Dust cover

Abstract

To provide a dust cover that does not damage the interlocking claws when stacked and can be easily removed from a stacked state. [Solution] The cover body covers the outside of the smoke detector, including the smoke inlet, and has an open top. Four legs 20 are formed on the cover body at predetermined intervals in a ring shape in plan view, extending below the bottom surface of the cover body. A fitting recess 22 is formed on the side surface of the cover body between the legs 20, extending inward. A fitting claw portion 24 is formed extending further inward from the fitting recess 22. In a stack structure, a stack recess 30 is formed on each of the legs 20, extending from the bottom surface of the leg 20 to a stack surface at a predetermined height toward the bottom surface of the cover body. When dust covers are stacked so that the stack surface of the stack recess 30 abuts against the bottom surface of the legs 20 of the dust cover located on the upper side of the cover body, a spaced state is ensured so that the fitting claw portion 24 does not interfere with other dust covers.

Description

Technical Field

[0001] The present invention relates to a dust-proof cover to be attached to a smoke detector.

Background Art

[0002] Conventionally, smoke detectors are installed on the ceiling of a building due to construction work or the like. However, dust and dirt are likely to be generated at the construction site during construction, and the dust and dirt enter the interior from the smoke inlet of the smoke detector, causing clogging of the insect-proof net or affecting the detection sensitivity of the smoke detection unit and reducing the detection function. Therefore, by attaching a dust-proof cover to the smoke detector before use, dust and dirt are prevented from entering from the smoke inlet, and when the construction is completed and the use of the smoke detector is started, the dust-proof cover is removed from the smoke detector (Patent Document 1).

[0003] In addition, a fitting claw portion that fits into the smoke inlet is formed on the dust-proof cover so that the dust-proof cover does not fall naturally from the smoke detector installed on the ceiling.

[0004] Also, the process from the manufacture of the dust-proof cover to the installation of the smoke detector is, for example, as follows. First, the dust-proof covers manufactured by the dust-proof cover manufacturer are packed in a packing box in a stacked state and delivered from the dust-proof cover manufacturer to the smoke detector manufacturer. Then, one dust-proof cover is removed from the stacked dust-proof covers and attached to the smoke detector, and the smoke detector with the dust-proof cover attached is packed in a packing box and transported to the construction site. At the construction site, the smoke detector with the dust-proof cover attached is taken out and installed on the ceiling or the like.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Incidentally, when dust covers are delivered, or when they are removed from their packaging and stored, they are stacked. However, in this case, the fitting claws that engage with the smoke inlet interfere with and crush adjacent dust covers, making it impossible to engage the fitting claws with the smoke inlet and attach the dust cover to the smoke detector.

[0007] Furthermore, when dust covers are stacked, adjacent covers can stick together, making them difficult to remove. Attempting to remove them forcefully can damage the covers, requiring careful handling of stacked dust covers, which reduces work efficiency.

[0008] The present invention aims to provide a dust cover that can be easily removed from a stacked state without damaging the interlocking claws when stacked. [Means for solving the problem]

[0009] (Dust cover) The present invention is a dust cover that is attached to a smoke detector by fitting a fitting claw portion to at least the smoke inlet of the smoke detector, The dust cover is characterized by a stacking structure that ensures a spaced-out state where the interlocking claws do not interfere with each other when the dust covers are stacked.

[0010] (Structure of the dust cover) A cover body that covers the outside of the smoke detector, including the smoke inlet, with an opening on the upper side where the smoke detector will be installed, Multiple legs are formed on the cover body at predetermined intervals in a ring shape when viewed from above, so as to protrude below the bottom surface of the cover body, A fitting recess is formed on the side of the cover body portion that protrudes inward between the designated legs, A fitting claw portion formed by protruding further inward from a predetermined fitting recess, Equipped with, In the stack structure, a stack recess is formed on a predetermined leg, extending from the lower surface of the leg to the lower surface of the cover body up to a stack surface at a predetermined height. When dust covers are stacked so that the stacking surface of the stack recess is in contact with the lower surface of the legs of the dust cover located on the upper side of the cover body, a separation is ensured.

[0011] (Arrangement of stack recesses) The stack recess is formed in each of the legs, and the position of the recess on each leg is different for each leg. By rotating one dust cover to a predetermined angle relative to the other dust cover to be stacked, the dust covers are stacked so that the legs with stacking recesses formed at different positions overlap, thereby ensuring that they are spaced apart.

[0012] (Details of the stack recess arrangement) The legs are formed in a ring shape in a plan view on the main body of the cover at four predetermined intervals. By rotating one dust cover to 90°, 180°, or 270° relative to the other dust cover to be stacked, the dust covers are stacked so that the legs with stacking recesses formed in different positions overlap, thereby ensuring that they are spaced apart.

[0013] (Tapered surface) A tapered surface is formed between the mating recess and the lower surface of the cover body, sloping inward from top to bottom.

[0014] (Laminated sheet structure of environmentally friendly resin and synthetic resin) The dust cover has a laminated sheet structure in which a sheet of environmentally friendly resin, which is a mixture of a predetermined synthetic resin and a predetermined non-synthetic resin, is flanked on both sides by a sheet of a predetermined synthetic resin.

[0015] (Environmentally friendly resin) The specified non-synthetic resin contains either calcium carbonate, starch, or cellulose.

[0016] (Reinforcement of the dust cover) A plurality of reinforcing ribs extending in the vertical direction are formed on the side surface of the foot portion.

[0017] (Structure for attaching and detaching the dust cover) The fitting concave portion and the fitting claw portion are fitted to the smoke inlet of the smoke detector to be attached to the smoke detector, and by applying a rotational force around an axis with the vertical direction as the axis to the leg portion, the fitting of the fitting concave portion and the fitting claw portion can be released to remove the dust cover from the smoke detector.

[0018] (Color of the dust cover) The dust cover is made of a predetermined chromatic color different from the color of the installation environment where the smoke detector is installed.

[0019] (Chromatic color of the yellow system) As the predetermined chromatic color, a predetermined chromatic color belonging to the yellow system is used. [Effect of the invention]

[0020] (Effect of the dust cover) The present invention is a dust cover that is attached to a smoke detector by fitting a fitting claw portion at least to the smoke inlet of the smoke detector. When the dust covers are stacked, a stack structure is provided to ensure a separated state where the fitting claw portion is not interfered with by other dust covers. Therefore, when the dust covers are stacked, the fitting claw portion is not crushed by the adjacent dust cover, and since the adjacent dust covers do not adhere to each other, it is easy to remove them from the stacked state, preventing damage to the dust cover and making it possible to facilitate the handling of the dust cover.

