One-way double-layer anti-theft zipper
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG DUOLING THREAD BELT TECH CO LTD
- Filing Date
- 2025-07-21
- Publication Date
- 2026-08-07
AI Technical Summary
传统单层拉链结构在使用中暴露出如下缺陷：①当箱包装载过量物品时，拉链布带承受持续拉伸力，导致单排链齿的缝合处应力集中，易发生“纵向撕裂”，而且搬运过程中的震动、碰撞产生动态冲击载荷，单层链齿因啮合面积不足容易发生“链齿群集性滑脱”；②现有拉链依赖齿距加密或拉头自锁等“局部加固”手段，但单排链齿形成的缝隙仍可被刀片、螺丝刀等工具从“侧向斜插”撬开，破坏者还通过“挑线”直接剥离整排链齿；③反复开合摩擦导致链齿根部应力疲劳形成微裂纹，在箱包撑满时诱发“链齿崩飞式爆开”
[0015]1.双重防纵向撕裂与抗冲击：采用双层链齿条并列缝合于单侧拉链布，配合垫布形成复合加强结构，双排链齿通过两道缝合线形成分布式应力承载结构，将传统单层拉链的集中应力分散至多个齿牙单元，有效抑制布带纵向撕裂；同时双倍啮合面积大幅提升抗动态冲击能力，避免搬运震动导致的“链齿群集性滑脱”；
Smart Images
Figure CN224597665U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of bag accessories and zipper technology, specifically to a single-sided double-layer anti-theft zipper. Background Technology
[0002] As an essential tool for carrying items in daily life and travel, the reliability of the zipper closure of bags directly affects the safety of the contents. Traditional single-layer zipper structures have the following defects in use: ① When the bag is overloaded, the zipper tape is subjected to continuous tensile force, causing stress concentration at the seams of the single row of teeth, which easily leads to "longitudinal tearing". Moreover, vibration and collision during handling generate dynamic impact loads, and the single-layer teeth are prone to "chain tooth cluster slippage" due to insufficient meshing area; ② Existing zippers rely on "local reinforcement" methods such as denser tooth spacing or self-locking zipper pulls, but the gaps formed by the single row of teeth can still be pried open from the side by tools such as blades and screwdrivers. Vandals can also directly peel off the entire row of teeth by "picking up the thread"; ③ Repeated opening and closing friction causes stress fatigue at the root of the teeth, forming micro-cracks, which can induce "chain teeth flying out and bursting open" when the bag is full.
[0003] To address the fragility of the "fabric tape-tooth" basic connection structure and improve its resistance to human-caused damage, a zipper architecture that is reconstructed from a mechanical perspective is urgently needed. Utility Model Content
[0004] In order to overcome the above-mentioned defects of traditional single-layer zipper structures, this utility model provides a single-sided double-layer anti-theft zipper.
[0005] The technical solution adopted by this utility model is as follows: a single-sided double-layer anti-theft zipper, comprising: two zipper fabrics arranged in pairs; four chain teeth, which are long strips formed by continuous winding of plastic strips and have multiple spiral coil-shaped teeth; a sewing thread for sewing the two layers of chain teeth to the same side of the side edge of each zipper fabric; a padding fabric sandwiched between the two layers of chain teeth and sewn together by the sewing thread; and a zipper head for synchronously engaging or disengaging the two layers of chain teeth on one side.
[0006] Preferably, the side of the zipper fabric with the chain teeth faces the inside of the bag.
[0007] Preferably, it also includes a core wire that fills the inside of the teeth of the chain rack.
[0008] Preferably, the core wire tightly fills the internal cavity of the teeth of the chain rack, and the core wire generates a preload force extending outward in the radial direction.
[0009] Preferably, the cross-section of the core wire within the outer chain tooth has an axially extending notch on the side away from the zipper fabric, and the teeth of the chain tooth are deformed to form a groove for accommodating the suture thread, so that the suture thread is submerged below the tooth plane of the chain tooth.
[0010] Preferably, each zipper fabric has two parallel stitches, which run through each tooth of the zipper rack and the zipper fabric in a continuous lockstitch pattern, forming a distributed stress-bearing structure.
[0011] Preferably, the breaking strength of the core wire is not less than 150% of the strength of the zipper fabric body.
[0012] Preferably, the core wire is composed of multiple strands of high-strength fibers twisted together or a high-density braided tape.
[0013] Preferably, the tooth pitch of the chain rack is 1.2-1.8 mm, the tooth height is 2.0-2.5 mm, and the total meshing depth after tooth engagement is ≥3.5 mm.
