UMBRELLA TO PROTECT AGAINST RAIN WITH A CANOPY OF REFRACTING, FLUORESCENT OR PHOSPHORESCENT FABRICS

DISCLOSURE OF INVENTION

This invention referts to an umbrella wich will be constructed of a traditional frame consisting of flexible ribs and stretchers, made from wood, steel or any other flexible material providing support for a new type of canopy (figure 1) using refracting, fluorescent or phosphorescent fabrics, depending on the use.

The umbrella can open either manually or automatically. The product may be commercialized for the following usages:

1) Personal protection in case of breakdown on hard shoulder of motorway or roadside, for this usage folding compactly, as equipment for motor vehicles,

2) Basic model; to be affordable for everyone,

3) Exclusive designer models, with brand use to be authorized by the applicant.

The prototype umbrella of my patent uses a canopy in highly visible fabrics at night in compliance to UNI EN 471, official version of the European norm EN 471. In Italian: translated by the UNI specifying the requirements for highly visible garments under conditions of danger, at day or night under the headlights of a motor vehicle (including performance requirements, such as colour, retro-reflectivity, dimensions and position of materials, methods to test fabrics and system effectiveness).

The idea of this patent stems firstly from the observance of the aforesaid norm, which must be applied also to the protection of pedestrians and cyclists carrying ordinary umbrellas whilst going along or crossing a road in conditions of poor-visibility. Therefore, the first aim is the protection and safety of the individual, by applying well- known scientific principles that can offer a solution to this problem. Contrary to the solutions that have been proposed so far, which use optical fibres and LED technologies or any electric/electronic systems, this patent uses well-known natural technologies and commonly used fabrics, with refracting, fluorescent and phosphorescent characteristics.

TECHNICAL FIELD

Below, is a description of the scientific principles on which the utility model is based.

Refractivity

Refracting material is a material that reflects light towards the same direction from which it comes. The ideal refringent succeeds in sending back the light to the source, no matter what the angle of incidence is. As it is known, in a reflecting surface the angle of reflection and the angle of incidence of the beam are equal; therefore the beam will be reflected towards the source only if it is a 90-degree angle of incidence. Let us examine a bidimensional situation (fig 1) in which the incident beam belongs to a certain plane. In this case, in order to reflect the beam towards the direction of the source, no matter what the predetermined plane is, it will be sufficient to place two mirrors with an angle of 90 degrees between them, and perpendicular to the plane containing the beam. The beam will fall onto the first mirror with a β angle and will be reflected with the same angle towards the second mirror. Being perpendicular mirrors, the angle of reflection and the angle of incidence on the second mirror will be 90-β. Therefore, the angle of reflection, in respect to the first mirror, will be equal to β, and so the beam will be reflected towards the same direction from which it has come. If the distance of the source of the beam is sufficiently large with respect to the size of the mirrors, it is possible to assume that the beam will be sent back to the source, no matter where it is on the semi-plane between the two mirrors. The same considerations can be made in the event of a three-dimensional situation, with three mirrors placed at 90 degrees, like the three inner faces of a cube corner. Reflectors are built by placing reflecting microcells next to each other, so that it is possible to attain variable surfaces, according to the need (if we observe a reflecting surface; we can see that it is indeed made of adjacent cells). In case of large-capacity need for reflection, it is possible to use reflectors consisting of a single larger glass prism, with mirror-covered inner surfaces. Reflectors have wide use and application.

Fluorescence

Fluorescence is the property of some substances of re-emitting the radiations received with a lower frequency, absorbing ultraviolet light and emitting it as visible. Examples of this are all the materials containing fluorescent pigments, such as markers' ink and fluorescent paints. The fluorescent properties of an object become visible by using the Wood's Lamp; however, depending on the materials used, a lower wavelength may be needed. Fluorescence and phosphorescence are radiative processes, by which the relaxation of an excited molecule can be observed. The distinction between the two processes was originally made based on the lifetime of the radiation: in the case of fluorescence the luminescence stops shortly after eliminating the exciting radiation, whereas in the phosphorescence case, the radiation is emitted for a while after eliminating the exciting source. The two processes can be distinguished also according to the nature of the electronic states involved in the transitions responsible for the radiations' emission. In the fluorescence case, the radiation is generated by the transitions among states with the same variety of spin (as an example SI→ SO), while in the case of phosphorescence, the transition involved causes a variation in the spin multiplicity: the most frequent are the triplet-singlet transitions.

Phosphorescence

Phosphorescence is a radiative emission, peculiar of some chemical substances, as a result of an electronic excitation, deriving from the drop of lower quantum energy levels. It is different from the fluorescence, as in the latter the effect is immediate and stops as soon as the energy terminates, whereas in the case of phosphorescence, the effect continues after that. The principle is the same: an energy source, generally visible light or ultraviolet radiation, excites the atoms, some electrons are transferred to a more external orbital. When they return to the inner orbital, they emit light. This phenomenon occurs because of the action of an exciting source, like a photon, the electrons in the fundamental orbital level are transferred to a higher level of singlet (unitary spectral multiplicity, presence of matched electrons).Afterwards, in addition to other non-radiative decay phenomena, the return to the stable fundamental state with radiant emission may take place in two ways: a singlet-singlet conversion or, alternatively, a passage to a quantum- mechanical triplet-state configuration (spectral multiplicity three, presence of two unmatched electrons) and the subsequent decay to the state of lower singlet. In the first case, fluorescent radiant emission takes place, while in the . second, phosphorescent emission occurs. Besides the described fundamental difference between the two ^* luminescent phenomena, it is worth noticing that the decay time producing

phosphorescence is longer (10 ^"3 s versus the 10 ^"9 - 10 ^"12 s) than the fluorescence one: phosphorescence follows excitation with some delay and lasts for some minutes afterwards. The emergent radiation turns out to be less energetic, therefore characterized by a greater wavelength, as during the de-excitation process part of the energy is used to re-establish the singlet state, another part is lost during the passage of the electron in the vibrational sub-levels of the excited state. The temperature decrease prevents the competitive processes of relaxation and causes an increase in the quantum phosphorescent efficiency, efficiency Φ defined from the equation Φ = OF/ΦΑ where OF and ΦΑ are, respectively, the emitted and absorbed radiation quanta. Basically, it is possible to produce phosphorescence from substances that normally are not phosphorescent, by working at the temperature of liquid nitrogen.