Snap matchlock

The snap matchlock is a type of matchlock mechanism used to ignite early firearms. It was used in Europe from about 1475 to 1640, and in Japan from 1543 until about 1880.
Description.
The serpentine (a curved lever with a clamp on the end) was held in firing position by a weak spring, and released by pressing a button, pulling a trigger, or even pulling a short string passing into the mechanism. The slow match held in the serpentine swung into a flash pan containing priming powder. The flash from the flash pan travelled through the touch hole igniting the main propellant charge of the gun. As the match was often extinguished after its relatively violent collision with the flash pan, this type fell out of favour with soldiers, but was often used in fine target weapons.
In Japan the first documented introduction of the matchlock which became known as the "tanegashima" was through the Portuguese in 1543. The "tanegashima" seems to have been based on examples of "snap matchlocks" purchased from Portuguese traders, and originally produced in the Portuguese armories present in Asia including Portuguese Malacca and Goa in Portuguese India, which were cities captured by the Portuguese in 1511 and 1510, respectively. The Malay arquebus, istinggar, ulitized this type of mechanism. There were 2 different lock mechanisms used in Indo-Portuguese matchlock guns. One has single leaf mainspring of the Lusitanian gun prototypes, which can be found in Ceylon, Malay peninsula, Sumatra, and Vietnam, and the other has V-shaped mainspring, can be found in Java, Bali, China, Japan, and Korea.