[0014] This utility model has the following beneficial effects:
[0015] 1. Double protection against longitudinal tearing and impact: Double-layer chain teeth are sewn side by side to the zipper fabric on one side, forming a composite reinforcement structure with padding. The double rows of chain teeth form a distributed stress-bearing structure through two stitching lines, dispersing the concentrated stress of the traditional single-layer zipper to multiple tooth units, effectively inhibiting longitudinal tearing of the fabric. At the same time, the doubled meshing area greatly improves the resistance to dynamic impact, avoiding "chain tooth cluster slippage" caused by handling vibration.
[0016] 2. Three-dimensional anti-pry and anti-theft mechanism: The double-layer chain teeth and padding form an interlocking interface, making it difficult for tools to insert into the gaps between the double rows of teeth from the side; the core thread tightly fills the tooth cavity and applies radial preload, so that the teeth and the stitching form a mechanical interlock; the outer teeth, through the groove formed by the deformation of the notch, sink the stitching below the tooth plane, completely blocking the path of tools to "pick the thread" and destroy it; the chain teeth of the zipper fabric face the inside of the bag, further increasing the difficulty of external prying.
[0017] 3. Long-lasting fatigue resistance and anti-explosion: The core wire uses high-strength fiber / woven tape with a breaking strength ≥150% of zipper fabric, forming a reinforced skeleton at the root of the teeth to inhibit the propagation of micro-cracks in the plastic teeth; the double rows of teeth bite synchronously to disperse the opening and closing friction load, and the core wire pre-tightening force compensates for plastic creep, significantly delaying stress fatigue and avoiding "chain teeth flying off and exploding".
[0018] 4. Lightweight and process compatibility: The chain teeth adopt a continuously wound plastic spiral coil structure, combined with standardized tooth pitch, which achieves lightweight while ensuring strength, and is compatible with existing zipper production line processes, greatly reducing upgrade costs. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of a single zipper fabric in an embodiment of this utility model.
[0020] Figure 2 This is a cross-sectional structural diagram of an embodiment of the present invention.
[0021] In the picture:
[0022] Zipper fabric 1;
[0023] Chain tooth 2, groove 2.1;
[0024] 3 sutures;
[0025] 4 pieces of padding cloth;
[0026] Core wire 5;
[0027] The zipper pull is not shown. Detailed Implementation
[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings.
[0029] In the embodiments, such as Figure 1 , Figure 2 The diagram shows a single-sided double-layer anti-theft zipper, comprising: two zipper fabrics 1 arranged in pairs; four chain teeth 2, which are long strips of plastic continuously wound together and have multiple spiral coil-shaped teeth; a sewing thread 3, which sews the two layers of chain teeth 2 to the same side of each zipper fabric 1; a padding fabric 4, sandwiched between the two layers of chain teeth 2 and sewn together by the sewing thread 3; and a zipper head, used to simultaneously engage or disengage the two layers of chain teeth 2 on one side. The double-layer chain teeth 2 are sewn side-by-side to the single-sided zipper fabric 1, forming a composite reinforced structure with the padding fabric 4. The double rows of chain teeth, through the sewing thread 3, disperse the concentrated stress of a traditional single-layer zipper to multiple tooth units, significantly suppressing longitudinal tearing of the zipper fabric 1; the doubled engagement area enhances resistance to dynamic impact, preventing the chain teeth from slipping off in clusters due to handling vibrations. The zipper head synchronously controls the engagement / disengagement of the double-layer chain teeth 2, increasing the difficulty of lateral insertion of tools and improving anti-theft performance.
[0030] In this embodiment, the side of the zipper fabric 1 with the chain teeth 2 faces the inside of the bag. With the chain teeth 2 side of the zipper fabric 1 facing the inside of the bag, burglar-prying tools cannot directly contact the chain teeth 2 and the stitching 3 from the outside, thus blocking the external path of damage.
[0031] In the embodiments, such as Figure 1 , Figure 2As shown, it also includes a core wire 5, which tightly fills the internal cavity of the teeth of the chain rack 2, forming a preload force in the radial direction. The core wire 5 fills the internal cavity of the teeth of the chain rack 2, forming a high-strength skeleton at the tooth root, inhibiting the propagation of microcracks in the plastic teeth and delaying fatigue fracture. The core wire 5 tightly fills the tooth cavity and applies a radially outward preload force, compensating for plastic creep deformation and maintaining the tooth profile stability and interlocking tightness of the chain rack 2.
[0032] In the embodiments, such as Figure 1 , Figure 2 As shown, the core wire 5 inside the outer chain tooth 2 has an axially extending notch on the side away from the zipper fabric 1. The teeth of the chain tooth 2 deform corresponding to the notch to form a groove 2.1 for accommodating the sewing thread 3, allowing the sewing thread 3 to sink below the tooth plane of the chain tooth 2. The notch in the cross-section of the core wire 5 of the outer chain tooth 2 causes the teeth to deform to form the groove 2.1, allowing the sewing thread 3 to sink below the tooth plane, completely blocking the path for the tool to pull the thread off the chain tooth 2. The preload of the core wire 5 enhances the interlocking strength between the teeth and the sewing thread 3, forming an integrated structure resistant to longitudinal shearing.