[0021] (Effect due to the structure of the dust cover) Furthermore, the structure includes a cover body that covers the outside of the smoke detector, including the smoke inlet, with an open top on the side where the smoke detector is mounted; multiple legs formed on the cover body at predetermined intervals in a ring shape in plan view, extending downward from the bottom surface of the cover body; fitting recesses formed on the side of the cover body between the predetermined legs, extending inward; and fitting claws formed further inward from the predetermined fitting recesses. In this stack structure, a stack recess is formed on a predetermined leg, extending from the bottom surface of the leg to a stack surface at a predetermined height toward the bottom surface of the cover body. This ensures that when dust covers are stacked so that the stack surface of the stack recess contacts the bottom surface of the leg of the dust cover located on the upper side of the cover body, a gap is maintained. Therefore, the stack height of the stack recess (length from the bottom surface of the leg to the stack surface) can be used to determine the height gap between adjacent dust covers when they are stacked, making it possible to set a suitable and easy gap to ensure an appropriate gap.

[0022] (Effect of the arrangement of the stack recesses) Furthermore, the stack recess is formed on each leg, and the position of the recess on each leg is different. By rotating one dust cover to a predetermined angle relative to the other dust cover to be stacked, the legs with stack recesses formed in different positions overlap, ensuring that the covers are spaced apart. This ensures that when the dust covers are stacked with the legs aligned, the covers are spaced apart as long as the legs with stack recesses formed in the same position do not overlap. It is also possible to stack the dust covers in a tightly packed state without ensuring spaced apart by overlapping the legs with stack recesses formed in the same position.

[0023] (Effect of tapered surface) Furthermore, by forming a tapered surface that slopes inward from top to bottom between the fitting recess and the bottom surface of the cover body, it is possible to reduce the height gap between adjacent dust covers when stacking them while maintaining spacing between them. This reduces the stacking height (vertical length) of the stacked dust covers, thus reducing storage space. It also makes it possible to increase the number of dust covers that can be placed in a single packaging box when stacking dust covers in a box.

[0024] (Effects of laminated sheet structure of environmentally friendly resin and synthetic resin) Furthermore, since the dust cover has a laminated sheet structure in which a sheet of environmentally friendly resin, which is a mixture of a predetermined synthetic resin and a predetermined non-synthetic resin, is flanked on both sides by a sheet of a predetermined synthetic resin, the amount of petroleum-derived resin used is reduced by using the environmentally friendly resin, thereby contributing to the reduction of CO2 emissions. In addition, since a sheet of synthetic resin is flanked on both sides by the sheet of environmentally friendly resin, the environmentally friendly resin does not come into direct contact with the smoke detector to which the dust cover is attached. This prevents chemicals used in the manufacture of the sheet of environmentally friendly resin, or liquids from which components of the environmentally friendly resin have leached due to moisture such as condensation, from coming into contact with the smoke detector, thereby eliminating any impact on the smoke detector. Furthermore, by preventing the intrusion of material-specific powders such as paper dust generated from the mixed non-synthetic resin, it is possible to eliminate any impact on the smoke detector.

[0025] (Effect of reinforcing the strength of the dust cover) Furthermore, by forming multiple reinforcing ribs that extend vertically on the sides of the legs, it is possible to ensure sufficient strength through the reinforcing ribs, even when there are concerns about a decrease in strength due to the use of environmentally friendly resins that are softer than synthetic resins such as polystyrene used in conventional dust covers, or when adopting a shape that is easy to thin.

[0026] (Effectiveness of the structure for attaching and removing the dust cover) Furthermore, the dust cover is attached to the smoke detector by fitting the fitting recess and fitting claw into the smoke inlet of the smoke detector, and the fitting recess and fitting claw can be released by applying rotational force to the legs around an axis in the vertical direction, thereby making it easy to attach and detach the dust cover to the smoke detector. In addition, when removing the dust cover from the smoke detector, the dust cover will not be deformed excessively by the impact, and dust and dirt attached to the dust cover will not be blown around, thus reliably preventing dust and dirt from entering through the smoke inlet, causing clogging of the insect screen, affecting the detection sensitivity of the smoke detection unit, and reducing the detection function.

[0027] (The effect of the color of the dust cover) Furthermore, by using a predetermined chromatic color that differs from the color of the environment in which the smoke detector is installed, such as a predetermined chromatic color belonging to the yellow family, the dust cover attached to the smoke detector is easily visible, preventing it from being forgotten and making it easier to retrieve a dust cover that has fallen off the smoke detector. [Brief explanation of the drawing]

[0028] [Figure 1] This is an explanatory diagram showing a smoke detector installed on the ceiling and an unattached dust cover. [Figure 2] This is an explanatory diagram showing a smoke detector with a dust cover attached. [Figure 3] This is an explanatory diagram showing how to remove the dust cover from a smoke detector. [Figure 4] This is an explanatory diagram showing a smoke detector with its dust cover removed. [Figure 5] This is an explanatory diagram showing the dust cover from the front. [Figure 6] This is an explanatory diagram showing the dust cover as viewed from above. [Figure 7] This is an explanatory diagram showing the dust cover viewed from a diagonal downward angle. [Figure 8] This is an explanatory diagram showing the dust cover viewed from a diagonal upward angle. [Figure 9] This is an explanatory diagram showing two dust covers in the same rotational position in a plan view. [Figure 10] This is a diagram illustrating two dust covers in different rotational positions, shown in plan view. [Figure 11] This is a schematic diagram illustrating the fitting recess, fitting claw portion, and stacking recess of the dust cover. [Figure 12] This is a schematic diagram illustrating the fitting recess, fitting claw portion, and stacking recess when two dust covers are stacked on top of each other. [Figure 13] This is an explanatory diagram showing the five dust covers stacked on top of each other. [Figure 14] This is an explanatory diagram showing a laminated sheet structure using environmentally friendly resin and a reinforcing structure for the legs. [Figure 15] This is a schematic diagram illustrating the fitting structure of a dust cover for a smoke detector. [Figure 16] This is an explanatory diagram showing a smoke detector with a dust cover attached, both in its boxed state and in a horizontal position. [Modes for carrying out the invention]

[0029] Embodiments of the dust cover according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0030] [Basic Concepts of the Embodiment] First, the basic concept of the embodiment will be explained. The embodiment generally relates to a dust cover to be attached to a smoke detector having a smoke inlet.

[0031] Here, a "smoke detector" is installed in a designated monitoring area and monitors for fires by detecting smoke generated in that area. The "monitoring area" is the area that is monitored by the smoke detector and is an outdoor or indoor space of a certain size, including areas such as rooms, corridors, and stairwells in a building.

