GB2284500A - Indelible vehicle identification - Google Patents

Abstract

A vehicle identification is produced by engraving indicia in the last 10cm of the upper part of the vehicle windshield, the last 10cm of the upper part of the rear window, or in the last 10cm of the lower part. Self-adhesive templates 15 containing letters or numbers are temporarily affixed to the window 11. The templates are covered by a protector housing 43 having a coupler for an aspirator hose 49 in its lower side, a rear opening for the barrel of a sand blasting gun 33, and an inclined window 23 in its top side. The engraved letters or numbers are then opaqued with epoxy paint. <IMAGE>

Description

IMPROVED IDENTIFICATION MEANS FOR VEHICLES AND PROCEDURE THEREFORE BACKGROUND OF THE INVENTION DESCRIPTIVE MEMORY The purpose of this invention is to provide a more visible identification, more difficult to eradicate and better located than the usual metal license plate. An identification that will help the authorities to identify vehicles with greater facility, that will create a problem of difficult solution for car-thieves, as it will greatly facilitate the authorities to locate stolen vehicles.

Up-to-now it has been easy to remove and immediately change automobile plates, thus losing the only visible identification that permits the search and location of stolen cars.

However, once the switch of license plates is made thieves can circulate freely with a stolen vehicle.

To remove all identifications which I hereby offer, all window glass must be removed, at least the windshield and rear window.

There is no doubt that organized gangs would invest money to change them too, but we must also consider that windows are spare auto-parts, whose sale could be controlled through legal means, so the attempt to change windows would serve only to find the stolen vehicles and thieves.

To obtain this new improved identification for vehicles, it was necessary to make a series of studies in order to obtain something which would not disfigure the vehicle, that is sufficiently visible and besides totally indelible.

SPECIFICATIONS IN ENGRAVING In order to obtain the best visibility with the best size possible, I have made an ample and detailed study on the actual visualization possibilities of various engravings, taking as a base the Snellen Chart, which is used by ophthalmologists and optometrists to measure the visual acuteness of persons, this chart presents a series of letters of different size printed in black on a white background.

To make a comparison I engraved glass sheets with like letters, trying.to obtain the same dimensions. By letters, for purpose herein are also considered numbers. I made three engraved glass sheets as follows: a) A sheet with superficial engravings, known as grinding.

b) A sheet with deep engravings, specifically 1 mm depth.

c) A sheet with deep engravings but where the engraved letters did not have the same proportion as to height,width. In Snellen's chart and in the two first engraved sheets, the signs are practically the same in width and in height, instead I consider that the normal letters are much higher than wider, thus in this third sheet the letters are proportionate.

The purpose of making two equal sheets, that varied only in depth, was to find out if there was some incidence or relation between the depth of an engraving and its visibility, either in the presence of more light, of water and of artificial light. In all tests that I made I did not appreciate differences, both engravings; superficial and deep, could be seen at the same distances, under the same conditions.

Therefore, I am proceeded to reproduce the comparative results between Snellen Chart, in black and white and the same chart with some modifications engraved in glass.

COMPARATIVE CHART No. 1 Conditions: In day time and with sunlight, 8:30 to 9:30 a.m. with clean glasses and few influence of shadows. I did not make measurements for Snellen Chart as same indicates the distance in'which a person with 20X20 vision may see each letter, here I specify the measurements of each letter of this chart, as well as measurements of the letters engraved in glass.

Readings: The letters measurements are expressed in centimeters and distances in meters.

Abbreviation: "E" means thickness of outline. "An means the height of the letter. "AN" the width of the letter and "D" the reading distance.

