A combined bottle cap with narrowed waist

Abstract

The utility model provides a kind of combined bottle cap with narrowing waist, including bottle cap assembly for connecting in the top of bottle body, bottle cap assembly is made of cover seat and top cover, the cover seat is made of injection molding process integral structure, the cover seat has upper barrel section and lower barrel section connected in upper and lower, upper barrel section expands outward from bottom to top, lower barrel section expands outward from top to bottom, so that cover seat is hourglass-shaped structure with narrowing middle part, the top cover is connected in the top of upper barrel section and covers upper barrel section top end, the lower barrel section inner cavity is provided with the screw joint ring part for being connected with bottle body thread with downward extension, the utility model aims at overcoming the deficiency of prior art, provide a kind of combined bottle cap with narrowing waist, which guarantees appearance quality and processing quality.

Description

Technical Field

[0001] This utility model specifically relates to a combination bottle cap with a narrow waist. Background Technology

[0002] Currently, most plastic bottle caps on the market are made of thermoplastic materials and molded in one piece using injection molding. To enhance the aesthetics and grip of products, some high-end packaging has begun to adopt "hourglass" or "slender waist" shaped bottle caps with a narrowing center. While this design has certain advantages in terms of visual appeal and human-computer interaction, it faces significant technical challenges in actual manufacturing.

[0003] Since injection molding relies on mold opening and closing for demolding, any structure with concave, undercut, or closed cavities may prevent the product from being smoothly removed from the mold. This is especially true when the bottle cap has a continuous curved surface structure that tapers inwards from the center, creating an undercut feature in the waist area that cannot be resolved by conventional sliders or angled ejector mechanisms. Forcing the use of complex mold structures (such as internal core pulling or rotary demolding) not only significantly increases mold costs and maintenance difficulty but also easily leads to stress deformation, shrinkage, and even cracking of the product due to excessive demolding resistance, severely affecting sealing performance and appearance quality, making it impossible to simultaneously guarantee both appearance and processing quality.

[0004] This utility model was developed precisely because of the aforementioned shortcomings. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a combined bottle cap with a narrow waist that ensures both appearance and processing quality.

[0006] This utility model is achieved through the following technical solution:

[0007] This utility model provides a combined bottle cap with a narrow waist, including a bottle cap assembly for connecting to the top of a bottle body. The bottle cap assembly consists of a cap base and a top cap. The cap base is made into an integral structure by injection molding. The cap base has an upper cylindrical section and a lower cylindrical section connected vertically. The upper cylindrical section expands outward from bottom to top, and the lower cylindrical section expands outward from top to bottom, so that the cap base has an hourglass shape with a narrow middle. The top cap is connected to the top of the upper cylindrical section and seals the top of the upper cylindrical section. The inner cavity of the lower cylindrical section is provided with a threaded ring portion that extends downward for threaded connection with the bottle body.

[0008] As described above, the waist-narrowing combination bottle cap has a partition plate in the middle of the cap base located between the upper and lower cylinder sections. The partition plate separates the inner cavities of the upper and lower cylinder sections, so that the top cap and the inner cavity of the upper cylinder section form a closed auxiliary cavity.

[0009] As described above, the waist-narrowing combination bottle cap has a panel portion and an insertion portion extending downward from the lower surface of the panel portion. The insertion portion matches the inner cavity of the upper cylinder section to be inserted into the inner cavity of the upper cylinder section. The side wall of the inner cavity of the upper cylinder section is provided with an annular step to accommodate the panel portion.

[0010] As described above, the waist-narrowing combination bottle cap has multiple circumferentially distributed vertical grooves on the inner wall of the upper cylindrical section, and vertical ribs that cooperate with the vertical grooves on the outer peripheral wall of the insertion part.

[0011] As described above, the waist-narrowing combination bottle cap has an inclined guide surface at the lower end of the vertical rib.

[0012] As described above, the waist-narrowing combination bottle cap has a sealing limiting part in the inner cavity of the lower section for abutting against the top of the bottle body when the cap seat is connected to the top of the bottle body.

