A collapsible cup holder

Abstract

The utility model discloses a cup stand can be folded, the utility model discloses technical scheme includes main part, the bottom support of being used for bearing of being arranged at the bottom of main part and the cup body support of being arranged at main part for side bearing. Cup body support rotatablely connect in main part, and cup body support is equipped with locking portion, and main part is correspondingly equipped with the matching portion. Locking portion is configured as, when cup body support rotates to bottom support, with the matching portion is matched, thereby limit the further rotation of cup body support, effectively prevent its contact with bottom support. Further, the matching portion can be configured as a groove to achieve smooth matching and separation. The utility model still conceived another independent technical scheme, namely rotatable bottom support cooperates with the matching portion through the locking portion to limit its downward rotation angle. The utility model discloses above-mentioned matching structure, effectively solved the technical problem of excessive rotation in the folding process of water cup stand, has the beneficial effect that structural stability and use safety are stronger.

Description

Technical Field

[0001] This utility model relates to the field of water cup holder technology, and in particular to a retractable cup holder. Background Technology

[0002] Collapsible cup holders, as a common space-saving product, are widely used in automobiles, homes, and offices. Users have a continuous demand for convenient folding and collapsing operation and structural stability when folded. Existing technologies already include various cup holder structures that achieve folding through rotation, aiming to meet these needs.

[0003] Currently, typical collapsible cup holders usually include a vertically extending main body, a rotatable base frame at the bottom of the main body, and a rotatable cup holder on the side of the main body. The cup holder is configured to support the side of the cup when unfolded, and to rotate towards the base frame to fold closer to the main body. However, such designs generally lack effective limits on the rotation angle of the cup holder. Specifically, during the process of the cup holder rotating towards the base frame to fold, due to the lack of sufficient mechanical interference structures, the cup holder is prone to excessive rotation due to inertia or misoperation, resulting in a rigid collision with the unfolded base frame. Existing technologies, due to their unrestricted rotating connection structure, pose a risk of interference or even damage between the cup holder and the base frame during operation, exhibiting significant deficiencies in structural stability and safety.

[0004] In summary, existing technologies suffer from insufficient structural stability and operational safety due to the lack of effective limits on the rotation angle of local structures. Summary of the Invention

[0005] The main purpose of this invention is to propose a collapsible cup holder, which aims to solve the technical problems of insufficient structural stability and safety in the existing technology due to the lack of effective limiting of the rotation angle of the local structure.

[0006] To achieve the above objectives, this utility model proposes a retractable cup holder, including a main body, a base frame, and a cup body holder. The base frame is located at the bottom of the main body and is used for bottom support. The cup body holder is located on the main body and is used for side support. The cup body holder is rotatably connected to the main body and is provided with a locking part. The main body is provided with a corresponding engaging part. The locking part is configured to engage with the engaging part when the cup body holder rotates toward the base frame, so as to limit further rotation of the cup body holder and prevent contact with the base frame.

[0007] Furthermore, the engaging part is constructed as a groove with an opening facing the rotation path of the cup holder. When the cup holder rotates toward the base, the locking part extends into and abuts against the engaging part.

[0008] Furthermore, the engaging portion has an upper wall and a lower wall that are arranged opposite to each other. The upper wall is constructed as a curved surface, and the distance between the upper wall and the lower wall gradually increases from the bottom toward the opening.

[0009] Furthermore, the cup holder is provided with a positioning part, and the main body is provided with a limiting structure. The limiting structure includes a limiting part and a track. There are at least two limiting parts, which are a first locking part and a second locking part, respectively. The track is provided between the limiting parts, and the positioning part is configured to move within the range of the track and abut against the limiting part, thereby fixing the cup holder in a preset position.

[0010] Furthermore, the limiting structure is positioned relative to the rotation center of the cup holder, and the first locking part and the second locking part correspond to the unfolded position and the folded position of the cup holder, respectively.

[0011] Furthermore, the depth of the first and second locking parts is greater than that of the track.

[0012] Furthermore, the positioning part is constructed as a protrusion, and the limiting part is constructed as a groove.

