ANIMAL-TRAP.
A spring-jaw rat trap that can be set with one hand.
A wire spring-jaw is pivoted to a wooden base that serves as the stationary lower jaw. Raising the jaw's rigid back piece cocks the spring; a trigger on the base is laid over the back and hooked under a detent loop on the bait pan. When the rat presses the pan, the pan descends, the trigger disengages, and the coiled spring drives the jaw down onto the base. In one variant the jaw carries pointed projections for impaling the animal, and a notch on the trigger locks the closed jaw so the victim cannot raise it.
“It will be seen that the trap may be set without necessity for handling the dangerous active portion of the jaw, and may be set with one hand.”— Chauncey Burdett Trumble, from the specification
And the world did not beat a path to his door.