Easy-open lid with pull ring not prone to breakage

Abstract

The utility model relates to the technical field of packaging container sealing, in particular to an easy-open cap with a pull ring not prone to breakage, which comprises a bottle cap and the pull ring riveted on the bottle cap, the inner edge of the pull ring extends along the center direction of the pull ring to form a riveting piece, and the riveting piece is riveted and fixed with a riveting column protruding upwards in the center of the bottle cap. The outer edge of the pull ring is folded inwards to form an outer curled edge, the inner edge of the pull ring is folded outwards except the connecting position of the pull ring and the riveting piece to form an inner curled edge, the outer contour of the outer curled edge is in a perfect circle shape, and the inner contour of the inner curled edge is in a C shape. Compared with the prior art, the utility model has the advantages that the stress is uniformly distributed, the fracture resistance is obviously improved, the structural strength and the connection flexibility are both considered, the processing technology is simplified, the appearance consistency is improved, the stress conduction path is optimized, and the opening reliability is enhanced.

Description

Technical Field

[0001] This utility model relates to the field of packaging container sealing technology, specifically to an easy-open cap suitable for bottled products such as carbonated beverages and beer with a pull ring that is not easily broken. Background Technology

[0002] Most existing easy-open bottle caps use a structure where the pull ring is riveted to the cap body and pre-marked to achieve convenient opening. However, the outer edge of the pull ring is often not closed. For example, some patents have an arc-shaped notch on the outer edge of the pull ring. Although this design claims to prevent hand scratches, in actual use, fingers mainly act on the inner ring of the pull ring. The notch on the outer edge has limited effect on preventing scratches, but it significantly increases the complexity of processing, requires higher precision molds, and is prone to problems such as burrs on the notch edge and irregular curling. At the same time, the non-closed curling disrupts the continuous smoothness of the outer edge of the pull ring, forming visual breaks or irregular areas, reducing the consistency and aesthetics of the overall appearance of the bottle cap. In particular, the structural abruptness at the notch can appear rough, affecting the product's sophistication and brand image. More importantly, this design weakens the strength of the pull ring itself, leading to stress concentration and reduced tear resistance, resulting in multiple contradictions between functional design, processing practicality, and aesthetic requirements. Utility Model Content

[0003] To address the problems of existing easy-open bottle caps, such as stress concentration, easy breakage, complex processing, and insufficient aesthetics due to the non-closed rolled edge of the pull ring, this utility model provides an easy-open cap with a less prone-to-break pull ring, achieved through the following technical solution:

[0004] A pull-tab cap that is not easily broken includes a bottle cap and a pull tab riveted to the bottle cap. The inner edge of the pull tab extends along its central direction to form a rivet piece. The rivet piece is riveted and fixed to a rivet post protruding upward from the center of the bottle cap. Unlike the prior art, the outer edge of the pull tab is folded inward to form an outward rolled edge, and the inner edge of the pull tab is folded outward except at the connection point with the rivet piece to form an inward rolled edge. The outer contour of the outward rolled edge is a perfect circle, and the inner contour of the inward rolled edge is C-shaped.

[0005] Furthermore, the upper ends of the rivet pieces narrow inward to form necks, the outer contour of the necks is a concave arc shape, and the upper and lower ends are tangent to the inner edge of the pull ring and the side edge of the rivet piece, respectively, forming a transition structure without sharp edges.

[0006] Furthermore, the two sides of the rivet piece, except for the neck area, are folded inward to form straight rolled edges.

[0007] Furthermore, the inner surface of the bottle cap is punched with a etched line for forming a tear. The etched line extends from the center of the bottle cap to the edge and bypasses the rivet post to form a preset tear path.

[0008] Furthermore, the engraving includes a left straight line segment located on the lower left side of the bottle cap and penetrating the bottle cap skirt, a right straight line segment located on the lower right side of the bottle cap and close to the bottle cap skirt, a semi-circular segment surrounding the riveting post and connecting the left and right straight line segments, and an arc segment that connects to and is tangent to the right straight line segment and extends toward the lower right corner but does not penetrate the bottle cap skirt.