[0032] The "dust cover" is a cover attached to the smoke detector to prevent dust and dirt from entering through the smoke inlet, and is removed from the smoke detector when monitoring by the smoke detector is started. The "dust cover" also functions as cushioning material when the smoke detector is packaged while still attached.

[0033] Furthermore, the "dust cover" of the embodiment is characterized by having a "stack structure".

[0034] The "stack structure" is a structure that ensures a "separated state" where the interlocking claws of dust covers do not interfere with each other when dust covers are stacked. By having a stack structure, when dust covers are stacked, the interlocking claws do not get crushed by adjacent dust covers, and because adjacent dust covers do not stick together, it is easy to remove them from the stacked state, preventing damage to the dust covers and making them easier to handle. Furthermore, "stacking of dust covers" includes not only manual stacking by people but also automatic stacking by machines such as dust cover manufacturing equipment, without human intervention.

[0035] Furthermore, the "dust cover" comprises a "cover body," "legs," "fitting recess," and "fitting claw," and has a "stacked structure" with a "stacked recess."

[0036] The "cover body" covers the outside of the smoke detector, including the smoke inlet, and has an opening on the upper side, which is the side to which the smoke detector is attached. In the specification and claims, the "upper side of the dust cover" is defined as the side to which the smoke detector is attached, and the opposite side is defined as the "lower side," and "height" refers to the length in the vertical direction.

[0037] The "legs" are formed on the main body of the cover in a ring shape at predetermined intervals when viewed from above or below, protruding below the bottom surface of the main body of the cover, and define the stacking position when stacking dust covers. The shape of the multiple legs formed is basically the same, except for the presence or absence of stacking recesses and the location where the stacking recesses are formed. The number of "legs" is arbitrary, but for example, it includes four legs formed in a ring shape at predetermined intervals when viewed from above.

[0038] The "fitting recess" is formed on the side of the cover body portion between predetermined legs, protruding inward, and the "fitting claw portion" is formed further inward from the predetermined fitting recess. The "fitting recess" and the "fitting claw portion" are formed to correspond to the position of the smoke inlet of the smoke detector.

[0039] The "fitting recess" does not necessarily have to be formed between all the legs. For example, if four legs are formed at predetermined intervals in a ring shape in a plan view, the recess may be formed in all four locations between the legs, or it may be formed in two opposing locations between the legs. Similarly, the "fitting claw" does not necessarily have to be formed in all the fitting recesses. For example, if fitting recesses are formed at four locations between four legs formed at predetermined intervals in a ring shape in a plan view, the claw may be formed in all four fitting recesses, or it may be formed in two opposing fitting recesses.

[0040] The "stack recess" in the "stack structure" is formed on a predetermined leg and is a recess that protrudes from the lower surface of the leg to the lower surface of the cover body to a stack surface at a predetermined height. By aligning the position of the legs and then stacking the dust cover so that the stack surface of the stack recess contacts the lower surface of the leg of the dust cover located on the upper side of the cover body, a separation state is ensured.

[0041] Furthermore, while "stack recesses" do not necessarily need to be formed on all legs, if stack recesses are formed on more legs, the number of contact points between the stack surface of the stack recess and the lower surface of the dust cover legs located on the upper side of the cover body increases. This allows for more stable stacking of dust covers while maintaining a degree of separation.

[0042] Furthermore, while the "stack height" from the underside of the leg to the stacking surface of the stack recess is arbitrary, it defines the height gap between adjacent dust covers when dust covers are stacked, so it must be a height that ensures a gap sufficient to maintain separation. Note that the "stack height" does not need to be the same height as the height from the underside of the leg to the underside of the cover body.

[0043] Furthermore, if stack recesses are formed on each of the legs, and the positions of the recesses on the legs are different for each leg, the separated state can be ensured by stacking the dust covers so that the legs with stack recesses formed at different positions overlap by rotating the other dust cover to a predetermined angle relative to the other dust cover being stacked. For example, if the cover body has four legs formed in a ring shape at predetermined intervals in a plan view, the separated state can be ensured by rotating the other dust cover to 90°, 180°, or 270° relative to the other dust cover being stacked so that the legs with stack recesses formed at different positions overlap.

[0044] Furthermore, when dust covers are stacked so that legs with stack recesses formed in the same position overlap, the stack surfaces of the stack recesses come into contact with each other, resulting in a state where separation cannot be ensured (tight contact). The "stack structure" is designed to allow the user to choose whether to ensure separation or tight contact when stacking dust covers. Note that "tight contact" does not only mean a state where there is absolutely no gap between adjacent dust covers, but also includes a state where there is a gap that does not ensure separation.

[0045] Furthermore, a tapered surface is formed between the fitting recess and the lower surface of the cover body, sloping inward from top to bottom. This tapered surface reduces the height gap between adjacent dust covers when stacked, while still ensuring adequate spacing. This reduces the storage space required for stacked dust covers and allows for an increase in the number of dust covers that can be placed in a single packaging box when stacking them.

[0046] Furthermore, the "dustproof cover" has a laminated sheet structure in which a sheet of environmentally friendly resin, which is a mixture of a predetermined synthetic resin and a predetermined non-synthetic resin, is flanked on both sides by a sheet of a predetermined synthetic resin.

[0047] The synthetic and non-synthetic resins used as materials for "environmentally friendly resins" are optional. For example, polypropylene can be used as the synthetic resin and calcium carbonate as the non-synthetic resin. Other non-synthetic resins include starch and cellulose. By using environmentally friendly resins, the amount of petroleum-derived resins used can be reduced, contributing to a reduction in CO2 emissions. Furthermore, since synthetic resin sheets are placed on both sides of the sheet made of environmentally friendly resin, the environmentally friendly resin does not come into contact with the smoke detector to which the dust cover is attached. This prevents chemicals used in the manufacturing of the environmentally friendly resin sheet, or liquids from which components of the environmentally friendly resin have leached due to moisture such as condensation, from coming into contact with the smoke detector, thereby eliminating any impact on the smoke detector. In addition, by preventing the intrusion of material-specific powders such as paper dust generated from the mixed non-synthetic resin, it is possible to eliminate any impact on the smoke detector.

[0048] Furthermore, these environmentally friendly resins are softer than synthetic resins such as polystyrene used in conventional dust covers, and dust covers made with these resins may have reduced strength. Also, if the dust cover is manufactured using a vacuum molding method with a convex mold, the legs may become thinner depending on the shape, potentially reducing strength. In addition, as mentioned above, since the "dust cover" functions as cushioning material when packaged in a box while attached to a smoke detector, a certain degree of strength is required.

