PURPOSE: To protect privacy normally, and automatically unlock at the time of fire or the like by using an unlocking element comprising shape memory alloy material which becomes superelastic and deformed as specified at the time of high temperature as a subsidiary lock.
CONSTITUTION: In a door lock comprising a receiving metal 2 to compose a receiving part of a lock provided on the side of a frame 1, and a latch 4 to compose a latch part provided on the side of a door 3, a circular shape memory alloy material unlocking element 6 which is flat in room temperature, and which becomes superelastic and circular when an abnormally high temperature, that is 60°C, for example, is reached is placed on a seat part 5 under the latch 4. When 60°C is reached around the door 3 by a fire or the like, the unlocking element 6 becomes superelastic and circular to lift the latch 4 to be unlocked. This unlocking element may be used in a catching member in a chain, or an unlocking element or the like which is recessed in room temperature and which becomes flat when heated may be used.
YOSHIDA MIZUMASA
HEII ISAO
| JPS60208577A | 1985-10-21 | |||
| JPS5921882A | 1984-02-03 | |||
| JPS59179981A | 1984-10-12 | |||
| JPS59179982A | 1984-10-12 |