US3443860A - Pleated shade for controlling heat and light - Google Patents

Description

.' May 13, 1969 I s. N. F, LUBOSHEZ 3,443,360

' PLEATED SHADE FOR CONTROLLING HEAT AND LIGHT Original Filed June 6 1962 v 5 v 3 I DRYER i NJ PLEATING I MACHINE no.3 H66 H68 FIGS 80 FIGIO INVENTOR.

S. N FERRIS LUBOSHEZ A 7 [OR NL m United States Patent Patent No. 3,257,486, dated June 21, 1966. Divided and this application Apr. 19, 1966, Ser. No. 543,636

Int. Cl. G02b 27/00; B32b 3/28, 3/30 US. Cl. 350-263 Claims ABSTRACT OF THE DISCLOSURE A shade which acts as a complete barrier to direct light radiation, while at the same time admitting indirect d1ffused light radiation and controlling the passage of heat therethrough. The shade consists of a substantially flat pleated sheet of light-transmitting resilient material having a coating situated on certain portions of the show areas of each pleat, said coating having heat and light reflective, and heat absorbent properties, or combinations thereof, the underlay areas of each pleating being uncoated, said shade when expanded presenting a formation having coated and uncoated areas in spaced relationship.

This invention is a division of my copending application, Ser. No. 200,366, filed June 6, 1962, and relates to the coatings to sheet material in spaced areas. This invention is similar to my prior invention disclosed in Patent No. 2,874,612.

In my foresaid patent there is disclosed a combined heat-reflector and light-transmitter structure for simultaneously excluding heat rays and for admitting light from a source of mixed radiation comprising a corrugated sheet of resilient, light-transmitting plastic material having a coating of metallic heat-reflecting material on one side only of each corrugation leading to its crest. The corrugated structure is intended to be hung in such position that radiant energy from a source above the horizon such as the sun, will impinge on the sides of the corrugations having the coating of metallic heat-reflecting material. When the corrugated structure is so hung, the heat rays of the mixed radiation will be reflected away from the corrugated structure and to the side thereof from which they emanate, while the alternating uncoated bands of the structure will transmit light.

The coating of alternating portions of a corrugated structure of the type described above presents certain problems. Attempts to apply the heat-reflective coating to the sheet before the sheet is corrugated have not been satisfactory for several reasons. The use of masks or stencils to block out the parts of the sheet to which the coating is not to be applied, when the coating is applied by spraying, vacuum metallizing and the like, is expensive. When the coating is applied to the sheet immediately prior to its being corrugated, care must be taken to assure that the coating is thoroughly dry before the sheet passes to the corrugated machine. This is particularly important Where the sheet is of plastic or other nonabsorptive material. In such cases very rapidly drying coatings must be used and drying means installed. The temperatures used in forming the corrugations when the corrugations are heat set, are sufiiciently high to damage certain coating materials, therefore limiting the choice of such materials. The coating on the sheet may adhere to and foul the corrugating machine, requiring dismantling and cleaning. A further, and probably an even more difficult problem which is encountered in connection with precoating, is that of registration. In corrugating a sheet of any appreciable length there is bound to be some stretching or shrinkage of the sheet, requiring the use of "ice sensitive speed and corrective controls to prevent gradual accumulative displacement between the coated pattern and the formed structure. Complete accuracy of correspondence bet-ween the coated pattern and the subsequent corrugations is essential for the etficiency of the structure.

While the objections to coating the sheet prior to corrugation may be avoided by first forming the corrugations and then applying the heat-reflective coating, this involves the application of the coating to a non-fiat surface. This is a difiicult and complex operation and requires special equipment as compared with the' usual methods of printing on a flat surface.

The present invention relates to a structure produced by the selective coating of spaced areas on a base sheet which avoids the disadvantages of precoating as outlined above, and which does not require any masking, stencilling or other special equipment.

