Cover and recording device using this cover

Abstract

Provided is a cover with which it is possible to improve the sealability of a gasket having a narrow-width section. A cover 19 is installed in an opening 17a in a base 17 of a housing 3 for housing an internal mechanism 5 in a space 3a, and the cover closes off the space 3a. The cover comprises: an outer peripheral section 19a that is received in the base 17; and a gasket 29 that is provided stretched in a circuiting form along the outer peripheral section 19a and that, protruding from the outer peripheral section 19a, is compressed by abutting on the base 17. The gasket 29 is provided with a broad-width section 31 the width of which across the inside and outside of the circuiting form is relatively large, and a narrow-width section 33 the width of which is relatively small, the narrow-width section 33 being given bulk along the direction of compression of the gasket 29 by a layered structure having a bulk-adding layer.

Description

Technical Field

[0001] The present invention relates to a cover for a recording device such as a hard disk drive and a recording device using the cover.

Background Art

[0002] A hard disk drive as a recording device houses an internal mechanism including a disk as a recording medium in a space portion, and airtightness is required so that dust, moisture, etc. do not enter the space portion.

[0003] In order to ensure such airtightness, it is common to provide a gasket between the base and the cover of the housing that partitions the space portion (for example, Patent Document 1). The gasket is provided in a circular shape along the outer peripheral portion of the cover that is received by the base, and is compressed and interposed between the cover and the base.

[0004] Due to space constraints, this gasket may sometimes have a narrow portion with a reduced width that partially extends around the inside and outside. The narrow portion can be easily set by changing the discharge conditions such as the discharge amount when applying a liquid gasket discharged from an applicator such as a needle to the cover and curing it.

[0005] However, since the protruding height from the cover is determined to some extent according to the width when the liquid gasket is discharged, the protruding height of the narrow portion becomes smaller compared to other parts of the gasket. As a result, the narrow portion may reduce the airtightness of the gasket.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem we are trying to solve is that the protrusion height becomes small in the narrow section of the gasket, which could lead to a decrease in sealing performance. [Means for solving the problem]

[0008] The present invention provides a cover that is attached to an opening in the base of a housing that houses an internal mechanism within a space, and that closes the space. The cover comprises an outer periphery that is received by the base, and a gasket that extends circumferentially along the outer periphery, protruding from the outer periphery and being compressed by contact with the base. The gasket comprises a wide portion with a relatively large width and a narrow portion with a relatively small width over the inner and outer sides of the circumferential shape. The narrow portion is raised in the compression direction of the gasket by a layer structure having a raising layer. The wide portion and the narrow portion are adjacent to each other in the extending direction of the gasket and each has a tip portion that abuts against the base. .

[0009] Furthermore, the present invention provides a recording device using the above-described cover. This recording device comprises a base that, together with the cover, constitutes a housing and houses an internal mechanism within a closed space. The base comprises an opening to which the cover is attached and a cover receiving portion that receives the outer periphery of the cover with the gasket interposed therebetween. [Effects of the Invention]

[0010] According to the present invention, the protrusion height of the gasket in the compression direction in the narrow width portion can be increased by raising the gasket, thereby improving the sealing performance of the gasket. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a plan view of a recording device according to Embodiment 1 of the present invention. [Figure 2] Figure 2(A) is a schematic cross-sectional view of the recording device shown in Figure 1 along line II-II, and Figure 2(B) is a schematic cross-sectional view of a modified example. [Figure 3] Figures 3(A) and 3(B) are schematic cross-sectional views showing an enlarged portion of Figure 2(A). [Figure 4]Figure 4 is a bottom view of the cover of the recording device shown in Figure 1. [Figure 5] Figure 5(A) is a bottom view of the cover showing the area around the narrow portion of the gasket provided on the cover in Figure 4, and Figure 5(B) is a cross-sectional view relating to the VV line in Figure 5(A). [Figure 6] Figure 6(A) is a cross-sectional view of the VIA-VIA line in Figure 5(A), and Figure 6(B) is a cross-sectional view of the VIB-VIB line in Figure 5(A). [Figure 7] Figure 7 is a graph showing an example of the correlation between gasket width and protrusion height in a single layer. [Figure 8] Figure 8(A) is a cross-sectional view relating to Embodiment 2 of the present invention, showing the area around the narrow portion of the gasket, and Figure 8(B) is a cross-sectional view along the line VIII-VIII in Figure 8(A). [Figure 9] Figure 9 is a cross-sectional view showing the area around the narrow portion of the gasket according to Embodiment 3 of the present invention. [Figure 10] Figure 10(A) is a bottom view of the cover showing the area around the narrow portion of the gasket according to Embodiment 4 of the present invention, and Figure 10(B) is a cross-sectional view along line XX in Figure 10(A). [Figure 11] Figure 11 is a cross-sectional view of a modified gasket according to Example 4. [Modes for carrying out the invention]

