Shoulder-Detecting Massage Chair Mechanism with Forked Swing Arms

The problem

Users of different heights sit in standard massage chairs, but the mechanical rollers follow a fixed path. If the rollers do not align with the user’s actual shoulder line, the massage heads press against the neck vertebrae or miss the trapezius muscles entirely. Manual adjustment requires the user to stop the session, change settings, and restart, which interrupts the experience. Relying solely on optical sensors or pressure mats adds electronic complexity and cost without solving the physical alignment of the rollers to the shoulder contour.

The solution

This massage machine places a moving core inside a backrest seat. The core contains at least one pair of massage assemblies driven by a motor, transmission mechanism, transmission shaft, and cylindrical cam.

1. Forked swing arms - Each assembly has two pairs of arms arranged at upper and lower positions along the length of the user’s back. The arms incline toward each other to create a fork opening sized to clamp the shoulder.
2. Soft rubber rollers - The ends of the swing arms hold massage heads made of soft rubber that abut the body during operation.
3. Movable mounting - The assembly sits on a cylindrical boss extending from a guide component. A tensioning spring and a limiting structure (an arc-shaped notch and a stop block) keep it stable but allow it to turn over in the thickness direction of the back when the user leans against only one swing arm.
4. Sensor detection - A trigger piece (such as a shading sheet or magnet) on the assembly interacts with a position sensor (photoelectric or Hall sensor) on the base. When the assembly tilts to a set position, the sensor generates an electrical signal.
5. Automatic adjustment - A judgment module in the control circuit processes this signal to generate shoulder information, directing the core to perform a massage operation suited to the user’s specific shoulder placement.

Who it is for

• Massage chair brands looking for a mechanical shoulder-detection method to integrate into their premium or mid-range seating lines.
• Contract furniture manufacturers supplying wellness centers, airports, or corporate breakrooms where users of varying sizes share the same equipment.
• Amazon private-label sellers sourcing differentiated massage chairs with automatic fit features to stand out in a crowded catalog.
• Wholesalers and distributors of health and wellness electronics seeking mechanisms that reduce manual calibration steps for the end user.

How it works

The main parts

Operating steps

1. The user sits against the backrest (110). The driving device (202) moves the massage assemblies (201a, 201b) along the transmission shaft (403).
2. As the assemblies travel, the fork openings formed by the swing arms (203a–203d) encounter the user’s shoulders.
3. When the back presses against only one swing arm, the massage member (405) rotates around the cylindrical boss against the tensioning spring (205), limited by the stop block inside the arc-shaped notch.
4. This rotation moves the trigger piece (206) past the position sensor (207), generating a position signal.
5. The judgment module reads the signal, determines the shoulder location, and commands the cylindrical cam to adjust the yawing motion of the arms for a targeted massage.

Applications

Home wellness rooms

Homeowners buy full-body massage chairs for use at home. Users of different heights in the same household need the chair to adapt without manual recalibration every time they switch seats.

Corporate breakrooms and offices

Employees use shared wellness chairs during short breaks. The automatic shoulder detection ensures the mechanism aligns correctly for each person immediately upon sitting down, saving time.

Airport lounges and waiting areas

Travelers of all sizes rest in lounge seating equipped with massage functions. According to the patent, the fork-arm assembly finds the shoulder mechanically, so the chair can match its routine to each seated user without a manual height setting.

Spas and recovery centers

Wellness facilities offer automated massage stations between treatments. The patent describes the control circuit choosing the massage operation from the detected shoulder information, which suits a facility where many different people use the same station.

Retail showroom demonstration units

Electronics and furniture stores display massage chairs for customer testing. Automatic detection allows shoppers to experience the correct massage routine instantly without staff assistance to program the remote.

Where it is less suitable

• Portable or handheld massagers - this mechanism relies on a backrest seat and a vertical moving core, which cannot be miniaturized for handheld devices.
• Leg and foot-only massage units - the forked arms and shoulder sensors are designed exclusively for the back and shoulder region.
• Basic entry-level chairs - the cylindrical cam, sensors, and judgment module add mechanical and electronic complexity compared to simple fixed-roller designs.