Chin strap assembly, chin strap assembly manufacturing method and safety helmet

Abstract

The invention is suitable for the technical field of safety helmets, and provides a chin strap assembly, a chin strap assembly manufacturing method and a safety helmet, the chin strap assembly comprises two main strap modules and an adjusting buckling module; each main band module comprises a main band, two hat hoop connecting pieces and a sub-band piece, the sub-band piece is provided with a buckling connecting part, and the hat hoop connecting pieces are provided with connecting structures matched with hat hoops; the adjusting buckling module comprises an adjusting belt, a first buckle integrally connected with one end of the adjusting belt through an insert injection molding process, a second buckle slidably arranged on the adjusting belt in a sleeving mode, and an adjusting buckle slidably arranged on the adjusting belt in a sleeving mode. And the first buckle and the second buckle and the buckling connection parts of the two main belt modules respectively form two detachably connected inserting buckle systems. The chin strap assembly solves the problem that an existing chin strap assembly adopting a sewing connection mode is obviously insufficient in connection strength, durability, production efficiency and design flexibility.

Description

Technical Field

[0001] This invention relates to the field of safety helmet technology, and in particular to a chin strap assembly, a method for manufacturing the chin strap assembly, and a safety helmet. Background Technology

[0002] Safety helmets are crucial personal protective equipment used in high-risk activities such as industrial production, construction, and sports to protect users' heads from injuries caused by falling objects and impacts. A safety helmet typically consists of a shell, a liner (including a crown strap and headband), and a chin strap. The chin strap, as a vital component that securely fastens the helmet to the user's head, plays a crucial role in preventing the helmet from shifting or falling off during work or under stress due to shaking, collisions, or changes in head posture, thus ensuring continuous and effective head protection.

[0003] Currently, most chin strap assemblies on the market use traditional industrial sewing techniques to connect the webbing to plastic fasteners (such as connecting buckles, adjusting buckles, and snap buckles). Specifically, workers or automated equipment use high-strength sewing thread to repeatedly pierce and sew the end of the webbing to the connecting ring or webbing hole of the plastic fastener for fixation. While this sewing connection method can meet basic usage requirements to some extent, its inherent defects become increasingly apparent under long-term use and stringent safety standards.

[0004] Insufficient connection strength and low reliability: The strength of the seam depends entirely on the material of the suture, the density of the stitches, and the quality of the workmanship. However, the suture itself, especially in harsh environments such as outdoors, dusty, humid, or chemically corrosive conditions, is highly susceptible to wear, UV aging, mold, or chemical degradation, leading to decreased strength or even breakage. When the helmet is subjected to significant external impact or pulling, the stress around the seam holes becomes highly concentrated, making the seam a weak point in the entire chin strap system, prone to tearing or unraveling, causing chin strap failure and posing a serious safety hazard.

[0005] Low production efficiency and high costs: Even with automated equipment, the sewing process involves multiple steps such as threading, positioning, sewing, and cutting the thread, making it relatively cumbersome and slow in production. Furthermore, manual operation easily leads to inconsistent product quality and a high defect rate. In addition, sewing processes consume additional materials such as sewing thread and require specialized sewing equipment and operators, increasing manufacturing and management costs.

[0006] Poor comfort and aesthetics: Unavoidable loose threads and rough seams at the seams can cause friction, indentations, or even scratches when worn, reducing comfort. Furthermore, messy threads and uneven seams detract from the overall appearance of the product, making it look less refined and professional.

[0007] Limitations in maintenance and design: Traditional chin straps are typically a single, integrated structure. Damage to any part (such as worn webbing or broken fasteners) often necessitates replacing the entire component, resulting in high maintenance costs. Their integrated design also restricts modular and customized development, making it difficult to meet the individualized needs of different users or application scenarios.

[0008] In summary, existing chin strap components using sewing connections have significant shortcomings in terms of connection strength, durability, production efficiency, wearing comfort, and design flexibility, and a new technical solution is urgently needed to fundamentally solve these problems. Summary of the Invention

[0009] Therefore, the purpose of this invention is to provide a chin strap assembly, a method for manufacturing a chin strap assembly, and a safety helmet, so as to fundamentally solve the problems that existing chin strap assemblies using sewing connection methods have significant deficiencies in connection strength, durability, production efficiency, and design flexibility.

[0010] A chin strap assembly according to an embodiment of the present invention is applied to a safety helmet, comprising two main strap modules and an adjustment buckle module detachably connected to the two main strap modules;

[0011] Each main strap module includes a main strap, two headband connectors integrally connected to the two ends of the main strap via an insert injection molding process, and a branch strap for the main strap to be folded and threaded through. The branch strap has a fastening connection part, and the headband connector has a connection structure for engaging with the headband of the safety helmet.

[0012] The adjusting fastening module includes an adjusting belt, a first fastener integrally connected to one end of the adjusting belt via an insert injection molding process, a second fastener slidably sleeved on the adjusting belt, and an adjusting buckle slidably sleeved on the adjusting belt and located between the first fastener and the second fastener.

[0013] The first and second buckles on the adjusting buckle module and the buckling connection parts on the two main belt modules respectively constitute two buckle systems that can cooperate with each other and achieve detachable connection, thereby realizing the detachable connection between the adjusting buckle module and the two main belt modules.

[0014] In addition, a chin strap assembly according to the above embodiments of the present invention may also have the following additional technical features:

[0015] Furthermore, the fastening connection parts on the sub-belt components in both main belt modules are configured as male fastening connection parts or female fastening connection parts, and the first fastener and the second fastener are respectively provided with female fastening structure or male fastening structure that cooperates with the sub-belt.

[0016] Furthermore, the fastening connection on the branch component of one of the main belt modules is configured as a male fastening connection, and the fastening connection on the branch component of the other main belt module is configured as a female fastening connection; correspondingly, in the first buckle and the second buckle, one is provided with a female fastening structure and the other is provided with a male fastening structure.

