Hinge assemblies are commonly used to allow electronic device components to move relative to one another. For example, a laptop computing device can include a base component that is rotationally coupled to an upper display component by way of a hinge assembly. It is often desirable to provide some biasing or resistive force when moving the upper component of a laptop between closed and open positions, or between two different open positions. Many types of conventional friction-based clutches can provide such a resistive force for a hinge assembly. Such friction-based clutches can also provide a braking force that holds the upper component in a fixed position with respect to the base component once a user sets the upper component at a desired fixed position.
Unfortunately, many conventional friction-based clutches provide a fixed level of resistance at all times over a full range of motion of the hinge assembly. Consequently, the level of resistance cannot be lowered for specific portions of the range of motion, particular directions, or different times or circumstances. For example, a user may need to hold the base component at the same time that he or she adjusts the position of the upper component in order to prevent any simultaneous lift or following motion of the base component. This can be inconvenient when the user merely wishes to adjust slightly the upper component position and may only want or have one hand to do this. Further, a fixed level of resistance can often be too much and a nuisance when a user wishes to open a laptop from a closed position.
While current hinge and clutch designs for electronic devices have worked well in the past, there is often room for improvement. Accordingly, there is a need for improved clutch designs for electronic devices that allow for varying levels of resistance.