A dust mask

Abstract

This invention proposes a dustproof face mask, belonging to the field of wearable device technology. The dustproof face mask includes a mask and an air intake plate. Air intake cylinders are provided on both sides of the mask. A sleeve for threaded attachment to the outside of the air intake cylinder is provided on the air intake plate. An inner mating ring and an outer mating ring are respectively provided inside the air intake cylinder and the sleeve. An inner filter and an outer filter are respectively provided inside the mating ends of the inner and outer mating rings. Semi-circular half-shafts are provided on both sides of the inner and outer filters. When the sleeve is screwed into the air intake cylinder, the inner and outer filters switch positions by rotating about the half-shafts. When the sleeve is separated from the air intake cylinder, the outer filter remains on the inner mating ring, and the inner filter follows the outer mating ring away from the air intake cylinder. This invention has the advantages of allowing workers to directly replace the air intake plate and filters in the working environment, and is simple to operate and structurally.

Description

Technical Field

[0001] This invention relates to the field of wearable device technology, and more specifically to a dustproof face mask. Background Technology

[0002] In dusty work environments, dust masks are essential equipment for workers. Wearing dust masks prevents the inhalation of large amounts of dust, protecting their health. However, the filters on these dust masks need to be removed and replaced after a period of use. Since the filters are typically located inside the air intake, removing the filters requires workers to leave their original work area and return after replacement. This process is time-consuming and inconvenient, requiring workers to pause their work. Currently, there are several existing technologies to address these issues.

[0003] For example, patent CN118001628A discloses a dustproof face mask, including a face mask that fits the face and a filter box that can be detachably installed on the face mask. The filter box includes a rear cover that can be detachably installed on the face mask and a front cover installed on the rear cover. The front cover and the rear cover enclose a filter cavity. A driving component is installed in the filter cavity. A squeezing frame is slidably installed on the driving component. Both ends of the driving component have a body and a receiving cavity opened on the body. An active component is rotatably installed in one receiving cavity and a driven component is rotatably installed in the other receiving cavity. The active component and the driven component have a torsional force with opposite rotational directions. A filter element is wound on the driven component. The end of the filter element passes through the squeezing frame and is wound on the active component. An elastic component is also installed in the rear cover. The elastic component is used to push the squeezing frame to press the filter strip tightly on the front cover. The front cover has an air inlet hole that exposes the filter element, and the rear cover has an air intake hole that connects to the face mask. This allows the filter element to be replaced without disassembling it in the working environment, thus improving the filtration effect.

[0004] The dust masks mentioned above, although capable of replacing the filter element directly in the working environment, are complex in structure, expensive, and have high energy consumption and weight. In particular, after the filter element is completely used up, it is still impossible to avoid the problem that workers need to leave the working environment when replacing the entire roll of filter element. As a result, they can only enable workers to replace the filter element directly in the working environment to a certain extent. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a dustproof face mask.

[0006] The technical solution of this invention is implemented as follows:

[0007] A dust mask includes a mask and an air intake plate. Air intake cylinders are provided on both sides of the mask. A sleeve for threaded connection to the outside of the air intake cylinders is provided on the air intake plate. An inner mating ring and an outer mating ring are respectively provided inside the air intake cylinders and the sleeve. An inner filter and an outer filter are respectively provided inside the mating ends of the inner and outer mating rings. Semi-circular half-shafts are provided on both sides of the inner and outer filters. When the sleeve is screwed into the outside of the air intake cylinders, the inner and outer filters switch positions by rotating about the half-shafts. When the sleeve separates from the outside of the air intake cylinders, the outer filter remains on the inner mating ring, and the inner filter follows the outer mating ring away from the air intake cylinders.

[0008] Furthermore, the inner docking ring is slidably disposed inside the air intake cylinder, and a support spring is disposed inside the air intake cylinder. The outer end of the support spring is supported on the inner end face of the inner docking ring, and the support spring is used to keep the end face of the docking end of the inner docking ring flush with the outer end face of the air intake cylinder.

