Doctor device

Abstract

To prevent contact with a doctor blade by covering the doctor blade.SOLUTION: A doctor device 10 comprises a doctor blade 11, and a safety cover 30 for covering the doctor blade 11. The safety cover 30 has a stationary safety cover 31 that is provided for a holding plate 12a, and an oscillation safety cover 32. A first magnet 21 for magnetically attracting the oscillation safety cover 32 is attached to the holding plate 12a, and a second magnet 22 for magnetically attracting the doctor blade 11 is attached to a second plane 32a of the oscillation safety cover 32.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to a doctor device for scraping off excess ink or coating material adhering to a cylinder such as a plate cylinder in a gravure printing machine, a coater, or the like. [Background Art]

[0002] Conventionally, a doctor device used in a gravure printing machine includes a doctor blade and a pair of holding plates that hold both sides of the doctor blade. The doctor blade is made of sharp blade-shaped metal, and mere contact during operation may lead to an accident. However, the fact is that conventionally, no contrivance has been made to prevent contact accidents with the doctor blade. [Prior Art Literature] [Patent Literature]

[0003] [Patent Literature 1] Japanese Utility Model Laid-Open No. 5-46430 [Patent Literature 2] Japanese Patent Laid-Open No. 10-230584 [Patent Literature 3] Japanese Patent Laid-Open No. 2000-94634 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The present disclosure has been made in consideration of such a point, and an object of the present invention is to provide a doctor device in which the doctor blade can be covered by a safety cover provided openably and closably with respect to the doctor blade, and the safety cover can be reliably fixed in an open position and a closed position. [Means for Solving the Problem]

[0005] This disclosure relates to a doctor device comprising a doctor blade, a pair of retaining plates that hold both sides of the doctor blade, fasteners for fixing the pair of retaining plates, and a safety cover attached to one of the retaining plates and covering the doctor blade, wherein the safety cover comprises a fixed safety cover attached to the one retaining plate and a swingable safety cover swingably attached to the fixed safety cover via a rotatable mechanism, a first magnet is provided on either the one retaining plate or the swingable safety cover for fixing the swingable safety cover in the open position to the one retaining plate, and a second magnet is provided on either the swingable safety cover or the doctor blade for fixing the swingable safety cover in the closed position to the doctor blade.

[0006] This disclosure relates to a doctor device in which the doctor blade is held by a pair of retaining plates via a backing plate, and the swinging safety cover in the closed position is fixed to the doctor blade via a backing plate by a second magnet.

[0007] This disclosure relates to a doctor's device in which the safety cover is made of a non-magnetic material, the first magnet is provided on one of the holding plates, the oscillating safety cover is provided with a magnet receiver that is attracted to the first magnet, and the second magnet is provided on the oscillating safety cover and is attracted to the backing plate of the doctor's blade.

[0008] This disclosure relates to a doctor device in which the height and position of the first magnet are defined such that the swinging safety cover does not come into contact with the fastener when the swinging safety cover is fixed to the one holding plate by the first magnet.

[0009] This disclosure relates to a doctor blade device in which the fixed safety cover has a first plane, and the oscillating safety cover has a substantially U-shaped cross-section having a second plane that is continuous with the first plane in the closed position and covers the upper surface of the doctor blade, a side surface that descends from the tip of the second plane in a direction perpendicular to the second plane and covers the tip of the doctor blade, and a third plane that extends from the lower end of the side surface toward the base end of the doctor blade parallel to the second plane and covers the lower surface of the doctor blade.

[0010] This disclosure relates to a doctor device in which the side surface of the oscillating safety cover covers the tip of the doctor blade over the entire width of the doctor blade when the oscillating safety cover is in the closed position.