In accordance with the present invention, the sheet to which the spaced areas of coating are to be applied is first pleated and the coating material is applied to the desired spaced areas of the sheet while the sheet is still in its flat pleated form, that is before the pleats have been opened up. Since the pleated sheet still is in its flat form a planar surface is presented, and the coating can be applied in accordance with any conventional method used for coating such surfaces. When the sheet thus coated subsequently is extended to open up the pleats to form a corrugated structure, the intermediate layer, or infolded portion of the pleat which, during the coating operation, was covered or masked by the outer folds of the pleats, will be uncoated and the coated areas on each surface of the sheet will all be at the same side of the corrugations leading to the crests.

The invention will be further described in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic view illustrating the method of the invention;

FIG. 2 is a sectional view of the pleated and coated sheet, before it has been extended to form the corrugated structure;

FIG. 2A is an enlarged sectional view of a portion of the structure shown in FIG. 2;

FIG. 3 shows the pleated and coated sheet of FIG. 2 extended to form a corrugated structure and positioned vertically;

FIG. 4 discloses the structure of FIG. 3 mounted on a roller, as when used as a light-transmitting thermal barrier for a window;

FIG. 5 is a sectional view similar to FIG. 2, but showing the pleated sheet coated on one side only;

FIG. 6 shows the pleated and coated sheet of FIG. 5, extended to form a corrugated structure and positioned vertically;

FIG. 7 is a sectional view similar to FIG; 2, but showing the pleated sheet coated on opposite surfaces with different types of coating material;

FIG, 8 shows the structure of FIG. 7, extended to form a corrugated structure and positioned vertically;

FIG. 9 is a sectional view similar to FIG. 2, but showing the base sheet formed with box pleats, and

FIG. 10 shows the structure of FIG. 9, extended to form a corrugated structure and positioned vertically.

The method of applying the coating in spaced areas to the sheet is ilustrated in FIG. 1, where a sheet of material 1, preferably formed of a plastic transparent, flexible and resilient material, such as cellulose acetate, cellulose acetate-butyrate, polyester, polycarbonates, or the like, which is capable of taking a permanent set, is passed through a conventional textile pleating machine 2 and having means capable of imparting a permanent set to the pleats which are formed in the sheet. The sheet 1 may be quite thin, ranging from about 1 mil to 10 mils, or

thicker, depending upon the particular use to which the final corrugated structure is to be put. The pleats may vary in width from a fraction of an inch to several inches.

After the sheet is pleated in the machine 2, it emerges as a pleated structure in flat form 3 in which the folds forming the pleats lie substantially one upon the other so that a substantially continuous and flat planar surface is presented at each side of the pleated structure, The thickness of the coating may be from a fraction of a mil upwards to any convenient thickness, depending upon the opacity desired.

While the pleated structure is in the flat form it readily is adapted for coating by spraying, vacuum metalizing, printing, or any other conventional means used for coating flat surfaces. Thus, the pleated structure in its flat form may be coated on one or both surfaces by passing it beneath a spray nozzle 4 to have a coating 5 applied to its upper surface, or between the spray nozzle 4 and a lower spray nozzle 4' if it also is desired to apply a coating 6 to the lower side of the pleated structure. The coating material which is applied by the nozzle 4 or by both nozzles may be of any suitable material. Where the coated sheet is to be used as a thermal insulator, as is here disclosed, the coating material is a heat-reflective material, preferably one containing a metal component, such as aluminum paint.

After the coating has been applied to one or both sides, as desired, the coating may be dried in any manner, as by passing it through a dryer 7 from which it emerges in a form ready to be extended to provide a corrugated structure, such as the thermal insulator structure 3' of FIG. 3.

From FIG. 2, it will be noted that the inner fold 8 of each pleat is completely covered on both sides by the outer folds 9 and 10 of the pleated and coated structure 3. Consequently, during the coating operation of the pleated structure 3, the inner fold 8 is completely covered and protected on both sides by the outer folds 9 and 10 of the pleats, so that no coating is applied thereto, In other words, the outer folds 9 and 10 of the pleated structure form a mask for the respective sides of the inner fold 8 which is to remain uncoated.