[0013] This utility model also proposes a collapsible cup holder, including a main body and a base frame. The base frame is located at the bottom of the main body and is used for bottom support. The base frame is rotatably connected to the main body and is provided with a locking part. The main body is provided with a corresponding engaging part. The locking part is configured to engage with the engaging part when the base frame rotates downward toward the main body, so as to limit further rotation of the base frame.

[0014] Furthermore, the engaging portion is constructed as a groove with an opening facing the rotation path of the base frame. When the base frame rotates downward, the locking portion extends into and abuts against the engaging portion.

[0015] Furthermore, the engaging portion has an upper wall and a lower wall that are arranged opposite to each other. The upper wall is constructed as a curved surface, and the distance between the upper wall and the lower wall gradually increases from the bottom toward the opening.

[0016] This utility model includes a main body, a base frame at the bottom of the main body for load-bearing, and a cup holder on the side of the main body for load-bearing. The cup holder is rotatably connected to the main body and has a locking part, while the main body has a corresponding engaging part. The locking part is configured to engage with the engaging part when the cup holder rotates towards the base frame, thereby limiting further rotation of the cup holder and effectively preventing it from contacting the base frame. Furthermore, the engaging part can be constructed as a groove to achieve smooth engagement and disengagement. This utility model also conceives of another independent technical solution: the rotatable base frame, through the engagement part and locking part, limits its downward rotation angle. Through the above-mentioned engaging structure, this utility model effectively solves the technical problem of excessive rotation during the folding of the cup holder, and has the beneficial effects of strong structural stability and safe use. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention in its unfolded state; Figure 2 This is a schematic diagram of the planar structure of the present invention in its unfolded state from a side view. Figure 3 This is a schematic diagram of the unfolded planar structure of the present invention from a top-down perspective. Figure 1 ; Figure 4 This is a schematic diagram of the unfolded planar structure of the present invention from a top-down perspective. Figure 2 ; Figure 5 Analyzing the three-dimensional structure of this utility model Figure 1 ; Figure 6 Analyzing the three-dimensional structure of this utility model Figure 2 ; Figure 7 This is an exploded planar view of the present invention. Figure 8 This is a three-dimensional structural diagram of the present invention in its folded state; Figure 9 This is a schematic diagram of the planar structure of the present invention in its folded state.

[0018] The above figures include the following reference numerals: Main body; 11. Engaging part; 111. Upper wall; 112. Lower wall; 113. Opening; 12. Limiting structure; 121. First locking part; 122. Second locking part; 123. Track; 2. Base frame; 21. Drain hole; 3. Cup body holder; 31. Clamping part; 4. Locking part; 5. Positioning part; 6. Rotation center. Detailed Implementation

[0019] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0020] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0022] Implementation

[0023] This utility model proposes a collapsible cup holder.

[0024] In this embodiment of the utility model, such as Figures 1 to 9 As shown, the collapsible cup holder includes a main body 1, a base frame 2, and a cup body frame 3. The base frame 2 is located at the bottom of the main body 1 and is used for bottom support. The cup body frame 3 is located on the main body 1 and is used for side support. The cup body frame 3 is rotatably connected to the main body 1 and is provided with a locking part 4. The main body 1 is correspondingly provided with a locking part 11. The locking part 4 is configured to engage with the locking part 11 when the cup body frame 3 rotates towards the base frame 2, thereby limiting further rotation of the cup body frame 3 and preventing contact with the base frame 2. Understandably, compared to the shortcomings of existing technologies where the cup body frame 3 is prone to collision with the base frame 2 due to the lack of a rigid stop when collapsing, this invention provides a clear, mechanical termination point for the downward rotation of the cup body frame 3 by providing a locking mechanism consisting of the locking part 4 and the locking part 11 between the cup body frame 3 and the main body 1. This structure can mechanically prevent further rotation of the cup body frame 3, fundamentally avoiding direct contact and collision with the base frame 2. This not only effectively eliminates noise caused by collisions, but more importantly, it prevents scratches, wear, and even structural damage to the cup holder 3 and base 2 caused by long-term collisions, thus significantly improving the product's reliability, durability, and lifespan. Furthermore, this limiting mechanism ensures a consistent sense of completion in the closing action, enhancing the user experience and quality of the product.