[0009] Furthermore, when the inner docking ring and the outer connecting ring are docked, the docking ends of the inner docking ring and the outer docking ring are fitted together, and the docking ends of the inner filter screen and the outer filter screen are fitted together.

[0010] Furthermore, when the inner filter screen is connected to the outer filter screen, a receiving groove is formed between the inner filter screen and the outer filter screen.

[0011] Furthermore, both sides of the air intake cylinder are provided with strip grooves for shaft displacement. The width of the strip grooves is adapted to the outer diameter of the half shaft. A row of retractable ratchet teeth is provided on one inner wall of the strip groove. A set of ratchet grooves is provided at equal intervals on the outside of the half shaft. When the two half shafts are connected, the two sets of ratchet grooves form a circle. When the sleeve is screwed into the outside of the air intake cylinder, the ratchet grooves engage with the ratchet teeth to make the inner filter screen and the outer filter screen rotate.

[0012] Furthermore, the inner docking ring and the outer docking ring have the same outer diameter, the outer diameter of the inner docking ring is the same as the inner diameter of the air intake cylinder, and the outer end face of the half shaft and the outer surface of the air intake cylinder are located on the same circumferential surface.

[0013] Furthermore, the air intake cylinder includes a first cylinder and a second cylinder distributed inwards and outwards. The outer diameter of the first cylinder is larger than the outer diameter of the second cylinder. The face shield is fixedly connected to the inner end of the first cylinder. The surface of the first cylinder is provided with threads. The sleeve includes a third cylinder and a fourth cylinder distributed inwards and outwards. The inner wall surface of the third cylinder is provided with threads that are adapted to the first cylinder. The inner diameter of the fourth cylinder is set to be adapted to the outer diameter of the second cylinder. The strip groove is formed on the second cylinder. The length of the second cylinder is greater than the length of the third cylinder.

[0014] Furthermore, grooves are provided on both the upper and lower sides of the docking ends of the inner and outer docking rings, and limit blocks are provided in the grooves. The inner and outer filter screens are provided with a first limit groove and a second limit groove for the insertion of the two limit blocks, respectively. The first and second limit grooves are open on the side facing the docking ends. Limiting springs are provided in the grooves to provide elastic force for the two limit blocks to be inserted into the first and second limit grooves, respectively.

[0015] Furthermore, the limiting block includes an axial portion, a radial portion perpendicularly disposed on the side of the axial portion facing the docking end, and a pointed portion disposed at the front end of the radial portion. Both the first limiting groove and the second limiting groove include an inclined wall cavity adapted to the side of the pointed portion away from the docking end. The first limiting groove also includes a straight wall cavity extending radially outward from the inclined wall cavity. When the limiting block is inserted into the first limiting groove, the side of the radial portion away from the docking end contacts the straight wall cavity. When the limiting block is inserted into the second limiting groove, the tail end of the pointed portion is located outside the second limiting groove. The first limiting groove on the inner docking ring is located above, and the first limiting groove on the outer docking ring is located below.

[0016] Furthermore, when the limiting block is inserted into the first limiting groove, the side of the axial portion facing the center of the air intake cylinder is supported on the side of the groove facing the center of the air intake cylinder. The side of the inner and outer filter screens away from the docking end is an arc-shaped surface centered on the half-axis, and the circumference of the arc-shaped surface is located within the range of the inclined wall cavity of the first limiting groove. The circumference of the bottom end of the inclined wall cavity in the second limiting groove is located within the range of the inclined wall cavity of the first limiting groove.

