Apple working on tech to improve reliability of hinges for smart rings

This fiber composite friction hinge could have "first and second sets of interdigitated elongated fingers."

The patent application stresses that this can also apply when a device has more than one hinge, which could be a reference to certain proposed designs of folding iPhones.

"Electronic devices may have portions that are joined with hinges," says the patent application.

As Apple increasingly produces folding devices — from the rumored smart rings and a "folding iPhone" to the shipping MagSafe Duo Charger — it is researching how to make hinges stronger.

"Portions of [the] hinge may help grip the sides of a user's finger when device is mounted on the user's finger," continues the patent application. "