Inspection hatch

Abstract

To provide an inspection hatch installed on a ceiling or a wall surface with consideration given to its design so that its presence is not conspicuous, and which is easy and safe to open and close.SOLUTION: Provided is an inspection patch including a rectangular outer frame fixed to an opening provided on an installation surface, a rectangular inner frame installed inside the outer frame so as to be opened and closed, a lid material attached inside the inner frame and having a through hole on a free end side of the inner frame, a distal stay fixed to a distal side of an inner surface on the free end side of the inner frame, a proximal stay fixed to a proximal side of an inner surface on the free end side of the inner frame, a lock unit fixed to the distal stay and having a latch piece capable of being engaged with the outer frame and a keyhole for rotating the latch piece, and a key cover fixed to the proximal stay while passing through the through hole, and having an inner surface hole which is coaxial with the keyhole and penetrates in the vertical direction.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an inspection hatch that is opened in an installation surface such as a ceiling or wall of a building. [Background technology]

[0002] Inspection hatches are sometimes provided in the walls or ceilings of buildings to inspect structural or functional parts of the building that are normally not visible to building users (for example, ventilation, air conditioning, or electrical equipment). Inspection hatches have a cover that can be opened and closed to cover an opening provided on the installation surface. Examples of such inspection hatches include the technologies described in Patent Documents 1 to 3. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-204369 [Patent Document 2] Patent Publication No. 2021-017745 [Patent Document 3] Japanese Patent Application Publication No. 186650 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 aims to improve the appearance of the area around the inspection hatch by preventing the locking device from being exposed on the surface of the inspection hatch cover. However, with this technology, when opening the cover, a plate-shaped unlocking tool must be inserted through the gap between the ceiling panel material and the cover. Therefore, it is not immediately clear where the locking device is located on the four sides of the cover, making it difficult to know which side and which part of the cover the unlocking tool should be inserted into.

[0005] The technology described in Patent Document 2 aims to provide an inspection hatch that can improve security with a simple mechanism, and discloses a technology in which the inner frame is locked by engaging an engaging member provided on the inner frame of the lid with a locking leaf spring provided on the outer frame. However, even with this technology, when opening the inner frame, it is necessary to insert a plate-shaped unlocking tool through the gap between the outer frame and the inspection hatch cover to release the engagement. Therefore, it is difficult to know which side and which part of the four sides of the inner frame the unlocking tool should be inserted into. Furthermore, because the outer frame flange and inner frame flange are exposed on the surface, the presence of the inspection hatch is conspicuous.

[0006] The technology described in Patent Document 3 takes into consideration the problem that conventional ceiling inspection hatches look unattractive because they are made of a different material from the ceiling panel, and discloses a technology in which the ceiling inspection hatch is formed integrally with the ceiling panel and the cover is formed from the same material as the ceiling panel. However, this technology is effectively limited to ceiling panels made of metal, and therefore lacks versatility.

[0007] The embodiment of the present disclosure is a design for an inspection hatch installed on a ceiling or wall so that its presence is not noticeable. sex The objective is to make opening and closing operations easy and safe while taking into consideration the above. [Means for solving the problem]

[0008] The inspection hatch of an embodiment of the present disclosure comprises a square outer frame fixed to an opening provided on an installation surface, a square inner frame installed inside the outer frame so as to be able to open and close, a lid material attached inside the inner frame and having a through hole provided on the free end side of the inner frame, a distal stay fixed to the distal side of the inner surface of the free end side of the inner frame, a proximal stay fixed to the proximal side of the inner surface of the free end side of the inner frame, a lock unit fixed to the distal stay and having a latch piece capable of engaging with the outer frame and a keyhole for rotating the latch piece, and a key cover fixed to the proximal stay while passing through the through hole and having an inner surface hole that is coaxial with the keyhole and penetrates in the vertical direction.

