Fixing devices for roofing materials, etc.

Abstract

To provide a fixture for a roofing material or the like capable of preventing occurrence of deterioration of packings by preventing the mutual contact of two packings arranged by sandwiching a washer therebetween, and capable of maintaining both the suppression of vibration of a corrugated plate and water cut-off in an insertion hole part of the washer over a long period of time.SOLUTION: A fixture for a roofing material comprises a screw 5 provided with a head part 3 at one end of a shaft part 2 and a sharpened end 4 at the other end, and a washer 6 and a packing 7 attached to the shaft part 2 of the screw 5. The packing 7 is composed of a combination of an upper packing 7a externally fitted and attached to a position on the head part 3 side of the screw 5 and a lower packing 7b externally fitted and attached to a position on the sharpened end 4 side of the screw 5, which sandwich the washer 6 inserted into the shaft part 2 of the screw 5, with respect to the shaft part 2. The upper packing 7a and the lower packing 7b are different in hardness from each other, and the upper packing 7a is smaller in diameter than the lower packing 7b so that contact areas with the washer 6 are different from each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fastener for roofing materials, etc., which is mainly used for fastening corrugated sheets such as roofing materials. [Background technology]

[0002] Corrugated sheets used for building roofs have traditionally been made from a material called slate, which is made primarily from cement and mixed with fibers and admixtures. However, in recent years, sheets made from thin steel sheets (generally less than 1 mm thick) and resin materials have become more widely used due to the improved durability and corrosion resistance of synthetic resins.

[0003] Conventional fasteners used to secure such corrugated sheets to roof structures, as shown in Patent Documents 1 and 2, consist of a screw with a head at one end of the shank and a sharp tip at the other end, a washer shaped to circumscribe the outer surface of the crests of the corrugated sheet and with a through hole for the shank located in the center, and a gasket attached to the shank of the screw.The washer is placed on top of the crests of the corrugated sheet, and the screw that passes through this washer and the corrugated sheet is screwed into the roof structure.The corrugated sheet is fixed to the roof structure by being pressed down by the head of the screw via the washer, and the gasket is compressed between the washer and the corrugated sheet to waterproof the gap between the washer or the through hole in the corrugated sheet and the shank of the screw that passes through it.

[0004] Meanwhile, corrugated sheets made from thin steel sheets or synthetic resins are thinner, lighter, and more flexible than conventional slate corrugated sheets, making them easier to handle. Furthermore, even when subjected to external forces such as wind, they can flexibly deform and efficiently release the external forces they receive, effectively reducing damage not only to the corrugated sheets themselves but also to the underlying roof structure.

[0005] However, because corrugated sheets made from thin steel plates or synthetic resins are lightweight and flexible, they are prone to micro-vibrations when subjected to external forces such as wind. These micro-vibrations not only loosen the screws that fasten the corrugated sheets and generate noise, but the repeated dynamic distortion caused by the micro-vibrations also causes the gaskets that seal the washer insertion holes to deteriorate prematurely, leading to cracks in the gasket and creating new problems such as rainwater seeping into the interior of the roof through the gap between the screws and the gasket.

[0006] To address these issues, as in Patent Documents 1 and 2, fixing devices have been proposed that aim to improve watertightness and reduce compressive fatigue of the packing by combining and using packings of different hardness.

[0007] As mentioned above, it is known that by combining gaskets of different hardness, the range of vibration frequencies that can be absorbed is expanded, and as a secondary effect, a higher vibration-damping effect can be obtained compared to when a single gasket is used.By suppressing the vibration of the corrugated sheet, micro-vibrations can be suppressed, and deterioration due to dynamic distortion of the gasket and the occurrence of cracks can be reduced. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-336355 [Patent Document 2] Japanese Utility Model Application Publication No. 6-80020 Summary of the Invention [Problem to be solved by the invention]

[0009] Incidentally, when combining packings of different hardness, there are methods for changing the material hardness of the packing by changing the material of the combined packing or by combining the same material but formed through different processing or manufacturing processes, such as solid rubber and sponge rubber. In either case, if packings of different hardness are used in an arrangement where they are always in contact with each other, both before and during screw tightening, contact contamination or migration contamination will occur at the contact points between the packings because the vulcanization processes and additives of each material are different, which will cause the packing to deteriorate early and will give rise to new problems such as the occurrence of cracks.