[0017] The present invention has the following beneficial effects:

[0018] By incorporating an internal filter, the air entering the intake cylinder can be filtered after the intake disc is removed, allowing workers to replace the intake disc directly within the work area. Simultaneously, during intake disc replacement, the internal filter on the intake cylinder and the external filter on the newly installed intake disc are switched positions. During the next intake disc removal, the original internal filter is removed along with the intake disc, while the original external filter remains inside the intake cylinder. This ensures that the internal filter inside the intake cylinder is replaced simultaneously with each intake disc replacement, resulting in a highly effective and efficient solution. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a schematic diagram showing the inner and outer mating rings in a tightly fitted state during the installation of the dustproof face shield of the present invention on the air intake plate.

[0021] Figure 2 This is the present invention. Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 This is a partial disassembly diagram of the present invention;

[0023] Figure 4 This is the present invention. Figure 3 Enlarged view at point B in the middle;

[0024] Figure 5 This is the present invention. Figure 3 Another perspective view;

[0025] Figure 6 This is a schematic diagram showing the disassembly of the outer connecting ring and the outer filter screen of the present invention;

[0026] Figure 7 This is the present invention. Figure 6 Enlarged view at point C;

[0027] Figure 8 This is the present invention. Figure 6 Enlarged view at point D;

[0028] Figure 9 This is the present invention. Figure 1 A schematic diagram of the middle air intake cylinder, sleeve, inner docking ring, and outer docking ring after being cut open;

[0029] Figure 10 This is the present invention. Figure 9 Enlarged view at point E in the middle;

[0030] Figure 11 This is the present invention. Figure 9 Enlarged view at point F;

[0031] Figure 12 This is a schematic diagram of the expansion joint of the present invention.

[0032] In the diagram: 1. Face mask; 2. Air intake plate; 3. Air intake cylinder; 3-1. First cylinder; 3-2. Second cylinder; 4. Sleeve; 4-1. Third cylinder; 4-2. Fourth cylinder; 5. Inner docking ring; 6. Outer docking ring; 7. Inner filter; 8. Outer filter; 9. Half shaft; 10. Support spring; 11. Receiving groove; 12. Strip groove; 13. Ratchet; 14. Ratchet groove; 15. Groove; 16. Limiting block; 16-1. Axial portion; 16-2. Radial portion; 16-3. Tip portion; 17. First limiting groove; 18. Second limiting groove; 19. Limiting spring; 20. Inclined wall groove cavity; 21. Straight wall groove cavity; 22. Telescopic groove; 23. Telescopic spring. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0034] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] In addition, in the description of this application, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0036] like Figures 1 to 12As shown, this embodiment provides a dust mask including a mask 1 and an air intake plate 2. Air intake cylinders 3 are provided on both sides of the mask 1. A sleeve 4 for threading onto the outside of the air intake cylinder 3 is provided on the air intake plate 2. An inner docking ring 5 and an outer docking ring 6 are respectively provided inside the air intake cylinder 3 and the sleeve 4. An inner filter 7 and an outer filter 8 are respectively provided inside the docking ends of the inner docking ring 5 and the outer docking ring 6. A semi-circular half-shaft 9 is provided on both sides of the inner filter 7 and the outer filter 8. When the sleeve 4 is screwed into the outside of the air intake cylinder 3, the inner filter 7 and the outer filter 8 switch positions by rotating 180° around the half-shaft 9. When the sleeve 4 is separated from the outside of the air intake cylinder 3, the outer filter 8 stays on the inner docking ring 5, and the inner filter 7 follows the outer docking ring 6 away from the air intake cylinder 3.

[0037] When the intake disc 2 is separated from the face mask 1, the inner filter 7 is located at the outer end of the intake cylinder 3, and the inner filter 7 can filter the air entering the intake cylinder 3. When the intake disc 2 is installed onto the face mask 1, the outer mating ring 6 and the inner mating ring 5 are tightly attached. At this time, the two half-shafts 9 on the same side are mated to form a complete shaft structure. Then, the sleeve 4 is rotated so that the sleeve 4 is screwed in outside the intake cylinder 3. During this process, the inner filter 7 and the outer filter 8 can rotate 180° around the center of the half-shaft 9, so that the inner filter 7 and the outer filter 8 can switch positions. Furthermore, during the replacement of the intake disc 2, the inner filter 7 located in the intake cylinder 3 can be replaced by the outer filter 8 in the new intake disc 2, and when the intake disc 2 is removed, the replaced inner filter 7 is also removed.

