What it claims
Officially, it’s an “Improved Burial-Case or Coffin for the dead.” It’s a coffin with a square tube running from the lid directly over the deceased’s face up. Along with a ladder that the “supposed corpse” can use to climb to safety, the tube also includes a string attached to a bell at one end and a cord placed in the occupant’s hand. The coffin also includes air inlets to let the person inside breathe if needed, as well as a glass door so that onlookers can peer inside.
What it actually is
A coffin with an emergency exit. A chimney to the surface, a ladder inside it, a bell on top, and a rope you hold onto for the rest of your life or the rest of your death, whichever turns out to be shorter. The string-and-bell apparatus function as a primitive intercom system, while also fueling the nightmares of anyone who might have to walk through a graveyard.
Why, though
The patent says it plainly: the goal was to save anyone buried “ere life is extinct” from premature burial and death. And it includes the most practical line in the whole document: if, on inspection, the occupant really is dead, the tube is pulled out, the sliding door is closed, and the tube is reused for another grave. Fear of being buried alive, solved with a ladder. Then recycled.