[0009] In this application, the term "installation surface" refers to, for example, a ceiling or a wall surface. The ceiling may be indoors or outdoors, such as under an eaves. The wall may be indoors or outdoors.

[0010] As used herein, "distal" refers to the side that is hidden by a closed access hatch, and "proximal" refers to the side that is visible through the closed access hatch. For example, if an access hatch is installed in a ceiling, "distal" means above and "proximal" means below. Also, if an access hatch is installed in a wall, "distal" means the side inside the wall and "proximal" means the side facing the room.

[0011] By configuring it as described above, the lock unit, which is usually installed on the lid side, is positioned distal to the installation surface so that it is not directly exposed on the surface, and the design sex Furthermore, since the key cover having the inner hole is exposed to the surface, it is possible to insert an unlocking tool through the inner hole to the key hole to perform the unlocking operation easily and safely.

[0012] In addition, in the above-mentioned inspection hatch, the keyhole is located distal to the proximal edge of the inner frame and faces the distal end of the key cover. This configuration prevents the keyhole from being directly visible from inside the room, improving the design of the inspection hatch's appearance. It also makes it easy to insert an unlocking tool from the key cover to the keyhole.

[0013] In addition, in the above-mentioned inspection hatch, it is desirable that the cross section of the inner hole encompasses the cross section of the keyhole. With this configuration, it becomes easy to insert an unlocking tool from the inner hole to the keyhole.

[0014] Furthermore, in the above-mentioned inspection hatch, it is desirable that the cross section of the distal side of the inner hole be encompassed by the cross section of the proximal side of the inner hole. Furthermore, it is even more desirable that the cross section of the proximal side of the inner hole be circular, and the cross section of the distal side of the inner hole be a regular hexagon. This configuration allows the lock cover to be easily installed by inserting a tool such as a hexagonal wrench into the distal side of the inner hole with a regular hexagonal cross section. Since the proximal side of the inner hole encompasses the distal side cross section, it is easy to insert the tool. Furthermore, since the cross section of the proximal side of the inner hole is circular, the appearance of the inner hole of the inspection hatch is circular, improving its design.

[0015] Furthermore, in the above-mentioned inspection hatch, the proximal edge of the inner frame is located distal to the decorative surface, which is the proximal surface of the lid material. With this configuration, the proximal edge of the inner frame does not appear on the surface as a joint, thereby further improving the design.

[0016] Furthermore, in the inspection hatch, the proximal edge of the outer frame is located distal to the installation surface. With this configuration, the proximal edge of the outer frame does not appear on the surface as a joint, thereby further improving the design.

[0017] In addition, the inspection hatch is further provided with a trim covering the edge of the opening, and a protruding portion that is a ridge that protrudes into the gap between the inner frame and the outer frame is formed on the proximal edge of the trim. With this configuration, the protruding portion can further narrow the gap between the inner frame and the outer frame, improving the design and appearance of the inspection hatch. [Effects of the Invention]

[0018] Since the embodiment of the present disclosure is configured as described above, the inspection hatch installed on the ceiling or wall surface can be designed so that its presence is not conspicuous. sex While taking into consideration the safety of the door, opening and closing operations can be carried out easily and safely. [Brief explanation of the drawings]

