Battery and cover plate assembly for the same

Abstract

A cover plate assembly comprising a cover plate having a main body, a support portion and a limiting portion, wherein: the main body has a mounting opening, the support section is arranged around an edge of the mounting opening, the support section is provided with a through hole, the limiting section is connected to the edge of the mounting opening, at least a portion of the limiting portion is located on one side of the main body in a thickness direction of the cover plate and is spaced from the support portion, the main body, the support section and the limiting section are formed together in one piece, the cover plate is provided with a groove surrounding the through hole, the groove is located on a side of the main body opposite to the restricting portion, and the groove is arranged at an interval from the through hole; a terminal, wherein at least a portion of the terminal is located between the support portion and the boundary section; and a sealing element arranged around the terminal, wherein at least a portion of the sealing element is located between the support portion and the terminal, at least a portion of the sealing element is located in the through-hole, and the sealing element abuts the support portion.

Description

field of technology

[0001] The present disclosure relates to the field of novel energy battery technologies and, more particularly, relates to a battery and a cover plate assembly therefor. State of the art

[0002] A battery cover plate typically provides terminals to establish an electrical connection between the external environment and the interior of the battery cell. The terminal penetrates the cover plate, and a sealing ring is arranged between the cover plate and the terminal to isolate the interior of the battery from the external environment. In some cases, the terminal has a convex edge surrounding the terminal body, and the cover plate is provided with two projections for clamping to the convex edge, both projections being located at the terminal hole.

[0003] However, to form these two projections on the cover plate, material must be extruded from the cover plate onto the projection, resulting in grooves near the connection hole of the cover plate, which weakens the strength of the cover plate. If the load from the sealing ring acts on a section of the cover plate near the connection hole, this section of the cover plate is susceptible to deformation, resulting in seal failure. SUMMARY

[0004] The object of the present disclosure is to provide a battery and a cover plate assembly therefor which can reduce the problem of sealing ring failure due to cover plate deformation.

[0005] To achieve the above object, the present disclosure provides a cover plate assembly comprising a cover plate including a main body, a support portion, and a limiting portion, wherein: the main body has a mounting hole, the support portion is arranged around an edge of the mounting hole, the support portion is provided with a through hole, the limiting portion is connected to the edge of the mounting hole, at least a portion of the limiting portion is located on a side of the main body in a thickness direction of the cover plate and is positioned at a distance from the support portion, the main body, the support portion, and the limiting portion are integrally formed together, the cover plate is provided with a groove surrounding the through hole, the groove is located on a side of the main body opposite the limiting portion,and the groove is arranged at an interval from the through-hole; a terminal, at least a portion of the terminal being located between the support portion and the limiting portion;, a sealing element arranged around the terminal, wherein at least a portion of the sealing element is located between the support portion and the terminal, at least a portion of the sealing element is located in the through-hole, and the sealing element abuts the support portion.

[0006] The present disclosure also provides a battery comprising: a housing having an opening communicating with an interior of the housing; a battery cell arranged inside the housing; the cover plate assembly described above, which covers the opening.

[0007] Compared with the prior art, the present disclosure has the following advantageous effects: The cover plate assembly of the present disclosure includes a cover plate, a terminal, and a sealing element. The groove in the cover plate can provide additional accommodation space for the battery interior. The groove is arranged at an interval from the through-hole to ensure that the support portion has sufficient strength. When deformation occurs at the groove, the support portion compresses the sealing element located between the support portion and the terminal. The sealing element deforms, ensuring that the sealing effect is not reduced due to the deformation of the support portion.During compression, the sealing element also provides a reaction force to the support section, which reinforces the support force of the support section, so that the overall support force of the support section is improved and the problem of seal failure due to deformation of the cover plate due to loading by the sealing element is reduced.

