Patent ID: 7819158

Claim:
Ultrasonic welding apparatus comprising an ultrasonic welding stack mounted for linear movement and applying a controlled force, speed, or a combination of force and speed to a first workpiece to urge said first workpiece against a second workpiece to which said first workpiece is to be joined, an electrically powered linear actuator coupled to said ultrasonic welding stack for moving said stack while applying a controlled force, speed, or a combination of force and speed to said stack, said actuator including an electrical servo motor producing rotational mechanical motion, and a converter integrated with said servo motor for converting said rotational motion into linear motion of an output shaft, a position sensor coupled to said actuator and producing an electrical output signal representing the actual position of said output shaft, and a controller receiving said electrical output signal from said position sensor and controlling the force applied to said stack by said actuator or the speed of said actuator.