Acme Dynamite Plunger

So in the old Bugs Bunny cartoons, Rube Goldberg contraptions, and Three Stooges reruns, we see that a dynamite explosion is often initiated by a box with a plunger that is actuated by pushing downward.

My question is, why the plunger and what does it do? I’m led to understand it’s called a “dynamo” which is a sort of electric generator but I can’t figure how the plunger arrangement creates and delivers the charge in the correct way.

We’ve had a few threads on these. Here’s one:

http://boards.straightdope.com/sdmb/showthread.php?t=257431&highlight=plunger+explosive

If you don’t feel like clicking the link, the short, simplified version is that the plunger turns the dynamo and an energy-storing flywheel as it’s pushed down by engaging a straight gear on the plunger rod with a pinion gear on the dynamo. When the the plunger reaches the bottom of its travel, it depresses a switch which closes the circuit. BOOM. Coyote is toast.

Coyote? Toast? Surely not. Nothing appears to daunt that member of the canine race; he just gets covered in soot and goes off, coughing slightly, to plan his next dastardly attack on the Road Runner.

Wile E. Coyote always got my sympathy - he was always getting beaten up, without any reward whatsoever.

[/hijack as the OP seems to have been answered] :smiley: