Click to embiggenA patent for a device putting wood-cutting blades on a chain, so that people can cut down trees – or, in the wake of hurricanes, cut up ones that have fallen down.
Technically, this patent was merely an improvement on existing chainsaws, with better joints between the tooth-carrying links on the chain.
There’s a metaphor there.
The patent also calls it an “endless chain.”
There’s a metaphor there, too.