[0049] Therefore, by forming multiple "reinforcement ribs" that extend vertically on the sides of the legs, the strength of the dust cover can be reinforced.

[0050] Furthermore, in order to facilitate the attachment and removal of the dust cover and prevent dust and dirt adhering to the dust cover from entering the smoke detector through the smoke inlet, the "dust cover" is attached to the smoke detector by fitting recesses and fitting claws into the smoke inlet of the smoke detector, and can be removed from the smoke detector by applying rotational force to the legs around an axis in the vertical direction to release the fitting recesses and fitting claws.

[0051] Furthermore, since the installation environment of construction sites where smoke detectors are installed is often achromatic, such as black, gray, or white, the "dust cover" shall be a predetermined chromatic color different from the color of the installation environment where the smoke detector is installed, for example, a predetermined chromatic color belonging to the yellow family.

[0052] The following describes a specific embodiment. In the specific embodiment shown below, "legs" are formed at four locations on the lower side of the cover body, "fitting recesses" are formed at four locations on the side of the cover body between the legs, "fitting claws" are formed at two opposing fitting recesses, and "stack recesses" are formed on each of the legs, with the positions of the stack recesses on each leg being different.

[0053] [Specific details of the embodiment] The embodiments of the dust cover will be described in the following sections. a. Installation and removal of dust covers for smoke detectors. b. Structure of the dust cover c. Stacking dust covers d. Structure of a dust cover to ensure separation d1. Stack height d2. Tapered surface e. Laminated sheet structure using environmentally friendly resin and leg reinforcement structure f. Fitting structure of dust cover for smoke detector g. Anti-tipping structure for smoke detectors with dust covers installed h. Dust cover color i. Modified form of the present invention

[0054] [a. Installation and removal of dust covers for smoke detectors] First, we will explain how to attach and remove the dust cover to the smoke detector. In this explanation, please refer to Figure 1, which shows a smoke detector installed on the ceiling with an unattached dust cover; Figure 2, which shows a smoke detector with a dust cover attached; Figure 3, which shows the process of removing the dust cover from the smoke detector; and Figure 4, which shows the smoke detector with the dust cover removed.

[0055] In the explanation of Figure 1, the X, Y, and Z directions are mutually orthogonal. Specifically, when viewing the front view from the position where one fitting recess 22 on the dust cover 10 and one smoke inlet 1210 of the smoke detector 12 are centered, the X direction is the left-right direction, the Y direction is the up-down direction, and the Z direction, which is not shown in Figure 1, is the front-back direction. Furthermore, in the X direction, the +X side is the right side and the -X side is the left side, in the Y direction, the +Y side is the upper side and the -Y side is the lower side, and in the Z direction, the +Z side is the front side and the -Z side is the rear side. This is the same in Figures 2 to 6, 11 to 13, and 15.

[0056] As shown in Figure 1, for example, a ceiling member 14 is provided on the ceiling of a building construction site, and a detector base 13 for installing a smoke detector 12 is attached to the ceiling member 14. The smoke detector 12 is mechanically and electrically connected to the detector base 13 by fitting it into the detector base 13 from below and rotating it, and is installed on the ceiling member 14. The smoke detector 12 is transported to the construction site with a dust cover 10 attached, and is attached to the detector base 13 with the dust cover 10 attached. It is also possible to attach the dust cover 10 to the smoke detector 12 after it has been attached to the detector base 13.

[0057] Multiple smoke inlets 1210 are formed at predetermined intervals around the lower side of the smoke detector 12. In the embodiment shown in Figure 1, eight smoke inlets 1210 are formed in separate locations. In addition, an insect screen is arranged in a ring inside the smoke inlets 1210, and a smoke detection space is formed inside the insect screen, where a labyrinth structure (a light-shielding structure that allows smoke to pass through but blocks external light) is arranged in a ring.

[0058] The smoke detection space is provided with a scattered light detection structure in which a light-emitting unit and a light-receiving unit are positioned such that the light-receiving unit's optical axis is aligned with the light-emitting unit's optical axis at a predetermined scattering angle. The smoke detector 12 detects a fire based on the signal level of the received light signal, which is detected by the light-receiving unit receiving the scattered light generated by the irradiation of smoke from the light-emitting unit onto the smoke flowing into the smoke detection space.

[0059] The dust cover 10 comprises a cover body 18, legs 20, a fitting recess 22, and a fitting claw 24.

[0060] The cover body 18 covers the outside of the smoke detector 12, including the smoke inlet 1210, when the dustproof cover 10 is attached to the smoke detector 12, and has an opening at the top. It has a bowl-like shape with a circular opening at the top to correspond to the shape of the smoke detector 12. Furthermore, unlike the outer portion of the dustproof cover in Patent Document 1, which was cited as a conventional dustproof cover, the cover body 18 does not have a flange portion that protrudes outward from around the upper opening 1810, so that dust and dirt are less likely to accumulate on the dustproof cover 10.

[0061] The legs 20 are formed in four locations on the underside of the cover body 18, rotated 90° in a ring shape when viewed from above, so that they protrude below the underside (bottom) of the cover body 18.

[0062] The fitting recesses 22 are formed inwardly at four locations on the side of the cover body 18 between the leg portions 20. Some of the fitting recesses 22 have fitting claw portions 24 that extend further inward from the fitting recesses 22. The fitting claw portions 24 fit under the smoke inlet 1210 of the smoke detector 12, so that the dustproof cover 10 remains attached and does not fall naturally from the smoke detector 12 installed on the ceiling member 14, as shown in Figure 2. The detailed structure of the dustproof cover 10 will be described later.

[0063] Furthermore, the dust cover 10 is attached to the smoke detector 12, which reliably prevents dust and debris from the construction site from entering the smoke detector 12 through the smoke inlet 1201, causing clogging of the insect screen, affecting the detection sensitivity of the smoke detection section, and reducing its detection function.

[0064] Furthermore, when the construction of the building is completed and the smoke detector 12 is put into use, the dust cover 10 is removed from the smoke detector 12. To remove the dust cover 10, for example as shown in Figure 3, a rod-shaped member 16 of a predetermined length that reaches the dust cover 10 attached to the smoke detector 12 is brought into contact with one of the four legs 20 provided on the dust cover 10, and a rotational force is applied to the dust cover 10 around the Y axis. As shown in Figure 4, the dust cover 10 will detach from the smoke detector 12 and fall naturally.