[0019] [Figure 1] The appearance of the inspection hatch of the embodiment is shown in a bottom perspective view. [Figure 2] The dashed line portion of the inspection hatch in Figure 1 is shown enlarged. [Figure 3] 1 is a partially cutaway perspective view of an inspection hatch according to an embodiment of the present invention; [Figure 4] The main parts of the inspection hatch of the embodiment are shown in a side view with some parts shown in cross section. [Figure 5] 1 is a perspective view showing an assembly diagram of a lock unit and a key cover in an inspection hatch of an embodiment. FIG. [Figure 6] 6 is a bottom perspective view of the lock body and key cover in FIG. 5. FIG. [Figure 7] 10 is a partial cross-sectional side view showing a state in which a cover member is attached to an inspection hatch of an embodiment. [Figure 8] 1 is a bottom view showing the appearance of a key cover in an inspection hatch according to an embodiment. [Figure 9] 1 is a side view showing an embodiment of an unlocking device for an inspection hatch. [Figure 10] 1 is a bottom perspective view showing the state in which the inspection hatch of the embodiment is opened, with some components omitted. [Figure 11] 1 is a top perspective view showing the closed state of the inspection hatch of the embodiment. [Figure 12] 12 is a top perspective view showing the state in which the closed state of FIG. 11 is released. [Figure 13] 10 is a side view showing a cross section of a main part of an inspection hatch according to a second embodiment. [Figure 14] 10 is a side view showing a cross section of a main part of an inspection hatch according to a third embodiment. [Figure 15] 10 is a side view showing a part of a cross section of the main part of an inspection hatch of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the inspection hatch of the present disclosure will be described with reference to the drawings. Note that the reference numerals commonly used in the drawings indicate the same parts or components even if they are not mentioned in the description of each drawing. Furthermore, the materials of each component mentioned below are examples and are not limited to these.

[0021] FIG. 1 is a perspective view showing the exterior of an inspection hatch 10 in an embodiment of the present application. Note that this embodiment will be described assuming that the inspection hatch 10 is installed on a ceiling, which serves as the installation surface 100. The inspection hatch 10 is visible with a lid member 40 attached to a square opening 110 provided in the installation surface 100. A finishing material 43 (see FIG. 3), which will be described later, is attached to the proximal surface (in other words, the underside) of the lid member 40, and this is visible from the room side as a decorative surface 42. In addition, a lock cover 80 is exposed in the center of one of the four sides of the lid member 40.

[0022] As shown in Figure 2, which is an enlarged view of the dashed line portion of inspection hatch 10 in Figure 1, a circular finish portion 83 of lock cover 80 is exposed on the surface, and a circular inner hole 82 is opened in the center of the finish portion. In addition, at the parting point with installation surface 100, proximal edge 22, which is the lower edge portion of outer frame 20 (see Figure 3), which will be described later, can be seen.

[0023] 3 is a partially cutaway bottom perspective view of the inspection hatch 10 according to the embodiment. As described above, a rectangular outer frame 20 is fixed to the opening 110 provided in the installation surface 100. Specifically, the outer frame 20 is installed on the edge of the wall material 120 that constitutes the installation surface 100. The part of the lower edge of the outer frame 20 that separates from the opening 110 forms the proximal edge 22.

[0024] A rectangular inner frame 30 is installed inside the outer frame 20 so as to be able to open and close. A lid member 40 is attached to the inside of the inner frame 30. A flange 21 and a flange 31 are formed on the distal edges (i.e., upper edges) of the outer frame 20 and the inner frame 30, respectively. A finishing material 43 is attached to the proximal side of the lid member 40, and the surface of the finishing material 43 forms a decorative surface 42. In addition, a trim member 44 with a generally J-shaped cross section is attached to the edge of the lid member 40. As shown in FIG. 10, the trim member 44 is a long member made of synthetic resin and composed of a wide, plate-like wide portion 44a, a narrow, plate-like narrow portion 44c, and a plate-like intermediate portion 44b connecting these. The underside of the narrow portion 44c is shaped to be cut diagonally upward (see FIG. 7). A gap necessary for opening and closing the inner frame 30 is created between the edge of the lid material 40 and the proximal edge 22 of the outer frame 20. Furthermore, a through-hole 41 (see Figure 7) is provided on the free end side of the inner frame 30, through which the key cover 80 is inserted, and its lower end, a circular finishing portion 83, is visible on the decorative surface 42. An inner surface hole 82 opens in the center of the finishing portion 83.

