Inside Your Bingo
Stepping Units


stepping unit
The large backbox of bingo machines also contains a number of stepping switches that perform various functions. Most of these are mounted on the back door. One of these units, called the timer unit has two functions. First it acts as a ball counter indicating which of the first five balls has been raised to the playfield. The adept player may notice the sound of this unit being stepped up as each new ball of the normal five balls is raised. This unit controls the tripping of selector lock, and other ball in play sensitive features The other function of this unit is that of play timer. After the fourth ball is shot, this unit begins to step up at regular intervals. When it reaches the top step, after quite some time, it causes the machine to tilt, thus terminating the game if the player leaves the machine without completing the game.

There are usually a number of stepping switches controlling various game features, such as spot number selection, A-B-C-D,turning corners, etc. These units are spasmodically advanced during feature selection (under the control of the spotting disk, the mixers, and the reflex unit) and enable the feature with which they are associated. The lighted teaser arrows on the backglass are also advanced by these units.

Two of the most important stepping units in a bingo are the score (or odds) units and the replay counter(s). Earlier bingos had one each of these units. Later models (those with three color independent odds) had three of each, one score unit and replay counter for each of the three colors; red, yellow, and green.

The score unit(s) is advanced pseudo-randomly during feature selection and control the odds lights on the backglass, which indicate the number of replays a player will receive if he completes a 3-in-line, 4-in-line, or 5-in-line winning combination on the bingo card(s). This unit, in conjunction with the corresponding replay counter, controls the number of replays awarded during payout.


stepper unit at rest. the arm at the left is what pushes the gear clockwise one tooth at a time. The tab on the right keeps the gear from rotating counterclockwise.

stepper unit in action

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