[0065] [b. Structure of the dust cover] Next, the structure of the dust cover will be explained. In this explanation, please refer to Figure 5, which shows the dust cover viewed from the front; Figure 5, which shows the dust cover viewed from above (top); Figure 7, which shows the dust cover viewed from diagonally below; and Figure 8, which shows the dust cover viewed from diagonally above. In Figures 6 to 8, a reference position marker 15, indicated by "▼", is shown as a guide to the position of the dust cover 10 when viewed from the front in Figure 5.

[0066] The dust cover 10 is manufactured, for example, by a known molding method, and its thickness is approximately 0.2 to 0.3 mm. Furthermore, since the leg portion 20 is a deep-drawn shape and is prone to thinning, resulting in reduced strength, multiple reinforcing ribs 40 extending in the height direction (up and down direction) are formed on the leg portion 20 to increase its strength.

[0067] Furthermore, the cover body portion 18, legs 20, fitting recess 22, and fitting claw portion 24 of the dust cover 10 are basically as described above, and as shown in Figure 6, the fitting claw portion 24 is formed in the fitting recess 22 which is formed in two places, on the front and rear sides. When distinguishing the four legs 20, the right front leg is referred to as leg 20(20-1), the left front leg as leg 20(20-2), the left rear leg as leg 20(20-3), and the right rear leg as leg 20(20-4), and in Figures 5 to 12, they are referred to as legs 20(20-1) to 20(20-4).

[0068] Here, the reason why fitting claws 24 are not provided in the two fitting recesses 22 formed on the left and right sides is that the fitting claws 24 of the two fitting recesses 22 formed on the front and rear sides allow the dust cover 10 to be securely attached to the smoke detector 12 by fitting into the smoke inlet 1210, preventing it from falling off naturally. However, if it is desired to increase the fitting strength of the dust cover 10 to the smoke detector 12, fitting claws 24 may also be provided in the two fitting recesses 22 formed on the left and right sides.

[0069] Furthermore, as shown in Figures 6 to 8, since the legs 20 are formed at four locations on the lower side of the cover body 18, a circular bottom surface 26 is formed in the center of the bottom surface of the cover body 18, and a series of bottom surfaces 28 are formed that extend in four directions from the circular bottom surface 26 toward the fitting recess 22.

[0070] Furthermore, since the leg portion 20 is formed to protrude below the bottom surface of the cover body portion 18, the bottom surface of the leg portion 20 is located below the circular bottom surface 26 and the connected bottom surface 28 (the bottom surface of the cover body portion 18), and side walls of a predetermined height are formed at the boundary between the leg portion 20 and the circular bottom surface 26 and at the boundary between the leg portion 20 and the connected bottom surface 28.

[0071] Furthermore, tapered surfaces 35 are formed at the boundaries between the four fitting recesses 22 and the connected bottom surface 28, and tapered notched surfaces 34 are formed on both sides of the upper end of the fitting recesses 22. Details of the tapered surfaces 35 will be described later.

[0072] Furthermore, the dust cover 10 is characterized by having a stack structure that ensures a spaced state where other dust covers 10 do not interfere with the fitting claw portion 24 when the dust covers 10 are stacked. As shown in Figures 6 to 8, the stack structure has stack recesses 30 formed on each of the leg portions 20. When distinguishing between the four stack recesses 30, the stack recess formed on leg portion 20 (20-1) is called stack recess 30 (30-1), the stack recess formed on leg portion 20 (20-2) is called stack recess 30 (30-2), the stack recess formed on leg portion 20 (20-3) is called stack recess 30 (30-3), and the stack recess formed on leg portion 20 (20-4) is called stack recess 30 (30-4). In Figures 6 to 12, these are referred to as stack recesses 30 (30-1) to 30 (30-4).

[0073] The stack recess 30 extends from the bottom surface of the leg portion 20 toward the circular bottom surface 26 and the connected bottom surface 28 by a predetermined height. For example, the stack recess 30(30-1) and 30(30-2) are formed on the side walls at the boundary with the circular bottom surface 26 of the leg portions 20(20-1) and 20(20-2), and the stack recess 30(30-3) and 30(30-4) are formed on the side walls at the boundary with the connected bottom surface 28 of the leg portions 20(20-3) and 20(20-4).

[0074] Here, the positions in which the stack recesses 30(30-1) to 30(30-4) are formed for each of the legs 20(20-1) to 20(20-4) are all different. "The positions in which the stack recesses are formed for each leg are different" means that when the dust covers 10 are stacked by aligning the positions of the legs 20(20-1) to 20(20-4) which have different symbols, for example, when the dust covers 10 are stacked by aligning the position of the leg 20(20-2) of one dust cover 10 with the leg 20(20-1) of another dust cover 10, the stack recesses formed on the legs that are aligned at the same position will not overlap. For example, the stack recess 30(30-1) formed on the leg 20(20-1) of one dust cover 10 and the stack recess 30(30-2) formed on the leg 20(20-2) of the other dust cover 10 that are aligned at the same position will not overlap.

[0075] Furthermore, the stack height h of the stack recess 30 (height from the bottom surface of the leg portion 20 to the stack surface which becomes the top surface of the stack recess) is a predetermined height that does not exceed the height h0 from the bottom surface of the leg portion 20 to the circular bottom surface 26 and the connected bottom surface 28. When the dust covers 10 are stacked with the positions of the legs 20(20-1) to 20(20-4) which have different designations aligned, this height defines the gap in the height direction between adjacent dust covers 10. Therefore, this gap is set to a height that ensures a spaced state in which other dust covers 10 do not interfere with the fitting claw portion 24.

[0076] [c. Stacking dust covers] Next, we will explain how to stack the dust covers. For this explanation, please refer to Figure 9, which shows two dust covers in the same rotation position in a plan view, and Figure 10, which shows two dust covers in different rotation positions in a plan view.

[0077] For example, as shown in Figure 9, if dust covers 10(10-1) and 10(10-2) are stacked with the same rotational position, with dust cover 10(10-1) on the bottom and dust cover 10(10-2) on top, then the dust covers 10(10-1) and 10(10-2) will be stacked in such a way that the positions of the legs 20(20-1) to 20(20-4) with the same designation, such as the leg 20(20-1) of dust cover 10(10-1) and the leg 20(20-1) of dust cover 10(10-2), will align.

[0078] Therefore, as shown in Figure 9, when dust covers 10(10-1) and 10(10-2) are in the same rotational position, the positions of the stack recesses 30(30-1) to 30(30-4) of dust covers 10(10-1) and 10(10-2) align, and the stack surfaces of the stack recesses 30(30-1) to 30(30-4) come into contact with each other, causing them to stack on top of each other. As a result, dust covers 10(10-1) and 10(10-2) are stacked in a tightly packed state with no gaps in the height direction, ensuring that they are separated.

