Door lock with latch bolt and inside key

Central Europe, ca. 1550

Malleable iron locking mechanism riveted to a cutout support sheet. Latch connects to a spiralled handle. Curved forged tension rod decorated with notches. Open octagonal key case. Inside key with a spiralled bow.

H: 21.5 cm, W: 23cm

UMP 3141

The integrated inside key featured on such locks kept the bolt in the open position from the inside, preventing the latch from accidentally dropping and locking. Only a key used from the outside could release the bolt. The bows of the inside keys were often curled into spirals or wrought into volutes.