[0012] The objective of improving the airtightness of a gasket with a narrow section was achieved by raising the narrow section.

[0013] As shown in the figure, the cover 19 is attached to the opening 17a of the base 17 of the housing 3 that houses the internal mechanism 5 within the space 3a to close the space 3a. This cover 19 includes an outer peripheral portion 19a that is received by the base 17, and a gasket 29 that extends circumferentially along the outer peripheral portion 19a and protrudes from the outer peripheral portion 19a and is compressed by abutting against the base 17. The gasket 29 includes a wide portion 31 with a relatively large width extending across the circumference inside and outside, and a narrow portion 33 with a relatively small width. The narrow portion 33 is raised in the compression direction of the gasket 29 by a layer structure having a raised layer 35 or 37.

[0014] The narrow portion 33 includes a first layer 35 as a raised layer and a second layer 37 laminated on the first layer 35. The wide portion 31 may be integrally formed with the second layer 37 of the narrow portion 33. In this case, between the second layer 37 of the narrow portion 33 and the wide portion 31, it may be configured to include a transition portion 39 where the width and the height in the compression direction of the gasket 29 gradually decrease from the wide portion 31 toward the narrow portion 33.

[0015] The end portion 35a of the first layer 35 of the narrow portion 33 in the extending direction of the gasket 29 may be located within the transition portion 39, and may be configured such that the width and the height in the compression direction gradually increase as it moves away from the wide portion 31 in the extending direction.

[0016] The wide portion 31 can be single - layer or multi - layer. In the case of a multi - layer, it may include a first layer 41 and a second layer 43 that are respectively integral with the first layer 35 and the second layer 37 of the narrow portion 33. In this case, the second layer 43 of the wide portion 31 may be configured to enclose the first layer 41 of the wide portion 31.

[0017] The narrow portion 33 may use the second layer 37 as a raised layer. In this case, the first layer 35 is integrally formed with the wide portion 31, and the second layer 37 is laminated on the first layer. A transition portion may be provided between the first layer 35 of the narrow portion 33 and the wide portion 31. The end portion 37a of the second layer 37 of the narrow portion 33 in the extending direction of the gasket 29 may be located on the transition portion 39, and the width and the height in the compression direction may gradually increase as it moves away from the wide portion 31 in the extending direction.

[0018] The small-width portion 33 and the large-width portion 31 may be eccentric in the width direction. Also, the first layer 35 and the second layer 37 of the small-width portion 33 may be eccentric in the width direction.

[0019] The recording apparatus 1 using the cover 19 constitutes the housing 3 together with the cover 19 and includes a base 17 that houses an internal mechanism 5 in a closed space portion 3a. The base 17 includes an opening 17a to which the cover 19 is attached and a cover receiving portion 25 that receives the outer peripheral portion 19a of the cover 19 with a gasket 29 interposed therebetween.

Example

[0020] [Configuration of Recording Apparatus] FIG. 1 is a plan view of a recording apparatus according to Embodiment 1 of the present invention. FIG. 2(A) is a schematic cross-sectional view taken along line II-II of the recording apparatus of FIG. 1, and FIG. 2(B) is a schematic cross-sectional view according to a modified example. FIGS. 3(A) and 3(B) are schematic cross-sectional views showing an enlarged part around the gasket on both sides of FIG. 2(A).

[0021] The recording apparatus 1 of the present embodiment is a hard disk drive as a magnetic disk apparatus, and houses an internal mechanism 5 in a space portion 3a in the housing 3.

[0022] The internal mechanism 5 includes, in addition to a disk 7 as a recording medium, a spindle motor 9 and the like. The disks 7 are stacked in a plurality in the thickness direction (hereinafter simply referred to as the "thickness direction") of the recording apparatus 1 and are configured to be rotatably supported by a spindle motor 9. Information is read and written to and from these disks 7 through a head (not shown).