[0011] This disclosure relates to a doctor device in which the length of the third plane is shorter than the length of the second plane, and the minimum distance L between the tip of the doctor blade and the tip of the third plane when the swinging safety cover is swung is 1 mm ≤ L ≤ 5 mm. [Effects of the Invention]

[0012] As described above, according to this disclosure, a safety cover that can be opened and closed relative to the doctor blade can cover the doctor blade when it is not in use. Furthermore, the safety cover can be securely fixed in both the open and closed positions. [Brief explanation of the drawing]

[0013] [Figure 1A] Figure 1A is a side view showing a doctor device having a swinging safety cover in the closed position according to the present disclosure. [Figure 1B] Figure 1B is a side view showing a doctor device with a swinging safety cover in the open position. [Figure 1C] Figure 1C is a side view showing the swinging safety cover in a swinging state. [Figure 2A] Figure 2A is a plan view showing a doctor device with a swinging safety cover that assumes a closed position. [Figure 2B]Fig. 2B is a plan view showing a doctor device having an oscillating safety cover in an open position. [Figure 3] Fig. 3 is a view showing a second magnet attached to an oscillating safety cover in an open position. [Figure 4] Fig. 4 is a view showing a state where a pair of holding plates are installed on a base by fasteners. [Figure 5] Fig. 5 is a view schematically showing the entire doctor device, with the safety cover removed for convenience. MODE FOR CARRYING OUT THE INVENTION

[0014] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0015] Figs. 1 to 5 are views showing an embodiment of a doctor device according to the present disclosure.

[0016] First, the entire doctor device will be described with reference to Fig. 5.

[0017] As shown in Fig. 5, a doctor device 10 includes a doctor blade 11, and is provided in the vicinity of a cylinder 1 in a printing unit of a gravure printing machine or the like. A rotational force in the direction of arrow A is applied to the doctor device 10, the tip end of the doctor blade 11 is pressed against the cylinder 1, and excess ink on the surface of the cylinder 1 is scraped off.

[0018] In Fig. 5, the doctor device 10 provided in the vicinity of the cylinder 1 is shown schematically, and for convenience, a safety cover which will be described later is removed from the doctor device 10 in the illustration.

[0019] Next, the doctor device 10 will be described in detail with reference to Figures 1A to 2B. The doctor device 10 comprises a doctor blade 11 that scrapes off excess ink from the surface of the cylinder 1, a pair of retaining plates 12a and 12b that hold both the upper and lower surfaces of the doctor blade 11, fasteners 15 that fix the pair of retaining plates 12a and 12b, and a safety cover 30 attached to the upper retaining plate 12a that covers the doctor blade 11.

[0020] In this embodiment, the doctor blade 11 is held by a pair of rectangular retaining plates 12a and 12b in a plan view via backing plates 13a and 13b.

[0021] As described above, the pair of retaining plates 12a and 12b are rectangular in shape when viewed from above, and the fasteners 15 that secure the pair of retaining plates 12a and 12b are provided at three locations along the longitudinal direction of the pair of retaining plates 12a and 12b (which can also be called the width direction of the doctor blade 11) (see Figures 2A and 2B).

[0022] As shown in Figures 4 and 5, each fastener 15 that secures the pair of retaining plates 12a and 12b has an L-shape on its side and is fastened to the base 20 by fastening bolts 16 (see Figure 5). A handle 17 is connected to the fastening bolts 16, and by rotating the handle 17, the fastening bolts 16 are tightened, causing the L-shaped fasteners 15 to bend downward. This downward bending of the fasteners 15 firmly holds the doctor blade 11 by the pair of retaining plates 12a and 12b via the backing plates 13a and 13b. At the same time, the pair of retaining plates 12a and 12b that hold the doctor blade 11 are firmly fixed to the base 20.

[0023] As shown in Figure 5, the base 20 has an opening 20A into which a support rod that pivotably supports the base 20 is inserted, and the base 20 is pivotable around this support rod.

