BACKGROUND OF THE INVENTION Water shortages are a problem in many parts of the world. In many areas, the problem is a seasonal one, alleviated by substantial local rainfall during certain seasons of the year. In coastal areas and on islands, rainwater collection, which augments the supply of fresh water, could be enhanced by collecting rainwater over bodies of water. This method of rainwater collection alleviates the problem of rendering large areas of land unusable due to the presence of large collectors.

U. S. Patent 3,730,120 discloses a multilevel floating unit for collecting rainwater including a lower, storage level covered by a sloped deck on which rainwater falls and runs through a non-return valve to the storage level. The complexity of the multilevel structure, the sloped deck, and the valves, should, in practice, impose a significant limitation on the size of the collecting unit, as well as render it costly, so that, even when combining multiple units, the area made available for rainwater collection is limited both physically and by cost- effectiveness considerations.

U. S. Patent 4,092,827 discloses an apparatus for rainwater collection employing funnel-shaped collectors supported aerially by balloons which feed into storage reservoirs on the sea or ground surface level. In addition to the obvious complexity of the aerial collectors and of their deployment, it is likely that precisely the weather conditions that would provide the desired precipitation for collection would be accompanied by winds that would render the collectors too unstable to be usable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a system for collection of precipitation on the surface of a body of water that is simple, inexpensive, and modular, making it also simple to deploy. It should further be scalable to cover a very large area if desired and have a multiplicity of options for storing the precipitation collected.

There is thus provided, in accordance with a preferred embodiment of the invention, a system for collection of precipitation on the surface of a substantially liquid body which includes: one or more floating collectors made up of a buoyant support, which may be flexible and inflatable or substantially rigid, and a flexible collector sheet element, impermeable to liquid, fastened to the support which defines a partition between precipitation collected therein and the liquid body surface; a baffle, which may be flexible and inflatable or substantially rigid, and which may preferably be a double barrier, associated with the one or more floating collectors configured to prevent liquid from the liquid body from entering the collector sheet element; and a water transfer device, such as a pump and tubing, which may be at a fixed location such that the floating container and baffle are towable thereto, to transfer collected precipitation from said floating collector.

In accordance with a preferred embodiment of the invention, the system further includes a water storage container into which the water transfer device transfers collected precipitation from the floating collector. The water storage container may be on a floating platform which may be towable or self-propelled or may be included in a fixed platform or land-based.

Additionally, in accordance with a further embodiment of the invention, the system further includes a selectively applicable thin flexible covering, preferably formed of a light reflective material, to cover the one or more floating collectors at such times when precipitation is not to be collected, thereby substantially preventing evaporation of precipitation collected therein and providing further protection to the collected precipitation from impure water and other contamination.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood and appreciated from the following detailed description taken in conjunction with the drawings, in which: Figure 1 is a side view of a floating collector of a precipitation collection system constructed and operative in accordance with a preferred embodiment of the present invention; Figure 2 is a view from above of a precipitation collection system constructed and operative in accordance with a preferred embodiment of the present invention; Figure 3 is a lateral, cut-away view of a baffle for a precipitation collection system constructed and operative in accordance with a preferred embodiment of the present invention; Figure 4 is a lateral view of a precipitation collection system collecting precipitation on the sea, constructed and operative in accordance with an alternative preferred embodiment of the present invention ; and Figure 5 is a diagrammatic representation of a precipitation collection system in accordance with an embodiment of the present invention, being deployed from a ship.

DETAILED DESCRIPTION OF THE INVENTION Referring now to Figure 1, there is shown, a floating collector, referred to generally as 10, which is part of a system for collection of precipitation, constructed and operative in accordance with a preferred embodiment of the present invention. Floating collector 10 is shown in a side view, floating on a body of water 11 by means of buoyant supports 12 which support flexible collector sheet element 15 which is impermeable to both pure and salt water.

Flexible collector sheet element 15 assumes a generally concave, upward-facing profile as shown by solid line 16 when precipitation 18 is collected therein,-and a generally flat profile as shown by broken line 16A when no precipitation is contained therein. Buoyant supports 12 may, in alternative embodiments of the present invention, be solid or inflatable, and form a perimeter about flexible collector sheet element 15 which may have any suitable shape, such as a rectangle or a square. In a further preferred embodiment of the present invention, an inflatable set of buoyant supports 12 may be integrally fabricated with collector sheet element 15. Floating collector 10 further includes a roller 17 mounted on the buoyant support 12 on which flexible covering 19 is stored. Flexible covering 19, which may advantageously be fabricated of a light, reflective material, is unrolled from roller 17 to cover the collected precipitation in floating collector 10, when precipitation is no longer being collected, to prevent evaporation of the collected precipitation and to protect it from entry of impure water and other contamination.