[0025] In some embodiments of this invention, the engaging portion 11 is configured as a groove with an opening 113, which faces the rotation path of the cup holder 3. When the cup holder 3 rotates towards the base 2, the locking portion 4 extends into and abuts against the engaging portion 11. By specifically configuring the engaging portion 11 as a groove with an oriented opening 113, the locking portion 4 can be accurately and smoothly guided into the groove along the rotation trajectory of the cup holder 3. The inner wall of the groove provides a stable and reliable abutment surface for the locking portion 4, and its limiting effect is more explicit and robust than simple point contact or surface contact. This structure ensures that the cup holder 3 is immediately and effectively locked when retracted to a predetermined angle, the anti-collision limiting effect is more stable, and the risk of contact wear between components due to shaking or misoperation is further reduced.

[0026] Specifically, the engaging portion 11 has an upper wall 111 and a lower wall 112 disposed opposite to each other. The upper wall 111 is constructed as a curved surface, and the distance between the upper wall 111 and the lower wall 112 gradually increases from the bottom toward the opening 113. Understandably, the gradually widening opening 113 and the upper wall 111 together constitute a guide structure. When the locking portion 4 moves toward the groove, it can first contact the upper wall 111 on the curved surface and smoothly slide into the groove along the curved surface until it reaches and finally abuts against the bottom of the groove, which acts as a hard stop. This process effectively avoids hard collisions and jamming between the locking portion 4 and the edge of the engaging portion 11, making the closing action more effortless and smooth. At the same time, the curved surface design helps to disperse contact stress, and the smooth guiding process also reduces wear between components and possible abnormal noises during operation, further optimizing the user's feel and improving the durability of the components.

[0027] In some embodiments of this utility model, the cup holder 3 is provided with a positioning part 5, and the main body 1 is provided with a limiting structure 12. The limiting structure 12 includes a limiting part and a track 123. There are at least two limiting parts, namely a first locking part 121 and a second locking part 122. The track 123 is located between the limiting parts. The positioning part 5 is configured to move within the range of the track 123 and abut against the limiting part, thereby fixing the cup holder 3 in a preset position. The cooperation between the positioning part 5 and the limiting structure 12 provides a clear sense of stop and position feedback for the rotation process of the cup holder 3. When the positioning part 5 is engaged with any limiting part, a clear sense of resistance and positioning can be generated through mechanical interference, thereby stably holding the cup holder 3 in the preset position and effectively preventing it from rotating on its own when subjected to slight external force. The track 123 connecting the two ensures that when the cup holder 3 switches between the unfolded and retracted states, the positioning part 5 can move smoothly and continuously under its constraint, realizing the smoothness of state transition and the controllability of operation. This design not only enhances the ease of use and perceived quality of the product, but also improves structural reliability by avoiding ambiguity in positioning.

[0028] Specifically, the limiting structure 12 is positioned relative to the rotation center 6 of the cup holder 3, and the first locking part 121 and the second locking part 122 correspond to the unfolded position and the folded position of the cup holder 3, respectively.

[0029] More specifically, as a first optional implementation, the limiting structure 12 is located below the rotation center 6 of the cup body holder 3, and the first locking part 121 is located on the left side of the rotation center 6, while the second locking part 122 is located on the right side of the rotation center 6. The first locking part 121 is farther away from the base frame 2 than the second locking part 122, and the track 123 is constructed as a downwardly raised arc.

[0030] More specifically, as a second optional implementation, the limiting structure 12 is located above the rotation center 6 of the cup holder 3, and the first locking part 121 is located on the right side of the rotation center 6, while the second locking part 122 is located on the left side of the rotation center 6. The first locking part 121 is further away from the base frame 2 than the second locking part 122, and the track 123 is constructed as an upwardly raised arc.