[0024] As shown in Figures 4 and 5, a drive shaft 19 is provided on the base 20, connected to a pair of retaining plates 12a and 12b, which moves the pair of retaining plates 12a and 12b toward or toward the cylinder 1. The drive shaft 19 extends through a base 18 provided on the base 20. By rotating the actuation part 19A provided at the end of the drive shaft 19, the external thread of the drive shaft 19 engages with the internal thread in the base 18, and the drive shaft 19 moves along its longitudinal direction on the base 20 in the left-right direction as shown in Figure 6. As a result, the pair of retaining plates 12a and 12b, which are connected to the drive shaft 19 via a mounting fixture 19B, can also move on the base 20 in the left-right direction as shown in Figure 5.

[0025] In this embodiment, the drive shaft 19 provided on the base 20 is provided in a total of two on the inside of the two fasteners 15 on each side of the three fasteners 15 provided along the longitudinal direction of the pair of retaining plates 12a and 12b.

[0026] Furthermore, as shown in Figures 2A and 2B, the pair of retaining plates 12a and 12b are provided with two gripping portions 5 along their longitudinal direction. These two gripping portions 5 are used when the operator places the pair of retaining plates 12a and 12b, which hold the doctor blade 11, onto the base 20.

[0027] Next, the safety cover 30 attached to the upper retaining plate 12a will be described with reference to Figures 1A to 2B. The safety cover 30 covers the doctor blade 11 when it is not in use, preventing accidental contact with the doctor blade 11.

[0028] Such a safety cover 30 includes a fixed safety cover 31 attached to an upper retaining plate 12a, and a swingable safety cover 32 that is swingably attached to the fixed safety cover 31 via a pivoting mechanism 37 such as a hinge.

[0029] Of these, the fixed safety cover 31 has a first horizontal surface (also called the first plane) 31a. The swinging safety cover 32 swings relative to the fixed safety cover 31 via a rotation mechanism 37 to take a closed position (see Figure 1A) and an open position (see Figure 1B).

[0030] In the closed position shown in Figure 1A, the swinging safety cover 32 has a second horizontal plane (also called the second plane) 32a that is continuous with the first plane 31a and covers the upper surface 11a of the doctor blade 11, and a side surface 32b that descends from the tip 32a1 of the second plane 32a in a direction perpendicular to the second plane 32a and covers the tip 11b of the doctor blade 11. A third horizontal plane (also called the third plane) 32c is connected to the lower end 32b1 of the side surface 32b, extending parallel to the second plane 32a toward the base end of the doctor blade 11 (towards the left in Figure 1A). This third plane 32c connected to the side surface 32b covers the lower surface 11c of the doctor blade 11.

[0031] As shown in Figures 2A and 2B, both the fixed safety cover 31 and the swinging safety cover 32 of the safety cover 30 are substantially rectangular in plan view and extend in the same direction as the longitudinal direction of the pair of retaining plates 12a and 12b. Specifically, notches 31A and 32A are formed on both sides of the fixed safety cover 31 and the swinging safety cover 32 in the longitudinal direction (width direction of the doctor blade). Due to the notches 32A of the swinging safety cover 32, when the swinging safety cover 32 is in the closed position, both sides in the width direction of the upper surface 11a of the doctor blade 11 are slightly exposed from the second plane 32a of the swinging safety cover 32. However, when the swinging safety cover 32 is in the closed position, the tip 11b and lower surface 11c of the doctor blade 11 are safely covered over the entire width direction of the doctor blade 11 by the side surface 32b and the second plane 32a of the swinging safety cover 32.

[0032] Thus, in the closed position, the swinging safety cover 32 of the safety cover 30 has a second plane 32a, a side surface 32b, and a third plane surface 32c, and as a whole has a roughly U-shaped cross-section (see Figure 1A). In the closed position, the swinging safety cover 32 can cover the upper surface 11a of the doctor blade 11 with its second plane surface 32a, the tip 11b of the doctor blade 11 with its side surface 32b, and the lower surface 11c of the doctor blade 11 with its third plane surface 32c. As a result, when the doctor blade 11 is not in use, the swinging safety cover 32 can be brought to the closed position, and the upper surface 11a, tip 11b, and lower surface 11c of the doctor blade 11 can be effectively covered by the second plane surface 32a, side surface 32b, and third plane surface 32c of the swinging safety cover 32. Therefore, the risk of a worker coming into contact with the doctor blade 11, especially its tip 11b, due to the swinging safety cover 32 in the closed position can be minimized. Furthermore, as shown in Figures 1A and 1B, the length of the second plane 32a of the swinging safety cover 32 is L1, and the length of the third plane 32c is L2, with L1 > L2.

