The serious handicap of intravenous infusion droppers is well known: once the container has been empied of its medicine content, the descent of the liquid along the infusion line determines the inlet of air into the system and requests a quick intervention by the operator for the elimination and the restoring of the function, with the frequent arising of hospital infections and the risks of blood outlet from the system.

It is the aim of the present invention to completely solve above mentioned handicap, by means of an easy device, having a safe and automatic functioning.

The aim set forth is reached, according to the present invention, by means of a device that may be applied to a intravenous infusion dropper, consisting of a closing valve realized by means of a means floating in the infusion liquid which, by the progressive sinking of the level, is brought in correspondence to the end hole of said dropper, where said hole is sealingly closed and therefore the air inlet in the system prevented.

A further advantage of blocking the liquid at a greater height of the system is the one of maintaining a higher pressure inside the needle, which prevents blood from coagulating inside said needle.

The present invention wil be described more in detail hereinbelow relating to the enclose drawings, in which one embodiment is shown.

Figure 1 shows an axonometric transparency view of an intravenous infusion dropper provided with the device according to the present invention, in an intermediate functioning phase.

Figure 2 shows the condition of the device according to the present invention, at the end of the infusion.

The enclose figures show a dropper 1 for the infusion of a therapeutic liquid 2 coming from an upper bag 3 and connected by means of a pipe 4 towards the means 5 for the connection with the needle, and in which a spherical float 6 or of any other suitable shape, is provided inside said dropper 1 and, in an intermediate phase, allows a normal functioning while, at the end of the infusion, as it reaches near the end outlet hole 7, it closes the same due to gravity and contact, thus preventing any air inlet which, in the conventional system, enters in correspon- dence of level 8, filling up the overhanging part, with the already mentioned consequences.