How slots work

Playing slots

PULLING THE HANDLE

Slot pull

The handle rotates a hook mechanism which grabs the kicker, pulling it forward.
A catch on the opposite end of the kicker locks onto a control cam and pivots it forward, rotating a series of gears connected to the cam. A spring pulls the cam back to its original position, whilst gearing slows this movement acting as a mechanical delay.
When the control cam is pivoted forward, it releases a spring-mounted cam plate extending across the back of the machine.
The control cam also pulls the stoppers away from the notched discs. As the kicker moves it pushes the stoppers against several notches on the cam plate.
These hold the stoppers in place so the reels are free to rotate.
As the handle continues to move the kicker, the kicker paddles briefly push the discs forward. When the handle is pulled fully back and the kicker has passed the discs, the bottom of the hook mechanism moves up against a slanted surface. The slant pivots the hook forward and releases the kicker.
The kicker spring jerks the kicker back at speed, paddles hit the notches on the discs, spinning the reels at a rapid pace.
While all this is going on, the control cam is gradually returning to its original position. When it does return, it pushes the cam plate back, in turn releasing the stoppers.
Different catches engaging different stoppers are positioned so that the cam plate will release the stoppers one at a time. Each stopper springs forward to lock onto a notch, stopping the spinning reel.

All of this commotion, which lasts mere seconds, is hidden inside the machines' case.

It all starts by popping in a coin and pulling the handle. There is clunk as the reels start to spin.

Then, to highten suspense, they abruptly stop one by one, revealing a winning line - or not - as is usually the case.

Then it's time to start all over again.