[0013] As described above, the waist-narrowing combination bottle cap has an upper cylindrical section that is flared, wider at the top and narrower at the bottom, and its outer side wall is curved.

[0014] As described above, the waist-narrowing combination bottle cap has a lower cylindrical section that is flared, wider at the bottom and narrower at the top, and its outer side wall is curved.

[0015] As described above, the waist-narrowing combination bottle cap has a cap base made of polypropylene or high-density polyethylene material through injection molding, and the top cap is made of the same or compatible thermoplastic material as the cap base.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. This technical solution employs a unique component design, dividing the cover into upper and lower sections and sealing it with a top cover. This successfully solves the technical challenge of smooth demolding during injection molding of a narrow-center (i.e., "slender waist") shape due to its concave structure. Traditional one-piece hourglass-shaped structures, due to the inward contraction of the waist, create undercuts or closed areas in the mold, making it impossible to achieve damage-free demolding and easily leading to defects such as product deformation, shrinkage, and cracking. This solution, by designing the cover as a two-section structure that runs vertically through the body and using a top cover to seal the upper opening, retains the aesthetically pleasing and smooth hourglass shape while ensuring the feasibility of the injection molding process and a high yield rate.

[0018] 2. This modular structure also significantly improves product quality and reliability. Each component allows for independent optimization of molding parameters, reducing manufacturing difficulty. The central partition not only enhances sealing performance but also positions the mold parting line in the center of the structure, facilitating smooth demolding and reducing internal stress concentration. Simultaneously, the top cover and cover seat are securely connected via vertical grooves and ribs, effectively preventing loosening or detachment during use.

[0019] 3. Furthermore, the hourglass-shaped, tapered waist structure is ergonomic, providing a comfortable grip and good anti-slip properties, combining aesthetics and practicality. The auxiliary cavity formed inside the cap base can also accommodate functional components such as desiccants and flavor capsules, expanding the added value of the cap. Both the cap base and the top cap are preferably made of food-grade thermoplastic materials such as polypropylene (PP) or high-density polyethylene (HDPE), possessing good chemical stability, injection molding flowability, and material compatibility, further ensuring the durability of the seal and structural integrity. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the usage state of the combined bottle cap of this utility model. Figure 1 ;

[0021] Figure 2 This is a cross-sectional schematic diagram of the combined bottle cap of this utility model;

[0022] Figure 3 This is an exploded view of the modular bottle cap of this utility model. Figure 1 ;

[0023] Figure 4 This is an exploded view of the modular bottle cap of this utility model. Figure 2 ;

[0024] Figure 5 This is a schematic diagram of the usage state of the combined bottle cap of this utility model. Figure 2 . Detailed Implementation

[0025] The utility model will be further described below with reference to the accompanying drawings:

[0026] The orientations described in this utility model specification, such as "up," "down," "left," "right," "front," and "back," are based on the orientations in the accompanying drawings and are intended to facilitate the description of the relationships between the various components. They do not indicate the unique or absolute positional relationships between the various components, but are merely one embodiment of the utility model and are not a limitation on its implementation.

[0027] like Figures 1 to 5 As shown in the illustration, this embodiment introduces a waist-narrowing modular bottle cap, including a bottle cap assembly 100 for connecting to the top of the bottle body A. The bottle cap assembly 100 is mainly composed of a cap base 1 and a top cap 2. Both the cap base 1 and the top cap 2 are integrally molded using injection molding, preferably using polypropylene (PP) or high-density polyethylene (HDPE) materials. This material selection not only possesses good chemical stability, corrosion resistance, and food-grade safety, but also excellent injection flow and demolding performance, which is beneficial for achieving one-time molding of complex curved surface structures.