[0023] Note that the recording device 1 is not limited to a magnetic disk drive, but may be other disk drives such as an optical disk drive, or other recording devices other than disk drives. For example, the recording device 1 may be a tape-embedded drive as shown in Figure 2(B). In this recording device 1, the tape film 13 as a recording medium wound between two tape reels 11 and the head assembly 15 for reading and writing information are housed as an internal mechanism 5 in the space 3a of the housing 3.

[0024] The housing 3 consists of a base 17 and a cover 19, and seals or encloses the inside.

[0025] The base 17 is made of a metal such as aluminum and is constructed in a box shape with an opening 17a on one side in the thickness direction. The base 17 only needs to be box-shaped capable of housing the internal mechanism 5 including the disk 7, and can be any shape to that extent. In this embodiment, the base 17 is, for example, substantially rectangular in plan view. Note that "plan view" means the view from the thickness direction and does not distinguish between the top surface and the bottom surface.

[0026] The base 17 is closed by attaching a cover 19 to one of the openings 17a in the thickness direction. This seals the space 3a within the housing 3 that houses the internal mechanism 5. This sealed space 3a may be filled with a gas that has less resistance than air, such as helium.

[0027] The outer periphery of the base 17 is provided with a side wall portion 21a in a circular manner, and the opening 17a of the base 17 is demarcated by the side wall portion 21a. The outer periphery of the base 17 is the outer periphery region surrounding the internal mechanism 5, and in this embodiment, it refers to the portion where the side wall portion 21a is provided.

[0028] The side wall portion 21a is integrally erected from the plate-shaped bottom wall portion 21b of the base 17. However, the side wall portion 21a can also be formed integrally by joining separately formed parts to the bottom wall portion 21b of the base 17.

[0029] This side wall portion 21a is provided with a fastening portion 23 and a cover receiving portion 25.

[0030] The fastening portion 23 of the base 17 is the portion that fastens the cover 19 to the base 17. In this embodiment, there are multiple fastening portions 23, for example, six, spaced apart in the circumferential direction of the base 17. The fastening portions 23 may also be formed in a circumferential shape along the outer circumference of the base 17. The circumferential direction of the base 17 refers to the circumferential direction along the side wall portion 21a of the base 17.

[0031] The fastening portion 23 receives the cover 19 by joining it in the thickness direction. In this joined state, the cover 19 is fastened to the fastening portion 23 by fasteners, such as bolts 27. The cover 19 is also fastened to the spindle motor 9 by bolts 27. In addition to bolts 27, rivets or the like may be used as fasteners.

[0032] The cover support portion 25 receives the outer periphery 19a of the cover 19, with the gasket 29 attached to the cover 19 interposed between them. This compresses the gasket 29 in the thickness direction between the cover support portion 25 and the cover 19.

[0033] In this embodiment, the cover receiving portion 25 is provided in a circumferential manner in plan view along the side wall portion 21a of the base 17. However, the cover receiving portion 25 may be provided only partially on the outer periphery of the base 17.

[0034] The cover receiving portion 25 has a receiving surface 25a that is flat along the width direction. The gasket 29 is brought into contact with this receiving surface 25a to receive the outer periphery 19a of the cover 19. Note that the receiving surface 25a does not have to be flat; it may have irregularities such as bumps or ridges as long as the gasket 29 can be brought into contact with it.

[0035] Figure 4 is a bottom view of the cover of the recording device shown in Figure 1.

[0036] The cover 19 is made of a metal plate such as aluminum, as shown in Figures 1 to 4. The cover 19 is formed as a flat plate that covers the opening 17a of the base 17 as a whole. In this embodiment, the cover 19 has a substantially rectangular shape in plan view, corresponding to the base 17. However, the shape and other forms of the cover 19 are not particularly limited as long as they cover the opening 17a of the base 17. The material of the cover 19 is also arbitrary.

[0037] The cover 19 covers the opening 17a of the base 17, with its outer periphery 19a supported by the base 17. Specifically, the outer periphery 19a of the cover 19 is supported in the thickness direction by the cover receiving portion 25 of the base 17. The outer periphery 19a is a circumferential portion supported by the base 17. A sealing gasket 29 is attached to the outer periphery 19a of the cover 19.

