Spring bolt safety device of three-rod type cylinder lock

The utility model relates to a spring bolt safety device of three-rod type cylinder lock including a lock latch, a safety latch, two reeds, an arrester, and an arrester release device. The lock latch and safety latch contact respectively with one end of the two reeds. A support place contacting with the other end of one of the reeds is provided on the braking end of the arrester. A pivot is provided on the other end of the arrester which can swing around the pivot. The braking position of the arrester corresponds with the braking position of the lock latch at the extending status. The braking position of the lock latch is arranged on the upper or lower sides of the lock latch. The release position of the arrester is constituted by a convex arranged on one side of a latch plate hook connecting with the lock latch and a release plate connecting with the safety latch. The convex and the release plate are at the level higher than that of the braking position of the lock latch. The lock latch safety device provides simple actions for safety and safety-release, is not liable for troubles, demands low fitting requirements between various parts, and is relatively easy to fabricate.