When the pleated and coated structure 3 is extended, as in FIG. 3, to form a thermal insulative structure, such as might be used for a window, to reflect back the beamed radiation, including substantially all the heat rays while permitting the transmission of indirect light rays, the uncoated inner folds 8, which are light-transmitting, will form the horizontal sides 8a leading to the crests of the corrugations, while the coated outer folds 9 and 10 will form the inclined sides 9a leading to the crests of the corrugations.

Since all of the folds are of the same width, and since there are two outside folds for each inside fold, the width of the inclined sides 9a of each corrugation will be twice the width of the horizontal sides 8a of each corrugation. Also, since each inclined side 9a will consist of the coated top fold of one pleat, reference being made to FIG. 2, and the coated lower fold of an adjacent pleat, the coating 5a of the top fold 9 will be on one surface of the inclined side 9a while the coating 6a of the lower told 10 will be on the opposite surface of said inclined side. However, this is not important. By referring to FIG. 2A it will be noted that while the adjacent longitudinal edges of the pleats lie closely adjacent to one another, they are spaced sufficiently that the coatings on the opposite sides of the pleated structure extend downwardly into the crevices between the pleats so that the respective coatings terminate opposite a line extending transversely through the sheet at the point x. Consequently, when the pleated and coated sheet is extended, as shown in FIG, 3, there is no path through the sides 9a for the passage of radiant energy.

In practice, the angle formed by the sides 8a and 9a of the corrugations is not critical and may, in fact, vary, depending upon the latitude at which the thermal insulator is used, as well as the time of the year. However, the sides 9a of the corrugations should extend at an angle to the general plane of the corrugated sheet which is such that heat rays striking the heat-reflective coatings 5a and 6a at a predetermined range of angles from a source above a horizontal, such as the sun, will be reflected away from said surfaces and to the side thereof from which the rays originated.

The thermal insulator structure shown in FIG. 3 may be used in any place where a barrier for heat rays is desired, or where it is desired to reflect back the heat rays and still permit the transmission of light. It may be attached to a window frame, either on the inside or outside, to function as a storm sash, or as a substitute for the usual glass pane. If used in the nature of a storm sash or a dual pane, or as a thermal insulator for a window, it may, as shown in FIG. 4, be mounted on a springless roller 11, having a pulley 12 at one end thereof around which a cord or chain 13 is passed for rotating the roller to wind or unwind the thermal insulating screen 14. The cord or chain passes through a fastener 15 so that the roller can be held against rotation. The base sheet of the screen 14 is sufliciently flexible that the screen may be wound onto the roller without difficulty. The lower end of the screen is attached to a batten 16 which carries a hook 17 adapted to engage an eye 18 secured to the window sill 19, or the like, to anchor the lower end of the screen. By applying the proper tension to the unwound portion by means of the rope or chain 13, the sides 8a and 9a of the corrugations can be made to assume any angle, depending upon the extent to which it is desired to exclude heat and permit the transmission of light. When the desired angle between the sides of the corrugations has been obtained, with respect to the angle of incident radiation, the structure may be held in such position by the fastening device 15 which will maintain the structure under the desired tension, If an unobstructed view through the window is desired, it is only necessary to unhook the hook 17 from the eye 18 and roll the screen 14 up onto the roller 11. To facilitate the winding and unwinding of the screen, guide channels may be provided for the vertical edges of the screen.

When the structure 3' is in the extended condition shown in FIG. 3, direct sunlight approaching in the direction of arrow a will impinge on and be intercepted by the metallic coatings 5a and 6a and will not reach the uncoated side 8a of the corrugations. Since metals in general are opaque to heat rays and reflect them, all of the direct sunlight striking the structure 3 will be reflected away from the structure to the same side from whence it came and will not pass into the enclosure. However, as the sides 8a of the corrugations are light-transmitting, indirect light rays, that is, reflected light rays, approaching the structure in the direction of arrows b can pass through it into the enclosure to provide illumination.

