Patent Description:
Motorhomes are provided with a water tank which is periodically filled to guarantee a satisfactory water supply.

The tank is normally filled with a common flexible tube, the end of which is inserted into the inlet mouth of the tank.

Although the flexible tube usually has a smaller cross section than the inlet mouth of the tank so that it can be inserted into the tank inlet, the users who load the water usually hold the flexible tube in their hand to avoid spills.

The tank is normally very large to ensure a satisfactory water reserve for long distances and so the filling time is normally long, even longer than ten minutes.

The user is often tempted to leave the end of the flexible tube inserted into the inlet mouth while filling.

Disadvantageously, the overpressure in the hydraulic system can cause the end of the flexible tube to slip out of the inlet mouth of the tank and cause unwelcome spills.

Furthermore, the opening tap of the water network is often far away from the inlet mouth of the tank, or at least not close enough to allow it to be opened while holding the flexible tube near the end of the flexible tube inserted into the inlet mouth of the tank to prevent pulling out caused by the excessive water pressure.

The use of connectors, e.g., threaded connectors, is known to secure the flexible tube to the inlet mouth of the tank; however, the inlet mouth of the tank must be provided with a specific fitting associated with the end of the flexible tube, e.g., screw-nut screw connectors.

Disadvantageously, the situation may occur of having flexible tubes with different cross sections which are not adapted to a specific fitting. Furthermore, the fitting may not be compatible with the connector of the inlet mouth of the tank.

It is known to use adapters having a first threaded end which can be coupled to a complementary threaded connection of the inlet mouth of the tank, and a second end with protrusions to be able to withhold the end of the flexible tube able to fit onto said second end of the adapter. For example, see the solution suggested in <CIT>.

Disadvantageously, the diameter of the flexible tube must be complementary to the second end of the adapter, and the problem remains of needing to provide a thread in the first end complementary to the thread of the connector of the inlet mouth of the tank.

<CIT> shows a fitting for flexible tubes having different cross section, consisting of two stepped ends with retaining projections. Each end may be fitted on flexible tubes ends having different cross sections. Disadvantageously, <CIT> does not show how to associate a flexible tube with an inlet mouth of a tank, in particular of a motorhome.

Securing a flexible tube to the inlet mouth of a tank by means of a threaded coupling has the additional problem of removing the air present inside the empty tank, which in fact hinders the complete filling and also causes dangerous backflow of water under pressure.

<CIT> shows an adapter for motorhomes having a first end threaded for connection to the tank inlet mouth, and a second end having a quick coupling connector compatible with a fitting associated with the end of the flexible tube. Said adapter is used to drain water from the tank to prevent it from freezing during the winter.

Disadvantageously, the adapter requires complicated pressure relief and can only be used when emptying the tank.

<CIT> describes a fluid transfer adapter, comprising a first threaded coupling portion able to couple with an inlet mouth of a container, and a second coupling portion able to couple with an end of a flexible tube.

It is object of the present invention to make an adapter for filling the tanks of motorhomes which allows the use of flexible tubes of different size.

It is a further object of the present invention that said adapter allows coupling with an inlet mouth of the tank of the motorhome without spills of liquid.

It is a yet further object of the present invention that the coupling, with the flexible tube and the inlet mouth of the tank, is safe and allows the users to release their grip on the flexible tube during filling.

According to the invention, said and further objects are achieved by an adapter for filling a tank of a motorhome according to appended claim <NUM>.

Advantageously, it is possible to fill a tank in complete safety, without pressure backflows and unwelcome water leaks or even breakage of the adapter.

The user works safely by firstly securing the flexible tube to the adapter and then the adapter to the inlet mouth of the tank: only when the connection is established, he opens the water tap.

The adapter is also flexible in use, responding to different sizes of the flexible tube and of the inlet mouth of the tank.

These and other features of the present invention will become further apparent from the following detailed description of practical embodiments thereof illustrated by way of non-limiting example in the accompanying drawings, in which:.

An adapter <NUM> for motorhomes has an elongated shape and comprises two coupling portions <NUM>, <NUM>, a first coupling portion <NUM> able to couple with an inlet mouth of a tank of a motorhome, and a second coupling portion <NUM> able to couple with an end of a flexible tube.

The adapter <NUM> has a first end <NUM> and a second end.

The first coupling portion <NUM> develops starting from the first end <NUM>, while the second coupling portion <NUM> develops starting from the second end <NUM>.

The two coupling portions <NUM>, <NUM> thus develop towards each other to make maximum use of the length of the adapter <NUM>, which has a through hole <NUM> passing through it from one end <NUM>, <NUM> to the other end <NUM>, <NUM>.

The first portion of the coupling <NUM> provides pressure relief grooves <NUM> on the external surface <NUM>, preferably three angularly equidistant pressure relief grooves <NUM> (see <FIG>, in which two consecutive pressure relief grooves <NUM> are <NUM>° apart).

The pressure relief grooves <NUM> develop longitudinally from the first end <NUM> towards a middle zone <NUM> of the adapter <NUM>.

The pressure relief grooves <NUM> are formed on the external surface <NUM> of the first coupling portion <NUM>, preferably by milling. Each pressure relief groove <NUM> thus has a concave surface which develops longitudinally on the external surface <NUM> of the first coupling portion <NUM>, without entering the through hole <NUM>.