[0017] Furthermore, the routing path of the adjusting belt is as follows: starting from the end of the first buckle, passing through the adjusting buckle in sequence, then wrapping around and passing through the belt-passing structure on the second buckle, and finally passing back through the adjusting buckle to form an adjustable closed loop, wherein the second buckle is located on one side of the closed loop, and the free tail end formed after the adjusting belt passes through the adjusting buckle is provided with an anti-disengagement buckle that is integrally fixed by an insert injection molding process.

[0018] Furthermore, the integrated connection area between the headband connector and the main strap, the integrated connection area between the first buckle and the adjusting strap, and the integrated connection area between the anti-loosening buckle and the adjusting strap are all provided with at least one through hole formed during the injection molding process.

[0019] Furthermore, the strip component includes an integrally formed main body and a snap-fit ​​connection portion integrally extended from the lower edge of the main body;

[0020] The main body includes a guide frame at the front end for guiding and positioning the main belt, a support back plate at the rear end for providing a support contact surface for the sub-belt, and a transverse bearing beam at the rear end and below the support back plate for allowing the main belt to be folded around. The guide frame, the support back plate, and the transverse bearing beam together form a belt passage through which the main belt passes in a folded manner.

[0021] Another objective of this invention is to provide a method for manufacturing a chin strap assembly, for manufacturing a chin strap assembly as described above, the method comprising the following steps:

[0022] Provide non-injection molded components: provide a main belt, an adjusting belt, a branch belt component, a second fastener, and an adjusting buckle, and pass the main belt through the branch belt component in a folded manner;

[0023] Manufacturing insert injection molded components: Two headband connectors that are integrally connected to the end of the main belt, and a first buckle that is integrally connected to one end of the adjustment belt, are manufactured by insert injection molding process;

[0024] Final assembly: Assemble the insert injection-molded component with the non-injection-molded component to form a chin strap assembly including two main strap modules and an adjustment buckle module detachably connected to the two main strap modules.

[0025] Furthermore, the step of manufacturing two headband connectors integrally connected to the end of the main belt and a first buckle integrally connected to one end of the adjustment belt through insert injection molding includes:

[0026] The end of the pre-treated main band is placed in a first injection mold with a cavity that defines the shape of the headband connector, and the end of the main band is fixed by a component in the first injection mold. Molten first plastic is injected into the cavity of the first injection mold, and the headband connector is formed by injection molding and is integrally connected with the main band.

[0027] One end of the pre-treated adjustment band is placed in a second injection mold with a cavity that defines the shape of the first fastener, and the end of the adjustment band is fixed by a component in the second injection mold. Molten second plastic is injected into the cavity of the second injection mold, and the first fastener is integrally connected with the adjustment band by injection molding.

[0028] Furthermore, the step of fixing the end of the main belt by means of a component within the first injection mold includes:

[0029] The end of the main strip is pressed by a pressure block structure set in the cavity of the first injection mold to limit its displacement in the direction perpendicular to the parting surface of the first injection mold; and at least one first positioning post structure extending from one or both sides of the first injection mold abuts against or passes through the end of the main strip to limit its displacement in the plane parallel to the parting surface of the first injection mold, wherein the first positioning post structure retracts after injection molding and forms a through hole in the cap connector;

[0030] The step of fixing the end of the adjusting belt through a component inside the second injection mold includes:

[0031] The end of the adjusting belt is pressed by a pressure block structure disposed in the cavity of the second injection mold to limit its displacement in the direction perpendicular to the parting surface of the second injection mold; and at least one second positioning post structure extending from one or both sides of the second injection mold abuts against or passes through the end of the adjusting belt to limit its displacement in a plane parallel to the parting surface of the second injection mold, wherein the second positioning post structure retracts after injection molding and forms a through hole in the first fastener.

[0032] Another embodiment of the present invention aims to provide a safety helmet, including a helmet shell, a top strap fixedly connected to the helmet shell, a headband fixedly connected to the top strap, and a chin strap assembly as described above fixedly connected to the headband.

[0033] The chin strap assembly provided in this invention innovatively designs the overall structure of the chin strap as two main strap modules and a detachable adjustable buckle module, achieving independence and replaceability of each functional part, greatly reducing user maintenance costs and resource waste. By using insert injection molding technology at all key connection points such as the headband connector and the first buckle, and utilizing mold positioning pillars to form a reinforced structure with through holes after injection molding, a seamless, high-strength three-dimensional physical interlock between the webbing and the plastic parts is achieved. This fundamentally eliminates the safety failure risk caused by thread wear, aging, and breakage at traditional sewing connection points, significantly improving the product's durability and reliability. At the same time, insert injection molding enables highly automated production, not only eliminating sewing equipment and labor, reducing consumables such as thread, but also greatly shortening the production process and reducing overall manufacturing costs. Through integrated structural optimization of the sub-strap components, a guide frame, a support back plate, and a transverse load-bearing beam are set up. This design achieves effective guidance of the main strap and even distribution of wearing pressure, ensuring the webbing remains smooth and flat during use. This avoids discomfort caused by twisting or pressing on the skin, significantly improving wearing stability and comfort. By setting the corresponding first and second buckles of the two main strap modules and the adjustment buckle module as a mutually compatible snap-fit ​​system, it covers multiple connection possibilities, including symmetrical and asymmetrical designs. This allows for free combination and interchangeability between different modules, greatly enhancing the product's versatility and user choice. By optimizing the stitching path of the adjustment strap and using an insert injection molding process to fix the anti-disengagement buckle at the end, it achieves fast, self-locking, and reliable length adjustment. It also provides a physical safety limit for the adjustment stroke, effectively preventing the risk of the chin strap completely loosening due to misoperation. This solves the problems of existing chin strap assemblies using sewn connections, which have significant deficiencies in connection strength, durability, production efficiency, and design flexibility. Attached Figure Description

[0034] Figure 1This is a schematic diagram of the chin strap assembly in the first embodiment of the present invention from a first perspective.

