Folding Child Seat with Linked Backrest and Armrest Mechanism

The problem

Many portable child seats require users to perform multiple distinct actions to fold or unfold them. Typically, one must manually unlock the armrests, then tilt the backrest, and finally collapse the frame. This sequential process can be confusing, especially when managing a child simultaneously. Furthermore, if the locking mechanisms for the armrests and backrest are not engaged correctly, the seat may become unstable during use. There is a need for a mechanism that coordinates these movements so that rotating the backrest automatically handles the armrest locking and unlocking, reducing user error and improving convenience.

The solution

1. The fixed body serves as the base structure to which the backrest, armrests, and seat are rotatably connected.
2. A first idle stroke exists between the backrest and the armrests. When the backrest rotates from the open position towards the folding direction, it moves through this free range before engaging the armrests.
3. Once engaged, the linked rotational fit causes the backrest to drive the armrests. This action releases the armrests from their limit fit with the fixed body, allowing them to move inward.
4. A second idle stroke operates in reverse. When opening the seat, the backrest rotates through this free range relative to the armrests before forming a new linked fit.
5. As the backrest continues to rotate to an intermediate position along the opening direction, the linked fit releases, and the armrests form a limit fit with the fixed body, locking the structure securely.

Who it is for

• Stroller Manufacturers seeking integrated seating solutions that simplify the folding process for parents.
• Dining Chair Brands looking for high chairs that can be collapsed easily for storage under tables or in cars.
• Portable Nursery Equipment Suppliers who need robust, single-motion folding mechanisms for travel beds and seats.
• OEM Designers specializing in baby products who want to differentiate their lines with intuitive mechanical features.

How it works

The main parts

Operating Steps

1. To Fold: Rotate the backrest backward. It passes through the first idle stroke (no resistance from armrests).
2. Engagement: The backrest contacts the armrests, driving them to rotate inward and disengage from the fixed body’s locks.
3. Collapse: Continue rotating the backrest; the armrests follow, flattening the seat profile.
4. To Open: Rotate the backrest forward. It passes through the second idle stroke.
5. Locking: The backrest engages the armrests again, pushing them outward until they snap into the limit fit with the fixed body, securing the seat.

Applications

Travel Strollers

Parents can fold the stroller seat quickly with one hand while holding a child, as the armrests do not need to be manually removed or unlocked separately.

Portable Dining Chairs

High chairs used in restaurants or homes can be collapsed into a slim profile for storage in narrow closets or car trunks, saving significant floor space.

Nursery Room Organization

In small nurseries, folding chairs allow caregivers to clear floor space when the child is not eating or playing, maximizing room utility.

Car Seat Accessories

For families using in-car entertainment or feeding setups, these seats can be folded down flat when not in use, fitting easily alongside luggage or groceries.

Where it is less suitable

• Heavy-Duty Industrial Seats: The mechanism relies on plastic or light metal linkages suited for children’s weight, not adult loads.
• Fully Rigid Frames: If a product requires zero moving parts for durability reasons, this linked mechanism introduces necessary joints.
• Extreme Weather Exposure: Without specific material upgrades mentioned in the patent, standard finishes may degrade under prolonged UV or moisture exposure.