Seat Belt Buckle with Automatic Foreign Object Shield

The problem

Standard seat belt buckles have an open port where the metal tongue inserts. In daily use, especially in vehicles driven off-road or in sandy environments, small foreign objects like sand grains, seeds, paper clips, or coins can fall into this cavity. These intruders interfere with the internal locking mechanism, potentially preventing the latch from engaging securely or making it difficult to release. Cleaning these cavities is difficult because they are deep and narrow, often requiring disassembly of the trim panel. Existing solutions rely on manual covers or filters that users forget to replace, leaving the buckle exposed during normal operation.

The solution

1. The device integrates directly into the housing of the seat belt buckle. At the front end, a support piece is fixed using plug-in blocks that slide into slots on the housing.
2. A rotating piece is movably connected to this support piece. It acts as a lever arm. One part of the rotating piece connects to the support, while another part interacts with the cover.
3. The packaging swinging piece (the cover) is attached to the second part of the rotating piece. In its resting state, this piece physically blocks the insertion port.
4. When the user inserts the lock tongue, the physical presence of the tongue pushes against the packaging swinging piece.
5. This push rotates the rotating piece. As the rotating piece turns, it compresses the connection to the packaging swinging piece, moving it out of the way to allow the tongue to enter the locking chamber.
6. Simultaneously, the movement stores potential energy in the system, either through the deformation of the first/second part of the rotating piece or via torsion springs mounted on the connecting rods.
7. When the lock tongue is removed, the stored elastic force drives the rotating piece back to its original position. This action pulls the packaging swinging piece back over the port, resealing it automatically.

Who it is for

• Automotive Tier-1 Suppliers: Manufacturers looking to differentiate their buckle lines by offering enhanced durability features for commercial or off-road vehicle segments.
• Off-Road Vehicle Brands: Companies producing trucks, SUVs, or construction equipment where cabin dust and debris are common issues affecting component reliability.
• Interior Trim Integrators: Designers who need compact mechanisms that fit within existing buckle footprints without adding significant height or width to the console area.
• Aftermarket Safety Accessories: Brands selling replacement buckles for older vehicles where wear and tear has already compromised standard latches; this design offers a cleaner, more robust alternative.

How it works

The main parts

Operating Steps

1. Idle State: The packaging swinging piece rests over the insertion port, sealing it completely. The torsion springs are in their neutral or pre-loaded state.
2. Insertion: The user aligns the lock tongue with the port. The tip of the tongue contacts the packaging swinging piece.
3. Actuation: As the tongue pushes forward, it forces the packaging swinging piece to rotate around its connection point with the rotating piece. This rotation causes the rotating piece to pivot on the support piece.
4. Compression: The movement of the rotating piece winds up the torsion springs (or bends the elastic parts of the rod), storing energy. The port opens sufficiently for the tongue to reach the internal latch.
5. Latching: The tongue engages the locking mechanism inside the housing. The packaging swinging piece remains displaced as long as the tongue is present.
6. Release & Reset: When the user presses the release button, the tongue ejects. With the tongue gone, the torsion springs unwind, driving the rotating piece back. This pulls the packaging swinging piece across the port, closing it before debris can enter.

Applications

Off-Road Trucks and SUVs

Drivers in dusty or muddy conditions frequently open doors and interact with buckles in dirty environments. The auto-sealing port prevents grit from jamming the internal latch, reducing maintenance needs for rugged vehicles.

Commercial Fleet Vehicles

Trucks and buses undergo heavy daily use with multiple passengers entering and exiting. Coins, tickets, or trash often drop near the center console. This design ensures that incidental debris cannot fall into the critical locking cavity, improving uptime.

Construction Equipment Cabins

Heavy machinery operators work in highly particulate-rich environments. Standard buckles fail quickly due to sand ingress. A sealed port extends the service life of the restraint system in harsh industrial settings.

Marine and Boat Interiors

Salt spray and humidity cause corrosion and buildup in open mechanical parts. Keeping the buckle port covered when not in use protects the internal metal surfaces from environmental exposure, enhancing safety in marine applications.

Where it is less suitable

• High-Speed Racing Harnesses: Quick-release mechanisms often require minimal obstruction; added flaps might interfere with rapid unlatching protocols.
• Integrated Seat Electronics: If the buckle is heavily integrated with sensors and wiring in a tight space, the additional mechanical volume of the shutter may not fit.
• Low-Cost Economy Models: The extra parts (springs, precision rods) increase manufacturing complexity compared to basic stamped-metal buckles used in entry-level vehicles.