[0033] In this embodiment, the doctor blade 11, the backing plates 13a and 13b, and the pair of retaining plates 12a and 12b are all made of steel. The safety cover 30 is made of lightweight aluminum.

[0034] Furthermore, the safety cover 31 of the safety cover 30 is fixed to a pair of retaining plates 12a and 12b by fastening bolts 35.

[0035] As described above, the swinging safety cover 32 of the safety cover 30 swings between a closed position (see Figure 1A) and an open position (Figure 1B) relative to the fixed safety cover 31 via a rotation mechanism 37. During the swinging of the swinging safety cover 32, the minimum distance L between the tip 11b of the doctor blade 11 and the tip of the third plane 32c of the swinging safety cover 32 is 1 mm ≤ L ≤ 5 mm.

[0036] In this case, if the minimum distance L mentioned above is less than 1 mm, the swinging safety cover 32 in the closed position can cover the vicinity of the tip 11b of the doctor blade 11. However, it is also possible that the third plane 32c of the swinging safety cover 32 may come into contact with the doctor blade 11 during the swinging motion, causing interference with the swinging motion of the swinging safety cover 32.

[0037] On the other hand, if the minimum distance L is greater than 5 mm, there is little risk of the third plane 32c of the swinging safety cover 32 coming into contact with the doctor blade 11 during swinging, but the swinging safety cover 32 in the closed position cannot reliably cover the vicinity of the tip 11b of the doctor blade 11.

[0038] Therefore, during the oscillation of the oscillating safety cover 32, the minimum distance L between the tip 11b of the doctor blade 11 and the tip of the third plane 32c of the oscillating safety cover 32 is set to 1 mm ≤ L ≤ 5 mm.

[0039] In this specification, "upward," "downward," and "horizontal" refer to the "upward," "downward," and "horizontal" directions when the doctor device 10 is positioned as shown in Figures 1A and 1B.

[0040] Therefore, in Figures 1A and 1B, of the pair of retaining plates 12a and 12b, retaining plate 12a becomes the upper retaining plate and retaining plate 12b becomes the lower retaining plate.

[0041] Furthermore, in Figures 1A and 1B, the first plane 31a of the fixed safety cover 31 and the second plane 32a and third plane 32c of the swinging safety cover 32 are all arranged along the horizontal direction.

[0042] Furthermore, the side surface 32b of the swinging safety cover 32 is oriented vertically in Figures 1A and 1B.

[0043] Next, the structure for fixing the safety cover 30 will be described with reference to Figures 1A to 2B. A first magnet 21 is provided on the upper retaining plate 12a via a fixed safety cover 31, and a steel magnet receiver 38 that is attracted to the first magnet 21 is provided on the second plane 32a of the swinging safety cover 32. When the swinging safety cover 32 takes the open position, the magnet receiver 38 provided on the second plane 32a of the swinging safety cover 32 is attracted to the first magnet 21, and in this way the swinging safety cover 32 is fixed to the upper retaining plate 12a and can stably take the open position (see Figure 1B).

[0044] As described above, the pair of retaining plates 12a and 12b are fixed to the base 20 by three fasteners 15 provided along the longitudinal direction of the pair of retaining plates 12a and 12b.

[0045] In this embodiment, the height and position of the first magnet 21 are defined so that when the swinging safety cover 32 of the safety cover 30 swings to the open position, the swinging safety cover 32 does not interfere with the three fasteners 15.