[0035] Figure 2 This is an exploded view of the chin strap assembly in the first embodiment of the present invention from a second perspective;

[0036] Figure 3 This is another exploded view of the chin strap assembly in the first embodiment of the present invention from a third-person perspective;

[0037] Figure 4 This is a schematic diagram of the main band module in the chin strap assembly according to the first embodiment of the present invention from a fourth perspective.

[0038] Figure 5 This is a flowchart of the chin strap component manufacturing method in the second embodiment of the present invention;

[0039] Figure 6 This is an exploded view of the safety helmet in the third embodiment of the present invention from a fifth perspective;

[0040] Figure 7 This is a schematic diagram of the safety helmet in the third embodiment of the present invention from a sixth-angle perspective;

[0041] The following detailed description of the embodiments will further illustrate the present invention in conjunction with the above-described accompanying drawings. Detailed Implementation

[0042] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0043] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] Example 1

[0046] Please see Figures 1-4 The image shows a chin strap assembly in the first embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown. The chin strap assembly provided in the embodiment of the present invention is applied to a safety helmet and includes two main strap modules 41 and an adjustment buckle module 42 that is detachably connected to the two main strap modules 41.

[0047] Each main strap module 41 includes a main strap 411, two headband connectors 412 integrally connected to the two ends of the main strap 411 by an insert injection molding process, and a branch strap 413 for the main strap 411 to be inserted in a folded form. The branch strap 413 is provided with a fastening connection part 4132, and the headband connector 412 is provided with a connection structure 4121 for cooperating with the headband of the safety helmet.

[0048] The adjusting fastening module 42 includes an adjusting belt 421, a first fastener 422 integrally connected to one end of the adjusting belt 421 by an insert injection molding process, a second fastener 423 slidably sleeved on the adjusting belt 421, and an adjusting buckle 424 slidably sleeved on the adjusting belt 421 and located between the first fastener 422 and the second fastener 423.

[0049] The first buckle 422 and the second buckle 423 on the adjusting buckle module 42 and the buckling connection part 4132 provided on the sub-belt member 413 in the two main belt modules 41 respectively constitute two buckle systems that can cooperate with each other and achieve detachable connection, thereby realizing the detachable connection between the adjusting buckle module 42 and the two main belt modules 41.

[0050] In one embodiment of the present invention, the chin strap assembly is mainly used in safety helmets used in various industrial, construction, and sports fields to securely fix the helmet to the user's head. The entire chin strap assembly is divided into two main strap modules 41 and an adjustable buckle module 42 that can be detachably connected to them. Each main strap module 41 is the main lateral load-bearing and positioning part of the chin strap assembly. It includes a main strap 411, two headband connectors 412, and a branch strap 413. The main strap 411 is the main load-bearing part of the chin strap and is typically made of a woven material with high tensile strength and abrasion resistance, such as nylon, polyester fiber, or polyester webbing. The length of the main strap 411 is determined according to the safety helmet design, providing a basic support structure for the entire chin strap assembly and bearing the main tensile force.

[0051] In one embodiment of the present invention, the headband connector 412 is a key component connecting the main strap 411 to the headband of the helmet, and is typically injection molded from engineering plastics such as polyoxymethylene (POM) or polyamide (PA). The lower part of each headband connector 412 is integrally connected to the end of the corresponding main strap 411 via an insert injection molding process. Specifically, during the injection molding of the headband connector 412, the end of the main strap 411 is pre-placed in the cavity of the injection mold, and then molten engineering plastic is injected. After solidification, the engineering plastic firmly encapsulates the end of the main strap 411, forming a seamless, high-strength assembly. The upper part of the headband connector 412 is also provided with a connecting structure 4121, such as a T-hole, hook, or slot, for a secure and detachable connection with a corresponding fixing point (such as a fixing post) or interface on the helmet headband.

[0052] In one embodiment of the present invention, the split strap component 413 is the core component for achieving wearing comfort and modular connection. The main strap 411 is folded in half and threaded through the split strap component 413, forming a stable V-shaped structure. Its function is to divide the main strap 411 from a wide band into two, which wrap around the front and back of the user's ears respectively, making the wearing more stable and comfortable. The split strap component 413 is provided with a fastening connection part 4132, which serves as an interface for connecting with the adjustment fastening module 42, enabling a detachable connection with the adjustment fastening module 42. Depending on the design, the fastening connection parts 4132 on the two main strap modules 41 can be configured as identical male (or female) fastening connection parts, or they can be configured as one male fastening connection part and one female fastening connection part to prevent incorrect assembly.

[0053] Therefore, by modularizing the main strap module 41, production and inventory management become extremely convenient, while assembly becomes simple and quick, reducing the complexity of final assembly. Standardized main strap modules 41 can be pre-manufactured, and then users can replace them with adjustment and fastening modules 42 of different functions or materials (e.g., those with reflective strips, magnetic buckles, different colors or materials) according to order requirements, enhancing product personalization and applicability. Furthermore, users can easily disassemble the three modules for thorough cleaning and drying, ensuring personal hygiene. More importantly, traditional one-piece chin straps require complete replacement if damaged. In this embodiment, if the adjustment strap 421 of one side of the main strap 411 or adjustment and fastening module 42 is worn, the user only needs to replace the corresponding main strap module 41 or adjustment and fastening module 42, rather than the entire chin strap, reducing maintenance costs and resource waste. Furthermore, the main strap 411 and the headband connector 412 are integrated using an insert injection molding process. This allows the plastic to completely cover the connection and penetrate the gaps in the webbing fibers, forming a strong mechanical lock. This significantly improves the pull-out resistance and durability of the connection point, far exceeding that of traditional sewing. It eliminates the risk of thread aging and breakage, making the connection between the chin strap assembly and the helmet extremely reliable. Simultaneously, the fast injection molding speed enables automated production, reducing manual sewing processes, thus increasing production efficiency and lowering manufacturing costs. The integrated connection also results in a smooth and neat joint, effectively enhancing the overall aesthetics of the product.