[0038] In this way, not only can the intake disc 2 be replaced, but also the inner filter 7 inside the intake cylinder 3 can be replaced. At the same time, during the replacement of the intake disc 2, the replaced inner filter 7 is always kept inside the intake cylinder 3 to prevent dust from being inhaled by workers. Thus, the intake disc 2 can be replaced directly in the worker's workplace.

[0039] In addition, after each replacement of the intake disc 2, the inner filter 7, which was originally kept in the intake pipe, will move to the side of the intake cylinder 3 away from the mask 1, while the outer filter 8 on the newly replaced intake disc 2 will move to the side of the intake cylinder 3 closer to the mask 1. This ensures that the outer filter 8, which is unused, more hygienic, and cleaner, is always near the worker's mouth and nose, thus better protecting the worker's body from environmental dust damage.

[0040] The inner docking ring 5 is slidably disposed within the air intake cylinder 3. A support spring 10 is installed within the air intake cylinder 3, with its outer end resting on the inner end face of the inner docking ring 5. The support spring 10 is used to keep the end face of the inner docking ring 5 flush with the outer end face of the air intake cylinder 3. When the inner docking ring 5 docks with the outer connecting ring 6, the docking ends of the inner docking ring 5 and the outer docking ring 6 are in contact, and the docking ends of the inner filter screen 7 and the outer filter screen 8 are in contact.

[0041] After removing the intake disc 2, the outer filter 8, retained on the inner connecting ring 5, is located at the outermost end of the intake cylinder 3, preventing environmental dust from entering the intake cylinder 3. During the installation of the intake disc 2, the outer connecting ring 6 is inserted into the intake cylinder 3, causing the inner connecting ring 5 to move inward within the intake cylinder 3, and the support spring 10 is compressed. This ensures that after the intake disc 2 is installed, both the inner connecting ring 5 and the outer connecting ring 6 are located within the intake cylinder 3. At this point, the inner connecting ring 5 and the outer connecting ring 6, under the limiting effect of the intake cylinder 3, can fit more tightly. Furthermore, the cooperation between the inner connecting ring 5 and the outer connecting ring 6 can also seal the intake cylinder 3 more tightly from the external environment, ensuring that all air entering the intake cylinder 3 from the intake disc 2 passes through the outer filter 8 and the inner filter 7.

[0042] During the removal of the intake disc 2, both the inner docking ring 5 and the outer docking ring 6 will move outward within the intake cylinder 3. During this process, the support spring 10 keeps the inner docking ring 5 and the outer docking ring 6 in close contact. Once the outer docking ring 6 has moved outside the intake cylinder 3, it can separate from the inner docking ring 5. This prevents dust between the inner filter screen 7 and the outer filter screen 8 from falling into the intake cylinder 3.

[0043] When the inner filter 7 and the outer filter 8 are connected, a receiving groove 11 is formed between them. Specifically, both the inner filter 7 and the outer filter 8 include an annular portion and a mesh portion. The annular portion extends forward relative to the mesh portion on the side facing the connection end. When the inner filter 7 and the outer filter 8 are connected, the receiving groove 11 is formed between the two extensions. This arrangement ensures that after the new air intake disc 2 is installed, the receiving groove 11 makes the dust distribution between the inner filter 7 and the outer filter 8 more loose, resulting in better airflow performance for the inner filter 7 and the outer filter 8, and providing better air supply for the workers' breathing.