Snellen Chart Engraved Glass E X A .X AN = D E X A X AN = D 1) 1.8 x 8.7 x 8.95 = 61 1) 1.7 X 8.1 X 8 = 42 2) 0.9 x 4.4 x 4.5 = 30.5 2) 0.9 x 6 x 8 = 34 3) 0.6 x 3 x 3.1 = 21.7 3) 0.6 x 3.9 x 3.0 = 27.25 4) 0.4 x 2.2 x 2.2 = 15.2 4) 0.4 x 2.2 x 2.2 = 15.15 5) 0.25 x 1.35 x 1.35 = 9.1 5) 0.25 x 1.3 x 1.3 = 7.95 6) 0.15 x 0.9 x 0.9 = 6.1 6) 0.2 x 0.9 x 0.9 = 5.50 7) 0.1 x 0.7 x 0.65 = 4.6 7) 0.1 x 0.7 x 0.6 = 4.15 8) 0.08 x 0.45 x 0.45 = 3.05 NOTE: I did not make any comparisons in sizes 3 x 3 and 0.45 x 6.45 but these values can be calculated.

Although I did not make comparisons in sizes 3 x 3 and 0.45 x 6.46, these values may be calculated. As can be appreciated, the difference in visibility is very little, having reached in letter "4" equal values, nevertheless, I must indicate that while I stepped back from the glass sheet keeping my eyes on same, there were movements in which the shadows due. to changes in light (glare) made it impossible to read the engraving, but then, going still farther, I could read same, this perturbation was basically due to the reflection angle of the light on the glass sheet.

Taking as a base the visibility of'the engravings, these can be classified in three types; a) Less Visible: Comprise those engravings that can only be read at distances less than 4 meters. These engravings only serve as marks to identify vehicles from a short distance.

b) Visible: Comprise those that can be read at distances between 4 and 15 meters and therefore serve as vehicles identification.

c) Very visible; Comprise engravings that can be read from 15 to 50 meters. These engravings are very visible and inclusive may also substitute for metal license plates.

It must be taken into consideration that during the visibility test made on engraved glasses it was observed that: 1) In day time and with a clean glass, the shadows and light reflections prevented readings from different angles.

2) In day time and with rain, the distance of readings was reduced 70%.

3) At night time: with artificial light this distance was also reduced 708.

4) When all factors are against, that is, with artificial light and rain, the reading distance was reduced approximately 90%.

This study demonstrated that engravings provide unstable identification. In determined circumstances, the very visible engravings could be seen and read at some 5 meters approximately, therefore these engravings do not entirely fulfill their purpose, which is to provide vehicles with an identification as visible as those of the plates.

Having as an aim the search for the greatest visibility with least dimension, I made other studies where I verified or determined the influence in the visibility of the proportion of the width of a letter with its height, as well as other studies, where I assigned a letter to a determined height and made variations in the width and thickness of the outline.- The result was that for a determined height of a letter the width can be the same as the height and be reduced up to 30% without affecting its reading distance. As to the width of the outline, this could vary between 12% of the height of the letter and 188, obtaining the best result when the width of the outline is equivalent to 15% of the height of the letter.

The engraving of the vehicle glasses which serve to identify them must have a standardized size, as they will not be fully useful to the authorities nor will give good result if within the same country, each vehicle uses a different one. The must also have a size that does not disfigure the vehicles as it could be disagreeable for their owners.

After taking into account all these factors I have determined that the ideal dimensions for the letters to be engraved in the vehicles are as follows: For engravings to be made in the windshield and rear window. The. height of each letter must be 5 cm., its width 3.5 cms., and line thickness of 0.75 cms; a letter must be at a distance of 1 cm. with respect to the immediate next letter.

Letters engraved with these dimensions may be read at 30 meters distance, therefore, a series of 6 or 7 letters would occupy a total width of 26 cms. or 30.5 cms respectively, the separation of 1 cm between one letter and another is necessary so that each of the engraved letters can be read at a 20 meters distance of approximately 20 meters.

For side windows it is not necessary that the engravings be large, it must be taken into account that in the majority of the vehicles, the side windows can be lowered and with this simple act the engravings would not be seen.

Nevertheless, they should be engraved in dimensions easy to read, as when the cars go through a police control or when they are parked, as well as when for certain climatic conditions automobiles have to circulate with the windows up this will be of help. In practice, I have found that for these windows to be agreeable to sight, letters engraved with 1 cm height, for cases in which more. than 7 letters are to be engraved, and of 1.5 cms. height of the cases in which 7 or less letters are to be engraved. The width will be equivalent of 70% of the selected height, and will be equivalent to 70% of the selected height, and thickness of the outline must have 158 of the height of the letter. The separation between one letter and another will be of 3 mms. Engravings made in this manner may be read at 6 meters and 9 meters approximately.

