Adjustable Height-Increasing Insole with Internal Shim Stack

The problem

Most height-increasing insoles come as a single piece with a fixed thickness. If the lift is too high, the wearer feels unstable; if it is too low, they do not get the desired effect. Because these insoles are usually molded as one unit, there is no way to adjust the height after purchase. Users must buy multiple pairs to find the right fit, which is wasteful and inconvenient. Additionally, thick foam or rubber blocks often trap heat and sweat against the foot, causing discomfort during extended wear.

The solution

The patent describes a two-part insole system that separates the structural support from the height-adjustment mechanism.

1. Upper Insole (1): This is the top layer that touches the foot. It features a series of ventilation holes along its length. Each hole contains two layers of mesh: a coarse filter on top and a fine filter below, designed to block debris while allowing air flow.
2. Lower Insole (2): This base layer contains the height-adjusting mechanism. It has an internal cavity (groove) that houses a stack of backing plates.
3. Connection Mechanism: The upper and lower insoles are joined by a sliding groove (4) on the underside of the upper insole and a fixed slider (3) on the lower insole. The slider fits into the curved groove. Additionally, interlocking tabs (5) and blocks (6) lock the two parts together to prevent lateral shifting.
4. Shim Assembly: Inside the lower insole’s cavity, there are multiple “gasket combinations.” Each combination consists of a long backing plate (10) and a short backing plate (12) connected by a pin shaft (11). These plates have slots and insert blocks that allow them to be stacked and locked at different heights.
5. Access Door: The side of the cavity is covered by a movable door plate (9) attached to a pivot shaft (8). This allows the user to open the compartment, add or remove shim plates, and close it securely.

Who it is for

• Footwear brands looking to offer customizable comfort options in their casual or dress shoe lines.
• Amazon sellers who want a differentiated product that solves the “one size doesn’t fit all” problem of standard heel lifts.
• Wholesalers supplying comfort and footwear-accessory ranges that want an adjustable lift option without stocking several fixed-height SKUs.
• Private label manufacturers seeking a mechanical height-adjustment option rather than a fixed-thickness insole.

How it works

The main parts

Adjusting the Height

1. Open the Compartment: Flip the movable door plate (9) outward using the pivot shaft (8).
2. Modify the Stack: Add or remove the linked long (10) and short (12) backing plates. The plates slide into each other via their respective slots (14, 15) and inserts (13).
3. Close the Door: Secure the door plate back into place to cover the cavity.
4. Insert the Insole: Slide the upper insole onto the lower insole using the curved groove (4) and fixed slider (3). Ensure the tabs (5) engage with the blocks (6) for a stable fit.

Applications

Casual Dress Shoes

Men wearing oxford or derby shoes can use this insole to gain subtle height without altering the shoe’s exterior appearance. The adjustable nature allows them to dial in the exact lift wanted for a formal event or a subtle height boost.

Athletic Training

Runners or gym-goers can try different lift heights in training shoes before committing to a fixed pair. The ventilation holes help keep feet cool during activity, reducing sweat buildup inside the shoe.

Stage and Cosplay

Performers who need extra height on stage can adjust the lift to match a costume or a specific character look. The bamboo charcoal lining absorbs moisture during long wear under stage lights.

Uniform Compliance

Professionals required to meet specific height standards for uniforms (e.g., military, police, security) can use these insoles discreetly. The secure locking mechanism ensures the insole does not shift during movement, providing reliable elevation throughout the day.

Where it is less suitable

• Tight-Fitting Sneakers: The added thickness of the two-part system may make it difficult to insert into shoes with very low volume interiors.
• Heavy Industrial Boots: The rubber construction is optimized for comfort and adjustment, not for extreme abrasion resistance or steel-toe compatibility.
• Single-Piece Molded Needs: Custom shoe makers who prefer glued-in liners may find the modular assembly too complex for mass production integration.