Safteycoffin was made to save life
During the 1800 century many people where afraid of beeing buried alive, one of them was the Danish author H.C Anderssen, he use to leave a note beside his bed saying that he was just sleeping.
So in 1868 a new safteycoffin where constructed, after the funeral the top of the coffin stands up from the ground. If the dead still would be alive he could sound the alarm by pulling a string of rope that sounded a bell that where attached to the top of the coffin. Then he just had to wait that someone would dig him up.