Painting of the Engraving Due to interferences by reflections of the light and reductions in visibility that the glass engravings suffer, due to rain, lack of light, it is necessary to coat the engravings.

Engravings painted with while paint are not influenced by the problems of light reflection during day time and are very visible, whether it is raining, or when there is little light.

Therefore, engravings when painted can be provide the vehicles a sufficiently visible identification under any circumstance.

Paint that must be applied in the window must be of no other than a permanent quality such as an epoxy paint which has excellent adherence to glass and additionally is highly resistant an difficult to-remove. It could be said that this coating is as.

difficult to remove as the enamel paint used on metal.

Also, in order to make the engravings more visible, application can be made over the epoxy paint, of a reflecting paint which will help the photographic camaras of the police.

It must be understood that-the invention itself is to present a more reliable and visible identification than the metal license plates. It is therefore a vital part of same to achieve the total capacity of the engravings made in the windows of the vehicles, in-such manner to be visible and therefore useful in - any and all circumstances.

It is true that in patent No: 2,555 077 of T.J.D.

- Fuller, Jr., of May 29, 1951, mention is made of a paint in the engravings made in order to embellish same. In the present case, I am trying to produce new identifications for vehicles and the visibility of the engravings is vital to achieve this purpose.

The opacity for the engravings in car glass, is the result of numerous studies made with the thought of obtaining a reliable identification.

Depth of Engravings In different studies it was determined that depth does not have influence in the major or minor visibility of an engraving, but it definitely affects the inviolability of same.

Superficial engravings are those whose depth is less than 0.2 mm and may be removed by sand-abrading its surface with glass sand-paper of fine grain (grain 150) and subsequently polishing same with cerium oxide. Nevertheless, an engraving of 0.4 mm depth or more, cannot be removed and the engraved letters will always be readable. The only way to eliminate such engraving is by breaking the glass. For this reason it is necessary that the engravings have at least 0.4 mm depth.

Location of Engraving Since the engravings if located in the last 10 cms of the upper part of the windshield and rear window do not reduce visibility of the driver, and since the purpose of the engravings is to be the most visible as possible, it has been determined that the best location is in the center, since if placed there they can be seen from a great variety of angles, in traffic, parked in line and even from the air.

As to the rear window one must make an exception with those vehicles that have rear windows which are excessively inclined. If one makes engravings in this type on very inclined rear window on the upper part, they will not be as legible as one would wish; in these cases it is advisable to make the engraving in the last 10 cms of the lower part.

As to the side windows, the engravings must be located in the part that will disfigure the vehicle the least since the purpose of these engravings is to corroborate the identity of the vehicle, whether it is examined closely or when being in circulation one cannot see the windshield or rear windows, nor the car license plates. These engravings can be seen well when located within the last 5 cms of the upper edge of the glass or the last 5 cms of the lower edge.

Letters that must be engraved in the windows It is advisable to engrave the letters taken from the metal license plate in order to reproduce the official identification of the vehicle in the window, nevertheless, in those countries where the plates are not fixed and do not stay with the vehicle for its life, the indicia from these plates should not be engraved, since the engravings are indelible so when changing license plates all engraved windows would also have to be changed, which would be very costly. The best thing in these cases is to engrave the last 6 or 7 letters of the series number of the car-body in the windshield and the rear window and perhaps engraving the complete serial number in the side windows. Also and with 1 cm of height for each letter, engraving can be made in the lower part of the windshield and rear window showing the name of the country or the city, as deemed appropriate.

NECESSARY DEVICES AND EQUIPMENT TO MAKE THE ENGRAVING Patterns (Templates) To engrave deeply it is necessary to manufacture templates that adhere firmly to the glass and that subsequently may be removed without a problem. The identification requires a-homogenous quality capable of achievement by persons with little training and also requires speed. A lengthy procedure will bring a considerable increase in costs. Therefore, the template must qualities to allow their easy and rapid placement and removal. Existence in the market of adhesive vinyl constitutes a solution. Vinyl having more than 12 microns of thickness is capable of supporting without distruction the engraving blasting for the time necessary to achieve a depth of more than 2 mms. Templates or patterns can be manufactured in typographies with metal dies which always and will be the same for each letter, will be easy to place on the glass to be engraved. They do not require the expertise of an artisan.