[0008] The battery of the present disclosure includes the above-mentioned cover plate assembly, which can reduce the problem of seal failure caused by deformation of the cover plate due to stress from the sealing member. Short description of the drawings Fig. 1 is a schematic structural diagram of a cover plate assembly of an embodiment of the present disclosure. Fig. 2 is an enlarged schematic diagram of a section B in Fig. 1. Fig. 3 is a schematic structural diagram of the cover assembly in Fig. 1 from a different perspective. Fig. 4 is an enlarged schematic diagram of a section C in Fig. 3. Fig. 5 is a sectional view along a line AA in Fig. 1. Fig. Figure 6 is an enlarged schematic diagram of a section E in Fig. 5. Fig. 7 is a schematic structural diagram of the cover plate of an embodiment of the present disclosure. Fig. Figure 8 is an enlarged schematic diagram of a section D in Fig. 7. Fig. 9 is a schematic structural diagram of a terminal of an embodiment of the present disclosure. Fig. 10 is a schematic structural diagram of an insulating member of an embodiment of the present disclosure. Fig. 11 is a schematic structural diagram of a sealing member of an embodiment of the present disclosure.

[0009] List of reference symbols: 1. cover plate; 2. terminal; 3. sealing element; 4. insulating element; 11. main body; 12. support portion; 13. restricting portion; 14. groove; 15. reinforcing rib; 111. mounting hole; 121. through hole; 141. groove edge; 21. terminal body; 22. convex edge. DETAILED DESCRIPTION

[0010] The specific implementation of the present disclosure is described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are intended to illustrate the present disclosure, but are not intended to limit the scope of the present disclosure.

[0011] For the purpose of describing the present disclosure, it should be noted that terms such as "central," "longitudinal," "transverse," "above," "below," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside," which represent orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings. These terms are used for convenience of description and convenience only and do not indicate or imply that the designated devices or elements must have specific orientations or be constructed and operated in specific orientations. Thus, they should not be considered limitations of the present disclosure. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative priority.

[0012] In the description of the present disclosure, terms such as "mounted," "connected," and "coupled" should be understood in a broad sense unless explicitly stated and limited otherwise. For example, they may refer to permanent connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections via intermediate elements or internal communication between two elements. Those skilled in the art will understand the specific meanings of these terms in the present disclosure according to specific situations.

[0013] Furthermore, in the description of the present disclosure, “multiple” means two or more unless otherwise specified.

[0014] Those skilled in the art will understand the specific meanings of the above terms in the present disclosure according to specific situations.

[0015] Referring to the Fig. 1 and Fig. 2, a cover plate assembly 1 of the present disclosure includes: a cover plate 1, a connector 2, and a sealing element 3.

[0016] Referring to the Fig. 7 and Fig. 8, the cover plate 1 includes a main body 11, a support portion 12, and a restricting portion 13. The main body 11 has a mounting hole 111, the support portion 12 is arranged around the edge of the mounting hole 111, the support portion 12 is provided with a through hole 121, the restricting portion 13 is connected to the edge of the mounting hole 111, at least a portion of the restricting portion 13 is located on one side of the main body 11 in a thickness direction of the cover plate 1 and is spaced from the support portion 12, and the main body 11, the support portion 12, and the restricting portion 13 are integrally formed together.

[0017] The cover plate 1 is a component used to cover an opening of a battery case and, together with the battery case, forms a space for accommodating a battery cell.

[0018] Referring to the Fig. 3 and Fig. 4, the cover plate 1 is provided with a groove 14 surrounding the through-hole 121. The groove 14 is located on one side of the main body 11, away from the limiting portion 13, and is arranged at an interval from the through-hole 121. At least a portion of the groove 14 is located in the main body 11. A groove wall of the groove 14 near the through-hole 121 is referred to as a groove edge 141, which is located in the main body 11 or the support portion 12.

[0019] The mounting hole 111 is used to provide an installation space for the terminal 2, the support portion 12 can provide support for the terminal 2, and the limiting portion 13 is designed to limit the position of the terminal 2. The through hole 121 enables the terminal 2 to be connected to the battery cell within the battery case.

[0020] The portion of the main body 11 surrounding the connector 2 is formed in two layers, with one layer being extruded and formed as the limiting portion 13, and the second layer being the support portion 12. The limiting portion 13 and the support portion 12 together clamp and fix the connector 2.

[0021] The groove 14 can provide additional accommodation space for the battery interior and can also provide installation and assembly positions for other battery components.

[0022] Referring to Fig. 9, the terminal 2 penetrates the through hole 121, and at least a portion of the terminal 2 is located between the support portion 12 and the limiting portion 13.

