Hi, all.

I took a look at the Coin Accumulator photo and figured it out. I'm
including a marked-up copy of the photo.

The large toothed wheel is a counter. It is shown in the "Zero" position
where there are no coins deposited. Notice the metal pin at the 8
O'clock position. It is pressing downward on the right end of a pivot
arm. This raises the left end of the pivot which lifts the movable
contact on the switch, shutting down power.

When coins are deposited down the gray chute at the right of the photo
each coin presses and releases a lever in the chute which then lets the
counter advance clockwise by one tooth. This now lifts the pin off the
pivot and closes the switch. Additional coins advance the counter one
more tooth each.

At the end of the tune the "Stop" perforation on the tracker bar
activates the pneumatic on the left, moving the counter wheel back
(counter clockwise) by one tooth until the last coin's worth has played.
The next activation of the pneumatic then brings the wheel back to the
"Zero" position and opens the switch.

Keep on Rollin' Along,
Austin Matlow

 [ Accumulator/Coin Counter with reference Markings
 [ http://www.mmdigest.com/Attachments/20/02/02/200202_224945_Acc%20Done.JPG