[0009] Furthermore, the left and right line segments are parallel to each other and have no angle between them.

[0010] Furthermore, a guide mark for indicating the direction of force application is formed by downward stamping on the rivet tab.

[0011] Furthermore, the guide sign consists of a first line segment extending vertically from top to bottom and a second line segment that connects to the lower end of the first line segment and extends downwards and to the right, with an arrow at the end of the second line segment.

[0012] Furthermore, the outer surface of the bottle cap, which is located outside the projection area of ​​the rivet piece on the bottle cap within the projection area of ​​the inward rolled edge on the bottle cap, is the product identification area; graphic markings are formed in the product identification area by stamping or printing.

[0013] Furthermore, the width of the inward rolled edge is less than the width of the outward rolled edge, the inclination of the inward rolled edge is less than the inclination of the outward rolled edge, and the ends of the inward rolled edge and the outward rolled edge are not connected.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects:

[0015] 1. Uniform stress distribution and significantly improved fracture resistance: The outer edge of the pull ring is folded inward to form a closed circular rolled edge, which is different from the non-closed notch or opening structure of the existing technology. This achieves a complete closed loop of the rolled edge, so that the pulling force when opening is uniformly transmitted along the circumference of the rolled edge, avoiding stress concentration at the notch or opening. This fundamentally reduces the risk of tearing of the pull ring body due to local overload, and the measured tear resistance is increased by more than 30%.

[0016] 2. Balancing structural strength and connection flexibility: The inner edge adopts a C-shaped inward rolled edge (opening only at the connection with the rivet piece), which not only enhances the rigidity of the inner edge of the pull ring by folding outward, but also reserves space for the transition connection between the rivet piece and the pull ring, forming a synergistic structure of "external closed reinforcement - internal flexible connection". While improving the overall strength, it ensures the rotational flexibility of the pull ring and bottle cap rivet point, avoiding stress concentration at the connection part caused by the interruption of the rolled edge in the existing technology.

[0017] 3. Simplified processing and improved appearance consistency: The perfectly round closed structure of the outer rolled edge eliminates the need for additional stamping notches or complex bending processes, making mold design simpler and processing precision easier to control. This reduces common problems in non-closed rolled edges, such as burrs and irregular edges. At the same time, the continuous and smooth contour of the outer rolled edge enhances the overall aesthetics of the bottle cap, avoiding appearance defects caused by notches or openings. It is especially suitable for high-end product packaging with high visual requirements.

[0018] 4. Optimized stress transmission path and enhanced opening reliability: The closed outer rolled edge and the C-shaped inner rolled edge form a "double ring reinforced structure". Combined with the transition design of the rivet and pull ring, the pulling force during opening is more directly applied to the pre-marked area of ​​the bottle cap (not the weak point of the pull ring body). This reduces the additional torque or bending stress caused by uneven force on the pull ring, improves the stability and reliability of the opening process, and reduces the risk of breakage during user operation. Attached Figure Description

[0019] Figure 1 This is a front structural diagram of the present utility model.

[0020] Figure 2 This is a schematic diagram of the reverse side structure of this utility model.

[0021] Figure 3 This is a front structural diagram of the pull ring of this utility model.

[0022] Figure 4 This is a schematic diagram of the reverse side structure of the pull ring of this utility model.

[0023] Figure 5 yes Figure 4 Enlarged cross-sectional view at point AA. Detailed Implementation

[0024] like Figure 1-5 The illustrated easy-open cap with a pull ring that is not easily broken includes a bottle cap 1 and a pull ring 2 riveted to the bottle cap. The inner edge of the pull ring extends along its central direction to form a rivet piece 21. The rivet piece 21 is riveted and fixed to a rivet post 11 that protrudes upward from the center of the bottle cap 1. The outer edge of the pull ring is folded inward to form an outer rolled edge 22. The inner edge of the pull ring, except for the connection with the rivet piece 21, is folded outward to form an inner rolled edge 23. The outer contour of the outer rolled edge 22 is a perfect circle, and the inner contour of the inner rolled edge 23 is C-shaped.

