A newly granted patent shows that Apple has improved on its previous hinge design and is now describing a foldable iPhone display with more complex gears. When foldable iPhones, iPads, and even MacBook Pros finally launch, their folding hinges are likely to look generally smooth and simple. However, looking at the internals, it now looks like Apple is at least leaning towards a design with interlocking gear meshes.
Previous design drawings showed up to three or four small gears rotating around a larger gear. The new patent, titled "Hinge for Folding Display Devices," includes the design of four pairs of seemingly small gears that are assembled into a complex assembly of six static components.
"Foldable display devices may have case portions connected by hinges," Apple said. "The hinge may have a series of interconnected links...the links may be formed by interdigitated fingers in a friction clutch."
In addition to the gears or cogs that allow movement, Apple also describes pins that move the device in a set direction.
"The fingers or other portions of the connecting rod may be provided with crescent-shaped grooves that receive the pins," the patent continues. "During device folding, the pins can slide along the crescent-shaped grooves, ensuring that adjacent links rotate relative to each other about a rotation axis located outside the hinge and within the flexible display panel."
A separate sketch shows a row of four directly interlocking gears, while other sketches depict gears within different rigid elements.
"Links may also be formed from link members with curved mating bearing surfaces that slide relative to each other as adjacent links rotate relative to each other," Apple said. "A housing rotation synchronization mechanism may be formed using a set of gears extending between the first and second housing portions."
All of this suggests that Apple is moving away from one or more large hinge mechanisms to a system that utilizes many smaller gears. The newly granted patent appears to be more sophisticated and complex than the previous patent. However, Apple may be pursuing more than one hinge design. Previous patents and patent applications seemed clearly focused on iPhones or iPads, but this patent specifically describes a wider range of devices, from large to small.
"[The device] may be a cell phone, tablet, laptop, watch device or other wearable device, television, stand-alone computer monitor or other display, computer monitor with an embedded computer (such as a desktop computer)," it said, "[or] a system embedded in a vehicle, kiosk or other embedded electronic device, media player or other electronic device."
However, patents are always written to cover the widest possible range of possible applications of their technology. Additionally, while the new design appears to be a development from the previous one, Apple may still be working on both.
The patent is credited to 10 inventors, including Bradley J Hamel, whose previous work includes another granted patent on friction hinges. There's also Kevin M. Robinson, who was previously listed in a patent application for a hinge mechanism, possibly designed for the MacBook Pro.
According to reports, Apple has been developing the iPhone Fold. However, recent rumors suggest that it will focus on folding iPads and MacBook Pros.