'The fact that the coatings 5a and 6a are on the opposite surfaces of the sides 9a of the corrugations, and the sunlight will impinge directly on the portion of the transparent base sheet 1 opposite the coating 6a, is immaterial as far as the effectiveness of the structure for its intended purpose is concerned. While the portion of the base sheet overlying the coating 6a will absorb heat from the incident heat radiation from the sunlight striking it, because of the relation between emission and absorption, the coating 6a ibeing metallic will not emit heat absorbed from the overlying portion of the base sheet in any significant amount. The important factor is that at least one of the surfaces of the sides of the corrugations upon which the heat rays impinge presents a substantially bare metallic surface to the atmosphere.

As previously indicated, the angle between the metalliccoated sides 9a and the uncoated, light-transmitting sides 81: of the corrugations may be varied by longitudinally stretching the pleated and coated structure to the desired extent in accordance with the angle of incident radiation so as to exclude the maximum amount of heat radiation and the admit the maximum amount of visual radiation.

When the structure 3 is stretched out to the extent shown in FIG. 3, that is with the sides 8a of the corrugations horizontal, the reflective metallic coatings 5a and 6a will intercept and reflect back all heat rays emanating fI'OlIIl the sun from sunrise to sunset. Also, it will give substantial privacy as far as the enclosure is concerned as there is no direct horizontal path of visual radiation through the structure into the room. If greater transmission of light through the structure is desired when the sun is at a higher position in the sky, it is only necessary to apply greater tension to the structure to widen the angle between the sides 8a and 9a and thereby bring the corrugated structure closer to a planar position. Thus, the structure can be adjusted, regardless of latitude, the time of the year, or the time of the day, to exclude the entry of direct radiation from the sun together with its attendant glare and destructive effect on draperies and furnishings, even with the structure extended to permit visibility through it, Actually, in most instances, adjustment will not be necessary. This is important Where the device is applied to large, inaccessible glass areas to which the device may be directly adhered or otherwise permanently attached.

With the structure extended as shown in FIG. 3, penetration of radiation from the sun directly therethrough is excluded in toto. If direct visibility through the structure is desired, the structure may be further extended so that the sides 8a of the corrugations extend outwardly and upwardly at a substantial angle to the horizontal and :still be effective to prevent direct passage of radiation from the sun throughout those portions of the day when the sun is high in the sky and creates the greatest problems. In early morning and late afternoon when the sun is low in the sky, the radiation from the sun passes through a much greater portion of the earths atmosphere and much of the heat radiation and the destructive ultraviolet radiation is absorbed by particles in the atmosphere so that the suns rays reaching the earth are soft and weak.

When the sheet 1 is of resilient material and all tension is removed from it, the structure will spring back to its original pleated form of FIG. 2, and form an opaque screen with respect to visible radiation and will provide for complete privacy of the enclosure. At the same time, the metallic coating on the side of the structure facing the incident heat radiation provides an unbroken surface covering the entire area of the outer surface of the structure for highly effective reflection of heat rays. The similar unbroken metallic coating covering the entire inner surface of the structure will emit an insignificant amount of heat into the room. The combination of the outer and inner unbroken metallic surfaces provides a highly efficient barrier against heat radiation and protection against heat from high intensity explosions. Furthermore, when the structure is in the collapsed form of FIG. 2, it provides good insulation against heat transfer by conduction and convection, since the small spaces between the three layers provide dead air spaces which act as effective insulating barriers to heat transmission.

If desired, the intermediate fold 8, or all of the folds may be perforated to provide ventilation.