[0025] 4 is a side view, partially in cross section, of the main components of the inspection hatch 10 of this embodiment. A base material holder 46 is attached to the inner frame 30 with screws, a base material 45 is attached to this base material holder 46 with set screws 45a, and a lid material 40 is attached to the proximal side of this base material 45 with an adhesive. A through-hole 41 is formed on the free end side of the lid material 40. A proximal edge 32, which is the edge on the proximal side of the inner frame 30, is located distal to a decorative surface 42, which is the surface on the proximal side of the lid material 40, so that the proximal edge 32 is not visible on the surface.

[0026] A distal stay 50 is attached to the distal side (i.e., upper side) of the inner surface of the free end side of the inner frame 30 with a mounting screw 54. A lock unit 70 is fixed to the distal stay 50 with a nut 53. The lock unit 70 has a latch piece 73 that can be engaged with the flange 21 of the outer frame 20 and the flange 31 of the inner frame 30. The latch piece 73 is attached to the distal end of the lock unit 70 with a mounting screw 77 via a washer 76. Furthermore, a keyhole 74 (see Figures 6, 8 and 10) for rotating the latch piece 73 is provided at the proximal end of the lock unit 70.

[0027] Furthermore, the proximal stay 60 is attached to the proximal side (i.e., the lower side) of the inner surface of the free end side of the inner frame 30 with a mounting screw 64. The key cover 80 is passed through the through hole 41 and fixed to the proximal stay 60 with a nut 63. The key hole 74 is located distal to the proximal edge of the inner frame 30 and faces the distal end of the key cover 80 (see Figure 6). The key cover 80 has an inner surface hole 82 (see Figures 6 and 7) that penetrates in the vertical direction. This inner surface hole 82 is coaxial with the key hole 74 of the lock unit 70 described above (see Figures 6 and 8).

[0028] FIG. 5 is a perspective view showing the assembly of the lock unit 70 and the key cover 80 in the inspection hatch 10 of this embodiment. FIG. 6 is a bottom perspective view showing the lock body 78 and the key cover 80, which are part of the lock unit 70 in FIG. 5. The distal stay 50 that secures the lock unit 70 is formed as an L-shaped metal fitting, with a mounting piece 51 having a screw hole 51a for securing the lock unit 70 to the inner frame 30 and a mounting piece 52 having a mounting hole 52a through which the lock unit 70 is inserted, intersecting at right angles. The edges of the mounting hole 52a are formed by a pair of opposing arc-shaped portions 52b and a pair of opposing linear portions 52c that connect them. The proximal side 51b of the mounting piece 51 has a proximal convex shape. A nut 53, separate from the distal stay 50, is provided to secure the lock unit 70 to the distal stay 50.

[0029] The proximal stay 60 that secures the key cover 80 is formed as an L-shaped metal fitting, with a mounting piece 61 having a screw hole 61a for securing it to the inner frame 30 and an attachment piece 62 having an attachment hole 62a through which the key cover 80 is inserted, intersecting at right angles to form an L shape. A nut 63 is welded to the distal surface of the attachment piece 62 so that the position of the attachment hole 62a coincides with the hole. The distal side 61b of the mounting piece 61, which is the distal side, is concave toward the distal side, and the proximal side 51b of the distal stay 50 fits into this. This allows the mounting piece 51 and the mounting piece 61 to have sufficient lengths, ensuring sufficient attachment strength of the distal stay 50 and the proximal stay 60 to the inner frame 30.

[0030] The lock unit 70 is composed of a lock body 78 that is inserted into the mounting hole 52a of the distal stay 50, a sleeve 75 that is fitted onto the lock body 78, a latch piece 73 that is attached to the distal end of the lock body 78, and a mounting screw 77 that screws the latch piece 73 in place via a washer 76.

