On July 19, 1892, U.S. Patent No. 479,207, issued to G.Q. Seaman on a Time Alarm Bed:

The bed is constructed to “eject the occupant of the bed, so that the said occupant will not only be awakened, but must necessarily arise.”

This is probably the logical escalation of Samuel S. Applegatte’s Device for Waking Persons form Sleep, (U.S. Patent No. 256265), which merely employed 60 bells suspended over the bed to wake the occupant: