GB2026971A

GB2026971A - An aerostatic balloon of air type heated by solar energy

Info

Publication number: GB2026971A
Application number: GB7927126A
Authority: GB
Original assignee: SOLAR Srl
Current assignee: SOLAR Srl
Priority date: 1978-08-04
Filing date: 1979-08-03
Publication date: 1980-02-13
Also published as: SE7906575L; FI792236A; IT1103648B; BR7905008A; BE877756A; NL7905997A; JPS5539886A; PT70024A; NO792567L; LU81569A1; DK322979A; FR2432435A1; AU4957179A; ES251732U; GR64904B; GB2026971B; FR2432435B3; IT7809554A0; ES251732Y; DE2930755A1

Abstract

An aerostatic balloon comprises an envelope 1 made of thin plastics sheet material e.g. polyethylene, which is of a dark colour 1, preferably black, and is open at one zone 2 thereof for being partially filed with air and then closed. The heating of the inner air in the envelope 1, after exposure to solar rays, develops a lift exceeding the weight of the balloon, so that the latter will fluctuate in the atmosphere. The balloon may be used for advertising or as a scientific toy. A mass may be hung from it to maintain the balloon in a desired attitude. <IMAGE>

Description

SPECIFICATION An aerostatic balloon of air type heated by solar energy This invention relates to a heated air type of aerostatic balloon, wherein air heating is provided by taking advantage of solar thermic radiation.

A balloon according to the invention may be used in many applications, but is particularly suitable as a simple scientific game and/or advertising vehicle.

Hot air balloons are already known. In their classical design, such balloons generally comprise a nearly spherical envelope with a wide aperture at the bottom, just below which a heating means is provided, such as a free flame heating the air filling up the balloon, thus producing an aerostaticthrust according to well known principles of physics.

Such balloons have various disadvantages. The free flame may set fire to the envelope forming the balloon, or cause it to fuse, most of thermic energy is scattered, upon exhaustion of the energy source, which cannot be too heavy, the balloon loses its lift due to cooling of the inner air and the balloon will collapse and fall to ground.

On the other hand, the present invention solves the above mentioned drawbacks by proposing a balloon, in which the energy for heating the air therein is comprised of solar energy.

For this purpose, a balloon according to the invention is characterised by comprising an envelope made of dark colour, soft light film-like material, open at one zone thereof for being partly filled with air and then closed.

The weight by volume unit of said envelope is such that, after exposure of the envelope to solar rays for a sufficient time, with consequent expansion of air therein, the resulting aerostatic thrust will exceed the balloon weight.

Experimentally, it was found that a suitable matervial forth envelope may be a sheet of plastics material, such as polyethylene, of the smallest thickness as possible consistent with the dimensions and structure of the envelope and modern technologies for the production of such sheets.

According to the uses to which the envelope is intended, the envelope can be anchored to ground by a suitable cable or wire, or allowed to follow freely the air streams.

Where the envelope is used in advertising fields, it may carry writing printed on its outer surface and it may be kept in stabilized horizontal or vertical attitudes by suitable counterweights or by suitable sling through thin net.

Where the balloon is intended for freely following the air streams, and accordingly not recoverable, it is convenient that the envelope has a tubular shape, since its production can be obtained with relatively low costs by conventional extrusion heads with pneumatic inflation prior to cooling, that is by a technique quite similar to that for the production of standard tubular manufactured articles. Moreover, such a tubular shape allows better visible writing to be developed lengthwise of the envelope and the cutting of sections from a continuous tubular body, with each section being intended to form an envelope, can be carried out without any particular accuracy, since the correct length is not a determining factor.

Each individual section may be sealed at one end on manufacture, also by simple thermoplastic welding of the material, whilst the other end may be left open and then sealed, or be simply closed by binding after partially filling with air the envelope so obtained. Such a filling can also be carried out by taking advantage also of light wind streams, by a relative movement with respect to atmosphere, or by means such as fans even of a highly limited head.

A preferred embodiment of the invention is shown by mere way of unrestrictive example in the figures of the accompanying drawing, in which: Figure 1 shows the balloon in a perspective view; and Figure 2 and3 show two possible stabilized attitudes of the balloon in air, either under free conditions, or under anchoring conditions.

The balloon comprises a tubular envelope 1 provided by extruding a continuous tubular body of polyethylene which is of dark colour, translucent, having a thickness of 10 microns and a diameter of 0.71 m, the operation being carried out by a conventional machine. The continuous tubular body or stock was divided into sections, each of which had a length of 3m, and one end of each section was sealed by thermoplastic welding, or was merely closed by binding. The tubular envelope 1 was then partially filled with air to about 60-70% of its total volume, which filling could be obtained by relative movement between ambient air and envelope (for example, by exposing the open end 2 to wind, or by running and holding said end open wide apart), or also by using a mechanical means, such as a fan of comparatively limited head.Upon completion of partial filling, the open end 2 of the envelope was closed by simple binding, and such an envelope was exposed to solar rays.

The balloon can be stabilized, both in anchoring and under conditions of free flight, by suitable counterweight means 3 for holding it in a vertical attitude (Fig. 3), or it can be held in an horizontal attitude (Fig.

2) by properly balancing the ends, or also by a counterweight 4 anchored to two tie rods 5 diverging therefrom and suitably engaging the envelope 1 at symmetrical positions relative to the center or also directly to the ends. The counterweights 3 and 4 may be replaced by an anchoring cable, or form the hooking or connecting means for such a cable.

The balloon envelope according to the embodiment had a weight by volume unit of 60-70 grams/cu.m. and a lift of 200 g after exposure to solar rays for a few mintues with an ambient atmospheric temperature to the sun of 25"-35"C.