The device of the invention, when used as a heatreflective, light-transmitting thermal insulator does not serve merely to reduce directly beamed radiation pari passu with indirect diffused radiation. It actually discriminates between direct, beamed radiation and indirect diffused radiation, rejecting the former and admitting the latter. This function of the device is particularly important where the sun is concerned. lFor purpose of illumination it is desirable to admit the diffused light to a room and to reject strong direct sunlight in order to avoid glare, excessive contrast, and above all, to prevent the entry of heat through glass areas in summer.

The pupil of the human eye, by varying in diameter from 8 mm. to 2 mm. with increasing light intensity greatly deceives a beholder as to the true range intensity by decreasing the apparent intensity in a ratio of 16 to 1. However, the destructive effect of the sun or draperies and furnishings shows how great the discrepancies are between the actual and apparent amounts of radiation. This becomes still more apparent when the difference between power consumption and installed capacity required for cooling without the sun shining into an enclosed space is appreciated. In accordance with the invention the balance is redressed by admitting as much diffused radiation and rejecting as much direct radiation as possible.

The pleated and coated structure 3 of FIGS. 2 and 2A is coated on both sides. In many instances, coating the pleated structure on one side only will suffice, and often is preferable. This is shown in FIGS. 5 and 6. When the pleated structure is so coated, the sides 20 of the corrugations leading to the crests thereof will be coated only over one-half their transverse area. When the structure is positioned vertically, as shown in FIG. 6, with the metallic coating 21 on the outside surface of the lower half of the sides 20, the upper, uncoated halves 22 will lie in the shadow of the coating 21 when the suns rays are coming in the direction indicated by the arrow c, and at any time when the sun is higher in the sky.

The operation of the structure of FIG. 6 is the same as that of FIG. 3 in that the metallic coating 21 intercepts and reflects back all heat waves, while diffused light may pass in the directions indicated by the arrows d and e through the upper, uncoated halves 22 of the sides 20 of the corrugations and the sides 23, respectively.

A structure coated on only one side, as shown in FIG. 6, provides for greater visibility therethrough since there is a direct visual path from an eye E both through the upper uncoated half 22 of the side 20, in the direction of the arrow and also through the uncoated side 23, in the direction of the arrow g.

Where less visibility through the structure of FIG. 6 is not objectionable, the interception of heat rays from a source at a lesser angle to the horizontal can be obtained by releasing the tension on the structure and letting it collapse to a position where the sides 20 and 23 of the corrugations subtend a lesser angle. This has the effect of raising the upper edge of the metallic coating 21 of a lower corrugation relative to the lower edge of the coating of a superadjacent corrugation, thus bringing it farther into the shadow of the metallic coating of the upper corrugation.

Instead of coating the pleated structure 3 on both sides, as shown in FIGS. 1 to 3, with a metallic heatreflective coating, it may be coated on one side with such a coating and on the other side with a different type of coating. This is illustrated in FIGS. 7 and 8 Where the metallic, heat-reflective coating is indicated at 30 and the other coating at 31, the difference in the coatings being indicated by the differences in the thickness of the cross-hatching lines. The use of different types of coatings on different sides of the pleated sheet is desirable for certain purposes.

One example where the use of coatings of a different character on opposite sides of the pleated sheet is important, is where it is desired to prevent the entry of the energy contained in that portion of the suns spectrum which is visible. In such case the coating 31 may be of a light reflective substance, such as a white pigment. Such substances being dielectrics, will absorb the infrared heat waves, thereby heating the structure which, if in its extended position shown in FIG. 8, would reradiate heat inwardly into the enclosure. However, if the structure is used in its collapsed form, as shown in FIG. 7, the inner surface will present a continuously bare metallic surface, and no significant amount of energy will be re-radiated inwards because of the relationship between emissivity and absorbitivity. Moreover, the opacity of the metallic coating 30 will prevent the transmission of any heat transmitted by the white coating 31.