[0023] Terminal 2 is used for electrical connection between the battery and external devices. Terminals 2 are classified as positive terminals 2 and negative terminals 2 with different polarities, and each battery can have multiple positive or negative terminals 2. In this embodiment, one positive terminal 2 and one negative terminal 2 are provided. In actual product implementation, the number and positions of terminals 2 can be determined according to requirements.

[0024] Referring to the Fig. 5, Fig. 6 and Fig. 11, the sealing element 3 is arranged on the connection 2 and surrounds the connection 2, wherein at least a portion of the sealing element 3 is located between the support portion 12 and the connection 2, at least a portion of the sealing element 3 is located in the through hole 121 and the sealing element 3 rests against the support portion 12.

[0025] The sealing element 3 provides a seal at the terminal 2 and thus closes the gap between the battery interior and the external environment of the battery by means of the sealing element 3.

[0026] To ensure the sealing effect, the connection 2 and the support section 12 jointly compress the sealing element 3, and the sealing element 3 also exerts a load on the connection 2 and the support section 12 in a similar manner.

[0027] The groove 14 and the through-hole 121 are spaced apart to maintain sufficient strength of the support section 12. However, due to the presence of the groove 14, the strength of the cover plate 1 at the groove is comparatively low and prone to deformation under load. Furthermore, the spacing of the groove 14 and the through-hole 121 can reduce the deformation of a side of the support section 12 facing away from the connection 2.

[0028] When deformation occurs at the groove 14, the support portion 12 compresses the sealing element 3 located between the support portion 12 and the terminal 2. In this case, the sealing element 3 deforms, ensuring that the sealing effect is not reduced due to the deformation of the support portion 12. During compression of the sealing element 3, the sealing element 3 also provides a reaction force to the support portion 12, which reinforces the supporting force of the support portion 12, thus improving the overall supporting force of the support portion 12 and reducing the problem of seal failure due to deformation of the cover plate due to stress from the sealing element 3.

[0029] In some embodiments, the cover plate 1 further includes a reinforcing rib 15 formed in the interval between the groove 14 and the through hole 121; on a plane on which the main body 11 is located, a projection of the restricting portion 13 at least partially overlaps a projected area of ​​the groove 14.

[0030] Since the restricting portion 13 and the supporting portion 12 jointly clamp and fix the terminal 2, disposing the reinforcing rib 15 on the projected surface of the restricting portion 13 on the cover plate 1 can improve the overall strength in the corresponding area and prevent deformation of the supporting portion 12 due to upward and downward loads by the sealing member 3, so that the strength and sealing reliability of the supporting portion 12 are improved and sealing failure due to deformation of the supporting portion 12 is prevented.

[0031] If the projected areas of the groove 14 and the boundary section 13 do not overlap at any point, this would cause forming problems when forming the boundary section 13 due to the large distance of material migration.

[0032] In some embodiments, the interval between the groove 14 and the through-hole 121 may have a length specified in L mm and for which the following applies: 1 ≤ L < 5. Advantageously, L may be 1.5, 2, 2.5, 3, 3.5 or 4 or have other values.

[0033] When L is in the above-specified range, both the molding problems in molding the restricting portion 13 due to the large distance of material migration and the strength of the support portion 12 can be ensured, so that the strength and sealing reliability of the support portion 12 are improved and sealing failure due to deformation of the support portion 12 is prevented.

[0034] Conventional length measuring tools such as tape measures or rulers can be used to measure the size of L.

[0035] When measuring L, in particular the distance between the groove edge 141 and an inner wall of the through hole 121 corresponding thereto must be measured; for this purpose, several measurements must be taken and these averaged in order to determine the interval distance L mm between the groove 14 and the through hole 121.

[0036] In some embodiments, the projection of the groove edge 141 on a plane on which the main body 11 is located is located outside the projected area of ​​the sealing element 3, and the projection of the groove edge 141 is located away from the port 2 on the side of the projected area of ​​the sealing element 3.

