The Pop Bumper is one of the most recognizable objects on a pinball playfield. When the ball hits the "skirt" it pushes down on that side of the skirt. There is a stem that extends down from the skirt and into the center of a concave tip on a leaf switch. Pushing down on one side of the skirt cause the rod, by lever action, to move to the opposite side of this concave tip, pushing down on the switch. The switch then activates the coil which rapidly pulls in on an iron core. The core attaches to a metal flange which acts to propel the ball away from the pop bumper. The pop bumper in like-new condition can be made even stronger with some simple modifications. Generally a pop bumper can be hit from any direction and serves to speed up the motion of the ball.

The physics:

A rolling pinball pushes down on one side of the bumper skirt. The skirt which is suspended above the playfield by a spring around the stem, acts as a lever and the stem swings away from vertical.

As the stem tip moves to the side it pushes down on a concave tip attached to the end of a leaf switch.

The closed switch completes a circuit to the pop bumper coil.

The energized coil magnetizes the iron core which is pulled in and attracted to the coil stop at the bottom of the coil.

The metal flange which is physically attached to the iron core also pulls down quickly and applies a force to the pinball, shooting it away from the pop bumper. The force of the flange for a moment of time (impulse) produces a change in momentum of the ball (direction change as well as speed increase).

Also when the plunger pulls down, a plate attached to the core allows a scoring switch to close, completing a circuit to a scoring device.

The spring force returns iron core to its original position.