Trapped in the wall?!... springlock failure

I scrambled down past the pinball apron straight into an open metal repair bay beneath the machines! Right inside rested a funny old brass casing filled with intricate gears and heavy coil springs. You wanted to see a spring mechanism in action, and boy, did I find one! I leaned in to inspect a gleaming brass latch, but when my boot pressed a tiny tension bar—snap-click! A pair of hinged metal calipers sprang tight, clamping snugly around the sides of my denim overalls like a toy lockbox! I was pinned right against the wooden frame, boots dangling! With a hearty chuckle and a firm wiggle, I wedged my gloved thumb under the release pin and popped it wide open. Safe and free!