Referring now to Figure 2, there is shown, a system for collection of precipitation, referred to generally as 20, constructed and operative in accordance with a preferred embodiment of the present invention. Collection system 20 consists of a number of floating collectors 10 deployed together, advantageously adjacent to one another as shown, so as to form a floating island with a large open area for collecting precipitation. The drawing shows three collectors 10 arranged side by side in a generally rectangular arrangement, though the number and arrangement shown are strictly by way of example ; the present invention includes any suitable arrangement of any number of collectors 10. The set of collectors 10 is surrounded by a baffle comprising four baffle sections 22, joined at the corners 23 of the perimeter of the rectangular arrangement of collectors 10, which serves as a buoyant barrier to waves on the body of water on which collection system 20 floats, thereby preventing salty or otherwise impure water from getting into collectors 10. This may also be accomplished, in an alternative embodiment of the present invention, by any suitable breakwater apparatus or technique.

Referring briefly to Figure 3, there is shown a lateral, cut-away view of a section of a baffle, referred to generally as 30, for a precipitation collection system constructed and operative in accordance with a preferred embodiment of the present invention. Baffle 30 has a number of rigid or inflatable supports 32 connected by a frame 34, which may be fabricated, for example, of a light metal covered with a plastic protective coating 36. In the case wherein baffle 30 is comprised of a number of sections 22 as shown in Figure 2, adjacent sections 22 connect to one another as well as to adjacent floating collectors to fully enclose the precipitation collection area. Baffle 30 may further include a chain 38 or other provision to link to an anchor or other support (not shown) to stabilize baffle 30 and, thereby, the entire precipitation collection system. When floating on the body of water, baffle 30 should be high enough to block expected waves for precipitation weather conditions. In an alternative preferred embodiment of the present invention, baffle 30 is a double baffle, to further ensure that the clean water being collected is protected from contamination.

Referring briefly to Figure 4, there is shown a precipitation collection system, referred to generally as 40, collecting precipitation in a storm on the sea, constructed and operative in accordance with an alternative preferred embodiment of the present invention. In the present embodiment, an array of floating collectors 42 which are tied together at adjacent sides 44, is preferably surrounded by a double row of baffles, individual elements 46 of which are also tied together at adjacent sides 48, to enclose and surround array of floating collectors 42. It is worth noting that in the present embodiment, both floating collectors 42 and baffle elements 46 are inflatable. In the drawing, precipitation collection system 40 is deployed on the sea in a rainstorm and water is shown accumulating in floating collectors 42 while waves 49 impinge on baffle 46, but do not break thereover.

Returning now to Figure 2, there is further shown a boat-mounted pump unit, generally referred to as 25, with an inlet tube 26 extending into one of the floating collectors 10 to allow pump 27 to pump collected water therefrom, via outlet tube 28, to a water storage unit (not shown). The water storage unit may be a towable floating unit, a powered floating unit or boat, or it may be a fixed storage unit on or near the shore. Alternatively, outlet tube 28 of pump unit 25 may extend directly to a land-based water utility. In an alternative embodiment of the present invention, each floating collector 10 includes a valve and outlet tube configured to connect with inlet tube 26 of pump unit 25, to allow transfer of the collected water therein to a storage unit. The system may be configured for the connection to be either above or below the surface of the body of water on which precipitation collection system 20 is deployed. In an alternative embodiment of the present invention, pump unit 25 may be fixed on or near the shore and floating collectors 10 may be towed, once full of water, to pumping unit 25 to have the collected water pumped therefrom.

Referring now to Figure 5, there is shown a diagrammatic representation of a precipitation collection system according to an embodiment of the present invention being deployed from a ship 51. Inflatable floating collectors 55 are stored on roller 56 and are unrolled and inflated on ramp 57 which has a float 58 on its lower end to support it in the water. Ramp 57 may be stored on boat 51 or may fold or telescope for storage on the side of boat 51 when not in use.

It will further be appreciated, by persons skilled in the art that the scope of the present invention is not limited by what has been specifically shown and described hereinabove, merely by way of example. Rather, the scope of the present invention is defined solely by the claims, which follow.