[0037] Due to the stress that the sealing element 3 exerts on the support portion 12, the projection of the groove edge 141 on the plane on which the cover plate 1 is located is located outside the projected area of ​​the sealing element 3 on the plane on which the cover plate 1 is located, that is, the portion between the groove 14 and the through hole 121 completely covers the projection of the sealing element 3. When the above-mentioned reinforcing rib 15 is provided, this means that the projection of the reinforcing rib 15 completely covers the projection of the sealing element 3, so that sealing failure for the terminal 2 due to deformation and bending of the support portion 12 caused by the sealing element 3 exerting a stress on the support portion 12 is prevented.

[0038] In some embodiments, referring to Fig. 9, the connector 2 includes a connector body 21 and a convex edge 22. The convex edge 22 surrounds the outer peripheral surface of the connector body 21, and at least a portion of the convex edge 22 is located between the support portion 12 and the limiting portion 13. A portion of the sealing element 3 is located between the support portion 12 and the connector body 21, and another portion of the sealing element 3 is located between the support portion 12 and the convex edge 22.

[0039] The terminal 2 is clamped together by the limiting portion 13 and the supporting portion 12, which is realized by the convex edge 22 being clamped together by the limiting portion 13 and the supporting portion 12.

[0040] The convex edge 22 and the support portion 12 jointly compress the sealing element 3 located between the convex edge 22 and the support portion 12, and the terminal 21 and the support portion 12 jointly compress the sealing element 3 located between the terminal 21 and the support portion 12, that is, the sealing element 3 at the through hole 121.

[0041] On the plane on which the body 11 is located, the projection of the groove edge 141 is located within the projected area of ​​the convex edge 22.

[0042] In this case, the pressure exerted by the convex edge 22 on the support portion 12 is mainly transmitted through the sealing element 3, ensuring that the area between the groove 14 and the through hole 121 covers the area of ​​the sealing element 3, thus improving the overall strength. When the aforementioned reinforcing rib 15 is provided, the reinforcing rib 15 can cover the area of ​​the sealing element 3.

[0043] In some embodiments, the projection of the groove edge 141 on the plane on which the main body 11 is located is located outside the projected area of ​​the convex edge 22, and the projection of the groove edge 141 is located away from the terminal 2 on one side of the projected area of ​​the convex edge 22.

[0044] In this case, it is possible to increase the clamping force on the convex edge 22, so that the overall structural strength increases.

[0045] Referring to the Fig. 6 and Fig. 10, the cover plate assembly of this embodiment further includes an insulating member 4 surrounding the outer peripheral surface of the terminal 2. The insulating member 4 is disposed between the restricting portion 13 and the terminal 2 to separate the terminal 2 from the restricting portion 13.

[0046] The insulating element 4 can separate the terminal 2 from the limiting section 13 and thus provides electrical insulation between the terminal 2 and the cover plate 1.

[0047] In some embodiments, the projection of the groove edge 141 on the plane on which the main body 11 is located is located within the projected area of ​​the insulating element 4.

[0048] In this case, the hardness of the insulating member 4 is comparatively high, so the groove edge 141 is less susceptible to bending under downward pressure. When the aforementioned reinforcing rib 15 is provided, the bottom of the reinforcing rib 15 is also less susceptible to deformation under downward pressure.

[0049] In some embodiments, the projection of the groove edge 141 on the plane on which the main body 11 is located is outside the projected area of ​​the insulating element 4.

[0050] In this case, this can increase the clamping force of the insulating element 4 between the limiting portion 13 and the supporting portion 12 and thus ensure the insulating effect.

[0051] In some embodiments, the distance between the groove edge 141 and the through hole 121 may be equal to the width of the reinforcing rib 15, where the width D mm is: 1 ≤ D ≤ 5. Advantageously, D may be 1.5, 2, 2.5, 3, 3.5, 4 or 4.5 or have other values.

[0052] In this embodiment, the reinforcing rib 15, the main body 11, the limiting portion 13, and the support portion 12 are integrally formed. The reinforcing rib, like the limiting portion 13, is also formed by extrusion.

[0053] The larger the value of D, the more material must be extruded to form the reinforcing rib 15, leaving less material for the limiting section 13. To balance the strength of both the reinforcing rib 15 and the limiting section 13, the width of the reinforcing rib 15 is within the aforementioned range.

[0054] Conventional length measuring tools such as tape measures or rulers can be used to measure the size of D.