[0054] Furthermore, in one embodiment of the present invention, the splitter 413 is ingeniously designed as a multifunctional integrated component. The splitter 413 includes an integrally formed main body 4131 and an integrally formed fastening connection 4132 extending from the lower edge of the main body 4131; wherein the main body 4131 includes a guide frame 41311 at the front end for guiding and positioning the main belt 411, a support back plate 41312 at the rear end for providing a support contact surface for the splitter 413, and a transverse bearing beam 41313 at the rear end and below the support back plate 41312 for the main belt 411 to be folded around. The guide frame 41311, the support back plate 41312, and the transverse bearing beam 41313 together enclose a belt passage through which the main belt 411 passes in a folded form. The guide frame 41311 is located at the front end of the main body 4131, defining the position and angle at which the main strap 411 enters and exits, preventing the webbing from twisting or folding. The support back plate 41312 is located at the rear end of the main body 4131, forming a smooth, curved surface of a certain area. This curved surface conforms to the user's chin or cheek during use, providing comfortable support. The transverse load-bearing beam 41313 is located below the support back plate 41312 and is the main stress point when the main strap 411 is folded. Furthermore, an inclined guide surface extends from below the transverse load-bearing beam 41313, guiding the main strap 411 to smoothly complete a U-shaped turn. At this point, the support back plate 41312 distributes the pressure, avoiding discomfort caused by direct pressure from a single webbing strip on the skin. The guide frame 41311 ensures that the main strap 411 always passes smoothly and evenly, preventing webbing twisting from affecting stress or aesthetics. Meanwhile, the one-piece molding design results in a compact structure and high strength, enabling it to withstand the tension of the webbing for a long time.

[0055] Furthermore, in one embodiment of the present invention, the adjusting buckle module 42 is a key component for realizing the quick fastening and length adjustment functions of the chin strap. It includes an adjusting belt 421, a first buckle 422, a second buckle 423, and an adjusting buckle 424. The adjusting belt 421 is typically made of a similar material to the main belt 411, and one end is integrally connected to the first buckle 422 via an insert injection molding process, thus possessing the advantages of high strength and high durability brought by the aforementioned insert injection molding process. The second buckle 423 is slidably fitted onto the adjusting belt 421, rather than being fixedly connected. In this case, the structures of the first buckle 422 and the second buckle 423 correspond to the fastening connection portions 4132 of the branch straps 413 on the two main belt modules 41, together forming two mutually cooperating buckle systems. For example, the snap-fit ​​connection 4132 on the branch strap 413 of the first main strap module 41 snaps into the first buckle 422 of the adjusting snap-fit ​​module 42, while the snap-fit ​​connection 4132 on the branch strap 413 of the second main strap module 41 snaps into the second buckle 423 of the adjusting snap-fit ​​module 42. At this time, through these two snap-fit ​​systems, the three modules (that is, the two main strap modules 41 and the adjusting snap-fit ​​module 42) are combined into a complete chin strap assembly. Since it is a snap-fit ​​connection, disassembly and assembly are very convenient and quick, and the quick disassembly and assembly between the adjusting snap-fit ​​module 42 and the two main strap modules 41 can be easily realized.

[0056] Furthermore, the two independent buckle systems have multiple connection combinations. In one connection combination of this embodiment, the buckling connection portion 4132 on the sub-belt component 413 in both main belt modules 41 is configured as a male buckle connection portion or a female buckle connection portion. The first buckle 422 and the second buckle 423 are respectively provided with a female buckle structure or a male buckle structure that cooperates with the sub-belt. For example Figures 2-4 As shown, this is a preferred embodiment of the present invention, in which the fastening connection portions 4132 on both split-belt components 413 are designed as male fastening connections. Correspondingly, the first fastener 422 and the second fastener 423 on the adjusting fastening module 42 are both designed as female fastening structures that cooperate with them. Since the structures of the two main belt modules 41 are completely identical, only one set of molds is needed when manufacturing the split-belt components 413. The first fastener 422 and the second fastener 423 of the adjusting fastening module 42 can also share some molds or designs, thereby simplifying mold development and production management and reducing manufacturing costs. At the same time, the two main belt modules 41 can be used interchangeably without distinguishing between left and right, simplifying the installation process.

[0057] In another connection configuration of this invention, the fastening connection portion 4132 on the branch strap member 413 of one main strap module 41 is configured as a male fastening connection portion, and the fastening connection portion 4132 on the branch strap member 413 of the other main strap module 41 is configured as a female fastening connection portion. Correspondingly, in the first buckle 422 and the second buckle 423, one is provided with a female fastening structure, and the other is provided with a male fastening structure. This asymmetrical design fundamentally eliminates the possibility of incorrect installation by the user, ensuring that the main strap module 41 on the left side is necessarily connected to the corresponding side of the adjusting fastening module 42, and the same applies to the right side. This avoids twisting of the chin strap assembly or discomfort due to incorrect installation, improving the convenience and safety of use. It should be noted that this invention is not limited to specific male and female head forms; users can choose different types of adjusting fastening modules 42 to use with the standard main strap module 41 according to their preferences.