[0031] It should be noted that both of the above embodiments, through the cooperation of the positioning part 5 and the limiting structure 12, provide a clear sense of position and feedback for the rotation of the cup holder 3, effectively preventing accidental displacement in the unfolded or folded state. However, due to the different layouts, their mechanical characteristics and optimized focuses also differ. Furthermore, it is understood that the rotation center 6 can be achieved through conventional rotating connection structures in the art, such as, but not limited to, shafts, rivets, or screws. Any structure that allows the cup holder 3 to rotate relative to the main body 1 should be included within the protection scope of this utility model. Given that this connection structure is prior art in the art, it will not be described in detail here.

[0032] In the first embodiment, the movement trajectory of the positioning part 5 from the left (expanded position) to the right (folded position) matches the downward-rising arc-shaped track 123. This path can be assisted by the component of the cup holder 3's own weight, making the folding action particularly effortless and smooth.

[0033] In the second embodiment, the positioning part 5 moves from the right side (expanded position) to the left side (folded position), and its anti-locking structure brings unique advantages. When the cup holder 3 is in the unfolded state, since the positioning part 5 is locked in place by the first locking part 121 above the rotation center 6, the center of gravity of the cup holder 3 is located on the other side of the rotation center 6. This mechanical relationship provides additional holding force for the unfolded state, effectively preventing accidental folding due to slight disturbances, and significantly improving the stability and safety during use.

[0034] Specifically, the depth of the first locking part 121 and the second locking part 122 is greater than that of the track 123. This structural design with a difference in depth results in less resistance when the positioning part 5 slides within the track 123, allowing for rapid switching between states. When it moves to and falls into the first locking part 121 or the second locking part 122, a significant mechanical click and a clicking sound are produced due to the sudden change in depth. This clear auditory and tactile feedback informs the user that the cup holder 3 has accurately reached the preset working position of "fully unfolded" or "fully closed" without visual confirmation. More importantly, the greater depth means that the positioning part 5 needs to overcome greater travel and friction to disengage from the locking part. This provides higher holding force and self-locking stability for both unfolded and closed states, effectively preventing the cup holder 3 from accidentally coming loose from the preset position when carried or subjected to slight vibrations, greatly improving the product's reliability and operational feel.

[0035] Specifically, the positioning part 5 is constructed as a protrusion, and the limiting part is constructed as a groove. This protrusion-groove combination is an efficient and reliable mechanical positioning solution. The protrusion structure is easy to form on the cup body 3, and its small contact area helps to reduce friction during sliding and locking; while the precisely matched groove provides the protrusion with a stable and reliable guide path (in track 123) and a firm locking space (in the locking section). This fit transforms the limitation of the rotation angle of the cup body 3 into a precise mechanical constraint on the range of motion of the protrusion, with a simple structure and reliable operation. In addition, this solution is very manufacturing-friendly. Both the protrusion and the groove can be formed in one piece by injection molding without the need for additional parts, effectively controlling production costs while achieving precise positioning.

[0036] In some embodiments of this utility model, the base frame 2 is provided with a drain hole 21. The drain hole 21 allows liquid accidentally spilled on the base frame 2 to be drained in time, effectively preventing liquid accumulation. This not only facilitates cleaning and maintenance, but also prevents bacterial growth or component corrosion and aging caused by long-term water accumulation, further improving the product's hygiene and long-term durability.

[0037] In some embodiments of this utility model, the cup holder 3 is provided with a clamping part 31, which is located on the inner side of the cup holder 3 and is used to hold the water cup. The number of clamping parts 31 is not specifically limited; commonly, three to five are provided. Within this range, the clamping parts 31 can achieve a sufficient fixing effect, such as... Figure 3 and Figure 4The diagram shows the configurations with three and four clamping parts 31. Preferably, the clamping parts 31 are constructed as protrusions made of flexible or elastic materials to accommodate water cups of different diameters. The structure of the clamping parts 31 provides an active clamping function to the cup holder 3, enabling it to support the water cup more stably and effectively prevent it from tipping over during shaking. In particular, when the clamping parts 31 are constructed as flexible or elastic protrusions, they can adapt to the outer walls of water cups of different diameters through their own deformation, providing sufficient clamping force while avoiding scratches or jamming that may be caused by rigid contact. This design improves the compatibility and applicability of the cup holder to different sized water cups, enhancing the product's versatility and user experience.