[0046] Specifically, the height H1 of the first magnet 21 is 10mm ≤ H1 ≤ 15mm. Also, the distance L3 between the first magnet 21 and the rotating mechanism 37 is 35mm ≤ L3 ≤ 45mm. By defining the height H1 of the first magnet 21 and the distance L3 from the rotating mechanism 37 in this way, the swinging safety cover 32 does not interfere with the fastener 15 even when it swings to the open position.

[0047] Incidentally, since the safety cover 30 is made of non-magnetic aluminum material as a whole in order to reduce weight, the magnet receiver 38 provided on the second plane 32a of the oscillating safety cover 32 is made of a magnetic material that can be attracted to the first magnet 21, such as steel.

[0048] The first magnet 21, which is provided on the upper retaining plate 12a via a fixed safety cover 31, and the magnet receiver 38, which is provided on the side surface 32b of the swinging safety cover 32, are both provided in groups of five along the longitudinal direction (width direction of the doctor blade 11) of the retaining plate 12 and the swinging safety cover 32 (see Figures 2A and 2B).

[0049] The first magnet 21 is provided on the upper retaining plate 12a via a fixed safety cover 31, but the first magnet 21 may also be provided directly on the upper retaining plate 12a without the fixed safety cover 31.

[0050] Furthermore, as shown in Figures 1A to 2B and Figure 3, the second plane 32a of the swinging safety cover 32 is provided with a second magnet 22 on its back side, which fixes the second plane 32a of the swinging safety cover 32 to the upper backing plate 13a when the swinging safety cover 32 is in the closed position. That is, when the swinging safety cover 32 is in the closed position, the second magnet 22 provided on the second plane 32a of the swinging safety cover 32 attracts the backing plate 13a made of steel. As a result, the swinging safety cover 32 is fixed to the backing plate 13a that holds the doctor blade 11, and can stably assume the closed position (see Figure 1A).

[0051] In this embodiment, five second magnets 22 are arranged along the longitudinal direction of the second plane 32a of the swing safety cover 32 (the width direction of the doctor blade 11) (see Figures 2A and 2B).

[0052] Furthermore, when the swinging safety cover 32 is in the closed position, the second magnet 22, which is provided on the back side of the second plane 32a, is attracted to the backing plate 13a. At this time, the height H2 of the second magnet 22 is set such that the second plane 32a of the swinging safety cover 32 is continuous with the first plane 31a of the fixed safety cover 31, and both the first plane 31a and the second plane 32a face horizontally.

[0053] Next, the operation of this embodiment, which has the above configuration, will be described.

[0054] First, the doctor blade 11 of the doctor device 10 takes its working position (see Figure 5), and the doctor blade 11 scrapes off excess ink applied to the surface of the cylinder 1 installed in the printing unit such as gravure printing. In this case, the swinging safety cover 32 of the safety cover 30 is swung via the rotation mechanism 37 to take the open position (see Figures 1B and 2B).

[0055] As shown in Figures 1B and 2B, when the swinging safety cover 32 is in the open position, the magnet receiver 38 provided on the second plane 32a of the swinging safety cover 32 is attracted to the first magnet 21 provided on the upper holding plate 12a via the fixed safety cover 31. By attracting the magnet receiver 38 to the first magnet 21 in this way, the swinging safety cover 32 can be stably fixed in the open position.

[0056] As a result, when the doctor blade 11 scrapes off excess ink from the surface of the cylinder 1, the swinging safety cover 32 does not suddenly swing to the closed position, and the ink scraping operation by the doctor blade 11 is not hindered.

[0057] Next, once the doctor blade 11 has finished scraping off the excess ink from the surface of cylinder 1, the base 20 swings around the support rod, and the doctor blade 11 moves away from cylinder 1 (to a retracted position).

[0058] When the doctor blade 11 moves away from the cylinder 1 in this manner, there is a possibility that the operator may come into contact with the tip 11b of the doctor blade 11. In this case, the doctor blade 11 must be covered by the safety cover 30.

