Pivotable Footwear Sole with Tongue and Bar Retainer

Patent & Production

At a glance

What the claims cover, in plain language

Claim 1 defines footwear comprising a sole with a Part I and Part II pivotally coupled. Part I includes a tongue, and Part II includes a depressed part to accommodate the tongue. A bar extends across the sole’s width, passing through the tongue to attach Part I to Part II. A retainer attached to the tongue or Part II limits the relative pivoting action.

Claims 2-3 specify that the parts can be arranged as front/rear or rear/front portions of the sole. Claims 4-7 detail the passage in the tongue for the bar and the aligned passage in Part II. They describe depressed parts surrounding the entrance to the passage to house the bar head. An interference fit between the head and sidewall suppresses bar motion. Claims 8-9 mention openings in the bar ends for securing members. Claims 10-12 introduce a holding element opening in Part I for a holding element (likely for the foot) and nail protuberances on the bar head that penetrate Part II to prevent bar movement. Claim 13 is an independent claim for footwear with a pivotable bottom, reiterating the tongue, depressed part, and bar configuration. Claims 14-24 provide dependent variations similar to Claims 2-12, applying them to the structure defined in Claim 13.

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 in China and has lapsed due to non-payment of fees, meaning it no longer restricts anyone in China either. The public record shows no US or other foreign counterpart.

Two points to settle early:

• Other patents may exist. Footwear construction, particularly articulated soles and hinge mechanisms, is a competitive field with numerous active patents held by major global brands (e.g., Nike, Adidas, New Balance) and specialized component suppliers. A freedom-to-operate (FTO) review is critical before tooling, focusing on the specific geometry of the tongue, bar, and retainer interaction.
• Material Safety. While the mechanical design is key, the materials used (rubber, EVA, TPU, adhesives) must comply with US regulations regarding restricted substances (like certain phthalates or azo dyes) depending on the target market segment.

Customization and manufacturing

What can be customized

Things to plan for (US market)

• CPSC Regulations: General safety standards for consumer products apply.
• State Laws: California Prop 65 requires warnings for certain chemicals commonly found in rubber and plastics.
• Textile Acts: Care labeling requirements for any fabric components in the upper.
• FTC Guidelines: Any performance claims (e.g., “enhanced flexibility”) must be substantiated.

How a project runs

1. Inquiry - Define target shoe type, size range, and desired flexibility profile.
2. Design - CAD modeling of the tongue, bar, and retainer; FEA analysis for stress points.
3. Prototype - Create samples using 3D printing or quick-turn molding for fit and function testing.
4. Testing - Durability cycles, pivot resistance measurement, and material safety checks.
5. Production - Tooling for molds, sourcing of bars and retainers, assembly line setup.

Quantities & timeline

Tooling for multi-part soles involves complex molds for the tongue and recess areas. Injection molding cycles for EVA/TPU are standard, but the precision required for the bar passage dictates tighter tolerances. Send us your target price, quantity, and design specs and we will reply with options.

Production notes

Tooling and process

The sole likely requires injection molding for the EVA or TPU base parts, given the integrated passages for the bar. Cutting and sewing would be used for attaching the upper and lining. Rubber outsole molding might be employed if a distinct tread layer is added. Heat pressing could secure the tongue to the main sole body if they are separate pieces initially.

Cost drivers

Sole mold complexity is likely the main cost driver due to internal channels. The number of sizes also affects tooling costs significantly. Fabric grade and stitch density impact the upper’s cost. Packaging adds minor overhead.

Prototyping path

We would typically start with sewn first samples using mock-up soles. Use 3D-printed or cast components for the pivot mechanism to test fit. Conduct wear trials to check for seam slippage or hardware corrosion. Proceed to fit grading and production patterns once the pivot action is validated.

What we would change before tooling

We would likely adjust the interference fit tolerance in the depressed parts to ensure consistent pivot resistance. Verify the nail protuberance design to prevent breakage during assembly. Optimize the retainer geometry to avoid premature wear on the tongue.

Common failure points

Seam slippage where the upper meets the sole is the most likely first issue. Color fading on exposed plastic parts. Sole delamination between layers. Size deviation affecting the bar alignment. Hardware corrosion if metal bars are used in wet conditions. Hinge boss and pivot wear over time.

Patent drawings

Drawings reproduced from the public patent document for reference.

Frequently asked questions

How does the pivot actually work?

The sole is split into two sections. A “tongue” from one section slides into a “recess” in the other. A metal or hard plastic bar runs through both, acting like a door hinge pin. A small retainer piece stops the sections from swinging too far, giving you controlled flexibility.

Is the bar visible from the outside?

Typically, no. The bar is housed inside the sole structure, within the passages formed by the tongue and the second sole part. It is protected from external impacts and weather.

Can this be used for all shoe types?

It works best for athletic, casual, and orthopedic shoes where forward flex is important. It may not be ideal for heavy-duty work boots or stiff-soled dress shoes that require rigid stability.

How durable is the mechanism?

Durability depends on the materials chosen for the bar and the sole body. High-wear areas like the pivot point are reinforced. The patent suggests using interference fits and optional nails/spikes to keep the bar from sliding out.

Can I customize the amount of flex?

Yes. By changing the shape of the retainer and the friction fit of the bar, we can adjust how much force is needed to bend the sole and how far it bends.

Does it affect the shoe’s weight?

Adding a pivot mechanism introduces extra components (bar, retainer, reinforced tongues). However, these are generally lightweight. The overall weight increase is usually minimal compared to the comfort benefits.

Can this design be made and sold in the US?

The patent was filed in China and has lapsed, and the public record shows no US counterpart, so it does not restrict the design in the US or in China. However, footwear technology is heavily patented by other companies. We recommend a freedom-to-operate check to ensure no other active US patents cover this specific hinge configuration.

Are you affiliated with the patent owner?

No. IP2M is an independent design and manufacturing service working from the public patent document.

Request a quote

Click Request a Quote below to see our email address - copy it, or open your email app with a ready-made message. Please mention patent CN205813724U in the subject.

Helpful details to include:

• Your company and channel (athletic brand, orthopedic supplier, casual footwear maker)
• Target shoe type and intended use
• Desired flex range (degrees of movement)
• Material preferences for the sole and bar
• Estimated quantity and target price
• Timeline - when you would like prototypes and mass production

You can also reach us at (332) 203-9997.