[0028] like Figures 2 to 4 As shown, the cover 1 has an upper cylindrical section 11 and a lower cylindrical section 12 connected vertically. The upper cylindrical section 11 expands outward from bottom to top, and the lower cylindrical section 12 expands outward from top to bottom, giving the cover 1 an hourglass shape that narrows in the middle (also known as a "slim waist" shape). This structure is more aesthetically pleasing and ergonomic, improving user comfort and grip. Due to the limitations of the injection molding process, if the cover 1 were a completely closed hourglass shape, the concave center would prevent it from easily exiting the mold, easily leading to product deformation, shrinkage, or even cracking. Therefore, this solution innovatively designs the cover 1 as a two-section structure that runs vertically through the top and bottom, and seals the upper opening by subsequently assembling the top cover 2, achieving both an ideal appearance and ensuring the feasibility of injection molding and a high yield rate. Specifically, by manufacturing two sections and then connecting the top cap 2 to the top of the upper cylindrical section 11 and sealing the top of the upper cylindrical section 11, an hourglass shape or a narrow waist shape is created. This also allows for demolding and avoids problems such as deformation, shrinkage, and cracking. Meanwhile, the lower cylindrical section 12 has a threaded ring 13 extending downwards into the inner cavity for threaded connection with the bottle body A. The threaded ring 13 connects with the external thread of the bottle body A through its internal thread, thereby realizing the function of a bottle cap and ensuring reliable sealing and smooth opening.

[0029] As a preferred method, such as Figures 2 to 4 As shown, the cap base 1 has a partition plate 14 located in the middle between the upper cylindrical section 11 and the lower cylindrical section 12. This partition plate ensures sealing performance even without the top cap 2, effectively preventing the contents from evaporating or external contaminants from entering. Simultaneously, the partition plate 14 is positioned precisely between the upper cylindrical section 11 and the lower cylindrical section 12, allowing for smooth demolding with the mold opening and parting point in the middle, simplifying the mold structure and improving production efficiency. Furthermore, the partition plate 14 separates the inner cavities of the upper cylindrical section 11 and the lower cylindrical section 12, forming a closed auxiliary cavity 110 with the top cap 2 and the inner cavity of the upper cylindrical section 11. This auxiliary cavity 110 can then perform other discharge functions, such as storing desiccants, flavor capsules, and two-component mixed excipients, expanding the multi-functional application scenarios of the bottle cap.

[0030] As a preferred option, such as Figures 2 to 4 As shown, the top cover 2 has a panel portion 21 and an insertion portion 22 extending downward from the lower surface of the panel portion 21. The insertion portion 22 matches the inner cavity of the upper cylindrical section 11 for insertion into the inner cavity of the upper cylindrical section 11. The side wall of the inner cavity of the upper cylindrical section 11 is provided with an annular step 111 to accommodate the panel portion 21. This structure can achieve axial limiting and circumferential positioning of the top cover 2, ensuring stable assembly and a flat appearance.

[0031] As a preferred embodiment, in order to ensure that the top cover 2 can be securely connected to the cover base 1, such as Figures 2 to 4As shown, the inner wall of the upper cylinder section 11 has multiple circumferentially distributed vertical grooves 112, and the outer wall of the insertion part 22 has vertical ribs 221 that mate with the vertical grooves 112. This snap-fit ​​structure provides reliable anti-torsional and anti-pull-out properties, preventing the top cover 2 from loosening or falling off during use. As a further optimization, the lower end of the vertical rib 221 is provided with an inclined guide surface 222 to facilitate the insertion of the insertion part 22 into the inner cavity of the upper cylinder section 11, improving assembly efficiency and reducing assembly stress.

[0032] As a preferred option, such as Figure 2 As shown, the lower cylinder section 12 has a sealing and limiting part 121 inside, which abuts against the top of the bottle body A when the cap seat 1 is connected to the top of the bottle body A. The sealing and limiting part 121 is annular, and when the cap seat 1 is connected to the top of the bottle body A, the sealing and limiting part 121 abuts against the bottle mouth end face of the bottle body A. This structure forms an end face seal, which works in conjunction with the threaded connection to significantly improve the overall sealing reliability, and is especially suitable for packaging liquids or volatile contents.