The first coupling portion <NUM> is slightly tapered towards the first end <NUM>, and the pressure relief grooves <NUM> with it, to facilitate the coupling with the inlet mouths of tanks of different size.

In a first embodiment (<FIG>, and <FIG>), the second coupling portion <NUM> provides a step external surface <NUM>, wherein the steps are able to progressively reduce the cross section of the second coupling portion <NUM> towards the second end <NUM>.

In a second embodiment (<FIG> and <FIG>), the second coupling portion <NUM> provides a quick coupling connector <NUM> at the second end <NUM>. Preferably, an step external surface <NUM> of the same type as the step external surface <NUM> of the first embodiment of the second coupling portion <NUM> is provided between the middle zone <NUM> and the quick coupling connector <NUM>.

A quick coupling connector <NUM> is a snap-on coupling type, e.g., of the type known in gardening.

The through hole <NUM> preferably comprises a first constant cross section in the first coupling portion <NUM>, and a second constant cross section in the second coupling portion <NUM>, wherein the first constant cross section is greater than the second constant cross section. An oblique section of the through hole <NUM> is provided in the middle zone <NUM> to connect the two different sizes of the cross section of the through hole <NUM>. The larger cross section area of the through hole <NUM> at the first coupling portion <NUM> allows a reduction in the pressure of the water entering the tank.

It is worth noting that the relief pressure grooves <NUM> do not change the first cross section of the first coupling portion <NUM>, which remains constant. The pressure relief grooves <NUM> do not enter the through hole <NUM> but remain outside to avoid disturbing said reduction of water pressure at the tank inlet.

Operationally, if the user has available a flexible tube with an end fitting able to couple with the quick coupling connector <NUM>, the adapter <NUM> will be used according to the second embodiment (<FIG> and <FIG>).

The flexible tube is easily secured to the quick coupling connector <NUM> and the first coupling portion <NUM> is inserted into the inlet mouth of the tank.

The outwardly tapered shape of the first coupling portion <NUM> allows an easy adaptation to different cross sections of the inlet mouth.

For example, if a first tank has a first inlet mouth having a larger cross section than a second inlet mouth of a second tank, the first coupling portion <NUM> will fit deeper into the first inlet mouth of the first tank than it fits into the second inlet mouth of the second tank.

As can be seen in <FIG>, the tapering is continuous towards the first end <NUM>. The variation of the insertion depth of the first coupling portion <NUM> is thus progressive according to the cross section of the tank inlet.

Once the adapter <NUM> has preferably been blocked by interference with the outer surface of the inlet mouth of the tank, the user can release the grip of the flexible tube and safely open the water tap, the water beginning to flow under pressure into the tank through the flexible tube and through the through hole <NUM> of the adapter <NUM>.

Advantageously, the pressure relief grooves <NUM> allow the air in the tank to escape as it fills: the incoming water occupies the volume of the tank, pushing the air out.

Once the tank is filled, the user can close the tap and easily uncouple the adapter <NUM> from the inlet mouth because the pressure relief grooves <NUM> result in a discontinuity of the coupling surface between the adapter <NUM> and the inlet mouth of the tank. Otherwise, the first portion of coupling <NUM> would tend to remain attached to the inlet mouth; an effort would be needed to pull it out which would damage both adapter <NUM> and the tank inlet mouth.

If the flexible tube has a free end, namely without a complementary fitting to the quick coupling connector <NUM>, it is necessary to insert the second coupling portion <NUM> into the flexible tube at the free end of the flexible tube.

If the adapter <NUM> in addition to the quick coupling connector <NUM> also has the step external surface <NUM>, the same adapter <NUM> may be used if the cross section of the flexible tube permits. Two steps of the step external surface <NUM> are shown in <FIG>.

If a smaller cross section size of the second coupling portion <NUM> is required, the adapter <NUM> may be used according to the first embodiment, wherein the step external surface <NUM> has many more steps than the step external surface <NUM>.

The step external surface <NUM> of the adapter <NUM> according to the first embodiment can be extended, but it is unlikely to achieve a sufficient reduction in the cross section useful for coupling flexible tubes with very small cross sections.

Instead, the first portion of coupling <NUM> is identical for both embodiments.

The user works safely by firstly securing the flexible tube to the adapter <NUM> and then the adapter <NUM> to the inlet mouth of the tank: only when the connection is established does the user open the water tap.

The adapter <NUM> is also flexible in use, responding to different sizes of the flexible tube and of the inlet mouth of the tank.

The adapter <NUM> can be used to transfer drinking water when it is made of food-grade material, e.g., nylon delrin pom C.

Claim 1:
Adapter (<NUM>) for filling a tank of a motorhome with a liquid under pressure, comprising a first coupling portion (<NUM>) able to couple with an inlet mouth of the tank, a second coupling portion (<NUM>) able to couple with one end of a flexible tube connected to a water tap of a water network, and a through hole (<NUM>) which passes thought the adapter (<NUM>) from a first end (<NUM>) to a second end (<NUM>) of the adapter (<NUM>), wherein the first coupling portion (<NUM>) develops starting from the first end (<NUM>) and the second coupling portion (<NUM>) develops starting from the second end (<NUM>),
characterized in that
the first coupling portion (<NUM>) is tapered towards the first end (<NUM>) to allow the coupling with inlet mouths of tanks with different cross section, and provides an external surface (<NUM>) with pressure relief grooves (<NUM>).