[0010] Therefore, the object of this invention is to provide a fixing device for roofing materials, etc., which employs two gaskets for watertightness, arranges these gaskets between a washer, and prevents the two gaskets arranged via the washer from coming into contact with each other through the screw insertion holes provided in the washer before and after the screw is screwed in, thereby preventing deterioration of the gaskets and capable of maintaining both the suppression of vibration of the corrugated sheet and watertightness at the washer insertion hole portion for a long period of time. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, the invention of claim 1 is a roofing material fixing device consisting of a screw having a head at one end of the shank and a sharp tip at the other end, and a washer and gasket attached to the shank of the screw, wherein the washer has an insertion hole for the shank of the screw, and the gasket consists of an upper gasket that is fitted externally to the head side of the screw, sandwiching the washer inserted into the shank, and a lower gasket that is fitted externally to the sharp tip side of the screw, and the upper gasket and lower gasket have different hardnesses and a smaller diameter than the lower gasket so that they have different contact areas with the washer.

[0012] The invention of claim 2 is such that the washer has at least one pair of opposing side walls that surround the outer periphery of the lower gasket so that the deformation of the lower gasket is directed toward the axial direction of the screw when the screw is tightened.

[0013] The invention of claim 3 is such that the head of the screw has an annular protrusion on the outer periphery of the seating surface, and the upper gasket has an outer diameter that is the same as or smaller than the outer diameter of the head of the screw, and its outer periphery is set to an outer diameter within a range that allows it to be sandwiched between the annular protrusion and the washer.

[0014] The invention of claim 4 is such that the insertion hole provided in the washer is formed with a diameter that allows it to fit loosely onto the outer diameter of the shank of the screw, and the upper and lower gaskets have inner diameters that allow them to elastically fit onto the shank of the screw.

[0015] Here, the screw may have either a conical pointed end with threads formed on the outer surface or a structure equipped with cutting blades, and the shank has threads formed between the pointed end and the head, which is hexagonal or pan-shaped, and has an annular protrusion on the seat side arranged coaxially with the shank.

[0016] Furthermore, if the upper and lower packings are made of the same material, the hardness can be made different by varying the foaming conditions, or by making the upper packing out of EPDM rubber and the lower packing out of a single resin or a composite material made by impregnating a fiber material such as felt with resin, thereby making the hardness different. [Effects of the Invention]

[0017] According to this invention, an upper packing is fitted onto the shank of the screw at a position closer to the head of the screw and a lower packing is fitted onto the sharp end of the screw, with a washer inserted into the shank between them. As a result, the washer is positioned between the two packings, and the two packings do not come into contact with each other when the screw is not tightened, preventing contact contamination and migration contamination. Furthermore, the two packings have different hardnesses, and the upper packing has a smaller diameter than the lower packing so that the contact areas with the washers are different. As a result, when the screw is tightened, the upper packing is compressed while twisting in the direction of screw rotation, but this In this case, the upper packing expands and deforms in both the inward and outward directions due to compression, and when force is applied in the rotational direction, the applied force is directed from the center of rotation in the combined direction of the rotational direction and the radially outward direction (away from the axis of the screw), so the upper packing, which has a small amount of compressive deformation, naturally deforms so as to move away from the axis of the screw.This prevents the upper packing from entering the gap between the shank of the screw and the insertion hole of the washer, eliminates contact between the upper and lower packings, and prevents contact contamination and migration contamination of the upper and lower packings even when the screw is tightened, making it possible to achieve both vibration suppression and watertightness.

[0018] Furthermore, by making the hardness of the packings arranged above and below the washer different, the range of vibration frequencies that can be absorbed can be made wider than when a single packing is used.

[0019] Furthermore, by making the contact (pressure) area of ​​the upper and lower gaskets with the washer different, the pressure per unit area applied to each of the upper and lower gaskets when the screws are tightened is different, and when combined with the difference in hardness between the upper and lower gaskets, the range of vibration frequencies that the corrugated plate can more reliably absorb can be expanded. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a front view showing a state in which the fixture according to the present invention is disassembled into upper and lower parts; [Figure 2] An exploded perspective view of the upper and lower packings and washers of the fixture [Figure 3] A front view showing the state in which the corrugated sheet is fixed by the fixture [Figure 4] An enlarged front view of the main part of the fixture that secures the corrugated sheet, with a portion cut away. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0022] As shown in Figure 1, a fixing device 1 for roofing materials, etc., is composed of a screw 5 having a head 3 at one end of a shaft 2 and a sharp tip 4 at the other end, a washer 6 attached to the shaft 2 of the screw 5 and pressing and fixing the corrugated sheet a when the screw 5 is screwed in, and a packing 7 that waterproofs the washer 6 and the portion of the screw 5 that penetrates the corrugated sheet a.Two types of packing 7 are used: an upper packing 7a that is fitted externally to the shaft 2 of the screw 5 at a position on the head 3 side, with the washer 6 inserted into the shaft 2 between them, and a lower packing 7b that is fitted externally to the sharp tip 4 side of the screw 5.

