At a glance
| Patent number | CN113057436B (application CN202110325335) |
| Type | China invention patent (发明专利) - protects product method and structure |
| Original title | Multifunctional draw-bar backpack (一种多功能拉杆背包) |
| Patent owner | Shanghai Weixiang Industrial Co ltd |
| Inventors | Hu Haibo, Huang Na, Yang Diqing |
| Filing date | 2021-03-26 |
| Grant date | 2022-05-20 |
| Status (China) | Lapsed - terminated for non-payment of annual fees (recorded 2024-04-05) |
| Patent family | Chinese filings only - no US, European, Japanese, PCT or other filings listed |
| Cited by | 0 later documents |
| Source | Google Patents (search for CN113057436B) |
What the claims cover, in plain language
Claim 1 - a draw-bar backpack comprising a body, a back plate, and shoulder straps. The key feature is that the straps are wound onto rotating rollers housed within the back plate. A pull rod slides vertically through a groove. The rod interacts with a connecting pipe via spiral protrusions and grooves, causing the pipe to rotate when the rod moves. This rotation is transmitted via bevel gears to the rollers, winding or unwinding the straps. A pressure plate and sliding blocks with inclined planes provide a locking mechanism for the handle position.
Claim 2 onward - details specific dimensions of the spiral interactions, the arrangement of the five protrusions/grooves, and the specific geometry of the communicating grooves and spring-loaded sliding pieces that ensure the mechanical linkage functions smoothly during extension and retraction.
This is a simplified reading for orientation only. The legal scope is defined by the exact claim wording in the official Chinese document.
What this means for US production
This patent was filed only in China and has lapsed due to non-payment of fees. Therefore, it currently provides no exclusive rights to anyone, including the original owner, in China or internationally. It has no US or other foreign counterpart.
Two points to settle early:
- Other patents may exist. Luggage mechanisms, especially those involving integrated electronics or novel folding structures, are heavily patented by major brands like Samsonite, Travelpro, and American Tourister. While this specific gear-driven strap retraction appears unique in public records, a freedom-to-operate (FTO) review is strongly recommended to check for broader utility patents covering “automatic strap management” or similar functional outcomes in US markets.
- Material Safety. The internal rollers and gears are structural components. In the US, children’s products or certain consumer goods have strict limits on heavy metals (lead, cadmium) in plastics and coatings. Ensure your polymer suppliers provide RoHS/REACH compliant materials if targeting global markets.
Customization and manufacturing
What can be customized
| Area | Options |
|---|---|
| Strap Material | Nylon webbing, polyester, leather accents, padded mesh |
| Back Plate Rigidity | ABS plastic, aluminum alloy frame, or reinforced polycarbonate |
| Gear Ratio | Adjusted to change the speed of retraction relative to handle movement |
| Capacity | Backpack volume from 20L to 45L depending on body shell size |
| Finish | Matte black, silver, custom colors for the visible hardware |
| Locking Mechanism | Integration with TSA locks or additional manual release buttons |
Things to plan for (US market)
- ASTM F2460 - Standard Specification for Backpacks. Covers durability, strap strength, and zipper performance.
- CPSC Lead Limits - Strict regulations on lead content in accessible substrates (plastics, paints) for general consumer goods.
- California Prop 65 - Warning requirements for certain chemicals potentially present in dyes, plastics, or metal plating.
- Flammability Standards - Depending on marketing claims (e.g., “outdoor”), specific flammability tests may apply.
How a project runs
- Inquiry - Define capacity, target retail price, and desired strap materials.
- Design - CAD modeling of the gear train and back plate interface; stress analysis on the spiral groove interaction.
- Prototype - 3D printed housings and machined gears to test the retraction torque and smoothness.
- Pilot Run - Injection molding tools for plastic parts; assembly line testing for alignment of rollers and straps.
- Production - Mass manufacturing, quality control checks on gear meshing, and final packaging.
Quantities & timeline
The precision of the spiral grooves and bevel gears dictates the tooling cost. High-tolerance molds are required to prevent binding. Assembly involves threading straps through narrow channels, which may require semi-automated jigs. Send us your capacity, material preferences, estimated quantity and target price and we will reply with options.
Patent drawings
Drawings reproduced from the public patent document for reference.
