Snorkels are devices that allow to breathe while keeping one's face underwater.

A snorkel is substantially constituted by a rigid tube that is provided with a mouthpiece and with an end that protrudes from the surface and through which it is possible to continue breathing when one's face is immersed in the water and directed toward the bottom.

These devices are used at sea by skin divers and also by scuba divers for safety reasons if it is necessary to swim or float at the surface.

Typically, these devices are coupled to the strap of the mask by means of a hook or a clip and are directed so that the end of the tube to which the mouthpiece is connected is directed toward the mouth of the swimmer, while the other end rises above the surface, allowing the swimmer to breathe in and out air from the atmosphere.

When the skin diver dives, the snorkel of course fills with water, which is expelled, when the skin diver surfaces, by means of a vigorous blowing action.

As mentioned, breathing devices of this type are also used by scuba divers, who however normally do not use the snorkel except in exceptional cases.

While scuba diving, the snorkel can be tied to the mask, in the normal position of use, without of course holding it in one's mouth; however, this position is inconvenient because the snorkel interferes with the regulator line and can also move around, causing discomfort to the scuba diver.

For this reason, divers often carry the snorkel in other positions, applied to the BCD, or jacket, by means of hooks, inserted in the belt or in a pocket of the BCD, et cetera.

In any case, the snorkel is bulky and uncomfortable and is also easy to lose if not attached properly.

It is therefore evident that it is necessary to provide a snorkel that is less bulky and easy to carry when not in use.

Collapsible snorkels have been proposed whose dimensions can be reduced when not in use. Collapsible snorkels have been described for example in US- 5906199, US-6079410, and US-6321745.

Those prior art collapsible snorkels, however, have several drawbacks: some are not entirely practical, because they require a complex maneuver in order to place the snorkel in operating conditions; others are scarcely reliable, and still others are constructively complicated.

The aim of the present invention is to provide a collapsible snorkel particularly for aquatic activities that overcomes the drawbacks of the cited prior art.

A particular object of the invention is to provide a collapsible snorkel that has a simple and reliable structure.

Another object is to provide a collapsible snorkel that is extremely easy to use.

An important object of the invention is to provide a collapsible snorkel that can be manufactured with conventional equipment and technologies and at competitive costs.

This aim and these and other objects that will become better apparent hereinafter are achieved by a collapsible snorkel as claimed in the appended claims.

Further characteristics and advantages of the invention will become better apparent from the description of preferred but not exclusive embodiments thereof, illustrated by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a front view of the snorkel according to the invention, in the extended position for use; Figure 2 is a view, similar to Figure 1, in which the snorkel is instead shown in the collapsed position; Figure 3 is a sectional front view of the snorkel according to the invention in the extended position for use; Figure 4 is a view, similar to Figure 3, in which the snorkel is instead shown in the collapsed position;

Figure 5 is a side view of the snorkel according to the invention in the extended position for use; Figure 6 is a sectional view, taken along the line VI-VI of Figure 4.

With reference to the cited figures, a snorkel according to the invention, generally designated by the reference numeral 1, comprises two or more frustum- shaped telescopic tubes, that define at least two working positions: a collapsed or retracted position, in which the tubes are substantially one inside the other and the longitudinal extension of the device is reduced, and an extended position, in which the tubes are partially extracted with respect to each other into a position of mutual interference that ensures a stable and watertight connection between them. In the extended position, the snorkel can be used as a tool for breathing while keeping one's face in the water.

In the specific case, the snorkel 1 has three frustum-shaped tubes: a base tube 2, which accommodates at least partially an intermediate tube 3, which in turn accommodates at least partially an end tube 4.

The base tube 2 has a lower end that is associated with an elbow 5, which supports a mouthpiece 6 at its free end.

The elbow 5 can be connected by interlocking or by means of another type of connection to the base tube 2, and can also be replaced with a corrugated coupling or other type of connection of the mouthpiece to the breathing tube, as per se known in the art.

The frustum-shaped. tubes 2, 3 and 4 have a polygonal cross-section,. for example a quadrangular one, with rounded corners, of the type shown in the figures.

The polygonal or otherwise noncircular (for example oval) cross-section offers the advantage that the tubes cannot rotate with respect to each other about their own longitudinal axis. This characteristic is useful, since the telescopic tubes 2,3 and 4 have a curved longitudinal axis, so that the air intake 8 of the end tube 4 is arranged, when the device is used, substantially above the user's head, as is customary in the art. If the tubes could rotate with respect to each other, the user

would have to take care, during the extension of the device, to position correctly the tubes with respect to each other, while instead by way of the noncircular cross-section the tubes are always arranged correctly automatically.

As shown more clearly in Figure 3, the tubes, in the extended position, are stably connected by interference along an interference portion, designated by the reference numerals 9 and 10, respectively for the portion comprised between the base tube 2 and the intermediate tube 3 and for the portion comprised between the intermediate tube 3 and the end tube 4.

The interference portion 9 and 10, together with the nature of the material of which the tubes are made, which is relatively elastic and is usually a rubber, ensures a stable connection and absolutely reliable watertightness.

The device has a hook 7 or other similar means that is suitable to attach the device to the strap of a mask, not shown in the figures, or to another object, typically to the BCD (buoyancy compensator device) to which one wishes to anchor the snorkel in order to avoid losing it.

In practice it has been found that the invention achieves the intended aim and objects, a simple and reliable collapsible breathing device having been provided.

The device according to the invention is susceptible of numerous modifications and variations, within the scope of the appended claims. All the details may be replaced with other technically equivalent elements.

The materials used, as well as the dimensions, may of course be any according to requirements and the to state of the art.