US Patent 7574912 Collapsible liquid level measurement device with attachment

A liquid level measuring device includes an elongate handle and an elongate frame arranged in telescoping relationship. The frame is movable between a collapsed position for storage and an extended position for usage. A float is movable lengthwise along the elongate frame. A control rod extends lengthwise in the elongate frame and through a passage in the float. The control rod controls movement of the float relative to the elongate frame. An actuator actuates the control arm to move the float from the locked position to the unlocked position in response to a downward pressure between a lower end of the elongate frame and a bottom surface of the container so that the float is free to seek the liquid level in the container and to move the float from the unlocked position back to the locked position when the downward pressure is released.