[0025] The core principle behind the pull ring's resistance to breakage in this invention lies in the targeted design of the pull ring's edge curling structure, optimizing both the stress transmission path and structural strength.

[0026] The outer edge of the pull ring is folded inward to form a complete circular rolled edge. This closed structure solves the stress concentration problem of non-closed rolled edges in existing technologies. When a pulling force is applied during opening, the closed rolled edge can distribute the external force evenly along the circumference, avoiding local stress overload caused by gaps or openings in the rolled edge. This makes the pull ring more evenly stressed and effectively reduces the risk of tearing caused by stress concentration in critical areas.

[0027] The inner edge of the pull ring features a C-shaped inward-curled edge design, folding outwards except at the connection point with the rivet piece. This creates a localized reinforcement structure on the inner side of the pull ring while providing flexible transition space for the riveting area. This design enhances the rigidity of the inner side of the pull ring and improves its bending resistance through the inward-curled edge, while also avoiding the formation of a closed constraint at the connection point between the rivet piece and the pull ring. This reduces shear or bending loads caused by stress coupling in that area, making the stress state at the riveting point simpler and more stable.

[0028] The closed circular outer edge and the C-shaped inner edge work together to create a balanced mechanical structure that combines rigidity and flexibility: the outer edge bears the main tensile force and transmits it evenly, while the inner edge helps to enhance the inner strength and release stress in the riveting area. Together, they ensure a more rational stress distribution during opening, significantly reducing stress concentration at key connection points. Furthermore, the continuous contour of the closed outer edge simplifies the manufacturing process, reducing defects caused by notches or openings, and further enhancing the integrity and reliability of the pull ring's edge structure. This combination of structural design and manufacturing process ensures the pull ring is less prone to breakage.

[0029] In another preferred embodiment, the upper ends of the rivet pieces 21 are narrowed inward to form necks. The outer contour of the necks is a concave arc shape, and the upper and lower ends are tangent to the inner edge of the pull ring and the side edge of the rivet piece 21, respectively, forming a smooth transition structure without sharp edges. In the connection area between the pull ring and the rivet piece, by narrowing the upper end of the rivet piece inward and designing a concave arc-shaped neck outline, a smooth connection without sharp edges is formed in this transition area, avoiding the stress concentration problem caused by traditional right-angle or sharp-angle transitions. This concave arc structure can more evenly distribute the tensile and bending stresses acting between the rivet piece and the pull ring when opening, enhance the fatigue resistance of the connection part, and effectively reduce the risk of fracture caused by stress concentration.

[0030] In another preferred embodiment, the two side edges of the rivet piece 21, excluding the neck region, are folded inward to form straight rolled edges 24. Folding the two side edges of the rivet piece (excluding the neck region) inward to form straight rolled edges increases the material thickness and rigidity in this area, providing additional structural support for the rivet piece body. The straight rolled edges and the flexible transition structure of the neck form a rigid-flexible mechanical design, which improves the rivet piece's ability to withstand lateral shear forces during opening without affecting the stress buffering effect in the neck region, further enhancing the overall strength and reliability of the pull ring and bottle cap riveting joint.

[0031] In another preferred embodiment, the inner surface of the bottle cap 1 is punched with a serrated line 12 for forming a tear. The serrated line 12 extends from the center of the bottle cap to the edge and bypasses the rivet post 11, forming a preset tear path. Punching the serrated line on the inner surface of the bottle cap guides the tear path during opening by creating a preset weak structure inside, allowing the bottle cap to break smoothly along the serrated line without damaging the pull ring. This design hides the serrated line inside the bottle cap, making it invisible from the outside. This maintains the integrity and aesthetics of the bottle cap's outer surface while preventing the serrated line from being exposed to the outside and causing corrosion or wear due to moisture, impacts, etc., thus improving the durability of the structure. The serrated line bypasses the rivet post and extends to the edge, concentrating the main stress during opening in a preset area inside the bottle cap, rather than the connection between the pull ring and the bottle cap. This protects the pull ring from breaking due to localized overload under stress, while ensuring that the tearing process proceeds along the designed path, resulting in smooth and safe opening, balancing functional practicality and aesthetic integrity.

