette is designed to shield the sharp cutting edge of the blade 2 and includes a flexible fall protection device 18.The flexible fall protection device 18 can absorb kinetic energy if the transport cassette 4 falls or is impacted, thus preventing accidental opening of the blade coupling 3. Furthermore, the transport cassette 4 includes a wear scale 19, which indicates the size of the blade 2. Below a critical size, the wear on the blades is too great and the blade can no longer be resharpened. The wear scale 19 is a technical aid for assessing the current status of a blade.

[0040] Figure 3shows a schematic, not-to-scale, isometric representation of a handle 1 with features of the invention. The handle 1 comprises a centering mechanism 7, which includes a key device 10 suitable for opening a blade coupling 3 (not shown). Furthermore, the centering mechanism 7 is suitable for centering a blade 2 in a holding device 8. To assist in holding the blade 2, a magnet 9 is used in the handle 1. The handle 1 comprises a holding device 8, wherein the holding device 8 forms a structural unit with the handle 1. The holding device 8 comprises a lever 13 with which the effect of the magnet 9 can be switched on and off. In the switched-on state, a blade (not shown) is held on the holding device 5 of the handle 1. The blade 2 is then at least partially shielded from the environment by a protective device 12.

[0041] Figure 4shows a schematic isometric representation of a transport cassette 4, designed to accommodate a round blade 2 (not shown). The blade 2 is protected by the transport cassette 4 and, at the same time, the transport cassette 4 protects the surroundings from the sharp cutting edge of the round blade 2. The round blade 2 comprises an axial round opening which is positioned by means of a centering mechanism in the blade coupling 3 of the transport cassette 4. The transport cassette 2 comprises a locking device 11 suitable for clamping the blade 2 in the transport cassette 2. The transport cassette 4 has a square or rectangular basic shape, which enables simplified storage, for example in a transport box.The transport cassette 4 comprises a further locking device 15, which allows for easy placement in a storage device (not shown), such as a larger transport box or a blade rack. The further locking device 15 can also be provided for securing the transport cassette 2 to a guide rail 16.

[0042] Figure 5shows a not to scale schematic overview of a cutting device 5 of a roll cutter. A transport cassette 4 is arranged on the cutting device 5 to enable a safe blade change. The blade 3 is screwed into a cutting device 9, wherein the cutting device 9 is electrically driven and the blade 3 rotates at high speed during operation. The cutting device 9 is arranged on two guide rails 15. The guide rails 15 are aligned parallel to the paper web and allow the point at which the web is cut to be adjusted. In this way, different formats of paper rolls can be produced. The adjustment of the cutting device 9 along guide rail 15 can be automated or manual. To change the blades 2, the transport cassette 4 can be arranged next to the cutting device 5.The transport cassette 4 is releasably attached to the guide rails 16 by means of additional locking devices 15. The fastening of the additional locking devices 15 can comprise a screw mechanism or a clamping device, which enables quick and easy attachment of the transport cassette 4 to the guide rails 16.

[0043] Figure 6shows a further optional embodiment of a transport cassette 4 according to the invention for two blades 2 in a schematic isometric representation that is not to scale. The transport cassette 4 shown comprises two compartments, each for receiving a blade 2. This embodiment has proven to be particularly advantageous because the new or newly sharpened blade 2 can be arranged on one side of the transport cassette 4 and the blunt or used blade 2 on the other side. This allows for quick and safe replacement of the blades 2. The transport cassette 4 also comprises a display device 17 for each blade 2, which makes it visible from the outside whether one or two blades are located inside the transport cassette 4. The transport cassette 4 is constructed in two parts and can be closed via a hinge.If a large number of transport cassettes 4 are stored in a magazine, a shelf, or a transport device, the display device 16 can be used to see from the outside which transport cassette 4 contains blades 2. A colored display has proven particularly advantageous here. In an exemplary embodiment not shown, the used or blunt blades 2 are arranged on one side of the transport cassette 4, which triggers a red display with a display device 17. The new or sharpened blades are arranged on the other side of the transport cassette 4, which in turn includes a green display. In this way, in a storage area or transport box for transport cassettes 4, it is easily visible how many new and how many blunt blades 2 are present.The corners of the transport cassette 4 include several material recesses and are advantageously made of a flexible material. This allows the area of ​​the corners to form a flexible fall protection device 18 that can absorb kinetic energy in the event of an impact or fall. The transport cassette 4 further comprises a blade coupling 3 for each blade 2, which is designed to be opened by a key device 10 connected to it. The blade coupling 3 advantageously comprises at least three latches arranged in a holding device 8 or blade receptacle 6 and can securely hold the blade in the transport cassette 4. List of reference symbols