[0038] The gasket 29 extends circumferentially along the outer circumference 19a of the cover 19. The gasket 29 protrudes in the thickness direction from the outer circumference 19a and is compressed by contact with the base 17. Specifically, the gasket 29 protruding from the outer circumference 19a of the cover 19 contacts the cover receiving portion 25 of the base 17 and is compressed and interposed between the base 17 and the cover 19 as the cover 19 is fixed to the base 17.

[0039] In this embodiment, the protrusion direction and compression direction of the gasket 29 coincide with the thickness direction, but they can be different. Furthermore, while it is preferable that the protrusion direction and compression direction of the gasket 29 coincide, they can be different as long as the gasket 29 is convex relative to the cover 19 in the compression direction and sealing can be ensured by compression. In this embodiment, the protrusion direction and compression direction will be described as the thickness direction.

[0040] The compressed gasket 29 seals the space between the cover 19 and the base 17. In this embodiment, the gasket 29 is compressed between the cover 19 and the cover receiving portion 25 of the base 17, sealing the space between the cover 19 and the cover receiving portion 25.

[0041] In this embodiment, the gasket 29 is a liquid gasket such as FIPG (Foamed In Place Gasket). That is, the gasket 29 is pre-applied to the outer circumference 19a of the cover 19 by dispensing from an applicator such as a needle and then fixed in place by curing.

[0042] Figure 5(A) is a bottom view of the cover 19 showing the area around the narrow portion of the gasket provided on the cover 19 in Figure 4, and Figure 5(B) is a cross-sectional view of the VV line in Figure 5(A). Figure 6(A) is a cross-sectional view of the VIA-VIA line in Figure 5(A), and Figure 6(B) is a cross-sectional view of the VIB-VIB line in Figure 5(A).

[0043] Figure 5(B) shows a cross-section of the gasket 19 along its extension direction and thickness direction, while Figures 6(A) and (B) show a cross-section perpendicular to the extension direction of the gasket 19. Furthermore, Figures 6(A) and (B) show the relationship between the first layer 35, the second layer 37, and the transition section 39 of the narrow section 33, and the cross-section of the narrow section 33 is given a conceptual, angular shape.

[0044] The gasket 29 in this embodiment includes a wide portion 31 and a narrow portion 33.

[0045] The wide portion 31 is the part of the gasket 29 that has a relatively large width both inside and outside its circumference, and the narrow portion 33 is the part of the gasket 29 that has a relatively small width both inside and outside its circumference. Adjacent wide portions 31 and narrow portions 33 are arranged concentrically in the width direction. Concentric means that the centers of the wide portion 31 and narrow portion 33 in the width direction coincide in the width direction.

[0046] Note that the widths of the narrow section 33 and the wide section 31 refer to the largest width (maximum width) within the narrow section 33 and the wide section 31, respectively, but they may also refer to the smallest width (minimum width) or the average width. Within the wide section 31 and the narrow section 33, the width is constant in the extension direction, but it may be varied in the extension direction.

[0047] The narrowed portion 33 is formed by reducing the width of a part of the gasket 29 in the extending direction due to space constraints such as avoiding interference with the internal mechanism 5. One or more narrowed portions 33 are provided in the extending direction.

[0048] This narrow section 33 is raised in the thickness direction, which is the compression direction of the gasket 29, by a layer structure having a raising layer. Raising means making the narrow section 33 higher in the thickness direction compared to the wide section 31, which has the same number of layers. The number of layers here refers to the number of layers stacked on top of one layer, and does not include the number of layers embedded. An embedded layer is a multi-layer structure, but one layer is embedded within another layer, and in terms of the number of layers, it is a single layer made up of one layer. Therefore, the narrow section 33 has a greater number of layers than the wide section 31, including the raising layer.

[0049] With this configuration, fluctuations in the protrusion height in the thickness direction are suppressed between the narrow portion 33 and the wide portion 31 when the gasket 29 is in a free state. This makes it possible to improve the sealing performance of the gasket 29. The protrusion height refers to the height in the thickness direction, which is the direction in which the gasket 29 protrudes from the cover 19.

[0050] In this embodiment, the protruding height of the gasket 29 is the same between the narrow portion 33 and the wide portion 31 in the free state. However, the protruding height of the gasket 29 can be greater or less than that of the wide portion 31 in the narrow portion 33. The free state is the unloaded state in which no compressive load is acting on the gasket 29, and in this embodiment, it is the pre-closed state before the opening 17a of the base 17 is closed by the cover 19.

