Patent attributes
A lamp including: a casing, a light source, a radiator, a front cover, and a convex lens. The front cover includes: a rotary ring, a movable ring, and a stop ring. An annular groove is disposed outside of the rotary ring. A limiting structure extends inside the annular groove and limits the rotary ring to rotate relative to the casing. The stop ring is fixed inside the rotary ring and the stop ring and the rotary ring combine to form female threads. The movable ring is disposed inside the rotary ring and convex points of the movable ring match with the female threads. Guide columns are disposed on an end part of the movable ring close to the radiator. The guide columns match with guide holes of the radiator and are adapted to axially pass through the guide holes. The convex lens is fixed on the movable ring.
