Jet Bumpers

Williams’ proprietary name for Pop Bumpers, the solenoid-driven active bumpers that kick the ball away on contact. Williams adopted the “jet bumper” branding to distinguish its version of the mechanism, though the underlying design — a ring-and-rod assembly beneath a mushroom cap that fires when the ball depresses the skirt switch — is functionally identical across manufacturers. The name became so widely recognized that many players and operators use “jet bumper” interchangeably with “pop bumper” regardless of the machine’s manufacturer. The term appears throughout Williams documentation and schematics from the 1960s onward.