[0051] In this embodiment, the wide section 31 is single-layered, and the narrow section 33 is multi-layered, specifically two-layered. However, the number of layers of the wide section 31 and the narrow section 33 can be arbitrarily set as long as the narrow section 33 can be raised. Note that the single layer of the wide section 31 here refers to a single layer in terms of layer structure and number of layers, unlike the term "internal construction". Similarly, when simply referred to as "single layer," it refers to a single layer in terms of layer structure and number of layers.

[0052] The width and height of the single-layer wide section 31 are set when the liquid gasket is dispensed from the needle. Note that when simply referring to height, it refers to the dimension in the thickness direction, which is the compression direction, and is different from the protruding height from the cover 19 (the same applies hereinafter). The width and height of the liquid gasket when dispensed from the needle and hardened have a correlation that prevents either one from being made larger or smaller than the other within the single layer. The width and height of the wide section 31 are set according to this correlation.

[0053] Figure 7 shows an example of the correlation between the width and height of a single-layer gasket. In the example in Figure 7, different correlations C1 and C2 for width and height can be obtained by changing the discharge conditions, such as the amount of liquid gasket discharged, the needle's movement speed, and the distance between the coating surface of the cover 19 and the applicator. The width (and height) of the wide portion 31 is adjusted within the range between these correlations C1 and C2. Note that the needle's movement speed refers to the movement speed in the extension direction.

[0054] The two-layered narrow section 33 comprises a first layer 35 and a second layer 37.

[0055] The first layer 35 is a layer that contacts the cover 19 in the narrow portion 33 and functions as a raising layer. The second layer 37 is a layer laminated on the first layer 35 in the thickness direction. The second layer 37 is arranged concentrically with the first layer 35 in the width direction.

[0056] The first layer 35 and the second layer 37 consist of liquid gasket made of the same material. However, the first layer 35 and the second layer 37 may be liquid gaskets made of different materials. When the liquid gasket is dispensed from the needle and applied to the cover 19, the width and height of both the first layer 35 and the second layer 37 are set in the same way as the wide portion 31.

[0057] In the application of the first layer 35 and the second layer 37, the second layer 37 is applied together with the wide portion 31 after the first layer 35 has been applied. When there are multiple narrow portions 33, the first layer 35 is applied at the positions corresponding to each narrow portion 33. The second layer 37 is applied by changing the protrusion conditions at the positions corresponding to the narrow portions 33, along with the application of the wide portion 31. After that, the entire gasket 29 is cured. Alternatively, the first layer 35 may be cured after application, and the wide portion 31 and the second layer 37 may be cured separately after application.

[0058] Thus, the second layer 37 is formed integrally with the wide portion 31 and has a constant width and height. Because the second layer 37 is formed integrally with the wide portion 31, fluctuations in the protruding height of the gasket 29 can be suppressed, improving the sealing performance. Furthermore, a transition portion 39 is provided between the wide portion 31 and the second layer 37 of the narrow portion 33, and the transition portion 39 allows for a smooth transition between the wide portion 31 and the second layer 37 of the narrow portion 33, suppressing fluctuations in the protruding height of the gasket 29 and improving the sealing performance. Note that the transition portion 39 can be omitted.

[0059] The transition section 39 gradually decreases in width and height from the wide section 31 to the narrow section 33. Gradual decrease in width and height means that the width and height decrease continuously or in steps. In this embodiment, the transition section 39 decreases in width continuously in a linear shape with both sides in the width direction being inclined, and the height decreases continuously in a parabolic shape, but the shape can be arbitrarily set.

[0060] For example, both the width and height of the transition section 39 may decrease in a parabolic or linear manner. Alternatively, the gradually decreasing width and height may be a shape in which multiple sections with continuously decreasing width and height are connected by sections with constant width and height, or a shape in which multiple sections with constant but different widths and heights are connected.

[0061] The extension end 35a of the first layer 35 is located within the transition section 39. Unlike the transition section 39, the width and height of this end 35a gradually increase as it moves away from the wide section 31 in the extension direction. This makes it possible to suppress fluctuations in the protruding height of the gasket 29 together with the transition section 39.

