Patent US 4,947,154

An alarm device for dripping injection comprising a floating barrel which vertically moves up or down according to fluid volume in the dripping liquid barrel, a touch switch and sealing means which are provided in the upper area of the lower part of dripping liquid barrel, a socket which is provided in the dripping liquid barrel lower part for connection to touch switch, and a power lead and plug provided by a separate action box or a patient room's call assembly to plug the socket. As the contained fluid is used near empty and the fluid volume in the dripping liquid barrel diminishes meantime, the floating barrel, when loosing support by the fluid volume, moves down and touches the touch switch with its own weight, thereby conducting open the separate action box or the patient room's call assembly to alarm nurses or hospital orderly to come to handle.