[0059] When covering the doctor blade 11 with the safety cover 30, the swinging safety cover 32 of the safety cover 30 is first swung via the rotation mechanism 37 to bring the swinging safety cover 32 to the closed position, thereby covering the doctor blade 11 with the swinging safety cover 32 (see Figures 1A and 2A).

[0060] At this time, the backing plate 13a is attracted to the second magnet 22 provided on the back surface of the second plane 32a of the swing safety cover 32. By being attracted to the second magnet 22 in this way, the swing safety cover 32 can be stably fixed in the closed position.

[0061] By bringing the swinging safety cover 32 to the closed position in this way, the second plane 32a of the swinging safety cover 32 can cover the upper surface 11a of the doctor blade 11, the side surface 32b can cover the tip 11b of the doctor blade 11, and the third plane 32c can cover the lower surface 11c of the doctor blade 11.

[0062] As described above, the upper surface 11a, tip 11b, and lower surface 11c of the doctor blade 11 after the excess ink scraping work on the surface of the cylinder 1 has been completed can be effectively covered by the second plane 32a, side surface 32b, and third plane 32c of the swinging safety cover 32. This prevents contact accidents in which an operator comes into contact with the doctor blade 11, especially its tip 11b.

[0063] Furthermore, when the rocking safety cover 32 is in the closed position, the side surface 32b and the third plane 32c of the rocking safety cover 32 extend over the entire width of the doctor blade 11, thereby covering the tip 11b and the bottom surface 11c of the doctor blade 11 over the entire width of the doctor blade 11. Therefore, the side surface 32b and the third plane 32c of the rocking safety cover 32 in the closed position can reliably cover the tip 11b of the doctor blade 11 in particular.

[0064] As described above, according to this embodiment, when performing ink scraping work with the doctor blade 11, the swing safety cover 32 is brought to the open position. At this time, the magnet receiver 38 provided on the second plane 32a of the swing safety cover 32 is attracted to the first magnet 21. This makes it possible to stably fix the swing safety cover 32 in the open position, and prevents the swing safety cover 32 from suddenly swinging, which would interfere with the ink scraping work by the doctor blade 11.

[0065] On the other hand, once the doctor blade 11 has finished scraping off excess ink from the surface of the cylinder 1, the swinging safety cover 32 is oscillated via the rotation mechanism 37 to bring the swinging safety cover 32 to the closed position. This ensures that the doctor blade 11 is securely covered by the swinging safety cover 32, preventing any contact accidents involving the doctor blade 11. Furthermore, when the swinging safety cover 32 is in the closed position, the backing plate 13a on the doctor blade 11 side is attracted to the second magnet 22 provided on the second plane 32a of the swinging safety cover 32. This allows the swinging safety cover 32 to be stably fixed in the closed position. Therefore, the doctor blade 11 will not be exposed to the outside due to the sudden swinging of the swinging safety cover 32 in the closed position.

[0066] Furthermore, by simply swinging the swinging safety cover 32 via the rotation mechanism 37, the swinging safety cover 32 can take on an open position where the doctor blade 11 is exposed and a closed position where it covers the doctor blade 11. Therefore, compared to providing a separate safety cover from the doctor blade device and attaching this safety cover to the doctor blade device when the doctor blade 11 is not in use, the work of installing the safety cover on the doctor blade 11 can be made easier.

[0067] In the above embodiment, the first magnet 21 is provided on a fixed safety cover 31 attached to the upper holding plate 12a, and the magnet receiver 38 is provided on the second plane 32a of the swinging safety cover 32. However, the invention is not limited to this, and the first magnet 21 may be directly attached to the upper holding plate 12a without the fixed safety cover 31.

[0068] Alternatively, the first magnet 21 may be provided on the second plane 32a of the swing safety cover 32, and a magnet receiver 38 having a certain height (H1) may be provided on the holding plate 12a.

