We’ve been hearing for a while that the upcoming will get removable doors, and now we’re seeing a FoMoCo patent application for airbag-containing devices that would take the place of an off-road vehicle door that has been removed by the user. Here’s a look at that patent.

This patent application, discovered by , is for an “assembly and method using an inflatable device within a vehicle having a detachable door.” In other words, Ford is describing a way to protect passengers with an airbag that fills the void left by a door that has been removed.

The patent application provides some background, and describes the problem that this new invention aims to solve, writing:

Some vehicles, particularly off-road vehicles, have detachable doors. When desired, the detachable doors can be detached from the vehicle leaving behind door openings. Some vehicles incorporate cage members into the door opening areas. Other vehicles omit the cage members entirely. The detachable doors could incorporate an inflatable device, but detaching the detachable doors from the vehicle removes the inflatable device from the vehicle.

Since removing an “inflatable device” is probably not a great idea, the patent application—which you can read on the —describes an airbag that would remain present even without a door. From the patent application:

[The assembly is] an inflatable device that transitions between a less expanded position and a more expanded position. The inflatable device in the more inflated position is disposed within a door opening of a vehicle. A door of the vehicle is detached from the vehicle to provide the door opening.

The paper describes a number of different “embodiments” of this idea, but the main ones involve a tube-door (which is ) and a deployable, telescoping bar.

The tube-door concept seems fairly straightforward. Inside the body of the vehicle are some sensors, a control module, and an inflator. If the vehicle is involved in a crash and the vehicle knows the vehicle’s standard doors are off, the sensors and control module trigger the inflator, sending gases into the hollow tubes that make up the door.

Inside the top door tube, facing the inside of the vehicle, are some small holes, which allow the gases from the inflator to fill up a fabric airbag, protecting the occupant inside the vehicle.

From the patent application:

...the more expanded position provides a cushion or soft interface between the occupant and the cage member . The inflatable device essentially damps an impact force between the occupant and the cage member to reduce the effect of the impact force on the occupant.

Ford Global Technologies, LLC describes another example “embodiment” of this airbag-for-doorless-off-roader concept; instead of a tube-door, there’s a deployable, telescoping member that looks like this:

Ford describes how it works, writing:

The gas...passes through an interior area of the deployable assembly causing the deployable assembly to move from the stowed position...to the deployed position...Movement of the deployable assembly to the deployed position forces open the lid .

You can see the lid through which this deployable device would telescope in the image below, labeled “90":

And below is a look at the telescoping assembly:

The deployable assembly comprises...a plurality of individual segments that are telescopically received within one another when in the stowed position. Gas moving into the interior area of the deployable assembly cause the segments to extend relative to one another, which moves the deployable assembly to the deployed position The segments could be metal, metal-alloy, carbon fiber, or some other material composition. 

And here’s how the telescoping device actually inflates an airbag to protect occupants:

The inflatable device is directly connected to the segments . From the interior area of the deployable assembly , the gas passes through openings into tan interior of the inflatable device , which causes the inflatable device to transition from the less expanded position to the more expanded position.

There’s a lot more to the patent application, including mention of using a “chain or bar” as a cage member that would span from the front of the door opening to the rear, and contain an airbag.

Whether we’ll see any of these ideas implemented on a production vehicle like the upcoming Ford Bronco, I don’t now. But it’s still an interesting concept, and quite different from what what’s offered in the only mainstream production SUV currently on the U.S. market designed with removable doors, the Jeep Wrangler (as as I understand, the Wrangler simply has a side airbag that ).