[0044] Both sides of the intake cylinder 3 are provided with strip grooves 12 for shaft displacement. The width of the strip grooves 12 is adapted to the outer diameter of the half shaft 9. A row of retractable ratchet teeth 13 is provided on the inner wall of one side of the strip groove 12. A set of ratchet grooves 14 are provided at equal intervals on the outer side of the half shaft 9. When the two half shafts 9 are docked, the two sets of ratchet grooves 14 form a circle. When the sleeve 4 is screwed in outside the intake cylinder 3, the ratchet grooves 14 engage with the ratchet teeth 13, causing the inner filter screen 7 and the outer filter screen 8 to rotate. The strip grooves 12 are provided with telescopic grooves 22 for receiving the ratchet teeth 13. A telescopic spring 23 is provided in the telescopic groove 22, which provides elastic force to keep the ratchet teeth 13 extended out of the telescopic groove 22. The side of the ratchet teeth 13 facing the docking end is a plane parallel to the radial direction of the intake cylinder 3, and the side of the ratchet teeth 13 away from the docking end is a slope.

[0045] Specifically, as the inner docking ring 5 and the outer docking ring 6 dock, the two half-shafts 9 on the same side of the inner docking ring 5 and the outer docking ring 6 also dock. The ratchet grooves 14 on the outside of the two half-shafts 9 form a complete circle, and the circle of ratchet grooves 14 is distributed in a circular array outside the two half-shafts 9. As the sleeve 4 rotates inward outside the air intake cylinder 3, the two docked shafts move within the strip groove 12, and the meshing of the ratchet groove 14 and ratchet 13 causes the two shafts to rotate synchronously. Thus, when installing the air intake plate 2, the inner filter 7 and the outer filter 8 rotate and switch positions synchronously. When the sleeve 4 rotates inward to its maximum stroke outside the air intake cylinder 3, the air intake plate 2 is installed. At this time, the ratchet 13 and the ratchet groove 14 remain in a meshing state, and one of the half-shafts 9 contacts the side wall of the strip groove 12, which can lock the half-shaft 9, thereby locking the inner filter 7 and the outer filter 8 in their original rotation direction.

[0046] The inner docking ring 5 and the outer docking ring 6 have the same outer diameter. The outer diameter of the inner docking ring 5 is the same as the inner diameter of the air intake cylinder 3. The outer end face of the half shaft 9 and the outer surface of the air intake cylinder 3 are located on the same circumferential surface.

[0047] The air intake cylinder 3 includes a first cylinder 3-1 and a second cylinder 3-2 distributed inside and outside. The outer diameter of the first cylinder 3-1 is larger than the outer diameter of the second cylinder 3-2. The inner end of the first cylinder 3-1 is fixedly connected to the face shield 1. The surface of the first cylinder 3-1 is provided with threads. The sleeve 4 includes a third cylinder 4-1 and a fourth cylinder 4-2 distributed inside and outside. The inner wall surface of the third cylinder 4-1 is provided with threads that are compatible with the first cylinder 3-1. The inner diameter of the fourth cylinder 4-2 is set to be compatible with the outer diameter of the second cylinder 3-2. The strip groove 12 is opened on the second cylinder 3-2. The length of the second cylinder 3-2 is greater than the length of the third cylinder 4-1.

[0048] When installing the intake disc 2, when the outer docking ring 6 is in close contact with the outer docking ring 6 at the docking end, the fourth cylinder 4-2 has already been fitted onto the second cylinder 3-2. At this time, the fourth cylinder 4-2 and the second cylinder 3-2 are used to guide the forward displacement of the third cylinder 4-1, and enable the two half-shafts 9 to be precisely docked.

[0049] Grooves 15 are provided on both the upper and lower sides of the docking ends of the inner docking ring 5 and the outer docking ring 6. Limiting blocks 16 are provided in the grooves 15. The inner filter screen 7 and the outer filter screen 8 are provided with a first limiting groove 17 and a second limiting groove 18 for the insertion of the two limiting blocks 16, respectively. The first limiting groove 17 and the second limiting groove 18 are open on the side facing the docking end. A limiting spring 19 is provided in the groove 15 to provide elastic force for the two limiting blocks 16 to be inserted into the first limiting groove 17 and the second limiting groove 18, respectively.