[0079] On the other hand, as shown in Figure 10, for example, if dust cover 10(10-2) is rotated 90° clockwise relative to dust cover 10(10-1), and dust covers 10(10-1) and 10(10-2) are stacked with dust cover 10(10-1) on the bottom and dust cover 10(10-2) on top, then the legs 20(20-1) of dust cover 10(10-1) and the legs 20(20-4) of dust cover 10(10-2) will be in contact. The dust covers 10(10-1) and 10(10-2) are stacked so that the positions of the legs 20(20-2) of bar 10(10-1) and the legs 20(20-1) of dust cover 10(10-2), the legs 20(20-3) of dust cover 10(10-1) and the legs 20(20-2) of dust cover 10(10-2), and the legs 20(20-4) of dust cover 10(10-1) and the legs 20(20-3) of dust cover 10(10-2) are aligned.

[0080] Therefore, as shown in Figure 10, when the dust covers 10(10-1) and 10(10-2) are in different rotational positions, each of the stacking surfaces of the stacking recesses 30(30-1) to 30(30-4) of the lower dust cover 10 will come into contact with one of the bottom surfaces of the legs 20(20-1) to 20(20-4) of the upper dust cover 10. As a result, a gap in the height direction corresponding to the stacking height h of the stacking recesses 30 will be created between the dust covers 10(10-1) and 10(10-2), and the dust covers 10(10-1) and 10(10-2) will be stacked while maintaining a separation between them.

[0081] Furthermore, as an example of the case where dust covers 10(10-1) and 10(10-2) are in different rotational positions, Figure 10 shows the case where dust cover 10(10-2) is rotated 90° clockwise relative to dust cover 10(10-1). The same applies when dust cover 10(10-2) is rotated 180° and 270° clockwise relative to dust cover 10(10-1), and it is possible to stack dust covers 10(10-1) and 10(10-2) while ensuring a separation.

[0082] Furthermore, in the manufacturing process of the dust covers, the dust covers are stacked, but the system is programmed to stack the dust covers alternately so that the dust covers 10(10-1) and 10(10-2) are in different rotational positions, for example, the rotational positions of dust covers 10(10-1) and 10(10-2) shown in Figure 10, and the system automatically stacks them, thereby ensuring that the dust covers are stacked while maintaining a separation between them.

[0083] [d. Structure of the dust cover to ensure separation] Next, the structure of the dust cover for ensuring the separated state will be described. In this description, refer to Figure 11, which schematically shows the fitting recess, fitting claw portion, and stacking recess of the dust cover; Figure 12, which schematically shows the fitting recess, fitting claw portion, and stacking recess when two dust covers are stacked; and Figure 13, which shows five dust covers stacked. Note that Figures 11 and 12 show the dust cover 10 in a transparent view from the right side.

[0084] (d1. Stack height) First, let's explain the stack height of the stack recess.

[0085] As described above, a stack recess 30 is formed in each of the legs 20, and the stack height h of the stack recess 30 is a predetermined height that does not exceed the height h0 from the bottom surface of the leg 20 to the circular bottom surface 26 and the connected bottom surface 28.

[0086] Furthermore, as shown in Figure 12, when dust cover 10(10-2) is rotated 90°, 180°, or 270° clockwise relative to dust cover 10(10-1), and stacked with dust cover 10(10-1) on the bottom and dust cover 10(10-2) on top, the stack surface of the stack recess 30 of dust cover 10(10-1) abuts against the lower surface of the leg portion 20 of dust cover 10(10-2), and a gap in the height direction corresponding to the stack height h is formed between dust covers 10(10-1) and 10(10-2). Note that in Figures 12 and 13, stack recesses 30(30-1) and 30(30-4) are shown as representative examples of the stack recess 30.

[0087] The gap in the height direction between the dust covers 10(10-1) and 10(10-2) corresponding to this stack height h needs to be high enough to ensure that the fitting claw portion 24 of the lower dust cover 10(10-1) does not interfere with the upper dust cover 10(10-2), as shown in the enlarged section of part A. Therefore, the stack height h must be a predetermined height that does not exceed the height h0 from the bottom surface of the leg portion 20 to the circular bottom surface 26 and the connected bottom surface 28, and must be high enough to ensure this separated state.

[0088] (d2. Tapered surface) Next, the tapered surface will be described. The tapered surface 35 formed at the boundary between the fitting recess 22 and the connected bottom surface 28 makes it possible to reduce the gap in the height direction of the dust cover corresponding to the stack height h.

[0089] Here, as shown in Figure 12, when dust covers 10(10-1) and 10(10-2) are stacked, if a tapered surface 35 is not formed at the boundary between the fitting recess 22 and the connected bottom surface 28, in order to ensure a separated state without interference with the fitting claw portion 24, the connected bottom surface 28 of the upper dust cover 10(10-2) must be positioned above the fitting claw portion 24 of the lower dust cover 10(10-1).

[0090] In other words, because a tapered surface 35 is formed at the boundary between the fitting recess 22 and the connected bottom surface 28, the gap in the height direction of the dust cover 10(10-1) and 10(10-2) can be reduced without interfering with the fitting claw portion 24, compared to the case where the tapered surface 35 is not formed, thereby ensuring a separated state. Furthermore, since the gap in the height direction of the dust cover 10(10-1) and 10(10-2) corresponds to the stack height h, the presence of the tapered surface 35 in the dust cover 10 reduces the stack height h, and the height h0 from the bottom surface of the leg portion 20 to the circular bottom surface 26 and the connected bottom surface 28 can also be set lower, making it possible to reduce the size of the dust cover 10.

[0091] Furthermore, the dust covers 10 are stacked in multiple layers, for example, during the manufacturing process or when they are being packaged. The gap in the height direction of the dust covers (stack height h) naturally affects the stacking height of the stacked dust covers 10. For example, in Figure 13, where five dust covers 10 are stacked, if the height of one dust cover 10 is H, the stacking height H of the stacked dust covers 10 is H + 4h. In the "4h" portion, which is four stack heights, the presence or absence of the tapered surface 35 makes a difference.

[0092] Furthermore, the position where the fitting claw portion 24 is formed relative to the fitting recess 22 also affects the gap in the height direction of the dust cover while ensuring a separated state. Since the fitting claw portion 24 is formed in approximately the lower half of the fitting recess 22, it is possible to reduce the gap in the height direction of the dust cover 10 and ensure a separated state without interfering with the fitting claw portion 24.