[0031] The lock body 78 has a generally cylindrical outer shape and is broadly divided into a distal portion 71 that forms the upper half and a proximal portion 72 that forms the lower half. The outer peripheral surface of the distal portion 71 is formed with a curved portion 71a that is threaded and a flat portion 71b that has two facing chamfered portions. The planar shape of the distal portion 71 matches the planar shape of the mounting hole 52a of the distal stay 50. The upper end surface of the distal portion 71 is formed with a rectangular protruding portion 71c. Furthermore, a screw hole 71d into which a mounting screw 77 is threaded is formed at the center of the upper end surface of the distal portion 71. Meanwhile, the outer peripheral surface of the proximal portion 72 is cylindrical, and a step 72a is formed at the boundary with the flat portion 71b of the distal portion 71. Furthermore, a flange 72b is formed at the lower end of the proximal portion 72 against which the lower edge of the fitted sleeve 75 abuts. Furthermore, a keyhole 74 (see FIGS. 6, 8 and 10) is provided in the center of the lower end of the proximal portion 72.

[0032] A cylindrical sleeve 75 with open top and bottom faces is fitted onto the outer periphery of the lock body 78 and engages with a flange 72b on the lower edge of the proximal part 72. The upper edge of the sleeve 75 abuts against the lower surface of the installation piece 51 of the distal stay 50. As a result, the distance that the lock unit 70 protrudes distally from the distal stay 50 is restricted by the height of the sleeve 75.

[0033] The latch piece 73 is configured as a plate-like member that is bent in a stepped manner and has an upper step portion 73c and a lower step portion 73d. A recess 73a, which is a depression into which the protrusion 71c of the lock unit 70 fits, is formed on the underside of the lower step portion 73d. In addition, a through-hole 73b, through which the mounting screw 77 is inserted, is formed in the center of the lower step portion 73d.

[0034] The key cover 80, formed by injection molding of synthetic resin, is composed of a cylindrical insertion portion 81 that is inserted into the through-hole 41 (see FIG. 7) of the lid member 40, and a flange-shaped finishing portion 83 that is exposed to the outside of the decorative surface 42. The key cover 80 is formed from a synthetic resin of a color similar to the color tone of the finishing material 43 of the lid member 40, so that the finishing portion 83 does not stand out against the decorative surface 42. The key cover 80 also has an inner hole 82 that penetrates in the vertical direction. The cross section of the inner hole 82 is sized to encompass the cross section of the keyhole 74 of the lock unit 70 (see FIGS. 6 and 8). The cross-sectional shapes of the inner hole 82 differ between the distal and proximal sides, and the cross section of the distal-side inner hole 82a, which is on the distal side, is sized to be encompassed by the cross section of the proximal-side inner hole 82b, which is on the proximal side (see FIGS. 6, 7, and 8). Furthermore, the cross section of the proximal inner surface hole 82b is circular, and the cross section of the distal inner surface hole 82a is a regular hexagon (see FIGS. 6 and 8).

[0035] The lock unit 70 and key cover 80 are attached to the inner frame 30, for example, as follows. First, the sleeve 75 is fitted onto the lock body 78, and then the distal portion 71 is inserted from below into the attachment hole 52a of the distal stay 50. Then, a nut 53 is threaded onto the curved portion 71a to secure the lock body 78 to the distal stay 50. Next, with the convex portion 71c on the upper surface of the lock body 78 engaged with the concave portion 73a on the lower surface of the latch piece 73, an attachment screw 77 is inserted from above through the through hole 73b of the latch piece 73, sandwiching the washer 76 therebetween, and then threaded into the screw hole 71d of the lock body 78. This attaches the latch piece 73 to the lock body 78. This secures the lock unit 70 to the distal stay 50.

[0036] 7, the distal stay 50 to which the lock unit 70 is fixed is fixed to the inner frame 30 with the mounting screws 54, and then the proximal stay 60 is fixed to the inner frame 30 with the mounting screws 64. Then, the base material 45 is attached to the inner frame 30 via the base material holder 46.