[0038] Implementation

[0039] This utility model also proposes a collapsible cup holder, including a main body 1 and a base frame 2. The base frame 2 is located at the bottom of the main body 1 and is used for bottom support. The base frame 2 is rotatably connected to the main body 1 and is provided with a locking part 4. The main body 1 is correspondingly provided with a locking part 11. The locking part 4 is configured to engage with the locking part 11 when the base frame 2 rotates downward toward the main body 1, thereby limiting further rotation of the base frame 2. The structure of the locking part 4 and the locking part 11 in this collapsible cup holder is the same as in Embodiment 1 above. Since this Embodiment 2 adopts all the technical solutions of all embodiments in Embodiment 1 above, it has at least all the beneficial effects brought about by the technical solutions of Embodiment 1 above, and will not be described in detail here.

[0040] In some embodiments of the present invention, the engaging portion 11 is configured as a groove with an opening 113, the opening 113 being disposed toward the rotation path of the base frame 2, and when the base frame 2 rotates downward, the locking portion 4 extends into and abuts against the engaging portion 11.

[0041] Specifically, the engaging portion 11 has an upper wall 111 and a lower wall 112 disposed opposite to each other. The upper wall 111 is constructed as a curved surface, and the distance between the upper wall 111 and the lower wall 112 gradually increases from the bottom toward the opening 113.

[0042] It should be noted that by creatively applying the same anti-collision locking principle to the folding process of the base frame 2, this embodiment enables all major moving parts (cup body holder 3 and base frame 2) to remain in a predetermined, compact position after the cup holder is fully folded, thereby minimizing the overall storage volume and improving the regularity, and optimizing the convenience of carrying and storing.

[0043] Furthermore, it should be noted that in existing technologies, the main body 1 is fitted with a fixing structure (not shown) to the base frame 2. This fixing structure is generally a contact surface that prevents the base frame 2 from falling. Due to its intended use, the base frame 2 needs to be prevented from rotating downwards during use to avoid breaking the water cup. This invention, through the engaging cooperation between the locking part 4 and the engaging part 11, also reliably restricts the downward rotation of the base frame 2. While ensuring load-bearing safety, it eliminates the need for a separate fixing structure, simplifying the overall structure and providing a better operating feel.

[0044] Explanation of the working principle of this utility model It should be explained that the following working principle description defines the cup holder 3 in the first embodiment of the limiting structure 12 (located below the rotation center 6) and the base frame 2 in the second embodiment of the limiting structure 12 (located above the rotation center 6).

[0045] When in use, the user can rotate the cup holder 3 and the base 2 to unfold and fold the cup holder.

[0046] The operation of the cup holder 3 is as follows: When the cup holder 3 rotates from the unfolded state to the folded state, the positioning part 5 disengages from the first locking part 121 (unfolded position) located to the lower left of the rotation center 6 and moves along the downward-protruding track 123. During this process, the gravitational potential energy of the cup holder 3 is converted into kinetic energy, and its trajectory closely matches the direction of the track 123. It also receives the assistance of the gravitational component, making the folding action particularly effortless and smooth. The positioning part 5 finally engages with the second locking part 122 (folded position) located to the lower right of the rotation center 6. At the same time, when the cup holder 3 rotates to its lowest position, the locking part 4 engages with the corresponding engaging part 11 (groove) on the main body 1, forming a mechanical hard stop, which ultimately prevents it from rotating further, thereby ensuring a safe gap between the cup holder 3 and the base 2 and avoiding collisions.

