ANIMAL TRAP
The operator selects whether the falling plate crushes the animal.
A heavy plate slides on guide posts above an open-topped box, held up by a cord that runs over a crossbar to a pointed bar. The pointed bar is wedged between the turns of a cord wound on the bait pan's trigger arm. The mouse depresses the bait pan; the cord turns release the pointed bar and the plate falls. A weighted sleeve on a notched rod above the plate is positioned to determine how far the plate descends.
“It will be understood that a series of different weights 18 may be provided which may be employed as desired, also that the weight 18 may be adjusted along the rod 16 so as to allow the plate 14 to descend sufficiently to crush the animal or not, as may be desired.”— Michael Shutoff, from the specification
And the world did not beat a path to his door.