Motor-Driven Lifting Chair with Synchronized Frames and Swing Mechanism

The problem

When a child’s chair or adjustable seat needs to change height, simple scissor lifts or single-arm jacks often cause the seat pan to tilt as it rises. That tilt shifts the occupant’s center of gravity, makes the seat feel unstable, and forces the user to readjust their posture every time the height changes. Adding a separate recline or slide function usually requires extra motors or linkages, increasing the part count and the chance of mechanical failure. Parents and caregivers need a seat that moves vertically without changing its angle, while still offering some fore-aft adjustment for feeding or play.

The solution

This lifting chair addresses those issues through a specific linkage arrangement:

1. An installation base supports the entire structure on the floor.
2. A first lifting frame and a second lifting frame are mounted on the base and carry the seat main body.
3. A driving mechanism containing a motor, a rotating member fixed to the motor’s output shaft, and a driving member pivotally connected to the rotating member at a point offset from the shaft center.
4. The other end of the driving member connects to a first swinging member and a second swinging member, which actuate the two lifting frames so they rise and lower synchronously.
5. A seat body swing mechanism allows the seat body to move along the front-back direction relative to the base.
6. A lift limit mechanism restricts the opening angle between the pivotal rods of the frames, particularly when the seat is lowered.

Who it is for

• Children’s furniture brands looking for a motorized high chair or activity seat that adjusts height smoothly without tilting the seat pan.
• Wholesalers of juvenile products sourcing adjustable seating for retail chains where parents value easy height transitions between table and floor levels.
• Amazon sellers in the baby category needing a differentiated product listing with a clear mechanical advantage over manual crank or pneumatic chairs.
• Contract manufacturers building seating for daycares or pediatric therapy rooms where repeatable, stable height settings are required daily.

How it works

The main parts

Operating steps

1. Power the motor - the motor’s output shaft turns the rotating member.
2. Transfer motion - because the driving member is pivoted at a point offset from the shaft center, rotation pushes the driving member linearly.
3. Actuate frames - the driving member moves the first and second swinging members, causing the first and second lifting frames to open or close together.
4. Maintain angle - since both frames move synchronously, the seat main body retains a constant angle relative to the installation base throughout the travel.
5. Swing the seat - the seat body swing mechanism can be operated independently to shift the seat forward or backward.
6. Limit travel - the lift limit mechanism stops the frames from opening past a set angle, and limiters block lateral drift.

Applications

High chairs for dining

Parents adjust the chair height to match different dining tables or kitchen counters. The synchronized frames keep the seat level so the child does not slide forward when raised, while the swing mechanism pulls the seat closer to the table edge.

Activity and play seats

Toddlers use the chair at a low height for floor play and a higher setting for table crafts. The constant seat angle prevents tipping sensations during transitions, and the lift limit mechanism ensures the frames do not over-extend when lowered to the floor position.

Pediatric therapy seating

Therapists require precise, repeatable seat heights for children during sessions. The motor drive provides steady adjustment without manual cranking, and the limiters prevent lateral sway, giving a stable platform for postural exercises.

Daycare multi-use chairs

Staff change seat heights frequently to accommodate different age groups sharing the same room. The robust frame synchronization reduces maintenance compared to independent gas springs, and the support seat’s concave arc surface guides the moving parts smoothly.

Where it is less suitable

• Adult office chairs - the frame geometry and motor sizing described in the patent target lighter loads typical of children’s furniture; adult ergonomic chairs use different lift columns.
• Outdoor patio seating - the exposed motor, pivot points and swing mechanism are designed for indoor environments where weather sealing is not specified.
• Recliners requiring full backrest tilt - this design maintains a constant seat-to-base angle and offers fore-aft swing, but it does not describe a reclining backrest hinge.