US Patent 7147343 Flashlight

A flashlight has a lens moveable relative to an LED. The beam of light provided by the LED can be focused and provides a uniform light pattern across the range of focus. The lens is supported on a front housing section and the LED is supported on a back housing section threaded onto the front housing section. Twisting the front housing section closes a switch providing power to the LED, to turn the flashlight on. Twisting the front housing section also adjusts the focus of the beam. A timer circuit within the flashlight turns the flashlight off after a selected time interval, to preserve battery life.