In patent No: 2,555,077 of T.J.D. Fuller, Jr. of May 1951, vinyl is used, to make glass engravings, but these engravings were of an artistic nature and require a specialist to draw over the vinyl and then cut it, that is, a specialist capable of making the templates or patterns on site. In the present application the templates are made in a printing shop and it only has to be installed on the glass, which brings innumerable advantages.

Vinyl templates which are to be used in large engraving must have 0.5 cms of separation between the letter contained inside and each lateral edge, in such manner that when placing next to it the template containing another letter, it will automatically maintain a separation, one letter from the other, of 1 cm which is exactly the recommended separation.

In the upper and lower part the recess is not determination, nevertheless, it is advisable that it be less than 1 cm in each case; this is mainly to protect all the surroundings of the zone to be engraved with three layers of tape.

These templates can be cast-died in special printing shops, this can be done because the pressure sensitive adhesive face of the vinyl comes protected with waxed release paper, therefore, the dieing can be done without any problem.

In the templates of the small letters the side separations between the edge of the letter itself and the edge of the template,. are of 1.5 mm, in such manner, that when joining one template with the other, a separation of 3 mm. is achieved between one letter and the other.

As to the upper and lower part 1 cm must be maintained, as the surroundings of the engraving must also be protected with tape. In another modality, the templates may be made of rubber 3 mm thick, to which is applied strong glue "halata" type on the face to be placed against the glass, in such manner so as to adhere firmly so it may not be raised by air pressure during the engraving process, this particular glue has the advantage that it is not a permanent glue as it can be removed after the procedure, the same occurs with tape or contact paper.

Although these molds are recoverable and durable, their application impinges on the preparation time, as the procedure, using these templates is much slower than the procedure in which disposable vinyl templates are used Portable Protector of sand blasting procedure A device has been designed and created to permit the sand blasting application on small surfaces, in such manner so as not to require protection for the operator, or having a special area or room to apply the sand blasting and to obtain an inexhaustible source of sand. The sand is constantly and uninterruptedly recycled.

One of its advantages is the fact that it allows the operator to see the impact of the air-sand blasting without the window through which the operator is watching the process becoming glazed or opaque.

Within the protector, the operator can move freely the barrel of the sand blasting gun, pointing it in any direction and nearing or withdrawing it according to the needs of the engraving or work that is being done.

To describe this protection I am going to mention measurements, but they may be altered, this fact not greatly affecting the operation of the device.

The protector has generally a cube configuration in which all its faces are 10 x 10 cms.

The back face is open, this face is the one to be placed against the surface glass to be engraved.

The two side faces are enclosed with glass or transparent plastic, these sheets will not be used to see through them but will only service to allow the light to go through.

The upper face is irregular, consists of a top which although it slides by its edges in the slots of the device, is not plain, actually this cover forms a square which protrudes or sticks out by 3 to 4 cms from the front face of the device. This square face which protrudes, has at the end a square window, over which slots a small glass slides of approximately 7 x 7 cms.

It is through this glass located in-the front part of the device from which the operator observes the engraving in progress. Its distance from the surface which is being engraved (15 cms approx) and its location in the upper-rear part prevent it from being easily opaqued during its use, this small glass so located will permit the supervision of many engravings before needing to be replaced.

The device's front face present a horizontal slot in the middle, of 8 cms. long and 3 cms. height, this slot crosses with 3 vertical slots 8 cms. long, each one'of 2.5 cms. wide.

The purpose of these.slots is to allow the almost free displacement of the barrel of the sand blasting gun and at the same time to serve as support for the installation of a rubber sheet to form a bellow. Cuts are made in the rubber sheet which coincide with the slots, in this manner it is substantially reduced the exit of sand that bounces from the surface through the opening. Some sand will escape through the cracks or openings which remain between the circular barrel of the sand blasting gun and the horizontal or vertical opening of the bellows.