[0033] Preferably, the upper cylindrical section 11 is trumpet-shaped, wider at the top and narrower at the bottom, and its outer side wall is curved, such as a spherical or ellipsoidal surface. Such continuous smooth curved surfaces not only enhance aesthetic appeal but also reduce stress concentration and improve structural strength.

[0034] Preferably, the lower cylindrical section 12 is a trumpet shape, wider at the bottom and narrower at the top, and its outer side wall is curved, such as a spherical or ellipsoidal surface. This design corresponds to the upper cylindrical section 11, enhancing the overall streamlined appearance, while also increasing the bottom contact area and improving the stability of the bottle cap on the bottle opening.

[0035] Preferably, the cover 1 is integrally molded from polypropylene (PP) or high-density polyethylene (HDPE) through injection molding, and the top cover 2 is made of the same or compatible thermoplastic material as the cover 1. Material compatibility ensures that the two will not experience gaps or warping due to differences in thermal expansion coefficients during long-term use or under high-temperature environments, guaranteeing sealing durability and structural integrity.

[0036] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A combination bottle cap with a narrower waist, characterized in that: The bottle cap assembly includes a cap assembly for connecting to the top of the bottle body (A). The cap assembly consists of a cap seat (1) and a top cap (2). The cap seat (1) is made into an integral structure by injection molding. The cap seat (1) has an upper cylindrical section (11) and a lower cylindrical section (12) connected vertically. The upper cylindrical section (11) expands outward from bottom to top, and the lower cylindrical section (12) expands outward from top to bottom, so that the cap seat (1) has an hourglass-shaped structure that narrows in the middle. The top cap (2) is connected to the top of the upper cylindrical section (11) and seals the top of the upper cylindrical section (11). The lower cylindrical section (12) has a threaded ring (13) that extends downward for threaded connection with the bottle body (A).

2. The combined bottle cap with a narrower waist as described in claim 1, characterized in that: The cover (1) is provided with a partition plate (14) in the middle between the upper cylinder section (11) and the lower cylinder section (12). The partition plate (14) separates the inner cavity of the upper cylinder section (11) and the lower cylinder section (12), so that the top cover (2) and the inner cavity of the upper cylinder section (11) form a closed auxiliary cavity (110).

3. The combined bottle cap with a narrowed waist according to any one of claims 1 or 2, characterized in that: The top cover (2) has a panel portion (21) and a plug portion (22) extending downward from the lower surface of the panel portion (21). The plug portion (22) matches the inner cavity of the upper cylinder section (11) to be plugged into the inner cavity of the upper cylinder section (11). The side wall of the inner cavity of the upper cylinder section (11) is provided with an annular step (111) for accommodating the panel portion (21).

4. The combined bottle cap with a narrower waist as described in claim 3, characterized in that: The inner wall of the upper cylinder section (11) is provided with a plurality of vertical grooves (112) distributed along the circumference, and the outer wall of the insertion part (22) is provided with vertical ribs (221) that cooperate with the vertical grooves (112).

5. The combined bottle cap with a narrower waist as described in claim 4, characterized in that: The lower end of the vertical rib (221) is provided with an inclined guide surface (222).

6. The combined bottle cap with a narrowed waist according to any one of claims 1 or 2, characterized in that: The lower cylinder section (12) has a sealing limiting part (121) inside the cavity for abutting against the top of the bottle body (A) when the cap seat (1) is connected to the top of the bottle body (A).

7. The combined bottle cap with a narrowed waist according to any one of claims 1 or 2, characterized in that: The upper cylinder section (11) is a trumpet shape with a larger upper part and a smaller lower part, and its outer side wall is curved.

8. The combined bottle cap with a narrowed waist according to any one of claims 1 or 2, characterized in that: The lower cylinder section (12) is a trumpet shape with a smaller upper part and a larger lower part, and its outer side wall is curved.

9. The combined bottle cap with a narrowed waist according to any one of claims 1 or 2, characterized in that: The cover (1) is integrally molded by injection molding using polypropylene (PP) or high-density polyethylene (HDPE) material, and the top cover (2) is made of the same or compatible thermoplastic material as the cover (1).

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