[0058] Furthermore, to facilitate users in adjusting the tightness of the chin strap assembly according to their head shape, an adjustment buckle 424 is provided on the adjustment buckle module 42. The adjustment buckle 424 is typically a D-ring, a three-way buckle, or a similar plastic or metal component, which is slidably fitted onto the adjustment strap 421 and located between the first buckle 422 and the second buckle 423. It is used to lock the adjusted length, thereby realizing length adjustment and ensuring that the helmet will not shake or fall off during activities. This allows users to easily tighten or loosen the chin strap assembly to achieve a comfortable and safe wearing state. To adjust the tightness, the user simply pulls the free end of the adjustment strap 421. The strap's path is designed as follows: starting from the end of the first buckle 422, it passes through the adjustment buckle 424, then loops around the strap structure (such as a crossbeam or closed loop) on the second buckle 423, and finally returns to the adjustment buckle 424 to form an adjustable closed loop. The second buckle 423 is located on one side of the closed loop. This structure utilizes friction for self-locking, ensuring stability during wear as it is not easily slipped under pressure once adjusted to the appropriate length. The user can tighten the strap by pulling the free end of the adjustment strap 421 with one hand or loosen it by lifting the adjustment buckle 424, making the operation intuitive and simple. Furthermore, to address the excess free end of the adjustment band 421 after adjustment, an anti-slip buckle 425, integrally fixed via an insert injection molding process, is provided on the free end formed after the adjustment band 421 passes through the adjustment buckle 424. This anti-slip buckle 425 is also a small plastic part. In this case, the anti-slip buckle 425 at the free end effectively prevents the adjustment band 421 from completely slipping out of the adjustment buckle 424 when the adjustment is too loose, avoiding the risk of the chin strap assembly accidentally coming apart. The insert injection-molded anti-slip buckle 425 is more secure and aesthetically pleasing than traditional heat-cutting or sewing methods.

[0059] Furthermore, in one embodiment of the present invention, the integrated connection area of ​​the headband connector 412 and the main strap 411, the integrated connection area of ​​the first buckle 422 and the adjusting strap 421, and the integrated connection area of ​​the anti-disengagement buckle 425 and the adjusting strap 421 are all provided with at least one through hole formed during the injection molding process. These holes are a result of the injection mold design. Before injection molding, in order to accurately and firmly position the end of the webbing in a predetermined position within the mold cavity and prevent it from shifting under the impact of the molten plastic at high temperature and pressure, a positioning post structure is usually provided in the mold to precisely fix the soft webbing. These positioning posts extend from one or both sides of the mold, abutting against or passing through the end of the webbing. After injection molding is completed, the positioning posts retract, leaving holes on the plastic part corresponding to the shape of the positioning posts. At the same time, the pressure block structure within the mold presses the webbing tightly, ensuring it fits snugly against the mold surface. Therefore, these holes are a natural result of the insert injection molding process, mainly stemming from the need to ensure the precise positioning and fixation of the webbing during the injection molding process. The presence of these holes indirectly proves the use of precise positioning measures, ensuring the accuracy of the insert's position and product consistency. This helps guarantee that the webbing is properly covered, thereby ensuring the strength and reliability of the insert injection molding connection. Furthermore, in some cases, the plastic at the hole edge bonds more tightly with the webbing fibers, or plastic slightly flows into the webbing's pores, which can enhance the shear or peel resistance of the joint to a certain extent, forming a stronger physical lock. This further enhances the mechanical locking force at the microscopic level, far exceeding traditional connection methods, and greatly improves the product's durability and safety.

[0060] In this embodiment of the invention, the traditional chin strap is decomposed into two independently manufactureable main strap modules and a functionally integrated adjustment and fastening module. The modules are connected via a standard snap-fit ​​system, greatly improving the product's production flexibility, maintenance convenience, and user customization capabilities. Simultaneously, by widely employing insert injection molding technology at key connection points (such as the headband connector and the first fastener), the problems of low strength, easy aging, and unsightly appearance associated with traditional sewing connections are fundamentally solved, significantly improving the product's durability, safety, and overall quality.

[0061] In summary, the chin strap assembly in the above embodiments of the present invention innovatively designs the overall structure of the chin strap as two main strap modules and a detachable adjustment and fastening module, achieving independence and replaceability of each functional part, greatly reducing user maintenance costs and resource waste; by using insert injection molding technology at all key connection points such as the headband connector and the first buckle, and utilizing the mold positioning post to form a reinforced structure with through holes after injection molding, a seamless, high-strength three-dimensional physical interlock between the webbing and the plastic parts is achieved, fundamentally eliminating the safety failure risk caused by the wear, aging and breakage of traditional sewing connection points, significantly improving the durability and reliability of the product. At the same time, insert injection molding can achieve highly automated production, not only saving sewing equipment and labor, reducing consumables such as sewing thread, but also greatly shortening the production process and reducing the overall manufacturing cost; by optimizing the integrated structure of the sub-strap components, setting guide frames, support back plates and lateral load-bearing... The beam effectively guides the main strap and evenly distributes wearing pressure, ensuring the webbing remains smooth and flat during use. This avoids discomfort caused by twisting or pressing on the skin, significantly improving wearing stability and comfort. By setting the corresponding first and second buckles of the two main strap modules and the adjustment buckle module as a mutually compatible snap-fit ​​system, it covers multiple connection possibilities, including symmetrical and asymmetrical ones. This allows for free combination and interchangeability between different modules, greatly enhancing the product's versatility and user choice. By optimizing the stitching path of the adjustment strap and using an insert injection molding process to fix the anti-dislodgement buckle at the end, it achieves fast, self-locking, and reliable length adjustment, and provides a physical safety limit for the adjustment stroke. This effectively prevents the risk of the chin strap completely loosening due to misoperation, solving the problems of existing chin strap assemblies using sewn connections, which have significant deficiencies in connection strength, durability, production efficiency, and design flexibility.