To avoid the total exit of sand, it is necessary to close with material or very thin rubber all the face, gluing to the edges of this rear face, a piece of straining cloth (to strain coffee or similar), which ends in an elastic slot (elastic mouth) or adjustable slot. Through this slot is inserted first the barrel of the sand blasting gun and then passed through the slots of the rear face.

The lower face has an orifice located towards it rear-center part, within which is placed by pressure or by threading, a tube 1 1/4" diameter (3.2 cms.) in its middle part, that is, that in the orifice where the protector is connected, its diameter will be a little less than 3.02 cm and in the outlet orifice, its diameter will be higher than 3.02 cm. The purpose of this orifice is to permit the -coupling of a suction hose outlet of the aspirator.

The protector has a rubber lid in its front part, which is also totally opened in the center, but serves to even the support edge; with adequate glue, over this rubber is glued a strip of foam-rubber along the length of all its contact or support contact with the surface to be engraved, this in order to prevent sand dust leaks when sand blasting is being applied on somewhat irregular surfaces.

Air Compressor To obtain the necessary air pressure for sand blasting, an air compressor is necessary, in this specific case, where a barrel is to be used in the burst gun with an outlet of 5 mms diameter, at a pressure of some 50 ibis,, air flow of 26 feet/min is required, a great variety of compressors of different brands fulfill these needs, some inclusive of 5 H.P. are capable of producing in these conditions a flow of 45 feet/min which will be sufficient to feed 2 burst pistols at the same time, as it must be taken into account that sand blasting is applied with small intermittences to verify the depth reached.

Semi-industrial aspirator 1 H.P.

The aspirator used for this procedure is that which has no deposit bag, that is, the one that has a filter to prevent the exit of the aspired dust and uses as trash deposit all the tank.

The first thing to do is to substitute the original paper filter for a felt filter as felt has the property of retaining the finest dust particles generated during the sand blasting application.

In practice, a 1 H.P. aspirator is capable of suctioning the 26 ft/min of air-sand used during the sand blasting application. To obtain an inexhaustible source of sand, it is necessary to fix in the bottom of the reservoir tank of the aspirator, a three-nozzle connector, in the upper nozzle a 1/2" tube is placed which extends up to the edge of the reservoir of the aspirator, taking care that it does not interfere with the cover; of the two remaining available nozzles, one is left open in the interior of the tank and in the other another 1/2" tube is placed which goes through the reservoir. This tube is connected to the sand suction nozzle of the sand blasting gun. Sand is placed in the reservoir of the aspirator and from there is suctioned by the suctioning air current which generates the sand blasting procedure, in practice the procedure works up to a distance of 1.5 meters which therefore will be the maximum longitude of the tube that must supply sand to the gun.

The procedure works as the tube that is placed in the tank's interior, up to the edge of the mentioned deposit, permits the creation of the necessary air current to achieve continuous flow of the sand abrasive, if this tube should become obstructed, sand will.start arriving in parts to the pistol and the procedure will be slow and difficult.

The sand must be replaced when it is too pulverized, something that will occur in a period of 6 to. 7 days of use.

Sand Blasting Gun The sand blasting gun to be used must have about a 10 cms. long barrel. The diameter of the exit mouth of the barrel must be of 0.5 mm.

Rubber Template Once the vinyl templates are installed on the glass, a rubber template is installed over them of 2 mm maximum thickness.

in order to protect the joints between one template and the next.

In practice such unions cannot be perfect if the edges of the templates are not mounted or overlapped a bit, which is not advisable as the ideal separation of 1 cm that must exist between one letter and the other will vary, nevertheless, if these joints are not protected with this template, (most rapid and easy form) during the application of sand blasting the vertical lines of these joints will show in the glass, which disfigures the engraving.

A platform with adjustable height so the operator can sit down and wear the aspirator. This platform is necessary to be able to engrave the windshield in the center, without having to climb on the hood of the vehicle, as it could dent same.

Procedure: 1) The first step is to clean the window well especially in the zones where the templates will be glued so they can get a good hold on the glass.