[0062] Gradual increase in width and height means that the width and height increase continuously or in steps. In this embodiment, the width and height increase continuously in a parabolic shape, but they may also increase continuously in a linear shape. Furthermore, a shape in which the width and height increase gradually may be a shape in which multiple parts with continuously increasing width and height are connected by parts with constant width and height, or a shape in which multiple parts with constant width and height but different widths and heights are connected.

[0063] The width and height of the first layer 35, excluding the end portion 35a, are the same and constant as those of the second layer 37. Therefore, in the width direction, the edges of the first layer 35 and the second layer 37 coincide. However, the width and height of the first layer 35, excluding the end portion 35a, do not need to be the same as those of the second layer 37; they may be larger or smaller than those of the second layer 37.

[0064] In any case, the difference in protruding height between the narrow portion 33 and the wide portion 31 should be smaller than in the case where there is no rise due to the first layer 35. This is because it is preferable to suppress the height variation between the narrow portion 33 and the wide portion 31 in order to ensure the airtightness of the gasket 29.

[0065] [Manufacturing of recording devices] In this embodiment, the recording device 1 is manufactured by attaching a cover 19 to the base 17 of the housing 3 that houses the disk 7, thereby closing the space 3a of the housing 3 that houses the disk 7.

[0066] In other words, the cover 19 with the gasket 29 attached is positioned facing the opening 17a of the base 17 in the thickness direction. In this state, the cover 19 and the base 17 are brought close to each other, and the tip of the gasket 29 is brought into contact with the cover receiving portion 25 of the base 17.

[0067] When the cover 19 and base 17 are brought closer together, the gasket 29 is compressed between the cover 19 and the base 17. In this embodiment, since the protruding height of the narrow portion 33 of the gasket 29 is increased by raising it, it is sufficiently compressed not only in the wide portion 31 but also in the narrow portion 33. Therefore, the overall airtightness of the gasket 29 can be improved.

[0068] Furthermore, in this embodiment, since the second layer 37, which forms the surface of the narrow portion 33, and the wide portion 31 are integrated, the tip of the gasket 29 is smooth between the narrow portion 33 and the wide portion 31. Therefore, the gasket 29 can improve its sealing performance.

[0069] Furthermore, in this embodiment, the transition section 39 between the second layer 37 of the narrow section 33 and the wide section 31 gradually decreases in width and height toward the narrow section 33. On the other hand, the end portion 35a of the first layer 35 of the narrow section 33 is located within the transition section 39, and its width and height gradually increase as it moves away from the wide section 31 in the extending direction. As a result, fluctuations in the protruding height of the gasket 29 are more reliably suppressed, improving the sealing performance.

[0070] Subsequently, the cover 19 is fastened to the base 17 with bolts 27, closing the space 3a of the housing 3 that houses the disc 7. [Examples]

[0071] Figure 8(A) is a cross-sectional view relating to Embodiment 2 of the present invention, showing the area around the narrow portion of the gasket, and Figure 8(B) is a cross-sectional view along the line VIII-VIII in Figure 8(A). In Embodiment 2, the basic configuration is the same as that of Embodiment 1, so the same reference numerals are used for corresponding components, and redundant explanations are omitted. Figure 8(A) is a cross-section along the extension direction of the gasket. Also, Figure 8(B) shows a conceptual representation of the cross-section of the wide portion 31 with sharp corners.

[0072] In this embodiment, the wide portion 31 of the gasket 29 is made of multiple layers. That is, the wide portion 31 comprises a first layer 41 and a second layer 43.

[0073] The first layer 41 of the wide section 31 is integrally and continuously formed with the first layer 35 of the narrow section 33, and has the same width and height as the first layer 35 of the narrow section 33. However, the width and height of the first layer 41 of the wide section 31 do not need to be the same as those of the narrow section 33.

[0074] The second layer 43 of the wide portion 31 has the same width and height as the wide portion 31 of Example 1 and encloses the first layer 41. Therefore, the second layer 43 of the wide portion 31 has the first layer 41 embedded in it, and from the viewpoint of the number of layers, it is a single layer.

[0075] The second layer 43 of the wide section 31 is integrally formed with the second layer 37 of the narrow section 33 and is continuous with the second layer 37 of the narrow section 33 via a transition section 39. Similar to Embodiment 1, the width and height of the transition section 39 gradually decrease toward the narrow section 33. The other configurations are the same as in Embodiment 1.

