Hardness Adjustable Latex Foam Cushion with Layered Protection

The problem

Most latex or foam cushions come in a single, fixed density. Users who need variable support—such as those switching between sitting and lying positions, or individuals with different weight profiles—must purchase separate pads or compromise on comfort. Additionally, standard foam pads often lack integrated protections against moisture, pests, or fire hazards, leading to faster degradation or safety concerns in high-use environments like healthcare facilities, outdoor seating, or public transport. Existing adjustable solutions are often bulky, rely on air chambers that leak, or require electronic components that complicate maintenance and power supply. There is a need for a passive, mechanical solution that allows quick firmness changes while maintaining structural integrity and incorporating essential material safeguards directly into the pad’s construction.

The solution

1. A latex sponge pad body (1) forms the top surface, providing initial comfort and elasticity.
2. Beneath the body, sequential layers include a sweat-absorbing layer (2), waterproof layer (3), flame-retardant layer (4), fire-proof layer (5), insect-repelling layer (6), and a base layer (7).
3. Inside the base layer, a rigid keel (8) provides structural support for the adjustment mechanism.
4. Multiple first pressing sheets (9) and first pressing blocks (10) are arranged vertically, connected to second pressing blocks (11) and second pressing sheets (12).
5. Springs (16) connect the opposing sides of the first and second pressing sheets, offering elastic resistance.
6. An adjustment system uses a worm (19) and external thread rod (18) driven by an adjusting knob (20). This rotates to move a connecting rod (15) and support block (14) into or out of a movable groove (13).

Who it is for

• Medical and rehabilitation equipment manufacturers needing hygienic, adjustable seating or bedding surfaces for patient care.
• Outdoor furniture brands looking for durable cushions with built-in pest and moisture resistance for garden or camping setups.
• Public transport and aviation interior suppliers requiring fire-safe, easy-to-clean, and adjustable comfort options for passenger seats.
• Home office and ergonomic chair makers targeting consumers who want to customize seat firmness without buying multiple products.

How it works

The main parts

Operating Steps

1. Turn the Adjusting Knob: Rotate the external knob (20) clockwise or counter-clockwise.
2. Drive the Worm Gear: The knob turns the worm (19), which rotates the external thread rod (18).
3. Move the Support Block: The threaded action moves the connecting rod (15), sliding the support block (14) along its path.
4. Engage or Disengage:
   • To increase firmness: Move the support block (14) into the movable groove (13). This restricts the folding motion of the pressing blocks (10, 11), making the pad harder to compress.
   • To decrease firmness: Withdraw the support block (14) from the groove. The pressing blocks can fold more freely, allowing greater compression and a softer feel.

Applications

Healthcare Seating

In clinics and hospitals, patients often have varying needs for pressure relief. This pad allows caregivers to quickly adjust firmness for different body weights or conditions, while the waterproof and insect-repellent layers ensure hygiene standards are met without frequent replacement.

Outdoor Patio Furniture

Garden chairs face exposure to rain, humidity, and pests. The integrated waterproof and insect-repelling layers protect the foam core from degradation. Users can adjust the cushion firmness based on whether they prefer a soft lounge or a firmer dining posture.

Public Transport Interiors

Buses and trains require materials that meet strict fire safety regulations. The flame-retardant and fire-proof layers address compliance needs. Adjustable firmness helps accommodate diverse passenger demographics, improving perceived comfort without complex electronic systems.

Home Office Chairs

Remote workers spend long hours seated. Being able to tweak the seat’s resistance throughout the day helps prevent fatigue. The sweat-absorbing layer adds comfort during extended use, while the mechanical system requires no batteries or electronics.

Where it is less suitable

• Ultra-thin designs: The internal mechanism and multiple layers add thickness, making it unsuitable for slim-profile applications where minimal depth is required.
• High-frequency industrial machinery: While durable, the manual adjustment is designed for periodic changes rather than constant dynamic tuning in automated processes.