[0062] Example 2

[0063] Please see Figure 5 The image shows a method for manufacturing a chin strap assembly according to a second embodiment of the present invention. For ease of explanation, only the parts related to the embodiments of the present invention are shown. The method for manufacturing a chin strap assembly provided by the embodiments of the present invention is used to manufacture the chin strap assembly described in the foregoing embodiments. The method includes the following steps:

[0064] Step S10, providing non-injection molded parts: providing a main belt, an adjusting belt, a branch belt component, a second fastener, and an adjusting buckle, and inserting the main belt into the branch belt component in a folded-over manner;

[0065] In one embodiment of the invention, the method begins with the preparation of all non-injection molded standard parts and webbing materials. Specifically, operators or automated equipment retrieve all standardized non-injection molded parts from the material warehouse according to the product specification list. These include pre-cut and edge-treated main and adjusting belts; and plastic parts independently manufactured using conventional injection molding processes, namely, the split belt, the second fastener, and the adjusting buckle. These parts are standardized finished products that can be mass-produced and stockpiled in advance. The main and adjusting belts are typically cut to preset lengths using fully automated hot-cutting or ultrasonic cutting equipment. This process instantly melts and seals the cut edges of the webbing during cutting, forming a closed and regular edge structure. This effectively prevents fiber detachment or fraying during use and subsequent processing, ensuring the integrity and durability of the parts. It also facilitates precise positioning and fixing in the mold, helps form a better seal during injection molding, reduces plastic overflow (flash), and improves the final connection quality and appearance.

[0066] Further, a crucial pre-assembly step is performed: a pre-treated main belt is folded in half and threaded through the belt passage inside a sub-tape unit. Specifically, an operator or robotic arm grasps a main belt, feeds it through one opening of the sub-tape unit's guide frame, allowing it to slide smoothly into the belt passage, folds it in half, wraps it around the transverse support beam, and exits through another opening of the sub-tape unit's guide frame. At this point, the two ends of the main belt form a stable V-shaped structure within the sub-tape unit. This pre-assembly operation creates a preliminary semi-finished main belt module, allowing the complex threading action to be completed in advance, enabling the subsequent manufacturing of the headband connectors at both ends of the main belt through insert injection molding.

[0067] Step S20, manufacture insert injection molded components: manufacture two headband connectors that are integrally connected to the end of the main belt and a first buckle that is integrally connected to one end of the adjustment belt through insert injection molding process;

[0068] In one embodiment of the invention, the webbing and plastic fastener are integrated using an insert injection molding process to form a high-strength connection structure. This stage mainly manufactures various key insert injection molded components, specifically a headband connector integrated with the end of the main strap, and a first fastener integrated with one end of the adjustment strap. Optionally, an anti-disengagement buckle integrated with the other end of the adjustment strap may also be included.

[0069] Furthermore, the steps described above, which involve manufacturing two headband connectors integrally connected to the end of the main belt and a first buckle integrally connected to one end of the adjusting belt using insert injection molding, include:

[0070] The pre-treated end of the main strip is placed in a first injection mold with a cavity that defines the shape of the headband connector. The end of the main strip is fixed by a component in the first injection mold. Molten first plastic is injected into the cavity of the first injection mold. The headband connector is formed by injection molding and is integrally connected with the main strip.

[0071] One end of the pre-treated adjustment strip is placed in a second injection mold with a cavity that defines the shape of the first fastener, and the end of the adjustment strip is fixed by a component in the second injection mold. Molten second plastic is injected into the cavity of the second injection mold, and the first fastener is formed by injection molding and integrally connected with the adjustment strip.

[0072] Specifically, the two ends of a pre-treated main strip from the prepared semi-finished main strip module are manually or automatically and precisely placed into predetermined positions within the two cavities of a first injection mold. The shape of the mold cavities defines the final shape of the headband connector. To ensure that the flexible webbing does not shift during the high-temperature, high-pressure injection molding process, a precision fixing mechanism is integrated inside the first injection mold. This fixing mechanism preferably includes: a pressure block structure located at the bottom or side of the cavity to provide initial compression and positioning of the placed fabric strip; and at least one first positioning post structure that extends from one or both sides of the mold during or after mold closing, precisely abutting against or passing through the fabric strip, working in conjunction with the pressure block to ultimately and securely lock it in its spatial position. Therefore, the step of fixing the end of the main strip using components within the first injection mold includes: pressing the end of the main strip with a pressure block structure disposed within the cavity of the first injection mold to limit its displacement in a direction perpendicular to the parting surface of the first injection mold; and using at least one first positioning post structure extending from one or both sides of the first injection mold to abut against or pass through the end of the main strip to limit its displacement in a plane parallel to the parting surface of the first injection mold, wherein the first positioning post structure retracts after injection molding, forming a through hole in the cap connector. This combination of pressure block and positioning post can resist mold closing pressure and high-pressure melt impact, ensuring that the fabric insert does not shift during the entire injection molding process, thereby guaranteeing the consistency of the final product's dimensional accuracy, connection strength, and appearance quality.

[0073] Furthermore, the corresponding first injection mold is closed, and the injection molding machine injects molten first type of plastic (e.g., high-strength and tough polyoxymethylene) into the closed cavity of the first injection mold through a gating system (preferably a large gate or direct gate to reduce flow resistance). The molten plastic flows and completely covers the fixed end (or specific portion) of the fabric strip, flowing around the first positioning post structure, while partially penetrating into the fiber gaps of the fabric strip due to its high fluidity. Further, a preset holding pressure is applied (to compensate for plastic shrinkage), making the plastic filling denser and compensating for shrinkage. Then, it is rapidly cooled by the mold cooling system, allowing the plastic to solidify and set. During this solidification process, the plastic penetrates into the gaps of the fabric fibers and tightly grips these fibers and the hardened edges formed during cooling and shrinkage, creating a strong physical bond. This physical bond provides mechanical connection strength and fatigue resistance far exceeding that of traditional stitching. Furthermore, the first injection mold is opened, and the ejection mechanism (such as ejector pins or ejector plates) is activated to eject the formed headband connectors (fabric tape and cured plastic functional parts), resulting in two headband connectors integrally connected to the end of the main tape. During ejection, the headband connectors separate from the positioning pins, naturally forming holes in the connection area. This process directly reflects the three-dimensional physical interlock between the webbing and the plastic, and the through holes left by the positioning pins.