[0023] In the screw 5, the shank 2 has a predetermined length, and its pointed end 4 is shown as a conical, screw-in type with a thread formed on the outer surface in the illustrated example, but it may also have a drilling type structure with a cutting blade, and a thread 8 is formed on the shank 2 between the pointed end 4 and the head 3, and the head 3 has a shape with a horizontal seat 3a on the underside, such as a hexagonal or pan shape with an engagement groove for a rotary tool, and on the outer periphery of the seat 3a, which forms the contact surface for the upper packing 7a, an annular protrusion 9 is provided coaxially with the shank 2 for compressing the upper packing 7a with the washer 6.

[0024] As shown in FIG. 4, the annular protrusion 9 protrudes radially outward from the outer periphery of the portion of the head 3 where the seating surface 3a is located, and the underside of the annular protrusion 9 protrudes downward beyond the seating surface 3a, forming a packing compression protrusion 9a whose cross-sectional shape is, for example, a downward-facing semicircular or triangular, with a step occurring between the underside of the packing compression protrusion 9a and the seating surface 3a.

[0025] The washer 6 is positioned on the crest of the corrugated sheet a, which is the roofing material, and is used to press and secure the corrugated sheet a to the roof structure by screwing in the screw 5. It is made of metal plate or a molded synthetic resin product, and its shape and size can be selected to suit the conditions of the part to be fixed. For example, those with a horizontally long rectangular or elliptical planar shape have an arc-shaped shape that circumscribes the outer surface of the crest of the corrugated sheet a. Also, those that are placed on the crest of the crest have an open trapezoidal or box-like shape on the bottom so that they can rest stably on the crest.

[0026] The washer 6 shown in the drawings is made of a metal plate with a horizontally elongated rectangular planar shape, and the central portion of the metal plate is curved in an arc shape in the longitudinal direction so that the peaks of the corrugated sheet a run parallel to one another, forming a pair of side walls 10 that extend downward in a V-shape on both sides, forming a mountain-like shape when viewed from the front. The central curved portion has a trapezoidal protrusion 6a that protrudes upward at its center, making the top and bottom surfaces horizontal, with the upper horizontal surface being the contact surface for the upper packing 7a and the lower horizontal surface being the contact surface for the lower packing 7b.

[0027] An insertion hole 11 for the shank 2 of the screw 5 is provided in the central portion of the protrusion 6a, and this insertion hole 11 has a diameter slightly larger than the thread 8 provided on the shank 2 of the screw 5 and a diameter smaller than the inner diameter of the packing compression protrusion 9a of the annular protrusion 9 provided on the head 3.

[0028] As mentioned above, the structure of washer 6 is not limited to the illustrated example. For example, in the case of a washer with an elliptical planar shape, the above-mentioned protrusion 6a can be omitted and the overlapping surface of the upper and lower packings can remain a simple arc surface. In this case, the washer has side walls on both sides along the long axis direction of the elliptical shape. Also, in the case of a box-shaped washer, a protrusion 6a similar to the illustrated example can be provided in the center of the top, and a side wall can be provided on this protrusion to surround the periphery of the lower packing.

[0029] In addition, at least one pair of side walls 10 provided on the washer 6 not only serves to circumscribe and hold the pressed-down corrugated sheet a, but also functions to direct the deformation of the lower gasket 7b sandwiched between the corrugated sheet a toward the axial direction of the screw 5 when the screw 5 is tightened, and is designed to surround the outer periphery of the lower gasket 7b at the part that smoothly transitions from the inner surface of the peripheral wall of the protrusion 6a to the inner surface of the side walls 10.