2) The site of engraving is determined and marked with a proper marker, for example; for the windshield; first of all, the center of this glass must be determined, that is, total width is measured, then divided into two and a vertical line is drawn starting from the upper edge downwards, with a length of same 15 cms., after a horizontal line is drawn at 3 or 4 cms. distance from the edge of the upper frame, which line must be straight should the edge be curved, the straight line would maintain equidistant recesses in both sides.

The same procedure is repeated for the rear window. As to the side windows this is left for selection by the owner of the vehicle, either the lower rear angle of each one of these windows or the upper rear angle. A vertical line is drawn with 1 cm separation from the vertical frame and a horizontal line that has a separation of 2 cms from the lower or upper horizontal frame.

3) Then the disposable templates are glued in the following form: in the windshield and rear window from the center to the outside, but first the center of the total width of all templates must be determined.

For the side window placement is started from the last letter and is continued from back to front with all the rest in the same form and finally the bridges are cut and removed which necessarily will exist in the letters A, B. D. O, P, Q. and R and in the numbers 4, 6, 8, 9 and 0.

In the event that rubber re-usable templates are to be used, the face to be impregnated with the glue must be also cleaned then the glue is spread, taking special care that it is well applied in the edges, leaving same to dry for the time indicated in the manufacturer's instructions and then these are installed on the windows Reusable templates do not have bridges, the operator will have to glue the "centers" of the letters calculating same.

4) The following step consists in covering the templates with the joint protector, for which it is fixed to the glass but over the templates with adhesive tape, also covering with this same tape all the surroundings in some 5 cms. from the edges.

5) 4 or 5 kgs. of 40 grain sand is placed in the aspirator's tank, the hose of aspirator is coupled to a portable protector, air and sand hoses are connected to the gun, compressor and aspirator are activated, the barrel of the gun is introduced and adjusted in the rear part of the protector, the protector is thrust with some pressure on the letter (template) which is to be engraved and the trigger is squeezed.

The operator will distribute as equally as possible on the surface being engraved, the sand spraying action, in such form so as to be as uniform as possible, as far as depth is concerned. Protector may be withdrawn form time to time when desired and the operator can verify with his hand the state of the engraving work.

6) Once the engraving is finished, the epoxy paint is applied. on the engravings and when the paint is dry, the templates will be withdrawn.

Initial drying. for epoxy paint is approximately 1/2 hour, but its total drying occurs in 24 hours. This paint, once dried, penetrates any irregularities of the engraved gnash, being practically impossible its complete removal, reason for which is of vital importance for this identifications.

BRIEF DESCRIPTION OF THE DRAWINGS Figure l is a perspective view of the device of the present invention in position for sandblasting.

Figure 2 is a side view of the device in partial cross-section.

Figure 3 is a schematic of the entire system including the device, sand source, and compressor.

DETAILED DESCRIPTION OF THE INVENTION Reference numeral 15 represents plastic self-adhesive templates of vinyl, polyester, nylon, etc. which are attached to the surface of the glass to be engraved. Once the engraving site has been demarked in the windshield or rear window glass, the templates are directly adhered on the glass. These templates are designed in such manner that the number cut contained in its interior remains 1 cm. separated from the letter that contains the side template.

Once all templates are adhered, all their surroundings are protected by placing self-adhesive paper 3 cms. width and 6mm wide strips of self-adhesive paper over each one of the joints 13. A more rapid form is to place a thin rubber sheet that covers all the desired spaces 17. This protecting sheet is fixed over the template with self-adhesive paper. The purpose of protecting the joints is to prevent the formation (engraving) of vertical lines on the glass by the sand blasting action.

Once the glass 11 to be engraved is prepared the pressure hose from the compressor 59 is connected to the butt of the pistol 33 connection is made of the sand suction hose 50 coming from the vacuum cleaner 50 to a protector hose connection.

The vacuum cleaner 51 is turned on. The uncovered face of the protector 43 is placed against the prepared glass 11 and the trigger is activated. The recommended air pressure so that the tempered glass will not break.during the procedure is about 50 p.s.i.

During the sand blasting application care must be taken to apply same uniformly, which is achieved by slowly running thru the whole sign which is being engraved and not holting while engraving. To note the depth of the engraving, the process may be stopped, withdraw the protector 19 withdrawn and touched, for instance, then the engraving may be continued.

