I work a toy-store assembly line. My hands build other people's designs; my head builds its own. This one wouldn't leave me: a jack-in-the-box that lifts slowly under a crank, dwells, then pops hard.
Two springs can't do slow-then-pop: the soft lift spring is weakest right where it must release the pop. So I added a trip spring, charged off the crank through a cam that lifts, dwells, then drops off sharp.
Eight versions, each a caught failure: v1 no trip power source; v2 charged off the crank, but a 4 deg single-start worm self-locks and takes 20+ turns (music-box feel); v3 fixed the drop face; v4-v6 the pawl never tripped, then never re-armed.
Three versions I asked the wrong question. The real one: can the nose-ledge pair carry load both ways? It can't. The fix is one-sided contact with a clearance gap on the non-load side, so a downward poke runs free across it and re-contacts in the seating direction.