[0050] The limiting block 16 compresses the limiting spring 19 radially outward to separate itself from the inner filter 7 and the outer filter 8, allowing for the rotation of the inner filter 7 and the outer filter 8. The groove 15 provides space for the limiting block 16 to move outward and for the limiting spring 19 to be installed. At the same time, the elastic force of the limiting spring 19 allows the two limiting blocks 16 to be inserted into the first limiting groove 17 and the second limiting groove 18 respectively, preventing the inner filter 7 from detaching from the air intake cylinder 3 and preventing the outer filter 8 from falling off the air intake plate 2.

[0051] The limiting block 16 includes an axial portion 16-1, a radial portion 16-2 vertically disposed on the side of the axial portion 16-1 facing the docking end, and a pointed portion 16-3 disposed at the front end of the radial portion 16-2. The first limiting groove 17 and the second limiting groove 18 both include an inclined wall cavity 20 adapted to the side of the pointed portion 16-3 away from the docking end. The first limiting groove 17 also includes a straight wall cavity 21 extending radially outward from the inclined wall cavity 20. When the limiting block 16 is inserted into the first limiting groove 17, the side of the radial portion 16-2 away from the docking end contacts the straight wall cavity 21. When the limiting block 16 is inserted into the second limiting groove 18, the tail end of the pointed portion 16-3 is located outside the second limiting groove 18. The first limiting groove 17 on the inner docking ring 5 is located above, and the first limiting groove 17 on the outer docking ring 6 is located below.

[0052] The elastic force of the limiting spring 19 ensures that, in the initial state, the inner filter 7 is stably installed on the inner docking ring 5, and the outer filter 8 is stably installed on the outer docking ring 6. The inner filter 7 on the inner docking ring 5 is limited by the straight wall cavity 21 of the first limiting groove 17 and the radial portion 16-2 of the upper limiting block 16, preventing it from rotating its tip towards the docking side. Consequently, the inner filter 7 can only rotate its tip away from the docking side.

[0053] The outer filter 8 on the outer docking ring 6 is limited by the straight wall cavity 21 of the first limiting groove 17 and the radial portion 16-2 of the limiting block 16 below, and cannot rotate its top end away from the docking side. As a result, the outer filter 8 can only rotate its top end towards the docking side.

[0054] The above configuration ensures that during the installation of the intake disc 2, both the inner filter 7 and the outer filter 8 can only rotate in one direction. After the intake disc 2 is installed, the ratchet 13, in conjunction with the ratchet groove 14, locks the rotation direction of the inner filter 7 and the outer filter 8. Simultaneously, the first limiting groove 17, in conjunction with the limiting groove, locks the inner filter 7 and the outer filter 8 in the opposite direction of rotation. This allows for simultaneous locking of the inner filter 7 and the outer filter 8 on both sides of their rotation direction, ensuring that during normal use of the dust mask, the inner filter 7 and the outer filter 8 remain stably filtering dust.

[0055] The axial portion 16-1 is supported on one side of the intake cylinder 3 facing the center of the groove 15 on the side of the intake cylinder 3 facing the center of the groove 15. The side of the inner filter screen 7 and the outer filter screen 8 away from the docking end is an arc-shaped surface centered on the half shaft 9. The circumference of the arc-shaped surface is located within the range of the inclined wall cavity 20 of the first limiting groove 17. The circumference of the bottom end of the inclined wall cavity 20 in the second limiting groove 18 is located within the range of the inclined wall cavity 20 of the first limiting groove 17.

[0056] Specifically, during the installation of the intake disc 2 and the rotational switching of the inner filter 7 and the outer filter 8, the limiting block 16 inserted in the first limiting groove 17 on the inner filter 7 is squeezed upward by the bottom of the groove opening of the inclined wall cavity 20 of the second limiting groove 18 on the outer filter 8, and the limiting block 16 inserted in the second limiting groove 18 on the outer filter 8 is squeezed upward by the side wall of the inclined wall cavity 20 of the second limiting groove 18, thereby causing the two limiting blocks 16 located above to move upward.

