US Patent 10409379 Haptic actuator assembly having a magnetic pre-load device

A haptic actuator assembly comprising a haptic actuator and a pre-load device is presented. The haptic actuator is configured to generate a displacement along a first axis, wherein the haptic actuator is a piezoelectric actuator. The pre-load device is adjacent to the haptic actuator and configured to generate a compressive load on the haptic actuator along the first axis. The pre-load device includes a first component and a second component that are disposed on opposing surfaces of the haptic actuator, and are configured to generate a magnetic force that attracts the first component and the second component to each other in order to generate the compressive load on the haptic actuator along the first axis. The first component is a permanent magnet, and the second component is at least one of another permanent magnet, an electromagnet, or a ferromagnetic component that comprises ferromagnetic material.