Patent attributes
A portable information handling system rotationally couples housing portions with a variable torque hinge having a first axle that rotates with a first housing portion, a second axle that rotates with a second housing portion and a synchronizing gear assembly that translates rotation between the first and second axles. Variable torque is applied by selectively engaging and disengaging a coupler gear with the synchronizing gear assembly to apply and remove an increased torque that resists housing rotation. In one embodiment, the coupler gear is an idler gear of the synchronizing gear mechanism that selectively applies and removes an increase torque of the second axle to the first axle. The coupler gear slides in response to an actuator, such as an electro-permanent magnet acting on a ferromagnetic material with high and low magnetic attraction states.