[0044] 1Handle 2Blade 3Blade coupling 4Transport cassette 5Cutting device 6Blade holder 7Centering mechanism 8Holding device 9Magnet 10Key device 11Locking device 12Protection device 13Lever 14Safety lever 15Additional locking device 16Guide rail 17Indicating device 18Flexible fall protection 19Wear scale

Claims

1. Handle (1) for picking up, securely holding and releasing a round blade (2), wherein the blade (2) has a diameter of 140 mm to 400 mm and, wherein the blade (2) is designed to cut a paper web in a cutting device (5) of a roll cutter of a paper factory, wherein the handle (1) comprises a holding device (8) characterized in thatthe holding device (8) comprises a centering mechanism (7), a magnet (9) and a blade coupling (3), wherein the centering mechanism (7) is designed to center the blade (2) in the holding device (8), and wherein the magnet (9) and blade coupling (3) are designed to releasably fix the blade (2) in the holding device (8), wherein the holding handle (1) comprises at least one lever (13) designed to switch the fixing effect of the magnet (9) and / or the blade coupling (3), and wherein the holding handle (1) comprises a key device (10) which is designed to open or close a locking device (11) of a cutting device (5) or a transport cassette (4) which is related to it and thereby release or fix a blade (2) in the cutting device (5) or transport cassette (4).

2. Handle (1) according to claim 1, characterized in thatthe handle (1) comprises a protective device (12) which is designed to shield the cutting area of the blade (2) from the environment.

3. Handle (1) according to claim 1 or claim 2, characterized in that the handle (1) comprises at least one lever (13), wherein the lever (13) is designed to switch the magnetic effect of the magnet (9).

4. Handle (1) according to claim 3, characterized in that the handle (1) comprises at least one safety lever (14) which secures the switching position of the first lever (13).

5. Handle (1) according to one of the preceding claims, characterized in that the magnet (9) of the holding device (8) is designed to be switchable in its magnetic effect by a blade coupling (3) connected to the handle (1).

6. Handle (1) according to one of the preceding claims, characterized in thatthe handle (1) comprises at least one permanent magnet, preferably a neodymium magnet.

7. Blade coupling (3) for picking up, holding and releasing a round blade (2), the blade (2) having a diameter of 140 mm to 400 mm, characterized in that the blade coupling (3) is designed to receive the blade (2) from a handle (1) from one of the preceding claims, or to release the blade (2) to the handle (1), wherein the blade coupling (7) comprises a locking device (9) which is designed to be lockable by a key device (10) of a handle (1) which is related to it.

8. Blade coupling (3) according to claim 7, characterized in that the blade coupling (3) can be opened by means of a safety lever (14), whereby the blade (2) is released.

9. Transport cassette (4) for the safe transport of at least one round blade (2), the blade (2) having a diameter of 120 mm to 400 mm, characterized in that the transport cassette (4) comprises a blade coupling (3) according to claim 7 or claim 8, wherein the transport cassette (4) is designed to at least partially shield the circumference of the blade (2) from the environment.

10. Transport cassette (4) according to claim 9, characterized in that the transport cassette (4) can hold two blades (2).

11. Transport cassette (4) according to claim 9 or claim 10, characterized in that the transport cassette (4) comprises a further locking device (11), designed to arrange the transport cassette (4) securely in a fixed position on a guide rail (16).

12. Transport cassette (4) according to claim 9 to claim 11, characterized in thatthe transport cassette (4) comprises a display device (17), wherein the display device (17) indicates whether one or more blades (2) are located in the transport cassette (4).

13. Transport cassette (4) according to claim 9 to claim 12, characterized in that the transport cassette (4) comprises a wear scale (19), wherein the wear scale (19) is designed to indicate the wear of the blade (2).

14. Transport cassette (4) according to claim 9 to claim 13, characterized in that the transport cassette (4) comprises a flexible fall protection device (18) on at least one corner, which is designed to absorb kinetic energy in the event of an impact.

15. Cutting device (18) for cutting a paper, cardboard or fiber web in a roll cutter of a paper machine, characterized in that the cutting device (18) comprises a blade coupling (7) according to claim 7 or claim 8.

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