[0055] When measuring D, in particular the distance between the side wall of the reinforcing rib 15 near the through hole 121 and the side wall of the reinforcing rib 15 facing away from the through hole 121 must be measured. For this purpose, several measurements must be taken and these must be averaged in order to determine the width D mm of the reinforcing rib 15.

[0056] In this embodiment, the terminal 2 has the shape of a racetrack, and the width D mm of the reinforcing rib 15 is: 2 ≤ D ≤ 5. Advantageously, D can be 1.5, 2, 2.5, 3, 3.5, 4 or 4.5 or have other values.

[0057] The racetrack-shaped connector 2 is formed by long edges and short edges connected between the ends of the long edges. The long edges are straight, while the short edges are curved. The long edges have slightly lower strength, so the width of the reinforcing rib 15 must be within the aforementioned range to balance the strength of both the reinforcing rib 15 and the limiting portion 13.

[0058] In some embodiments, the groove 14 includes a single continuous groove or the groove 14 includes intermittent grooves.

[0059] In this embodiment, if the groove 14 is a groove comprising a single continuous groove, it is a continuous groove surrounding the outside of the through hole 121.

[0060] A single continuous groove simplifies the manufacturing process and improves production efficiency.

[0061] In other embodiments, intermittent grooves may also be used, for example, a plurality of arcuate grooves arranged at intervals, but these arcuate grooves collectively surround the outside of the through-hole 121. When deformation occurs in the intermittent grooves, the deformation of the sealing element 3 can ensure that the sealing effect is not reduced due to the deformation of the support portion 12, while at the same time improving the strength of the support portion 12 itself and thus increasing the seal between the support portion 12 and the terminal 2.

[0062] In some embodiments, the width value of the groove 14 varies along the direction of the outer peripheral surface of the terminal 2.

[0063] Since the terminal 2 in this embodiment is racetrack-shaped, the width of the groove 14 in the curved portions differs from that in the straight portions. At a portion of the groove 14 corresponding to the restricting portion 13, the width is larger so that the material that should be in the groove 14 can be extruded to form a projection, which is then machined to form the restricting portion 13. The width of a portion of the groove 14 that does not correspond to the restricting portion 13 can be set smaller. This arrangement simplifies the manufacturing process of the restricting portion 13.

[0064] In some embodiments, the depth of the groove 14 is h mm, and the depth of the groove 14 and the interval L mm between the groove 14 and the through hole 121 are: 0.02 ≤ h / L ≤ 0.5, 0.1 ≤ h ≤ 0.5. Preferably, h / L can have the values ​​0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4 or other values, and h can have the values ​​0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or other values.

[0065] Conventional length measuring tools such as calipers can be used to measure the size of h.

[0066] When measuring h, in particular, the distance between the surface of the main body 11 on which the opening of the groove 14 is located and the bottom of the groove 14 must be measured. To do this, several measurements must be taken and averaged to determine the depth h mm of the groove 14. Alternatively, the groove 14 can be cut to form a cross-section that can be measured under a microscope.

[0067] When h / L is within the above range, the supporting capacity of the support portion 12 between the groove 14 and the through-hole 121 is sufficient to compress the sealing element 3 and thus ensure the sealing effect. If the h / L ratio is too small, the end of the support portion 12 that contacts the sealing element 3 cannot provide sufficient compression of the sealing element 3 during deformation, resulting in seal failure. If the h / L ratio is too large, the strength of the groove 14 or the support portion 12 between the groove 14 and the through-hole 121 becomes too low to compress the sealing element 3, so that no sealing effect is achieved.

[0068] This embodiment also provides a battery comprising a housing, a battery cell, and the aforementioned cover plate assembly. The housing has an opening communicating with its interior, the battery cell being disposed inside the housing, and the cover plate assembly covering the opening. With this structure, the battery can reduce the problem of seal failure caused by deformation of the cover plate due to stress from the sealing element 3.

[0069] The above description merely describes the preferred embodiments of the present disclosure. It should be noted that those of ordinary skill in the art can make various improvements and substitutions without departing from the technical principles of the present disclosure, which are also within the scope of the present disclosure.

