- description
- [[manufacturer:bally]]'s proprietary name for [[gameplay-feature:pop-bumpers]], the solenoid-driven [[gameplay-feature: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 [[manufacturer: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 [[gameplay-feature:jet-bumpers]] found on Williams-branded tables. The "thumper" label remains familiar to collectors and operators who service Bally-era machines.