Actuator Coil Assembly Design Determines Direction of Coil Expansion
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
An encapsulated actuator coil assembly design directs coil expansion induced by in-use heating away from the actuator. This eliminates actuator binding experienced with the previous design shown in Fig. 1. Referring to Fig. 1, it is seen that actuator 1 occupies a space between opposing encapsulated magnets 2 and 3. (For clarity 2 is shown without encapsulation.) When the magnets are energized, non-magnetic actuator 1 moves in direction 4 as four magnetic areas 5 are pulled into alignment with four pairs of opposing magnet poles 6. It is seen that because coil and bobbin assembly 7 is mounted rigidly against stator 8, as shown at 9, any longitudinal expansion 10 of assembly 7, caused by in-use heating, is necessarily toward actuator 1. This effect commonly causes binding of the actuator. Referring to Fig.