[0033] In the embodiments, such as Figure 1 , Figure 2 As shown, each zipper fabric 1 has two parallel stitches 3. The two stitches 3 pass through each tooth of the chain tooth 2 and the zipper fabric 1 with continuous lockstitch stitches, forming a distributed stress-bearing structure. The two parallel stitches 3 pass through each tooth of the chain tooth 2 and the zipper fabric 1 with continuous lockstitch stitches, evenly distributing the load to the double-row tooth unit and avoiding cascading failures caused by the breakage of a single thread.
[0034] In the embodiments, such as Figure 1 , Figure 2 As shown, the breaking strength of the core wire 5 is no less than 150% of the strength of the zipper fabric 1 itself, and it is composed of multiple strands of high-strength fibers twisted together or high-density woven tape. The breaking strength of the core wire 5 is ≥150% of the strength of the zipper fabric 1 itself, forming a high-strength reinforcing layer at the tooth root to inhibit the plastic teeth from cracking under overload. The use of multiple strands of high-strength fibers twisted together or high-density woven tape (such as aramid or ultra-high molecular weight polyethylene) ensures tensile strength while avoiding increasing the overall weight of the chain teeth 2. Its high strength and lightweight characteristics balance anti-theft performance and zipper flexibility. The high breaking strength of the core wire 4 ensures that even if the chain teeth 2 are partially damaged, the core wire can still resist further tearing through inter-fiber friction, providing protection for the overall structure.
[0035] In the embodiments, such as Figure 1 , Figure 2As shown, the tooth pitch of chain rack 2 is 1.2-1.8mm, the tooth height is 2.0-2.5mm, and the total engagement depth after tooth engagement is ≥3.5mm. The combination of a tooth pitch of 1.2-1.8mm and a height of 2.0-2.5mm maximizes the number of engagement points within a limited space. The design of a total engagement depth ≥3.5mm prevents pry bar-like tools from simultaneously inserting into the gaps between two layers of teeth. The high pitch density adapts to the deformation of the fabric straps under overload conditions, ensuring that the teeth maintain effective engagement even under tension, preventing cracking.
[0036] Obviously, the above embodiments of this utility model are merely examples for illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Other obvious variations or modifications derived from the essential spirit of the present utility model still fall within the protection scope of the present utility model.
Claims
1. A single-sided double-layer anti-theft zipper, characterized in that, include: Two zipper fabrics arranged in pairs (1); The four-chain toothed bar (2) is a long strip made of continuously wound plastic strips, with multiple spiral coil-shaped teeth; The stitching (3) stitches the two layers of the chain teeth (2) to the same side of the side edge of each of the zipper fabrics (1); The padding cloth (4) is sandwiched between the two layers of chain teeth (2) and sewn together by the stitching line (3); Zipper head, used to simultaneously engage or disengage the two layers of chain teeth (2) on one side.
2. The single-sided double-layer anti-theft zipper according to claim 1, characterized in that, The side of the zipper fabric (1) on which the chain teeth (2) are arranged faces the inside of the bag.
3. The single-sided double-layer anti-theft zipper according to claim 1, characterized in that, It also includes a core wire (5) that fills the inside of the teeth of the chain rack (2).
4. The single-sided double-layer anti-theft zipper according to claim 3, characterized in that, The core wire (5) tightly fills the internal cavity of the teeth of the chain rack (2), and the core wire (5) forms a preload force that extends outward in the radial direction.
5. The single-sided double-layer anti-theft zipper according to claim 4, characterized in that, The cross section of the core wire (5) inside the outer chain tooth (2) has an axially extending notch on the side away from the zipper fabric (1). The teeth of the chain tooth (2) are deformed to form a groove (2.1) for accommodating the suture (3), so that the thread of the suture (3) sinks below the plane of the teeth of the chain tooth (2).
6. The single-sided double-layer anti-theft zipper according to claim 5, characterized in that, Each zipper fabric (1) is provided with two parallel stitches (3), which pass through each tooth of the chain tooth (2) and the zipper fabric (1) with continuous lock stitches to form a distributed stress-bearing structure.
7. The single-sided double-layer anti-theft zipper according to any one of claims 3-6, characterized in that, The breaking strength of the core wire (5) is not less than 150% of the strength of the zipper fabric (1).
8. The single-sided double-layer anti-theft zipper according to claim 7, characterized in that, The core wire (5) is composed of multiple strands of high-strength fiber twisted together or high-density braided tape.
9. The single-sided double-layer anti-theft zipper according to claim 1, characterized in that, The tooth pitch of the chain rack (2) is 1.2-1.8mm, the tooth height is 2.0-2.5mm, and the total meshing depth after the teeth are engaged is ≥3.5mm.