Claims

[1] Cover plate assembly comprising a cover plate having a main body, a support portion and a limiting portion, wherein: the main body has a mounting opening, the support section is arranged around an edge of the mounting opening, the support section is provided with a through hole, the limiting section is connected to the edge of the mounting opening, at least a portion of the limiting portion is located on one side of the main body in a thickness direction of the cover plate and is spaced from the support portion, the main body, the support section and the limiting section are formed together in one piece, the cover plate is provided with a groove surrounding the through hole, the groove is located on a side of the main body opposite to the restricting portion, and the groove is arranged at an interval from the through hole; a terminal, wherein at least a portion of the terminal is located between the support portion and the boundary section; and a sealing element arranged around the terminal, wherein at least a portion of the sealing element is located between the support portion and the terminal, at least a portion of the sealing element is located in the through-hole, and the sealing element abuts the support portion. [2] Cover plate assembly according to claim 1, wherein: the cover plate further comprises a reinforcing rib formed in the interval between the groove and the through hole; on a plane on which the main body is located, a projection of the limiting portion at least partially overlaps with a projected area of ​​the groove. [3] Cover plate assembly according to claim 1, wherein: the interval between the groove and the through hole has a length specified in L and for which the following applies: 1 ≤ L ≤ 5. [4] Cover plate assembly according to claim 1, wherein: on a plane on which the main body is located, a groove wall of the groove near the through hole is called a groove edge, and a projection of the groove edge is located on a side of a projected surface of the sealing element facing away from the connection. [5] Cover plate assembly according to claim 2, wherein: the connector comprises a connector body and a convex edge, wherein the convex edge surrounds an outer peripheral surface of the connector body, at least a portion of the convex edge is located between the support portion and the limiting portion, a portion of the sealing element is located between the support portion and the connector body, and another portion of the sealing element is located between the support portion and the convex edge; and on a plane on which the main body is located, a groove wall of the groove near the through hole is called a groove edge, and a projection of the groove edge is located within a projected area of ​​the convex edge. [6] Cover plate assembly according to claim 2, wherein: the connector comprises a connector body and a convex edge, wherein the convex edge surrounds an outer peripheral surface of the connector body, wherein at least a portion of the convex edge is located between the support portion and the limiting portion, a portion of the sealing element is located between the support portion and the connector body, and another portion of the sealing element is located between the support portion and the convex edge; and on a plane on which the main body is located, a groove wall of the groove near the through hole is called a groove edge, and a projection of the groove edge is located on a side of a projected surface of the convex edge facing away from the terminal. [7] The cover plate assembly according to claim 4, further comprising an insulating member surrounding an outer peripheral surface of the terminal, the insulating member being disposed between the restricting portion and the terminal to separate the terminal from the restricting portion; wherein a projection of the groove edge on a plane on which the main body is located is located within a projected area of ​​the insulating member. [8] The cover plate assembly according to claim 4, further comprising an insulating member surrounding an outer peripheral surface of the terminal, the insulating member being disposed between the restricting portion and the terminal to separate the terminal from the restricting portion; wherein a projection of the groove edge on a plane on which the main body is located is located outside a projected area of ​​the insulating member. [9] Cover plate assembly according to claim 2, wherein: a groove wall of the groove near the through hole is referred to as a groove edge, wherein a distance between the groove edge and the through hole is equal to a width of the reinforcing rib, and wherein the width of the reinforcing rib is given in D mm, where: 1 ≤ D ≤ 5. [10] Cover plate assembly according to claim 9, wherein: the connection has the shape of a racetrack, and the width D mm of the reinforcing rib is: 2 ≤ D ≤ 5. [11] Cover plate assembly according to claim 1, wherein: the groove comprises a single continuous groove or the groove comprises interrupted grooves. [12] Cover plate assembly according to claim 10, wherein: a value of a width of the groove varies along a direction of an outer peripheral surface of the terminal. [13] Cover plate assembly according to claim 1, wherein: a depth of the groove is given in h mm, the interval between the groove and the through hole having a length given in L mm, where: 0.02 ≤ h / L ≤ 0.5, 0.1 ≤ h ≤ 0.

5. [14] Battery comprising: a housing having an opening communicating with an interior of the housing; a battery cell arranged inside the housing; and The cover plate assembly of any one of claims 1 to 13, wherein the cover plate assembly covers the opening.

Images