[0057] Similarly, the limiting block 16 inserted into the second limiting groove 18 on the inner filter 7 will be pressed downward by the side wall of the inclined wall cavity 20 of the second limiting groove 18 on the inner filter 7, and the limiting block 16 inserted into the first limiting groove 17 on the outer filter 8 will be pressed downward by the top of the groove opening of the inclined wall cavity 20 of the second limiting groove 18 on the inner filter 7, thereby causing the two limiting blocks 16 located below to move downward.

[0058] After the limiting blocks 16 disengage from the inner filter 7 and the outer filter 8, under the action of the lower spring, all four limiting blocks 16 will return to their original state when inserted into the first limiting groove 17. When the inner filter 7 and the outer filter 8 rotate 180°, the arc-shaped surfaces of the inner filter 7 and the outer filter 8 will push the limiting blocks 16 they have passed through away from the center of the air intake cylinder 3, so that the limiting blocks 16 can be re-inserted into the first limiting groove 17 or the second limiting groove 18.

[0059] During the removal of the intake disc 2, since neither the inner filter 7 nor the outer filter 8 can rotate in the opposite direction, the half-shaft 9 remains stationary in the circumferential direction and moves outward within the slot 12. During this process, the ratchet groove 14 simultaneously and continuously squeezes the ratchet 13 to pass over it. At the same time, the half-shaft 9 on the original outer filter 8, located on the inner docking ring 5, will pass over the ratchet 13 under the action of the support spring 10. At this time, the support spring 10 provides force for the outer docking ring 6 to drive the half-shaft 9 on the original outer filter 8 to squeeze the ratchet 13, while keeping the inner docking ring 5 and the outer docking ring 6 in a tight fit.

[0060] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A dustproof face mask, characterized in that, Includes a face mask (1) and an air intake plate (2). Air intake cylinders (3) are provided on both sides of the face mask (1). A sleeve (4) is provided on the air intake plate (2) for threading onto the outside of the air intake cylinders (3). An inner mating ring (5) and an outer mating ring (6) are respectively provided inside the air intake cylinder (3) and the sleeve (4). An inner filter screen (7) and an outer filter screen (8) are respectively provided inside the mating ends of the inner mating ring (5) and the outer mating ring (6). The inner filter screen (7) and the outer filter screen (8) are connected... Both sides of the filter screen (8) are provided with a semi-circular cross-section half shaft (9). When the sleeve (4) is rotated into the outside of the air inlet cylinder (3), the inner filter screen (7) and the outer filter screen (8) switch positions by rotating 180° around the half shaft (9). When the sleeve (4) separates from the outside of the air inlet cylinder (3), the outer filter screen (8) stays on the inner docking ring (5), and the inner filter screen (7) leaves the air inlet cylinder (3) along with the outer docking ring (6). The inner docking ring (5) is slidably disposed inside the air inlet cylinder (3), and a support spring (10) is disposed inside the air inlet cylinder (3). The outer end of the support spring (10) is supported on the inner end face of the inner docking ring (5). The support spring (10) is used to keep the end face of the docking end of the inner docking ring (5) flush with the outer end face of the air inlet cylinder (3). The air intake cylinder (3) is provided with strip grooves (12) on both sides for shaft displacement. The width of the strip grooves (12) is adapted to the outer diameter of the half shaft (9). A row of retractable ratchet teeth (13) is provided on the inner wall of one side of the strip grooves (12). A set of ratchet grooves (14) is provided at equal intervals on the outside of the half shaft (9). When the two half shafts (9) are connected, the two sets of ratchet grooves (14) form a circle. When the sleeve (4) is rotated outside the air intake cylinder (3), the ratchet grooves (14) mesh with the ratchet teeth (13) to make the inner filter (7) and the outer filter (8) rotate.