1. An aerostatic balloon comprising an envelope made of light, soft film-like material of a dark colour, open at one zone thereof for being partially filled with air, and then closed.

2. A balloon according to Claim 1, wherein said envelope is of black polyethylene, having such a thickness that the total weight of the balloon is less

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An aerostatic balloon of air type heated by solar energy This invention relates to a heated air type of aerostatic balloon, wherein air heating is provided by taking advantage of solar thermic radiation. A balloon according to the invention may be used in many applications, but is particularly suitable as a simple scientific game and/or advertising vehicle. Hot air balloons are already known. In their classical design, such balloons generally comprise a nearly spherical envelope with a wide aperture at the bottom, just below which a heating means is provided, such as a free flame heating the air filling up the balloon, thus producing an aerostaticthrust according to well known principles of physics. Such balloons have various disadvantages. The free flame may set fire to the envelope forming the balloon, or cause it to fuse, most of thermic energy is scattered, upon exhaustion of the energy source, which cannot be too heavy, the balloon loses its lift due to cooling of the inner air and the balloon will collapse and fall to ground. On the other hand, the present invention solves the above mentioned drawbacks by proposing a balloon, in which the energy for heating the air therein is comprised of solar energy. For this purpose, a balloon according to the invention is characterised by comprising an envelope made of dark colour, soft light film-like material, open at one zone thereof for being partly filled with air and then closed. The weight by volume unit of said envelope is such that, after exposure of the envelope to solar rays for a sufficient time, with consequent expansion of air therein, the resulting aerostatic thrust will exceed the balloon weight. Experimentally, it was found that a suitable matervial forth envelope may be a sheet of plastics material, such as polyethylene, of the smallest thickness as possible consistent with the dimensions and structure of the envelope and modern technologies for the production of such sheets. According to the uses to which the envelope is intended, the envelope can be anchored to ground by a suitable cable or wire, or allowed to follow freely the air streams. Where the envelope is used in advertising fields, it may carry writing printed on its outer surface and it may be kept in stabilized horizontal or vertical attitudes by suitable counterweights or by suitable sling through thin net. Where the balloon is intended for freely following the air streams, and accordingly not recoverable, it is convenient that the envelope has a tubular shape, since its production can be obtained with relatively low costs by conventional extrusion heads with pneumatic inflation prior to cooling, that is by a technique quite similar to that for the production of standard tubular manufactured articles. Moreover, such a tubular shape allows better visible writing to be developed lengthwise of the envelope and the cutting of sections from a continuous tubular body, with each section being intended to form an envelope, can be carried out without any particular accuracy, since the correct length is not a determining factor. Each individual section may be sealed at one end on manufacture, also by simple thermoplastic welding of the material, whilst the other end may be left open and then sealed, or be simply closed by binding after partially filling with air the envelope so obtained. Such a filling can also be carried out by taking advantage also of light wind streams, by a relative movement with respect to atmosphere, or by means such as fans even of a highly limited head. A preferred embodiment of the invention is shown by mere way of unrestrictive example in the figures of the accompanying drawing, in which: Figure 1 shows the balloon in a perspective view; and Figure 2 and3 show two possible stabilized attitudes of the balloon in air, either under free conditions, or under anchoring conditions. The balloon comprises a tubular envelope 1 provided by extruding a continuous tubular body of polyethylene which is of dark colour, translucent, having a thickness of 10 microns and a diameter of 0.71 m, the operation being carried out by a conventional machine. The continuous tubular body or stock was divided into sections, each of which had a length of 3m, and one end of each section was sealed by thermoplastic welding, or was merely closed by binding. The tubular envelope 1 was then partially filled with air to about 60-70% of its total volume, which filling could be obtained by relative movement between ambient air and envelope (for example, by exposing the open end 2 to wind, or by running and holding said end open wide apart), or also by using a mechanical means, such as a fan of comparatively limited head.Upon completion of partial filling, the open end 2 of the envelope was closed by simple binding, and such an envelope was exposed to solar rays. The balloon can be stabilized, both in anchoring and under conditions of free flight, by suitable counterweight means 3 for holding it in a vertical attitude (Fig. 3), or it can be held in an horizontal attitude (Fig. 2) by properly balancing the ends, or also by a counterweight 4 anchored to two tie rods 5 diverging therefrom and suitably engaging the envelope 1 at symmetrical positions relative to the center or also directly to the ends. The counterweights 3 and 4 may be replaced by an anchoring cable, or form the hooking or connecting means for such a cable. The balloon envelope according to the embodiment had a weight by volume unit of 60-70 grams/cu.m. and a lift of 200 g after exposure to solar rays for a few mintues with an ambient atmospheric temperature to the sun of 25"-35"C. CLAIMS

2. A balloon according to Claim 1, wherein said envelope is of black polyethylene, having such a thickness that the total weight of the balloon is less than the lift produced by heating the inner air after exposure of said envelope to solar rays for some time.

3. A balloon according to Claim 2, wherein the thickness of said envelope is in the range of 5 to 50 microns, preferably in the order of 10 microns.

4. A balloon according to Claim 1, wherein the weight of the envelope is in the range of 60-70 grams for each cubic meter of the envelope capacity.

5. A balloon according to Claim 1, having an elongate tubular shape, closed at one end by welding, and open at the other end, intended to be closed after partial filling.

6. A balloon according to Claim 5, wherein means are provided for presetting its attitude.

7. An aerostatic balloon substantially as described herein with reference to and as illustrated in the accompanying drawings.