[0030] The upper gasket 7a and the lower gasket 7b are both formed in the shape of a disk with a mounting hole 12 passing through the center, the inner diameter of which is adapted to elastically fit onto the shank 2 of the screw 5, and the upper gasket 7a has a smaller diameter than the lower gasket 7b so that the contact areas with the washer 6 are different. The upper gasket 7a has a smaller diameter than the lower gasket 7b, and is the same as or smaller than the outer diameter of the head 3 of the screw 5, with the outer diameter set within a range such that its outer periphery can be sandwiched between the annular protrusion 9a and the washer 6.

[0031] In addition, it is desirable to set the outer diameter of the lower packing 7b to a diameter that is 1.4 times or more larger than the outer diameter of the upper packing 7a in order to reduce the compressive force per unit area and reduce deformation of the corrugated sheet a when compressed by tightening the screws 5.

[0032] The hardness of the upper packing 7a and the lower packing 7b described above is different from each other; specifically, the upper packing 7a is set to be harder than the lower packing 7b. Methods for making the hardness of the two different include, when the upper packing 7a and the lower packing 7b are made of the same material, making the degree of foaming of the two different to create a difference in hardness, or by forming the upper packing 7a from EPDM rubber and the lower packing 7b from a composite material in which a single synthetic resin or a fiber material such as felt is impregnated with resin.

[0033] Fastener 1 of the present invention has the above-described configuration, and is assembled by inserting upper gasket 7a, washer 6, and lower gasket 7b, in that order, onto shank 2 of screw 5, starting from the sharp end, as shown in Figure 3. When screw 5 is stored without being tightened, upper gasket 7a and lower gasket 7b do not come into contact with each other because washer 6 is sandwiched between them, preventing contact contamination or migration contamination between the two and enabling quality to be maintained for long periods of time.

[0034] Furthermore, when fixing the corrugated sheet a to a roof structure, a screw 5 is screwed into the top of the mountain shape of the corrugated sheet a, the screw 5 is passed through the corrugated sheet a, and a washer 6 is placed over the top of the mountain shape of the corrugated sheet a. By screwing the screw 5 into the roof structure, the lower gasket 7b is sandwiched between the washer 6 and the corrugated sheet a, and the upper gasket 7a is compressed between the head 3 of the screw 5 and the washer 6, so that the washer 6 presses down and fixes the corrugated sheet a.

[0035] First, when the screw 5 is tightened, the packing compression protrusion 9a of the annular protrusion 9 on the head 3 presses the upper packing 7a toward the washer 6 at a position near the outer periphery, and the upper packing 7a is compressed while being twisted in the rotational direction. In this case, the compression causes expansion and deformation in both the inward and outward directions, and when a force is applied in the rotational direction, the applied force is directed from the center of rotation in the combined direction of the rotational direction and the radially outward direction (away from the axis of the screw 5). Therefore, the upper packing 7a, which has a high hardness and a small amount of compressive deformation, naturally deforms away from the axis of the screw 5.

[0036] At this time, the packing compression protrusion 9a of the annular protrusion 9 on the head 3 of the screw 5 can apply concentrated pressure to the outer periphery of the upper packing 7a, and as a result, the upper packing 7a can be deformed significantly in the outward radial direction with a small amount of pressure.As the outer periphery of the upper packing 7a is pulled outward from the axis of the screw 5, the surrounding area of ​​the shank of the screw 5 is also pulled in the outer periphery direction, allowing the upper packing 7a to be reliably moved toward the outer periphery of the head 3 of the screw 5.As a result, the inner periphery of the upper packing 7a expands in diameter, moving away from the insertion hole 11 provided in the washer 6 and preventing it from coming into contact with the lower packing 7b by entering the gap between the shank 2 of the screw 5 and the insertion hole 11.

[0037] In addition, the outer periphery of the upper packing 7a is compressed by the packing compression protrusion 9a provided on the outer periphery of the seat surface 3a side of the head 3 of the screw 5 and the upper surface of the washer 6, so this compressed part surrounds the outside of the insertion hole 11 and provides a water-stopping function for the insertion hole 11 on the upper surface side of the washer 6.

[0038] Next, if the washer 6 rotates together with the upper gasket 7a when the screw 5 is tightened, the lower gasket 7b will also deform away from the axis of the screw 5, creating a gap between the shank 2 of the screw 5 and the lower gasket 7b, reducing the water-stopping function in that area.

