Horizontal glazing bench adapted for centering glass in any one door/window frame Description Field of the art The present invention operates in the field of installation of glass on frames for doors or windows. More specifically, the object of the present patent regards a system for installing the glass on the door/window frame by loading the glass in a very precise, quick and safe manner. Prior art The windows that are made today, both of artisanal and industrial type, are more technologically advanced than those of recent decades. The technical evolution of the products such as the Insulated Aluminum profiles, PVC profiles, gaskets and glass, have been increasingly performing, providing increased resistance against bad weather, reducing or in some cases eliminating the need for maintenance and improving the thermal dispersion performances (external/internal and vice versa) both in winter and in summer. Beyond the door/window frame, glass has contributed so much to technological progress, but in order to reach this objective and have high-performing glass from a thermal, safety and acoustic standpoint, this has greatly increased its thickness with respect to the standard glass of the past. The weight of the glass has considerably increased, passing from about 8-10 kg/m ² to about 25-30 kg/m ² of standard glass up to reaching 45-50 kg/m ² for the highest-performing glass. On average, on a window at a panel, there are about 0.7 m ² of glazed surface, which correspond to about 18-21 kg for a standard glass and 32-35 kg for highly-performing glass. In order to ensure the regular operation of the window over time, in addition to having to respect the technical limits of the product (such as for example the ratio between the width and the height that must be less than 2/3), it is necessary that in the panel-glass assembly step, the “Glass Load” operation be executed. Due to gravity, the weight of the window pushes downward, but since the window is hinged on one side, it creates a shelf effect, with bending downward in the part opposite the hinges. In order to limit this bending, which would create problems during opening/closing, damaging the door/window frame, during the assembly of the glass in the panel – in addition to blocking the glass in the panel itself through a series of thicknesses-wedges which come to fix the two together – the “Glass Load” is carried out, which consists of inserting greater thicknesses along the diagonal opposite the bending, thus to create a rotation of the center of gravity of the glass and compensate for the bending at the tip of the door/window frame. In the new products, still high-performing and minimalist, carrying out the “Glass Load” operation becomes very important. In order to resolve this limit of the new products, there is now the fixing of the glass in a structural manner through the gluing panel-glass, an operation that is completed through the high-seal double-sided tapes with sealants. The tapes - due to their characteristic of immediate gripping as soon as they are in contact with the glass - do not leave the operator the time for positioning and carrying out the “Glass Load”. Up to now, the solutions most used in industry for overcoming this problem are mainly two: A) before positioning the glass, the tape protection film is removed and a veil of water is sprayed on the tape surface, so as to create a wet coat that allows positioning the glass and carrying out the necessary operations without the double-sided tape blocking the glass; B) lifting and folding inward only 1-2 cm of the protection film of the double-sided tape and wetting only the exposed double-sided tape, inserting the glass, executing the activities of shimming and loading. Only afterwards, one proceeds with removing the protection film of the double-sided tape and making the glass adhere on the tape. There are pros and cons for both of the above-described solutions. Solution A is certainly the quickest to carry out, but (depending on the size of the door/window frame, ambient moisture and season) the quantity of water might be over-abundant, not allowing a safe and functional immediate movement, it being necessary to wait until all is dry before ensuring the complete fixing. Solution B allows an immediate movement after fixing according to a dry process. However, the film extraction operation is very long and complex, with the risk of ruining all the work by mistakenly breaking the protection film of the double-sided tape. Object of the present patent is therefore that of solving the aforesaid problems tied to a working that is still too much artisanal and consequently reducing the management costs and speeding up the work undertaken. Description of the invention According to the present invention, a glass fixing system on horizontal glazing bench is attained which effectively resolves the abovementioned problems. The glazing bench allows positioning a panel horizontally, through crosspieces that are manually adjustable, aligning and fixing the panel on the bench with the aid of clamps. Once the panel is positioned, one proceeds with a cleaning with compressed air or wet rag soaked with alcohol, which acts as degreaser, the guide wedges