[0076] In this embodiment 2, in addition to achieving the same effects as in embodiment 1, the first layers 41 and 35 of the wide portion 31 and the narrow portion 33 can be formed together in a continuous circumferential manner, making it easier to form the gasket 29. [Examples]

[0077] Figure 9 is a cross-sectional view showing the area around the narrow portion of the gasket according to Embodiment 3 of the present invention. In Embodiment 3, the basic configuration is the same as that of Embodiment 1, so the same reference numerals are used for corresponding components, and redundant explanations are omitted. Figure 9 is a cross-section along the extension direction of the gasket.

[0078] In this embodiment, the second layer 37 of the narrow section 33 is made into a raising layer.

[0079] In other words, the first layer 35 of the narrow section 33 is provided integrally with the single layer of the wide section 31. The first layer 35 is continuous with the wide section 31 via a transition section 39. The wide section 31 has the same width and height as in Embodiment 1. The width and height of the transition section 39 gradually decrease toward the narrow section 33, and the first layer 35 of the narrow section 33 has the same constant width and height as the first layer 35 of Embodiment 1. This forms a recess 45 extending from the transition section 39 to the first layer 35 of the narrow section 33.

[0080] The second layer 37 of the narrow portion 33 is located within this recess 45. In this embodiment, the recess 45 and the second layer 37 have the same cross-sectional shape. The second layer 37 has the same width and height as the second layer 37 of Embodiment 1 on the first layer 35, and the end portion 37a, which gradually increases in width and height, is located on the transition portion 39.

[0081] The cross-sectional shape of the second layer 37 may be made larger or smaller than the recess 45. If the cross-sectional shape of the second layer 37 is made larger than the recess 45, the second layer 37 will protrude in the thickness direction from the wide portion 31, and if the cross-sectional shape of the second layer 37 is made smaller than the recess 45, the second layer 37 will be recessed in the thickness direction from the wide portion 31.

[0082] The rest is the same as in Example 1.

[0083] Even in this configuration of Example 3, the same effects and advantages as in Example 1 can be achieved. [Examples]

[0084] Figure 10(A) is a bottom view of the cover showing the area around the narrow portion of the gasket according to Embodiment 4 of the present invention, and Figure 10(B) is a cross-sectional view along line XX in Figure 10(A). In Embodiment 4, the basic configuration is the same as that of Embodiment 1, so the same reference numerals are used for corresponding components, and redundant explanations are omitted. In Figure 10(B), the cross-section of the narrow portion 33 is given as a conceptual, angular shape.

[0085] In this embodiment, the narrow portion 33 is eccentric in the width direction relative to the wide portion 31. Accordingly, the shape of the transition portion 39 has been changed compared to Embodiment 1. Here, eccentricity refers to the displacement in the width direction between the center of the narrow portion 33 in the width direction and the center of the wide portion 31 in the width direction in a cross section perpendicular to the extension direction of the gasket 29.

[0086] Due to eccentricity, the narrow section 33 has an outer edge that coincides with the outer edge of the wide section 31 in the width direction. The amount of eccentricity can be set as appropriate, and the outer edges of the narrow section 33 and the wide section 31 do not necessarily coincide. The transition section 39 has a gradually decreasing width only at its inner edge in the width direction. Otherwise, it is the same as in Embodiment 1.

[0087] Even in this configuration of Embodiment 4, the same effects and advantages as in Embodiment 1 can be achieved. Furthermore, the eccentricity between the narrow portion 33 and the wide portion 31 can suppress inward protrusion or bulging in the width direction when the gasket 29 is compressed.

[0088] Figure 11 is a cross-sectional view showing the narrow portion 33 of the gasket 29 according to a modified example of Embodiment 4, in which the cross-section of the narrow portion 33 is given a conceptual, angular shape.

[0089] In the modified example shown in Figure 11, the first layer 35 and the second layer 37 of the narrow section 33 are eccentric in the width direction. That is, the second layer 37 is set to be smaller in width and height than the first layer 35, and is eccentric outward in the width direction relative to the first layer 35. In accordance with this eccentricity, the outer edge of the first layer 35 and the outer edge of the second layer 37 coincide in the width direction.