[0037] Meanwhile, a trim 44 is attached to the edge of a lid member 40, which has through-holes 41 formed in advance at predetermined positions, with the narrow portions 44c facing downward. Then, a finishing material 43 made of putty and paint in the same color tone as the installation surface 100 is applied to form a decorative surface 42. In this state, the through-holes 41 are aligned with the mounting holes 62a of the proximal stay 60, and the lid member 40 is bonded to the base material 45, thereby attaching the lid member 40 to the inside of the inner frame 30 (see FIG. 7 ). Finally, the key cover 80 is inserted from below the through-hole 41, and a hex wrench having a shape matching the distal inner surface hole 82a is inserted into the inner surface hole 82 and rotated to thread the insertion portion 81 onto the nut 63, thereby fixing the key cover 80 to the proximal stay 60.

[0038] As a result, the lock unit 70 and the key cover 80 are attached to the inner frame 30 as shown in FIG. 4. In other words, because the lock unit 70 is not directly attached to the cover member 40, the keyhole 74 is not visible on the surface of the cover member 40. In other words, the keyhole 74 is located distal to the proximal edge 32 of the inner frame 30 and is located close to but spaced from the distal end of the key cover 80. As shown in FIG. 8, a bottom view of this state, the finish of the key cover 80 is inconspicuous against the decorative surface 42 of a similar color. Furthermore, of the inner surface holes 82 visible from the proximal side, the proximal inner surface hole 82b, which is the most proximal, is circular. This prevents the regular hexagonal distal inner surface hole 82a, which is located further back and enclosed by it, from being conspicuous. 7, the narrow portion 44c of the trim 44 attached to the edge of the lid material 40 is covered by the finishing material 43 and does not appear on the decorative surface 42. In addition, because the proximal edge 32 of the inner frame 30 is located distal to the decorative surface 42, the inner frame 30 does not appear on the surface as a joint. These points combine to improve the design and appearance of the inspection hatch 10.

[0039] 9 is a side view of the unlocking tool 90 for the inspection hatch 10 of this embodiment. The unlocking tool 90 has a synthetic resin handle 91 to which an insertion rod 92, which is a hexagonal cross-section iron rod, is attached. To prevent damage to the surrounding area, the insertion rod 92 is covered, except for the tip, with a rubber tube, for example. The uncovered tip of the insertion rod 92 forms an unlocking section 93 with a cross-section large enough to be inserted into the keyhole 74.

[0040] 10 is a bottom perspective view showing the state in which the inspection hatch 10 of this embodiment is opened, with the lid 40 and key cover 80 omitted. The insertion rod 92 of the unlocking tool 90 is inserted into the inner surface hole 82, and the release part 93 at the tip is inserted into the keyhole 74. At this time, the size of the inner surface hole 82 gradually decreases from the proximal inner surface hole 82b, which is the entrance of the inner surface hole 82, through the distal inner surface hole 82a to the keyhole 74, and because the distal end of the key cover 80 is located near the keyhole 74, the release part 93 is smoothly guided into the keyhole 74.

[0041] FIG. 11 is a top perspective view showing the inspection hatch 10 of this embodiment in a closed state. As shown in this figure, the latch piece 73 of the lock unit 70 engages with the flange 21 of the outer frame 20, thereby maintaining the inspection hatch 10 in a closed state. In this state, when the release portion 93 of the unlocking tool 90 is inserted into the keyhole 74 and the handle 91 is rotated in a twisting motion as shown in FIG. 10, the latch piece 73 rotates in conjunction with the rotation of the keyhole 74, disengaging from the flange 21 of the outer frame 20, as shown in FIG. 12. In this state, when the handle 91 is moved downward with the unlocking tool 90 still inserted, gravity causes the free end of the inner frame 30 to rotate, opening the inspection hatch 10.