[0032] In another preferred embodiment, the engraving 12 includes a left straight segment 121 located on the lower left side of the bottle cap and penetrating the bottle cap skirt, a right straight segment 123 located on the lower right side of the bottle cap near the bottle cap skirt, a semi-circular segment 122 surrounding the riveting post 11 and connecting the left straight segment 121 and the right straight segment 123, and an arc segment 124 that connects to and is tangent to the right straight segment 123 and extends towards the lower right corner but does not penetrate the bottle cap skirt. This multi-segment engraving structure, through the coordinated design of different segments (e.g., the straight segment determines the tearing direction, the semi-circular segment buffers stress near the riveting post, and the arc segment guides the tearing endpoint), ensures that the bottle cap breaks regularly along a preset path when opened, avoiding irregular tears or fragments falling off. Because the engraving is hidden on the inner surface of the bottle cap, the tearing process only occurs in the internal weak area, while the outer structure remains intact and continuous. After opening, the pull ring and the bottle cap are still connected by the riveting structure, preventing independently falling fragments. This ensures safety (avoiding the risk of cuts) and facilitates overall recycling, meeting environmental protection requirements. This design achieves precise stress guidance while ensuring the cap maintains structural integrity after opening, facilitating subsequent recycling and reuse, thus balancing functionality and sustainability.

[0033] In another preferred embodiment, the left straight segment 121 and the right straight segment 123 are parallel to each other and have no included angle. This parallel, angle-free design ensures that the pulling force applied to the pull ring during opening is evenly transmitted along a symmetrical direction to the markings on both sides, avoiding stress concentration on one side caused by the angle between the segments. The parallel structure ensures that the load on both sides of the markings is consistent, guaranteeing a smooth tearing of the cap along a predetermined path, reducing twisting or bending deformation of the pull ring due to uneven force, and further improving the stability of the opening process.

[0034] In another preferred embodiment, a guide mark 25 for indicating the direction of force application during opening is stamped downwards on the riveting piece 21. The guide mark, stamped on the riveting piece, visually guides the user to apply force in the correct direction, ensuring that the direction of the pull force during opening aligns with the preset tear path of the cap's markings. This design avoids additional shear or torsional stress on the pull ring due to deviations in the direction of force application, allowing the pull force to act more directly and effectively on the marking area, reducing the risk of breakage due to incorrect force application, and improving the product's ease of use and reliability.

[0035] In another preferred embodiment, the guide mark 25 consists of a first vertical line segment extending from top to bottom and a second line segment that connects to the lower end of the first line segment and extends diagonally downward to the right. The end of the second line segment has an arrow. The guide mark adopts a zigzag structure with an arrow, using the vertical segment to indicate the vertical pulling direction, and the diagonal segment and arrow to clearly indicate the direction of subsequent force application, forming a clear operation guide. This visual design helps users quickly master the correct opening method, ensuring that the pulling force is transmitted along the preset path of the engraved lines, avoiding local overload of the pull ring due to improper force application angle, thereby protecting the pull ring structure from abnormal stress during the opening process and enhancing the overall structural durability.

[0036] In another preferred embodiment, the outer surface of the bottle cap, located outside the projection area of ​​the inwardly rolled edge 23 on the bottle cap and outside the projection area of ​​the rivet piece 21 on the bottle cap, constitutes a product identification area. Graphic markings are formed in this product identification area through stamping or printing. This method effectively utilizes the surface space of the bottle cap for brand display without affecting the riveting strength and stress transmission between the pull tab and the bottle cap. The stamped or printed graphic markings are far from the main stress area of ​​the pull tab, avoiding the impact of marking processing on the pull tab structure while also providing some protection for the markings using the edge structure of the inwardly rolled edge, thus achieving a combination of functionality and aesthetics.

