No-Work-Type Actuator With Laminated PZT Beam Spring
Original Publication Date: 1984-Jul-01
Included in the Prior Art Database: 2005-Feb-04
A no-work magnet actuator is considered as a superior design for a high speed printer actuator because of its fast response and rapid settle out. In the design of the no-work magnet actuator, the most difficult task is to match the spring force to the magnet force as nearly as possible with a sufficient safety factor to assure the spring being restored to rest position for next firing. As shown in Fig. 1, the force from the permanent magnet, curve A, has to be higher than the spring force, curve B. The spring force provides the print energy, and the magnet force restores the spring. Since the magnet force is proportional to the second power of the displacement and the spring force varies linearly with the displacement, the stroke of the actuator is limited by the safety margin of two forces (point E in Fig. 1).