ANIMAL-TRAP
A second pair of jaws fires in case the first misses.
The trap carries two pairs of spring-loaded steel jaws on one base plate, each held open by a latch and a baited trigger. The animal disturbs one trigger, releasing its latch, and that pair of jaws snaps shut. The tilting of the first trigger tensions a coiled spring connecting the two triggers, which then releases the second latch. The second pair of jaws closes in quick succession on whatever part of the animal the first pair did not catch.
“As the two pairs of jaws will close in quick succession, should one pair of jaws fail to catch a part of the animal's body, then the other pair is bound to trap the animal, thereby a trap is provided which will make a sure catch in most cases.”— John F. Arneth, from the specification
And the world did not beat a path to his door.