[0093] [e. Laminated sheet structure using environmentally friendly resin and leg reinforcement structure] Next, we will describe the laminated sheet structure using environmentally friendly resin and the leg reinforcement structure. In this description, please refer to Figure 14, which shows the laminated sheet structure using environmentally friendly resin and the leg reinforcement structure. Figure 14(A) shows the laminated sheet structure using environmentally friendly resin, and Figure 14(B) shows the leg reinforcement structure.

[0094] As shown in Figure 14(A), the dust cover 10 has a laminated sheet structure using environmentally friendly resin. The environmentally friendly resin layer 36 is a layer of resin obtained by mixing a predetermined synthetic resin such as polypropylene with a predetermined non-synthetic resin such as calcium carbonate, starch, or cellulose. For example, an environmentally friendly resin is used that contains 49% by weight of propylene and 51% by weight of calcium carbonate. By using such an environmentally friendly resin, the amount of petroleum-derived resin used can be reduced compared to conventional dust covers, contributing to the reduction of CO2 emissions.

[0095] Furthermore, the laminated sheet structure has a structure in which polypropylene layers 38 are arranged as synthetic resin on both sides of the environmentally friendly resin layer 36. When the dust cover 10 is attached to the smoke detector 12, the environmentally friendly resin layer 36 containing calcium carbonate does not come into direct contact with the smoke detector 12. This prevents chemicals used in the manufacture of the environmentally friendly resin layer 36, or liquids from which components of the environmentally friendly resin have leached out due to moisture such as condensation, from coming into contact with the smoke detector 12. This eliminates the impact on the smoke detector 12 caused by the leaching of components from the environmentally friendly resin due to moisture such as condensation that occurs in high-humidity spaces. In addition, the intrusion of material-specific powders such as paper dust generated from the mixed non-synthetic resins is prevented, thereby eliminating any impact on the smoke detector 12.

[0096] Furthermore, the dust cover, which has a laminated sheet structure consisting of an environmentally friendly resin layer 36 and a polypropylene layer 38, is heavier than the conventional dust cover made of polystyrene. The dust cover with the laminated sheet structure of the environmentally friendly resin layer 36 and polypropylene layer 38 weighs approximately 5.1 grams, while the dust cover made of polystyrene weighs approximately 3.7 grams. Therefore, as shown in Figure 4, when the dust cover 10 is removed from the smoke detector 12 and dropped, the dust cover 10 falls to a position close to the smoke detector 12 in a plan view, allowing for quick recovery of the removed dust cover 10.

[0097] Furthermore, as mentioned above, when the dust cover 10 is manufactured using a vacuum forming method with a convex mold, the legs 20 are easily made thin by deep drawing. In addition, since an environmentally friendly resin that is softer than the synthetic resins such as polystyrene that were conventionally used is used, the strength of the legs 20 will be further reduced.

[0098] Therefore, as shown in Figure 14(B), the strength of the leg portion 20 is reinforced by forming multiple reinforcing ribs 40 that extend in the height direction on the outer circumferential surface of the leg portion 20, which is a part that is prone to thinning.

[0099] [f. Fitting structure of dust cover for smoke detector] Next, the fitting structure of the dust cover to the smoke detector will be described. In this description, please refer to Figure 15, which schematically shows the fitting structure of the dust cover to the smoke detector. Figure 15 shows the dust cover 10 in a transparent view from the right side, and the cut end portion of the dust cover 10 is shown with a thick line to make the fitting state between the dust cover 10 and the smoke detector 12 easier to understand.

[0100] As shown in the enlarged section of part B in Figure 15, the upper part of the fitting recess 22 fits into the upper part of the smoke inlet 1210 and the fitting claw portion 24 fits into the lower part of the smoke inlet 1210, thereby fitting the dust cover 10 onto the smoke detector 12.

[0101] The fitting recess 22 determines the position of the dust cover 10 relative to the smoke detector 12 by restricting the rotation of the dust cover 10 around the Y axis, and the fitting claw portion 24 holds the dust cover 10 to prevent it from falling off the smoke detector 10 naturally.

[0102] As shown in Figure 3, when removing the dust cover 10 from the smoke detector 12, the rod-shaped member 16 is brought into contact with one of the legs 20, applying a rotational force around the Y-axis that exceeds the force restricted by the fitting recess 22. This deforms the side end of the fitting recess 22 in the direction of rotation, pushing it outwards from the side end of the smoke inlet 1210. As a result, the fitting recess 22 and the fitting claw portion 24, which were inserted into the smoke inlet 1210, detach from the smoke inlet 1210, causing the dust cover 10 to detach from the smoke detector 12 and fall. Furthermore, the tapered notch surface 34 formed in the fitting recess 22 makes it easier for the side end of the fitting recess 22 in the direction of rotation to be pushed outwards from the side end of the smoke inlet 1210.

[0103] By applying a rotational force around the Y-axis to the dust cover 10 in this way, the dust cover 10 can be removed from the smoke detector 12 without excessive deformation due to impact during removal, and dust and debris attached to the dust cover will not be blown around. This reliably prevents dust and debris from entering through the smoke inlet, causing clogging of the insect screen, affecting the detection sensitivity of the smoke detection unit, and reducing the detection function.

[0104] [g. Structure to prevent a smoke detector with a dust cover from tipping over] Next, we will explain the structure for preventing the smoke detector with a dust cover from tipping over. For this explanation, please refer to Figure 16, which shows the smoke detector with a dust cover attached in its boxed state and in a horizontal position. Figure 16(A) shows the smoke detector with a dust cover attached in its boxed state, and Figure 14(B) shows the smoke detector with a dust cover attached in a horizontal position.

[0105] As shown in Figure 16(A), the smoke detector 12 is packed in a packaging box 42 with the dust cover 10 attached and transported to the construction site. When packing the smoke detector 12 with the dust cover 10 attached into the packaging box 42, the smoke detector 12 is packed horizontally so that the top surface of the smoke detector 12 (the side that attaches to the detector base 13) is at a predetermined angle to the bottom surface of the packaging box, and the dust cover 10 also functions as cushioning material.

[0106] As described above, when packing the smoke detectors 12, the smoke detectors 12 with the dust cover 10 attached may be placed horizontally. Therefore, as shown in Figure 16(B), the smoke detectors 12 with the dust cover 10 attached are supported at three points: two of the four legs 20 that make contact with the workbench 44 (the surface on which the smoke detectors 12 with the dust cover 10 attached are placed), and P3 near the side wall on the opening side of the cover body 18. This makes it possible to keep the smoke detectors 12 with the dust cover 10 attached horizontally without them tipping over, thereby improving the work efficiency of packing and other operations.