calibrated for the glass are positioned and the protection on the double-sided tape is removed. Two jack panels are lifted, on which the operator lies the glass, carrying out an approximate centering. Once said jack plates start the descent, the glass encounters calibrated guide wedges, and they are automatically centered in the panel in a correct position with the glass load height. Once the descent of the glass has terminated, one proceeds by exerting manual pressure along the perimeter of the glass. At this point, the panel complete with glass is ready to be moved to the subsequent station, so as to free the bench and proceed with a new glazing while on the adjacent station the activities are completed, with the removal of the guide wedges, the insertion of fixing thicknesses and glass loading, sealing, foaming and all that necessary for completing the manufactured article. Advantageously the present invention allows using the double-sided tape, mounting the glass and carrying out all the above-described necessary operations, and simultaneously allowing an immediate movement of the door/window frame in the production cycle. Other variants of the glazing bench of the present invention provided that: - it is adjustable both eight-wise and width-wise, allowing the housing of panels of doors or windows of any size; - said jack plates are provided with bearings adapted to reduce the pressure on said glass pane; - the glazing bench comprises an automatic positioning instrument for said double-sided tape adapted to recognize, by means of an optical system, the internal perimeter of the panel on which said double-sided tape is positioned; - the guide wedges are automatically positioned by a robotic arm connected to said glazing bench; - the glazing bench comprises an optical detection and acoustic signaling system adapted to emit a sound signal when the glass is perfectly centered on the door/window frame; - the glazing bench comprises nozzles for emitting water or any other hygienizing substance adapted to allow executing a cleaning operation of the glass before executing the centering; - the bench integrates a sucker which preloads the glass, facilitating the action of the double-sided tape. The advantages offered by the present invention are evident in light of the description set forth up to now and will be even clearer due to the enclosed figures and to the relative detailed description. Description of the figures The invention will be described hereinbelow in at least a preferred embodiment, by way of a non-limiting example with the aid of the enclosed figures: - FIGURE 1 shows a 3D view of the component of the system for fixing a glass pane on a glazing horizontal bench. - FIGURE 2 illustrates a vertical view of the system for fixing glass on horizontal bench. Detailed description of the invention The present invention will now be illustrated as a merely exemplifying and non-limiting example, with reference to the figures which illustrate several embodiments pertaining to the present inventive concept. With reference to FIG. 1, a system is shown for fixing a glass on a French window panel executed on a glazing horizontal bench. The embodiment described herein represents a particular application of the invention, which can be extended to multiple uses. The glazing bench 15 allows positioning a panel 14 horizontally on manually adjustable crosspieces and aligning the panel 14 on the glazing bench 15 with the aid of clamps. Said fixing system consists of the following steps: A. the panel 14 is positioned on the glazing bench 15 and one proceeds with the cleaning of the panel 14 in order to eliminate the impurities before fixing, preventing their deposition on the double-sided tape 13; B. the guide wedges 11 are positioned on the perimeter of the panel 14, at least two per each side, in order to calibrate the correct and precise positioning of the glass pane within the panel 14 during the descent; C. the film of the double-sided tape 13 is removed in order to allow the fixing of the glass pane 10 on the panel 14; D. the glass pane 10 is approximately centered and rested on at least two jack plates 12 which are lifted by the glazing bench 15; E. the jack plates 12 start the descent and the glass pane 10 encounters the guide wedges 11 adapted to conduct the descent of the glass pane 10, positioning it perfectly at the center of the panel 14 with the glass load height; F. one proceeds by manually exerting pressure along the perimeter of the glass pane 10, ensuring that the double-sided tape is under tension; G. the panel 14 is moved onto the following station, the guide wedges 11 are extracted with the aid of blade and the fixing thicknesses, carrying out the “glass load”. Advantageously, the above-described present fixing system ensures a considerable speed of execution of the activities, a high quality and guarantee, both aesthetic and functional of the final manufactured process with respect to the current methods. Finally, it is clear that modifications, additions or variants that are obvious for those skilled in the art can be made to the invention described up to now, without departing from the protective scope that is provided by the enclosed claims.