Apple Patents Hinge Design for Foldable Devices With Interlocked Fingers, Friction Clutch Mechanism

Apple has been granted a patent for a hinge mechanism designed for foldable devices. The hinge designed by the company can be used on a range of devices, and might not be limited to its purported foldable smartphone. While the company's rivals Samsung and Huawei have already introduced foldables with two and three displays, respectively, Apple has yet to launch its first foldable device. It is working on smartphones, tablets, and computers with folding screens, according to recent reports.

Apple Patents Hinge Mechanism Designed to Prevent Excessive Rotation

Details of Apple's new hinge design are available in a document published on the US Patent and Trademark Office (USPTO) website (via GSMArena). It describes an electronic device that is equipped with a hinge structure that bends around an axis, along with a flexible display that is divided into two sections (Fig. 4).

The company's patent includes figures that show a hinge mechanism that features multiple links that are designed to rotate relative to each other (Fig. 21), to enable the folding and unfolding of the device. It is also equipped with a friction clutch mechanism that features interlocked 'fingers' and crescent-shaped slots that can control the movement of the aforementioned links, while ensuring it is not extended beyond a particular limit.

Figures showing the hinge design patented by Apple (tap to expand)
Photo Credit: USPTO/ Apple

According to Apple, the new hinge mechanism also features two sets of rotational synchronisation gears (Fig. 10), and it appears that they are designed to offer fine-grained control over how the device is unfolded. The document contains drawings that show the odd and even links working together to achieve this functionality.

A 'counterbalance mechanism' has also been described by the company, which would comprise a spring, a pad, and a roller (Fig. 17). These components would offer a folding torque that would work against the torque exerted when the display is unfolded, providing a controlled (and smooth) movement during this process.

Like other mechanical components, the hinge mechanism would also be affected by wear and tear over time. In order to minimise the impact, the links in the hinge are shown to feature curved surfaces, that would also enable smoother rotation. The functioning of the mechanism is seen from Fig. 22 to Fig. 25.

The company also describes other components that could be part of the foldable device — these include a camera that is covered when the screen is folded, as well as a two-dimensional array of haptic devices to provide feedback. It would also support audio playback via speakers that are located at the corners of the flexible display.

Apple's latest patent for a hinge mechanism is not indicative of the company's plans to launch a foldable phone. Given the company's tendency to keep its plans under wraps until it launches new devices, we will have to wait for an official announcement from the firm on when it will launch its first foldable device.