2. The dustproof face mask as described in claim 1, characterized in that, When the inner docking ring (5) docks with the outer connecting ring, the docking ends of the inner docking ring (5) and the outer docking ring (6) are in contact, and the docking ends of the inner filter screen (7) and the outer filter screen (8) are in contact.

3. A dustproof face mask as described in claim 1, characterized in that, When the inner filter (7) is connected to the outer filter (8), a receiving groove (11) is formed between the inner filter (7) and the outer filter (8).

4. A dustproof face mask as described in claim 1, characterized in that, The inner docking ring (5) has the same outer diameter as the outer docking ring (6), the outer diameter of the inner docking ring (5) has the same inner diameter as the air inlet cylinder (3), and the outer end face of the half shaft (9) and the outer surface of the air inlet cylinder (3) are located on the same circumferential surface.

5. A dustproof face mask as described in claim 1, characterized in that, The air intake cylinder (3) includes a first cylinder (3-1) and a second cylinder (3-2) distributed inside and outside. The outer diameter of the first cylinder (3-1) is larger than the outer diameter of the second cylinder (3-2). The inner end of the first cylinder (3-1) is fixedly connected to the mask (1). The surface of the first cylinder (3-1) is provided with threads. The sleeve (4) includes a third cylinder (4-1) and a fourth cylinder (4-2) distributed inside and outside. The inner wall surface of the third cylinder (4-1) is provided with threads that are compatible with the first cylinder (3-1). The inner diameter of the fourth cylinder (4-2) is set to be compatible with the outer diameter of the second cylinder (3-2). The strip groove (12) is opened on the second cylinder (3-2). The length of the second cylinder (3-2) is greater than the length of the third cylinder (4-1).

6. A dustproof face shield as described in claim 1, characterized in that, The inner docking ring (5) and the outer docking ring (6) are provided with grooves (15) on both the upper and lower sides of the docking end. Limiting blocks (16) are provided in the grooves (15). The inner filter screen (7) and the outer filter screen (8) are provided with a first limiting groove (17) and a second limiting groove (18) for the insertion of the two limiting blocks (16). The first limiting groove (17) and the second limiting groove (18) are open on the side facing the docking end. The grooves (15) are provided with limiting springs (19) for providing elastic force for the two limiting blocks (16) to be inserted into the first limiting groove (17) and the second limiting groove (18) respectively.

7. A dustproof face mask as described in claim 6, characterized in that, The limiting block (16) includes an axial portion (16-1), a radial portion (16-2) vertically disposed on the side of the axial portion (16-1) facing the docking end, and a pointed portion (16-3) disposed at the front end of the radial portion (16-2). The first limiting groove (17) and the second limiting groove (18) both include inclined wall grooves (20) adapted to the side of the pointed portion (16-3) away from the docking end. The first limiting groove (17) also includes a radially extending section from the inclined wall groove (20). When the limiting block (16) is inserted into the first limiting groove (17), the radial portion (16-2) on one side away from the docking end contacts the straight wall cavity (21). When the limiting block (16) is inserted into the second limiting groove (18), the tail end of the tip portion (16-3) is located outside the second limiting groove (18). The first limiting groove (17) on the inner docking ring (5) is located above, and the first limiting groove (17) on the outer docking ring (6) is located below.

8. A dustproof face mask as described in claim 7, characterized in that, When the limiting block (16) is inserted into the first limiting groove (17), the side of the axial portion (16-1) facing the center of the air inlet cylinder (3) is supported on the side of the groove (15) facing the center of the air inlet cylinder (3). The side of the circumferential surface of the inner filter (7) and the outer filter (8) away from the docking end is an arc-shaped surface centered on the half shaft (9), and the circumference of the arc-shaped surface is located within the range of the inclined wall cavity (20) of the first limiting groove (17). The circumference of the bottom end of the inclined wall cavity (20) in the second limiting groove (18) is located within the range of the inclined wall cavity (20) of the first limiting groove (17).

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