[0074] Accordingly, the principle of manufacturing the first fastener is exactly the same as that of manufacturing the headband connector. First, a pre-treated adjusting strip is taken and one end is placed in the cavity of a second injection mold, which defines the shape of the first fastener (usually a female fastener structure). Similarly, the end of the adjusting strip is firmly fixed by the pressure block and positioning post structure within the second injection mold. Specifically, the steps of fixing the end of the adjusting strip by the components within the second injection mold include: pressing the end of the adjusting strip with the pressure block structure located within the cavity of the second injection mold to limit its displacement in the direction perpendicular to the parting surface of the second injection mold; and using at least one second positioning post structure extending from one or both sides of the second injection mold to abut against or pass through the end of the adjusting strip to limit its displacement in the plane parallel to the parting surface of the second injection mold, wherein the second positioning post structure retracts after injection molding, forming a through hole in the first fastener. Next, a second type of plastic (which may be the same as or different from the first type of plastic) in a molten state is injected into the cavity of the second injection mold to complete the injection molding coverage of the end of the adjusting strip. After pressure holding, cooling, and ejection, the first fastener is obtained, which is integrated with one end of the adjusting belt.

[0075] Step S30, final assembly: Assemble the insert injection-molded parts and non-injection-molded parts to form a chin strap assembly including two main strap modules and an adjustment buckle module detachably connected to the two main strap modules.

[0076] In one embodiment of the present invention, the various injection-molded insert components prepared in the above steps are combined with non-injection-molded components to form the final chin strap assembly. The specific implementation process is as follows:

[0077] First, the adjusting buckle module is assembled. An adjusting belt with an integrated first buckle is taken. Following a preset routing path, the adjusting belt, already integrated with the first buckle, passes sequentially through the adjusting buckles, then around the belt-passing structure on the independent second buckle, and finally back through the adjusting buckles to form an adjustable loop. It should be noted that if the design includes an anti-disengagement buckle, after this step, an anti-disengagement buckle fixed to the free end of the adjusting belt needs to be manufactured using an insert injection molding process. That is, in other embodiments of the invention, the method further includes the following injection molding steps: placing the pre-treated free end of the adjusting belt at a predetermined position within a third injection mold having a cavity defining the shape of the anti-disengagement buckle, and fixing the end of the adjusting belt with components within the third injection mold; injecting a molten third type of plastic (which may be the same as or different from the first two) into the cavity of the third mold, encapsulating the fixed end of the adjusting belt through injection molding; and obtaining an anti-disengagement buckle integrally connected to the end of the adjusting belt through pressure holding, cooling, and ejection. The step of fixing the end of the adjusting strip by means of components in the third injection mold includes: pressing the end of the adjusting strip with a pressure block structure set in the cavity of the third injection mold to limit its displacement in the direction perpendicular to the parting surface of the third injection mold; and using at least one third positioning post structure extending from one or both sides of the third injection mold to abut against or pass through the end of the adjusting strip to limit its displacement in the plane parallel to the parting surface of the third injection mold, wherein the third positioning post structure retracts after injection molding and forms a through hole in the anti-disengagement device.

[0078] Furthermore, the first and second fasteners on the assembled adjusting fastening module are respectively inserted and fastened to the fastening connections on the straps of the two main belt modules (which already include the main belt, strap members, and headband connectors). Through the fastening of these two fastening systems, the three independent modules are securely and detachably connected together, thus forming a complete and fully functional chin strap assembly. At this point, a complete chin strap assembly consisting of two main belt modules and one adjusting fastening module is manufactured. This modular assembly method not only greatly improves the assembly efficiency at the end of the production line but also provides significant convenience for subsequent product maintenance and component replacement.

[0079] In this embodiment of the invention, by decomposing the manufacturing process into two core steps—manufacturing the insert injection-molded component and final assembly—a high degree of modularization and simplification of the production process is achieved. This significantly reduces the complexity of molds and the requirements for production lines, substantially improves production efficiency and product quality consistency, and solves the problems of cumbersome and costly traditional processes. Furthermore, by employing high-precision in-mold positioning technology during the insert injection molding process and leaving through holes on the plastic part as evidence of its manufacturing process, not only is the bonding quality between the webbing and the plastic ensured, but also a rivet-like anchoring point is formed, further enhancing the pull-out resistance of the connection point and providing microstructural-level protection for product reliability.

[0080] In this embodiment of the invention, the specific structure of the chin strap assembly manufactured using the method of this embodiment can be referred to the foregoing embodiments. Its implementation principle and the resulting technical effects are the same as those of the foregoing embodiments. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the corresponding content in the foregoing embodiments.

[0081] Example 3

[0082] Please see Figures 6-7 The image shows a safety helmet according to the third embodiment of the present invention. For ease of explanation, only the parts related to the embodiments of the present invention are shown. The safety helmet provided in the embodiments of the present invention includes a helmet shell 10, a top strap 20 connected and fixed to the helmet shell 10, a headband 30 connected and fixed to the top strap 20, and a chin strap assembly 40 as described in the previous embodiments connected and fixed to the headband 30.

[0083] Furthermore, in one embodiment of the invention, the helmet further includes a sweat-absorbing band 50 fixedly connected to the headband, wherein reference is made to... Figure 6 As shown, the headband 30 includes a ring strap, and adjustment straps and adjustment buckles respectively connected to both ends of the ring strap. The ring strap has ventilation holes, anti-collision posts, fixing posts for connecting and fixing the top strap and chin strap, and fixing protrusions for connecting and fixing the sweatband along its length. The ventilation holes increase the breathability of the ring strap for ventilation and heat dissipation, and disperse stress. The anti-collision posts disperse impact force, preventing direct contact between the helmet shell and the user's head, reducing the impact of helmet shell deformation on the top of the user's head, and preventing head injury. The fixing posts cooperate with the fixing holes on the top strap of the helmet and the connecting structure on the chin strap assembly for fixation. Specifically, in this embodiment, the fixing posts are T-shaped posts, and the corresponding fixing holes on the top strap and the connecting structure on the chin strap assembly are also T-shaped holes. The fixing protrusions pass through the fixing through holes of the sweatband to fix the sweatband.