[0069] Furthermore, although the above embodiment shows an example in which the second magnet 22 is provided on the back surface of the second plane 32a of the swing safety cover 32, the invention is not limited to this, and the second magnet 22 may be attached to the backing plate 13a, and a magnet receiver (not shown) may be provided on the second plane 32a, and the magnet receiver attached to the second plane 32a may be attracted by the second magnet 22 attached to the backing plate 13a.

[0070] Furthermore, although an example was shown in which the doctor blade 11 is held by a pair of retaining plates 12a, 12b via backing plates 13a, 13b, the doctor blade 11 may also be held directly by the retaining plates 12a, 12b without using backing plates. In this case, the doctor blade 11 is attracted by the second magnet 22 attached to the second plane 32a of the oscillating safety cover 32. Alternatively, the second magnet 22 may be attached to the doctor blade 11 without attaching it to the second plane 32a of the oscillating safety cover 32, and a magnet receiver (not shown) may be provided on the back surface of the second plane 32a. [Explanation of Symbols]

[0071] 1 cylinder 10 Doctor's device 11 Doctor Blade 11a Top surface 11b Tip 11c Bottom side 12a Holding plate 12b Holding plate 13a Backing 13b Guard 15 Fasteners 16 fastening bolts 17 Handle 20 base 20A aperture 21 First Magnet 22 Second Magnet 30 Safety Covers 31. Secure safety cover 31a 1st plane 32. Swivel safety cover 32a 2nd plane 32b side 32c 3rd plane 37 Rotating Mechanism 38 Magnetic receiver

Claims

1. In the doctor device, Doctor Blade and A pair of retaining plates that hold both sides of the doctor blade, A fastener for fixing the pair of retaining plates, It is equipped with a safety cover that is attached to one of the retaining plates and covers the doctor blade, The safety cover comprises a fixed safety cover attached to one of the retaining plates, and a swingable safety cover that is swingably attached to the fixed safety cover via a rotatable mechanism. A first magnet is provided on either the retaining plate or the swinging safety cover to fix the swinging safety cover, which is in the open position, to the retaining plate. A doctor's device in which a second magnet is provided on the oscillating safety cover or the doctor blade to fix the oscillating safety cover, which is in the closed position, to the doctor blade.

2. The doctor blade is held in place by the pair of retaining plates via a backing plate. The doctor device according to claim 1, wherein the swinging safety cover in the closed position is fixed to the doctor blade via a backing plate by the second magnet.

3. The safety cover is made of a non-magnetic material, the first magnet is provided on one of the holding plates, and the swinging safety cover is provided with a magnet receiver that is attracted to the first magnet. The doctor device according to claim 2, wherein the second magnet is provided on the swing safety cover and is attracted to the backing plate of the doctor blade.

4. The doctor device according to claim 3, wherein the height and position of the first magnet are defined such that the oscillating safety cover does not come into contact with the fastener when the oscillating safety cover is fixed to the one holding plate by the first magnet.

5. The aforementioned fixed safety cover has a first plane, The doctor device according to claim 1, wherein the swinging safety cover has a substantially U-shaped cross-section having a second plane that is continuous with the first plane and covers the upper surface of the doctor blade when in the closed position, a side surface that descends from the tip of the second plane in a direction perpendicular to the second plane and covers the tip of the doctor blade, and a third plane that extends from the lower end of the side surface toward the base end of the doctor blade parallel to the second plane and covers the lower surface of the doctor blade.

6. The doctor device according to claim 5, wherein the side surface of the swinging safety cover covers the tip of the doctor blade over the entire width of the doctor blade when the swinging safety cover is in the closed position.

7. The length of the third plane is shorter than the length of the second plane. The doctor device according to claim 5 or 6, wherein the minimum distance L between the tip of the doctor blade and the tip of the third plane when the swinging safety cover is swung is 1 mm ≤ L ≤ 5 mm.

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