[0107] [h. Dust cover color] Next, let's explain the color of the dust cover. The dust cover 10 is a predetermined chromatic color that is different from the color of the ceiling and walls of the construction site where the smoke detector 12 is installed. Here, since the ceiling and walls of the construction site where the smoke detector 12 is installed are often achromatic colors such as black, gray, or white, the dust cover 10 is a chromatic color that is different from the color of the installation environment, for example, a yellowish chromatic color.

[0108] Therefore, the dust cover 10 attached to the smoke detector 12 is conspicuously visible at the construction site, making it possible to prevent forgetting to remove the dust cover 10 and to easily retrieve the dust cover 10 if it falls off the smoke detector 12.

[0109] [i. Variations of the present invention] Modifications of the dust cover according to the present invention will now be described. In addition to the embodiments described above, the dust cover of the present invention includes the following modifications.

[0110] (leg) In the above embodiment, the legs are formed at four locations on the underside of the cover body, rotated 90° in a ring shape in a plan view. However, the embodiment is not limited to this, and for example, the legs may be formed at three locations on the underside of the cover body, rotated 120° in a ring shape in a plan view. If the legs are formed at three locations, for example, fitting recesses are formed at three locations between the legs, and fitting claws are formed in the three fitting recesses.

[0111] Furthermore, the number and position of the legs, fitting recesses, and fitting claws correspond to the number and shape of the smoke inlets formed in the smoke detector 12. A dust cover with legs and fitting recesses (fitting claws) formed in three locations by rotating them 120° in a ring shape corresponds to a smoke detector where, for example, the number of smoke inlets 1210 is a multiple of three, such as three or six.

[0112] (Color of the dust cover) In the above embodiment, the dust cover was made easily identifiable by using a predetermined chromatic color different from the color of the installation environment. However, a phosphorescent material may be added to the synthetic resin on the surface of the dust cover. This would make it even easier to identify the dust cover.

[0113] (Dust cover made with environmentally friendly resin) In the above embodiment, a laminated sheet structure using environmentally friendly resin is used, but it is not limited to this. A single-material environmentally friendly resin sheet material or a composite material of synthetic resin and environmentally friendly resin may be used as a single-layer sheet. In this case, since the dust cover comes into direct contact with the smoke detector, the influence of chemicals emitted from the environmentally friendly resin and components leached from the environmentally friendly resin due to condensation cannot be excluded, but it can be used if the influence of leached components is acceptable.

[0114] Furthermore, biodegradable resins (resins that decompose under specific conditions) and recycled resins may be used as environmentally friendly resins. For example, biomass-derived biodegradable resins include polylactic acid (PLA), polyhydroxyalkanoate (PHA), and polybutylene succinate (PBS), while fossil resource-derived biodegradable resins include polybutylene adipate terephthalate (PBAT) and polycaprolactone (PCL).

[0115] (others) Furthermore, the present invention includes appropriate modifications that do not impair its purpose and advantages, and is not limited by the numerical values ​​shown in the above embodiments. [Explanation of Symbols]

[0116] 10,10(10-1),10(10-2): Dust cover 12: Smoke detector 1210: Smoke inlet 13: Detector base 14: Ceiling components 15: Reference position marker 16: Rod-shaped member 18: Cover body 1810:Top opening 20,20(20-1)~20(20-4): Legs 22: Fitting recess 24: Fitting claw portion 26: Circular base 28: Continuous bottom surface 30,30(30-1)~30(30-4): Stack recess 34: Tapered notch surface 35: Tapered surface 36: Environmentally friendly resin layer 38: Polyprene layer 40: Reinforcement Ribs 42: Packaging box 44: Workbench

Claims

1. A dust cover that is attached to a smoke detector by fitting a fitting claw portion to at least the smoke inlet of the smoke detector, A dust cover characterized by having a stacking structure that ensures a spaced-out state where the fitting claws of dust covers do not interfere with each other when the dust covers are stacked.

2. A dust cover according to claim 1, A cover body that covers the outside of the smoke detector, including the smoke inlet, and has an opening on the upper side that faces the smoke detector to which it is mounted, Multiple legs are formed on the cover body at predetermined intervals in a ring shape in a plan view, so as to protrude below the lower surface of the cover body, A fitting recess is formed on the side surface of the cover body portion that is between the predetermined legs, and the fitting recess is formed to protrude inward. The fitting claw portion is formed by protruding further inward from the predetermined fitting recess, Equipped with, The stack structure is such that a stack recess is formed in a predetermined leg portion, extending from the lower surface of the leg portion to the lower surface of the cover body portion to a stack surface at a predetermined height. A dust cover characterized in that the separated state is maintained when dust covers are stacked such that the stack surface of the stack recess abuts against the lower surface of the leg portion of the dust cover located on the upper side of the cover body.

3. A dust cover according to claim 2, The stack recess is formed in each of the legs, and the position in which it is formed on each leg is different for each leg. A dust cover characterized in that the separated state is ensured by rotating one dust cover to a predetermined angle relative to the other dust cover to be stacked, so that the legs with stack recesses formed at different positions overlap.

4. A dust cover according to claim 3, The aforementioned legs are formed in four places on the cover body at predetermined intervals in a ring shape when viewed from above. A dust cover characterized in that the separation state is ensured by stacking the dust covers so that the legs with stack recesses formed in different positions overlap each other, by rotating one dust cover to 90°, 180°, or 270° relative to the other dust cover.

5. A dust cover according to claim 2, A dust cover characterized in that a tapered surface is formed between the fitting recess and the lower surface of the cover body, which is inclined inward from the top to the bottom.

6. A dust cover according to claim 1, A dust cover characterized by having a laminated sheet structure in which a sheet of environmentally friendly resin, which is a mixture of a predetermined synthetic resin and a predetermined non-synthetic resin, is flanked on both sides by a sheet of a predetermined synthetic resin.

7. A dust cover according to claim 6, The dust cover is characterized in that the specified non-synthetic resin contains any of calcium carbonate, starch, or cellulose.

8. A dust cover according to claim 2, A dust cover characterized by having multiple reinforcing ribs extending vertically formed on the side surface of the leg portion.

9. A dust cover according to claim 2, A dust cover characterized in that the fitting recess and the fitting claw portion are fitted into the smoke inlet of the smoke detector, thereby attaching it to the smoke detector, and the fitting recess and the fitting claw portion can be released by applying a rotational force to the leg portion about an axis in the vertical direction, thereby removing the dust cover from the smoke detector.

10. A dust cover according to claim 1, A dust cover characterized in that the dust cover is a predetermined chromatic color that is different from the color of the installation environment in which the smoke detector is installed.

11. A dust cover according to claim 9, A dust cover characterized in that the predetermined chromatic color is a predetermined chromatic color belonging to the yellow family.

Images