[0037] In another preferred embodiment, the width of the inner rolled edge 23 is smaller than the width of the outer rolled edge 22, the inclination of the inner rolled edge 23 is smaller than the inclination of the outer rolled edge 22, and the ends of the inner rolled edge 23 and the outer rolled edge 22 are not connected. The wider outer rolled edge and the larger inclination provide the main tensile load-bearing and stress homogenization functions, while the inner rolled edge helps to enhance the inner rigidity and release stress in the riveting area. The fact that the ends of the two are not connected avoids the coupling and accumulation of stress at the edge connection, so that the double rolled edge structure works together without interfering with each other, further optimizing the overall mechanical properties and fracture resistance of the pull ring.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A pull-tab cap that is not easily broken, comprising a bottle cap (1) and a pull tab (2) riveted to the bottle cap, wherein the inner edge of the pull tab extends along its central direction to form a riveting piece (21), and the riveting piece (21) is riveted and fixed to a riveting post (11) protruding upward from the center of the bottle cap (1), characterized in that, The outer edge of the pull ring is folded inward to form an outer rolled edge (22), and the inner edge of the pull ring is folded outward except at the connection with the rivet piece (21) to form an inner rolled edge (23). The outer contour of the outer rolled edge (22) is a perfect circle, and the inner contour of the inner rolled edge (23) is a C-shape.

2. The easy-open cap with a pull ring that is not easily broken according to claim 1, characterized in that, The upper ends of the rivet pieces (21) narrow inward to form necks. The outer contour of the necks is a concave arc shape, and the upper and lower ends are tangent to the inner edge of the pull ring and the side edge of the rivet pieces (21) respectively, forming a transition structure without sharp edges.

3. The easy-open cap with a pull ring that is not easily broken according to claim 2, characterized in that, The two sides of the rivet piece (21), except for the neck area, are folded inward to form straight rolled edges (24).

4. The easy-open cap with a pull ring that is not easily broken according to claim 1, characterized in that, The inner surface of the bottle cap (1) is punched with a etched line (12) for forming a tear. The etched line (12) extends from the center of the bottle cap to the edge and passes around the rivet post (11) to form a preset tear path.

5. A pull-tab cap that is not easily broken according to claim 4, characterized in that, The engraving (12) includes a left straight line segment (121) located on the lower left side of the bottle cap and passing through the bottle cap skirt, a right straight line segment (123) located on the lower right side of the bottle cap and close to the bottle cap skirt, a semi-circular segment (122) surrounding the riveting post (11) and connecting the left straight line segment (121) and the right straight line segment (123), and an arc segment (124) that is connected to and tangent to the right straight line segment (123) and extends toward the lower right corner but does not pass through the bottle cap skirt.

6. The easy-open cap with a pull ring that is not easily broken according to claim 5, characterized in that, The left straight line segment (121) and the right straight line segment (123) are parallel to each other and have no angle between them.

7. The easy-open cap with a pull ring that is not easily broken according to claim 4, characterized in that, A guide mark (25) for indicating the direction of force application is formed by downward stamping on the rivet piece (21).

8. The easy-open cap with a pull ring that is not easily broken according to claim 7, characterized in that, The guide sign (25) consists of a first line segment extending vertically from top to bottom and a second line segment that connects to the lower end of the first line segment and extends downward to the right. The end of the second line segment has an arrow.

9. A pull-tab cap that is not easily broken according to claim 1, characterized in that, The inner rolled edge (23) is located in the projection area on the bottle cap, and the outer surface of the bottle cap located outside the projection area of ​​the rivet piece (21) on the bottle cap is the product identification area; the product identification area is formed by stamping or printing.

10. A pull-tab cap that is not easily broken according to claim 1, characterized in that, The width of the inward rolled edge (23) is less than the width of the outward rolled edge (22), the inclination of the inward rolled edge (23) is less than the inclination of the outward rolled edge (22), and the end of the inward rolled edge (23) is not connected to the end of the outward rolled edge (22).

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