[0042] On the other hand, when closing the inspection hatch 10, the unlocking tool 90 is inserted into the inner surface hole 82, and the inner frame 30 is rotated so as to be pushed upward. When it hits the outer frame 20, the handle 91 is twisted in the opposite direction, transitioning from the state shown in FIG. 12 to the state shown in FIG. 11. This causes the latch piece 73 to engage with the flange 21 of the outer frame 20, and the inspection hatch 10 is again in the closed state. As described above, the operator can open and close the inner frame 30 with the unlocking tool 90 inserted in the key cover 80, so there is no need to touch the lid material 40 or the surrounding installation surface 100. This prevents the lid material 40 and the surrounding installation surface 100 from being soiled. In addition, because the key cover 80 is fixed by the proximal stay 60, the key cover 80 does not move when opening or closing the inner frame 30. RThis prevents the cover material 40 from being soiled. In addition, by positioning the key hole 74 of the lock unit 70 near the distal end of the key cover 80, the range over which the unlocking tool 90 inserted into the key hole 74 swings in the inner surface hole 82 is reduced, preventing the cover material 40 from being soiled by the key cover 80 when the inner frame 30 is opened or closed.

[0043] The shape of the keyhole 74 is not limited to a regular hexagonal shape as in the above embodiment, as long as it has a shape and size that can be accommodated in the inner hole 82 of the key cover 80. However, considering that a readily available hexagonal rod can be used as the unlocking tool 90, that the angle of movement required to align the keyhole 74 with the unlocking tool 90 is small, at 60° or less, and that strict insertion direction is not required as with a normal key, the shape of the keyhole 74 is desirably a regular hexagonal shape as in the above embodiment.

[0044] Furthermore, the shape of the inspection hatch 10 of the present disclosure is not limited to a rectangle with four approximately equal sides as shown in Figure 1, but can also be formed into a rectangle with long and short sides. In this case, it is desirable to provide two lock units 70 on the long side of the free end. In this case, the inspection hatch 10 can be unlocked in the same way by holding an unlocking tool 90 in each hand, inserting them into the keyholes 74 at the same time, and rotating the handle 91.

[0045] The above describes one example of an embodiment of the present invention, but the embodiment of the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0046] In addition, as shown in Figure 13 secondAs in the embodiment, the key cover 80 may be attached directly to the lid material 40 without providing the proximal stay 60 (see FIG. 4). The key cover 80 is inserted into the through hole 41 and fastened with a nut 63 via a washer 63a, thereby sandwiching the lid material 40 between the finishing part 83 (see FIG. 5) and the nut 63. In this case, as in the above-described embodiment, the inspection hatch 10 can be opened and closed using an unlocking tool 90. As shown in FIG. 7, the narrow portion 44c of the trim 44 attached to the edge of the lid material 40 is covered by the finishing material 43 and does not appear on the decorative surface 42. Furthermore, as in the above-described embodiment, the proximal edge 32 of the inner frame 30 is located distal to the decorative surface 42, so that the inner frame 30 does not appear on the surface as a joint. These features, combined, also improve the design and appearance of the inspection hatch 10.

[0047] Furthermore, as in a third embodiment shown in FIG. 14, the opening 110 (see FIG. 1) in the installation surface 100 may be covered with a trim 48 having a generally J-shaped cross section. Here, as shown in FIG. 14, the trim 48 is a long member made of synthetic resin and configured with a wide, plate-like wide portion 48a, a narrow, plate-like narrow portion 48c, and a plate-like intermediate portion 48b connecting these. The underside of the narrow portion 48c is shaped to be obliquely cut upward. The proximal edge 22 of the outer frame 20 covers the corners of the distal edge of the trim 48, and is therefore located distal to the installation surface. This prevents the proximal edge of the outer frame 20 from appearing as a joint on the surface, further improving the design.

[0048] Furthermore, a protruding portion 48d, which is a protrusion that protrudes inward, is formed on the proximal edge of the trim 48. This protruding portion 48d narrows the gap between the inner frame 30 and the outer frame 20, improving the aesthetic appearance of the inspection hatch 10. Furthermore, the upper surface of the protruding portion 48d is shaped to be cut diagonally downward, which prevents the rotating inner frame 30 from interfering with the trim 48 when the inspection hatch 10 is opened.

