Abstract: An all purpose ladder includes a fixed base ladder segment that is conventionally made with long side pieces that are connected together by rungs or steps. An upper ladder segment comprises a pair of long side pieces connected together by rungs. As is conventional with extendible ladders, the side pieces of the upper ladder segment are in sliding engagement with the side pieces of the base ladder segment. A screw or worm shaft is rotatably mounted to one side piece of the lower ladder segment and a threaded bracket engages both the upper ladder segment and the screw or worm shaft such that when the screw or worm shaft is rotated about its longitudinal axis, the bracket travels along the length of the screw or worm shaft, thereby moving the upper segment relative to the fixed base ladder segment. Gears and a handle are provided so that a user can adjust the relative extension position between the base ladder segment and the upper ladder segment on a continuous basis.

Abstract: The release of the safety button of a firearm is indicated by the lighting of a lamp and/or the sounding of a buzzer. Movement of the safety button is detected by a resiliently positioned coil of wire which acts as a switch contact to supply electrical energy from a battery to the indicator upon release of the safety.