A flash light of the type comprising:
- a metal barrel, said metal barrel comprising an insulative partition board on the middle, a metal rear cap, a battery set mounted in between said partition board and said rear cap, and a button hole at the periphery near a front end thereof;
- a lamp case fastened to the front end of said barrel;
- a rim covered on said lamp case at a front side, said rim having a sealing rubber mounted on the inside to hold a reflector within said lamp case and a lens in front of said lamp case;
- a holder shell assembly mounted in the front end of said barrel, said holder shell assembly comprising a negative pole metal contact plate mounted on the outside at one side and disposed in contact with said barrel, a positive pole metal contact plate provided at a rear end thereof and disposed in contact with the positive terminal of said battery set, and a front locating ring;
- a switch mounted on said holder shell assembly, said switch having a positive terminal contact connected to said positive pole metal contact plate at said holder shell assembly, a negative terminal contact, and a button extended out of the button hole at said barrel for operation by hand to close/open the circuit between the positive terminal contact and negative terminal contact of said switch;
- a lamp complete mounted in the front locating ring of said holder shell assembly, said lamp complete having a front cap holding a lamp bulb within said reflector, a metal rivet provided at an expanded rear end thereof and connected to the positive terminal contact of said switch, and a metal spring connected between said lamp bulb and said metal rivet, said lamp bulb having a positive terminal connected to the metal spring in said lamp complete and a negative terminal connected to the negative pole metal contact plate at said holder shell assembly;
- and
- a return spring mounted around said lamp complete and stopped between the front locating ring of said holder shell assembly and the expanded rear end of said lamp complete;
- wherein said lamp complete comprises a beveled stop edge at the expanded rear end thereof, and a stop flange backwardly extended from the expanded rear end;
- a focal length adjustment device is installed in said metal barrel around the button of said switch for adjusting the focal length of the flash light, said focal length adjustment device comprising a lower actuating member, an upper actuating member, and a button, said lower actuating member comprising a ring mounted around the button of said switch and having a plurality of equiangularly spaced hook holes, and an actuating rod extended from the ring of said lower actuating member and stopped at the beveled stop edge at the expanded rear end of said lamp complete, said upper actuating member comprising a ring coupled to said lower actuating member at a top side, and a lever extended from the ring of said upper actuating member for turning by hand to rotate said lower actuating member, the ring of said upper actuating member comprising a plurality of hooks respectively hooked in the hook holes at the ring of said lower actuating member, and a retaining notch on the inside, the button of said focal length adjustment device being mounted within the ring of said upper actuating member and supported on the button of said switch and having a locating rod engaged into the retaining notch in the ring of said upper actuating member;
- O-rings are respectively mounted around the button of said focal length adjustment device, the ring of said upper actuating member, the connecting area between said metal barrel and said lamp case, and the connecting area between said lamp case and said rim.