[0039] To prevent this, based on the idea that the magnitude of the frictional force generated in materials that undergo elastic deformation, such as the rubber that forms the packing, depends on the size of the contact area with the object it comes into contact with, the contact area between lower packing 7b and washer 6 is made larger than the contact area between upper packing 7a and washer 6, and the frictional force between lower packing 7b and washer 6 is made larger than the frictional force between upper packing 7a and washer 6, thereby preventing washer 6 from rotating together with upper packing 7a due to deformation accompanied by twisting.

[0040] In this case, by making the outer diameter of the lower gasket 7b 1.4 times or more the outer diameter of the upper gasket 7a, when the screw 5 is tightened, the small-diameter upper gasket 7a is sufficiently crushed by the concentrated compression force applied thereto, and is able to deform significantly outward from the axis of the screw 5. At the same time, the large-diameter lower gasket 7b receives a larger area, so the compression force is distributed and the compression force per unit area can be reduced, thereby reducing the deformation of the lower gasket 7b. Furthermore, the compression force can also be distributed to the corrugated sheet a, reducing the compression force per unit area, thereby reducing the occurrence of deformation of the corrugated sheet a.

[0041] In addition, the washer 6 is provided with at least one pair of opposing side walls 10 that surround the outer periphery of the lower gasket 7b from at least both sides. As a result of compressive deformation, the lower gasket 7b attempts to deform evenly in both the inward and outward directions relative to the axis of the screw 5. However, the inner surfaces of the side walls 10, which transition smoothly from the inner surface of the protrusion 6a, guide the lower gasket 7b to deform only in the axial direction, thereby more reliably sealing off the water from the screw insertion holes 11 provided in the corrugated plate a and the washer 6.

[0042] Furthermore, by providing a side wall 10 on the side of the washer 6 facing the lower packing 7b, the contact area between the washer 6 and the lower packing 7b is increased, and the frictional force generated between the washer 6 and the lower packing 7b is further increased, making it possible to more reliably prevent the washer 6 from rotating together with the upper packing 7a.

[0043] In this way, the lower packing 7b is subjected to a compressive force over the entire wide surface, so the compressive force per unit area is very small, and just like the contact surface between the washer 6 and the lower packing 7b, the corrugated sheet a is also in contact with and pressed against the lower packing 7b over a surface that is larger than the contact area between the upper packing 7a and the head seat surface 3a of the screw 5, so the compressive force applied per unit area is small and the deformation of the corrugated sheet a when the screw 5 is tightened can be kept small.

[0044] In the above, when suppressing the movement that tends to vibrate the corrugated plate a, the effect can be increased by pressing down on the vibrating object over a wide area, so it is desirable that the lower gasket 7b has as large a diameter as possible, and it is also desirable that the upper gasket 7a has as small a diameter as possible to avoid the effects of sunlight (especially ultraviolet rays). [Explanation of symbols]

[0045] 1 Fixture 2 Shaft 3 head 3a Seat 4 Sharp tip 5 screws 6 Washers 6a Protrusion 7. Packing 7a Upper packing 7b Lower packing 8 threads 9 Annular protrusion 9a Packing compression protrusion 10 side wall 11 Insertion hole 12 Mounting holes a Corrugated sheet

Claims

1. A roofing material fixing device consisting of a screw with a head at one end of the shank and a sharp tip at the other end, and a washer and gasket attached to the shank of the screw, wherein the washer has an insertion hole for the shank of the screw, and the gasket consists of an upper gasket that is fitted onto the shank of the screw at the head side, with the washer inserted into the shank in between, and a lower gasket that is fitted onto the shank of the screw at the sharp tip side, and the upper gasket and lower gasket have different hardnesses and the upper gasket has a smaller diameter than the lower gasket so that they have different contact areas with the washer.

2. A roofing material fixing device as described in claim 1, characterized in that the washer has at least one pair of opposing side walls that surround the outer periphery of the lower gasket so that the deformation of the lower gasket is directed toward the axial direction of the screw when the screw is tightened.

3. A roofing material fixing device as described in claim 1 or 2, characterized in that the head of the screw has an annular protrusion on the outer periphery of the seat, and the upper gasket has an outer diameter that is the same as or smaller than the outer diameter of the head of the screw, and its outer periphery is set to an outer diameter in a range that allows it to be sandwiched between the annular protrusion and the washer.

4. A roofing material fixing device as described in any one of claims 1 to 3, characterized in that the insertion hole provided in the washer is formed with a diameter that fits loosely onto the outer diameter of the shank of the screw, and the upper gasket and lower gasket have an inner diameter that fits elastically onto the shank of the screw.

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