[0049] 15, similarly to the third embodiment, the opening 110 (see FIG. 1) in the installation surface 100 may be covered with a trim 48 having a generally J-shaped cross section, while the edge of the lid material 40 may be covered with the inner surface of a regular inner frame 30. In this case, the proximal edge 32 of the inner frame 30 is flush with the lid material 40. In other words, the proximal edge 32 of the inner frame 30 is visible from the inside of the room, but the proximal edge 22 of the outer frame 20 is not visible from the inside of the room. [Explanation of symbols]

[0050] 10 Inspection hatch 20 Outer frame 21 Flange 22 Proximal edge 30 Inner frame 31 Flange 32 Proximal edge 40 Lid material 41 Through hole 42 Decorative surface 43 Finishing material 44 Edge material 44a Wide portion 44b Middle portion 44c Narrow portion 45 Base material 45a Set screw 46 Base material holder 48 Edge material 48a Wide portion 48b Middle portion 48c Narrow portion 48d Projection portion 50 Distal stay 51 Installation piece 51a Screw hole 51b Proximal edge 52 Mounting piece 52a Mounting hole 52b Arc-shaped portion 52c Straight portion 53 Nut 54 Mounting screw 60 Proximal stay 61 Installation piece 61a Screw hole 61b Distal edge 62 Mounting piece 62a Mounting hole 63 Nut 63a Washer 64 Mounting screw 70 Lock unit 71 Distal portion 71a Curved portion 71b Flat portion 71c Convex portion 71d Screw hole 72 Proximal portion 72a Step 72b Flange 73 Latch piece 73a Recessed portion 73b Through hole 73c Upper portion 73d Lower portion 74 Key hole 75 Sleeve 76 Washer 77 Mounting screw 78 Lock body 80 Key cover 81 Insertion portion 82 Inner surface hole 82a Distal inner surface hole 82b Proximal inner surface hole 83 Finishing portion 90 Unlocking tool 91 Handle 92 Insertion rod 93 Release portion 100 Installation surface 110 Opening 120 Wall material

Claims

1. a rectangular outer frame fixed to an opening provided on an installation surface; a rectangular inner frame that is installed inside the outer frame in an openable and closable manner; a cover material that is attached to the inside of the inner frame and has a through hole on a free end side of the inner frame; a distal stay fixed to the distal side of the inner surface of the free end side of the inner frame; a proximal stay fixed to a proximal side of an inner surface of the free end side of the inner frame; a lock unit fixed to the distal stay and having a latch piece that can be locked to the outer frame and a keyhole for rotating the latch piece; a key cover that is fixed to the proximal stay in a state where it is passed through the through hole, and that has an inner surface hole that is coaxial with the keyhole and penetrates in the vertical direction; Equipped with The keyhole is located distal to the proximal edge of the inner frame and faces the distal end of the key cover.

2. 2. The access hatch according to claim 1, wherein the cross section of the inner hole encompasses the cross section of the keyhole.

3. The access hatch of claim 2 , wherein a cross section of the distal side of the internal bore is subsumed within a cross section of the proximal side of the internal bore.

4. 4. The access hatch of claim 3, wherein the proximal cross section of the internal bore is circular and the distal cross section of the internal bore is a regular hexagon.

5. 2. The access hatch according to claim 1, wherein the proximal edge of the inner frame is located distal to a decorative surface which is the proximal surface of the lid material.

6. The access hatch according to claim 1 , wherein a proximal edge of the outer frame is located distal to the installation surface.

7. A trim material covering the edge of the opening is further provided, The inspection hatch according to claim 6, wherein a protruding portion, which is a protrusion that protrudes into the gap between the inner frame and the outer frame, is formed on the proximal edge of the trim.

Images