The required time to engrave a sign varies with regards to the intrinsic surface of the glass, an E glass delays more than an L, etc...nevertheless,.it..may be said that on average it delays approximately 1-1/2 minutes in each sign.

The pistol's barrel 37 is of 14 cms length. The barrel 37 extends through an opening of a flexible cover 27 which may be constructed of fabric, rubber or canvas. The end of the pistol barrel must be maintained at some 2 cms distance from the glass.

Thanks to the protector design the pistol's barrel 37 may be moved in all directions and the operator can see the sand blasting application through the inclined window 23.

Sand that falls within the protector 19 is aspirated through the vacuum cleaner's hose 49 and 50 and stored in the aspirator's tank of the vacuum cleaner 51, from this tank it is lightly and uniformly suctioned by the suction current which is created inside the pistol 31, due to the venturi effect of air pressure which circulates in its interior. This suction current may suction sand at a distance of 1.70 meters. In this case, the sand 52 is suctioned through the free orifice of the connector Tee (63) which is in the interior and transported up to the pistol thru the tube 39. This tube 39 is of 3/8" and is placed through an orifice opened in the tank's wall, therefore permitting the free passage of sand from the tank to the pistol.

In the upper opening of the connector t 63 a tube 64 is placed which goes up to some 5 cms from the cover of the aspirator, this tube is necessary so that the flow of sand through the tube 39 is uniform. If this tube is not placed, or if it is covered, the sand will start coming out of the pistol in intermittent gusts.

Converting the aspirator's tank in a sand deposit of continuous recycling, saves space, due to the elimination of the great hoppers (sand deposits) and of time, since the sand deposit does not have to be recharged. All this is possible thanks to the protector 19 which is where the vacuum's hose collects the used sand.

To avoid the fine dust generated during the process air goes out through the air expulsion outlet 60 of the vacuum cleaner 51. The original paper filter of which is substituted by one of felt filter 58 which is capable of retaining these fine particles.

In summary, the equipment contains two aspects: 1) Modifications in the conventional equipment, which are those made in the sand blasting pistol 31 and in the filter 58 tube 64, tee 63 and connection 39; and 2) the new innovations such as the self adhesive templates 15 plus the portable protector 19.

Once the engraving is done, the epoxic paint is applied.

The invention should not be limited by the above disclosed embodiment, but should be solely limited by the Claims that follow.

Claims (10)

Claims

1. Vehicle identification produced by indelible engraving of.indicia opaqued with epoxy paint located in the last 10 cms of upper part of windshield, or located in the last 10 cms of upper part of rear window or in the last 10 cms of lower part.

2. Vehicle identification produced by indelible engraving of indicia opaqued with epoxy paint, located in the last 5 cms of lower part of side window or in the last 5 cms of upper part of such window.

3. A procedure to mark indicia in vehicle window which comprises the transitory fixation of a plurality of self-adhesive templates containing letters or number, over which is applied a sand-air blast, for the period of time that may be necessary to obtain the desired depth in the engraving.

4. The procedure of claim 3 wherein the sand blasting engraving occurs in a protector which consists of a housing which has transparent sides, has an orifice with a coupler for an aspirator hose in its lower side, an opening in a face away from the window adapted to let a sand blasting gun barrel slide inside, and has in its upper part an inclined window which allows the operator to see the sand blasting application and is sufficiently opened in its front part to permit the sand blasting application on the desired surface.

5. The procedure of claim 4 wherein the protector transparent sides which are closed with transparent means which slide through slots in order to permit their replacement when necessary.

6. The procedure of claim 4 wherein the sand is recycled by an aspirator used as sand reservoir and from there is carried to the gun the spraying made with the gun is collected inside a portable protector of sand blasting means and carried to the aspirator's tank.

7. Sand blasting apparatus comprising the protector of Claims 4 or 5.

8. Vehicle identification means substantially as described herein.

9. A procedure to mark indicia in a vehicle window substantially as described herein.

10. Sand blasting apparatus substantially as described with reference to the drawings.