[0047] The operation of the base frame 2 is as follows: When the base frame 2 rotates and retracts towards the main body 1, the locking part 4 engages with the corresponding engaging part 11 on the main body 1 to form a downward rotation limit, thereby preventing the water cup from falling. Furthermore, the positioning part 5 of the base frame 2 moves within the limiting structure 12 (located above the rotation center 6). When the base frame 2 is in the unfolded load-bearing state, the positioning part 5 is engaged with the first engaging part 121 (unfolded position) on the upper right of the rotation center 6. At this time, the overall center of gravity of the base frame 2 is located on the other side of the rotation center 6. This anti-locking structure provides additional holding force using mechanical relationships, ensuring that the base frame 2 is stable and not easily loosened when under load. When it is necessary to retract the base frame 2, an upward external force must be applied to disengage the positioning part 5 from the first engaging part 121 and allow it to enter the second engaging part 122 along the track 123.

[0048] In summary, this utility model achieves a collapsible cup holder that is easy to close, stable to unfold, and prevents damage from collisions between components by configuring optimized limiting and locking structures for the cup holder 3 and the base frame 2.

[0049] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A collapsible cup holder, comprising a main body (1), a base frame (2), and a cup body holder (3), wherein the base frame (2) is disposed at the bottom of the main body (1) and is used for bottom support, and the cup body holder (3) is disposed at the main body (1) and is used for side support, characterized in that: The cup holder (3) is rotatably connected to the main body (1) and is provided with a locking part (4). The main body (1) is provided with a corresponding engaging part (11). The locking part (4) is configured to engage with the engaging part (11) when the cup holder (3) rotates toward the base frame (2) to limit further rotation of the cup holder (3) and prevent contact with the base frame (2).

2. The collapsible cup holder as described in claim 1, characterized in that: The engaging part (11) is constructed as a groove with an opening (113) facing the rotation path of the cup holder (3). When the cup holder (3) rotates toward the base (2), the locking part (4) extends into and abuts against the engaging part (11).

3. The collapsible cup holder as described in claim 2, characterized in that: The engaging part (11) has an upper wall (111) and a lower wall (112) arranged opposite to each other. The upper wall (111) is constructed as a curved surface, and the distance between the upper wall (111) and the lower wall (112) gradually increases from the bottom toward the opening (113).

4. The collapsible cup holder as described in claim 1, characterized in that: The cup holder (3) is provided with a positioning part (5), and the main body (1) is provided with a limiting structure (12). The limiting structure (12) includes a limiting part and a track (123). There are at least two limiting parts, namely a first locking part (121) and a second locking part (122). The track (123) is located between the limiting parts. The positioning part (5) is configured to move within the range of the track (123) and abut against the limiting part, thereby fixing the cup holder (3) in a preset position.

5. The collapsible cup holder as described in claim 4, characterized in that: The limiting structure (12) is set relative to the rotation center (6) of the cup holder (3), and the first locking part (121) and the second locking part (122) correspond to the unfolded position and the folded position of the cup holder (3), respectively.

6. The collapsible cup holder as described in claim 4, characterized in that: The setting depth of the first locking part (121) and the second locking part (122) is greater than that of the track (123).

7. The collapsible cup holder as described in any one of claims 4 to 6, characterized in that: The positioning part (5) is constructed as a protrusion, and the limiting part is constructed as a groove.

8. A collapsible cup holder, comprising a main body (1) and a base frame (2), wherein the base frame (2) is disposed at the bottom of the main body (1) and is used for bottom load bearing, characterized in that: The base frame (2) is rotatably connected to the main body (1) and is provided with a locking part (4). The main body (1) is provided with a corresponding engaging part (11). The locking part (4) is configured to engage with the engaging part (11) when the base frame (2) rotates toward the lower part of the main body (1) to limit further rotation of the base frame (2).

9. The collapsible cup holder as described in claim 8, characterized in that: The engaging part (11) is constructed as a groove with an opening (113) facing the rotation path of the base frame (2). When the base frame (2) rotates downward, the locking part (4) extends into and abuts against the engaging part (11).

10. The collapsible cup holder as described in claim 9, characterized in that: The engaging part (11) has an upper wall (111) and a lower wall (112) arranged opposite to each other. The upper wall (111) is constructed as a curved surface, and the distance between the upper wall (111) and the lower wall (112) gradually increases from the bottom toward the opening (113).

Images