Electric lamp with a single device for focus-control and switch-control

摘要

An electric lamp with a parabolic reflector in a threaded collar, provided with a device for adjusting the focus by relative displacement between the bulb and the reflector which occurs when turning the collar on its threads between first and second adjusting positions. The device furthermore controls a switch housed within the casing for the device. The device is particularly applicable as an electric headlamp for mountain-climbers or spelunkers.