Abstract: 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.
Abstract: Provided is a bulb holder locking apparatus, comprising a fixing mount, a bulb holder, a spring and a ratchet mechanism comprising a ratchet bar having a plurality of ratchets, a pawl and a movable cam having a curve contour; wherein the bulb holder is flexibly connected to the fixing mount; the spring is connected to the fixing mount, so as to force the bulb holder to move downwards; the ratchet bar is connected to the bulb holder; the pawl is connected to the fixing mount and elastically contacted with the ratchet bar; the movable cam is slidingly connected to the ratchet bar and elastically contacted with the pawl; and the curve contour comprises a plurality of crests engaged with the pawls.