[0084] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0085] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A chin strap assembly, characterized in that, Applied to safety helmets, it includes two main strap modules and an adjustment buckle module detachably connected to the two main strap modules; Each main strap module includes a main strap, two headband connectors integrally connected to the two ends of the main strap via an insert injection molding process, and a branch strap for the main strap to be folded and threaded through. The branch strap has a fastening connection part, and the headband connector has a connection structure for engaging with the headband of the safety helmet. The adjusting fastening module includes an adjusting belt, a first fastener integrally connected to one end of the adjusting belt via an insert injection molding process, a second fastener slidably sleeved on the adjusting belt, and an adjusting buckle slidably sleeved on the adjusting belt and located between the first fastener and the second fastener. The first and second buckles on the adjusting buckle module and the buckling connection parts on the two main belt modules respectively constitute two buckle systems that can cooperate with each other and achieve detachable connection, thereby realizing the detachable connection between the adjusting buckle module and the two main belt modules.

2. The chin strap assembly according to claim 1, characterized in that, The fastening connection parts on the sub-strip pieces in both main belt modules are configured as either male or female fastening connections, and the first and second fasteners are respectively provided with female or male fastening structures that cooperate with the sub-strip pieces.

3. The chin strap assembly according to claim 1, characterized in that, The fastening connection on the branch belt component in one of the main belt modules is configured as a male fastening connection, and the fastening connection on the branch belt component in the other main belt module is configured as a female fastening connection; correspondingly, in the first buckle and the second buckle, one is provided with a female fastening structure and the other is provided with a male fastening structure.

4. The chin strap assembly according to claim 1, characterized in that, The routing path of the adjustment belt is as follows: starting from the end of the first buckle, it passes through the adjustment buckle in sequence, then wraps around and passes through the belt passage structure on the second buckle, and finally passes back through the adjustment buckle to form an adjustable closed loop. The second buckle is located on one side of the closed loop. The free tail end formed after the adjustment belt passes through the adjustment buckle is provided with an anti-disengagement buckle that is integrally fixed by an insert injection molding process.

5. The chin strap assembly according to claim 4, characterized in that, The integrated connection area between the headband connector and the main strap, the integrated connection area between the first buckle and the adjusting strap, and the integrated connection area between the anti-loosening buckle and the adjusting strap are all provided with at least one through hole formed during the injection molding process.

6. The chin strap assembly according to claim 1, characterized in that, The belt-type component includes an integrally formed main body and a snap-fit ​​connection portion integrally extended from the lower edge of the main body; The main body includes a guide frame at the front end for guiding and positioning the main belt, a support back plate at the rear end for providing a support contact surface for the sub-belt, and a transverse bearing beam at the rear end and below the support back plate for allowing the main belt to be folded around. The guide frame, the support back plate, and the transverse bearing beam together form a belt passage through which the main belt passes in a folded manner.

7. A method for manufacturing a chin strap component, characterized in that, The method for manufacturing a chin strap assembly as described in any one of claims 1-6 includes the following steps: Provide non-injection molded components: provide a main belt, an adjusting belt, a branch belt component, a second fastener, and an adjusting buckle, and pass the main belt through the branch belt component in a folded manner; Manufacturing insert injection molded components: Two headband connectors that are integrally connected to the end of the main belt, and a first buckle that is integrally connected to one end of the adjustment belt, are manufactured by insert injection molding process; Final assembly: Assemble the insert injection-molded component with the non-injection-molded component to form a chin strap assembly including two main strap modules and an adjustment buckle module detachably connected to the two main strap modules.

8. The method for manufacturing a chin strap assembly according to claim 7, characterized in that, The steps of manufacturing two headband connectors integrally connected to the end of the main belt and a first buckle integrally connected to one end of the adjustment belt through insert injection molding include: The end of the pre-treated main band is placed in a first injection mold with a cavity that defines the shape of the headband connector, and the end of the main band is fixed by a component in the first injection mold. Molten first plastic is injected into the cavity of the first injection mold, and the headband connector is formed by injection molding and is integrally connected with the main band. One end of the pre-treated adjustment band is placed in a second injection mold with a cavity that defines the shape of the first fastener, and the end of the adjustment band is fixed by a component in the second injection mold. Molten second plastic is injected into the cavity of the second injection mold, and the first fastener is integrally connected with the adjustment band by injection molding.

9. The method for manufacturing a chin strap assembly according to claim 8, characterized in that, The step of fixing the end of the main belt through a component within the first injection mold includes: The end of the main strip is pressed by a pressure block structure set in the cavity of the first injection mold to limit its displacement in the direction perpendicular to the parting surface of the first injection mold; and at least one first positioning post structure extending from one or both sides of the first injection mold abuts against or passes through the end of the main strip to limit its displacement in the plane parallel to the parting surface of the first injection mold, wherein the first positioning post structure retracts after injection molding and forms a through hole in the cap connector; The step of fixing the end of the adjusting belt through a component inside the second injection mold includes: The end of the adjusting belt is pressed by a pressure block structure disposed in the cavity of the second injection mold to limit its displacement in the direction perpendicular to the parting surface of the second injection mold; and at least one second positioning post structure extending from one or both sides of the second injection mold abuts against or passes through the end of the adjusting belt to limit its displacement in a plane parallel to the parting surface of the second injection mold, wherein the second positioning post structure retracts after injection molding and forms a through hole in the first fastener.

10. A safety helmet, characterized in that, It includes a cap shell, a top strap fixed to the cap shell, a headband fixed to the top strap, and a chin strap assembly as described in any one of claims 1-6 fixed to the headband.

Images