[0090] Here, eccentricity refers to the widthwise displacement between the center of the first layer 35 of the narrow portion 33 and the center of the second layer 37 of the narrow portion 33 in a cross section perpendicular to the extension direction of the gasket 29. The amount of eccentricity can be set as appropriate, and the outer edge of the first layer 35 and the outer edge of the second layer 37 do not necessarily coincide. The modified example in Figure 11 is applicable to any of the narrow portions 33 of Examples 1 to 4.

[0091] In this modified example, the eccentricity between the first layer 35 and the second layer 37 makes it possible to suppress inward protrusion or bulging in the width direction when the gasket 29 is compressed. [Explanation of Symbols]

[0092] 1. Recording device 3 Housing 3a Space part 5 Internal mechanism 17 Bass 17a opening 19 Cover 19a Outer periphery 25 Cover receiving part 29 Gasket 31 Large portion 33 Narrow width section 35 First layer (narrow width part) 35a end 37 Second layer (narrow width part) 37a end 39 Transition section 41 First layer (large part) 43 Second layer (large part)

Claims

1. A cover that is attached to the opening of the base of a housing that houses an internal mechanism in a space, and closes the space, The outer periphery that is supported by the base, It comprises a gasket that extends in a circumferential manner along the outer circumference, protruding from the outer circumference and being compressed by contact with the base, The gasket comprises a wide portion with a relatively large width extending inward and outward along the circumferential shape, and a narrow portion with a relatively small width. The narrow portion is raised in the compression direction of the gasket by a layer structure having a raising layer. The wide portion and the narrow portion are adjacent to each other in the extending direction of the gasket and each has a tip portion that abuts against the base. cover.

2. A cover that is attached to an opening in the base of a housing that houses an internal mechanism in a space, and closes the space, The outer periphery that is supported by the base, It comprises a gasket that extends in a circumferential manner along the outer circumference, protruding from the outer circumference and being compressed by contact with the base, The gasket comprises a wide portion with a relatively large width extending inward and outward along the circumferential shape, and a narrow portion with a relatively small width. The narrow portion is a cover that is raised in the compression direction of the gasket by a layer structure having a raising layer, The narrow portion comprises a first layer as the raising layer and a second layer laminated on the first layer. The wide portion is formed integrally with the second layer of the narrow portion. The space between the second layer of the narrow portion and the wide portion is provided with a transition section in which the width and height in the compression direction gradually decrease from the wide portion towards the narrow portion. cover.

3. The cover according to claim 2, The end of the first layer of the narrow portion in the extending direction of the gasket is located within the transition portion, and the width and height in the compression direction gradually increase as it moves away from the wide portion in the extending direction. cover.

4. The cover according to claim 2, The wide portion comprises a first and second layer which are integral with the first and second layers of the narrow portion, respectively. The second layer of the aforementioned wide portion contains the first layer of the aforementioned wide portion. cover.

5. A cover according to any one of claims 1 to 3, The aforementioned wide section is a single layer. cover.

6. A cover that is attached to an opening in the base of a housing that houses an internal mechanism in a space, and closes the space, The outer periphery that is supported by the base, It comprises a gasket that extends in a circumferential manner along the outer circumference, protruding from the outer circumference and being compressed by contact with the base, The gasket comprises a wide portion with a relatively large width extending inward and outward along the circumferential shape, and a narrow portion with a relatively small width. The narrow portion is a cover that is raised in the compression direction of the gasket by a layer structure having a raising layer, The narrow portion comprises a first layer and a second layer, which is a raising layer, laminated on the first layer. The wide portion is formed integrally with the first layer of the narrow portion. Between the first layer of the narrow portion and the wide portion, there is a transition section in which the width and height in the compression direction gradually decrease from the wide portion toward the narrow portion. cover.

7. The cover according to claim 6, The end of the second layer of the narrow portion in the extending direction of the gasket is located on the transition portion, and the width and height in the compression direction gradually increase as it moves away from the wide portion in the extending direction. cover.

8. The cover according to claims 1 to 4, 6, and 7, The narrow portion and the wide portion are eccentric in the width direction. cover.

9. The cover according to claims 2 to 4, 6, and 7, The first and second layers of the narrow portion are eccentric in the width direction. cover.

10. A recording device using the cover of claim 1, The housing, together with the cover, includes a base that houses the internal mechanism within a closed space. The base comprises an opening into which the cover is attached, and a cover receiving portion that receives the outer periphery of the cover with the gasket interposed between them. Recording device.

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