Abstract: An impact switch sensitive to horizontally directed forces and to inversion of the switch is disclosed. The switch includes a U-shaped ball chase in which is mounted a movable actuating mass such as a steel ball. A permanent magnet located at the bottom of the ball chase defines a ball seat. An upper ball chase wall above the ball seat limits vertical motion of the ball to restrict switch actuation to horizontal impact forces. Switch actuators operating a common switch are located at the top ends of the U-shaped ball chase, whereby impact forces which move the ball off the ball seat will, if sufficiently large, cause the ball to run up one of the ball chase legs to strike one or the other of the switch actuators.