Thumper Bumpers

Bally’s proprietary name for Pop Bumpers, the solenoid-driven Active Bumpers that kick the ball away on contact. Bally adopted the “thumper bumper” branding to distinguish its version of the mechanism, and the name carried forward when Bally merged with Williams in the mid-1980s, appearing across Bally-branded schematics and parts lists well into the 1990s. The underlying hardware — a ring-and-rod assembly beneath a mushroom cap that fires when the ball depresses the skirt switch — is identical to the Jet Bumpers found on Williams-branded tables. The “thumper” label remains familiar to collectors and operators who service Bally-era machines.