Another example Where the use of coating of a different character on opposite sides of the pleated sheet is desirable is where the pleated and coated structure is to be used as a combined solar heater and thermal insulator. Thus, with the structure extended as in FIG. 8, if the coating 30 is metal and the coating 31 is a dark pigment, preferably black, it will absorb and radiate into the enclosure the maximum of the heat of the heat waves of the suns radiation striking it, while the metallic coating 30, being exposed to the atmosphere of the enclosure, will intercept and reflect back into the enclosure heat waves which otherwise would pass through the window, thereby conserving the heat in the enclosure. Such a structure would be desirable for use in the wintertime.

Instead of pleating the sheet 1 with side pleats, as heretofore described, it may be pleated with box pleats, as illustrated in FIGS. 9 and 10, and selectively coated on one or both sides. Also, if desired, side and box pleats may be used in the same structure to provide for special situations.

'In general, box pleats may be more efficiently used in structures where the lengthwise direction of the pleats is vertical, in the absence of special situations, while, absent special situations, side pleats will be used in structures where the lengthwise direction of the pleats is horizontal.

A special situation exists, for example, where it is desired totally to exclude the direct rays of the sun shortly before sunset, while simultaneously admitting the maximum amount of indirect light for illumination, and also to provide for good visibility through the structure from the inside to the outside. Under these conditions, in the Northern Hemisphere and in the summertime, the sun sets northwardly of the true east-west direction. For a window having a westerly exposure, the asymmetrical, side-pleated structure positioned so that the lengthwise direction of its pleats is vertical and with the coated sides 9a of the corrugations facing the sun and the uncoated sides 8a facing away from the sun and generally south, would be preferable.

Other special situations can be met by using the sidepleated or box-pleated structures heretofore described, either alone or in combination.

The structures heretofore described, when applied to an ordinary window provide in a single, lightweight and convenient unit, the equivalent of the following conventional units combined: (1) a heat reflective, light transmitting thermal insulator, (2) a dual pane or storm window, (3) a combined solar heater and thermal insulator, "(4) a venetian blind, and (5) a roller blind.

While maximum heat reflectivity from a metallic surface is obtained when the bare surface of the metal is exposed directly to the atmosphere, in some instances, because of the particular coating technique used, the outer surface of the metal will be coated with a thin film of a colorless lacquer. This will not materially affect the heatreflectivity characteristic of the metal. Also, it may be desirable to apply a thin film of a colorless lacquer to the exposed metal surface to prevent oxidation of the metal with its attendant lowering of the heat reflectivity of the metallic coating.

While the sheet 1 has been described as being transparent, it will be understood that, if desired, for greater privacy or otherwise, it may be of a translucent material.

The invention has been specifically described herein as applied to Windows for enclosures. However, it is to be understood that such specific description is only by way of exemplification, as the structures described may be used in many other applications, for example, openings of any kind, roofs, overhangs, heat barriers generally, greenhouses, and the like, in conjunction with well known control and support means, and in installations such as rollers, shutters, frames, panels and awnings. The pleated structure may be arranged to exclude heat in summer or, contr-ariwise, reversed to admit sunlight in winter and prevent the outflow of heat.

Various changes may be made in the details of the invention as described herein without sacrificing any of the advantages thereof or departing from the scope of the appended claims.

I claim:

1. A combined heat-reflective, light-transmissive, and thermal insulating shade which discriminates between direct radiation and diffused radiation emanating from a source which gives off both heat and light radiation, comprising a substantially flat pleated sheet of light-transmitting resilient material having a heat and light reflective coating situated on one side of the pleated sheet, the coating covering only show areas of each pleat, the underlay areas of each pleat being uncoated, said shade, when expanded, presenting a formation having coated and uncoated areas in spaced relationship.

2. A shade according to claim 1 wherein the heat and light reflective coating is situated on the upper portion of the show area of each pleat.

3. A shade according to claim 1 wherein the heat and light reflective coating is situated on the lower portion of the show area of each pleat.

4. A combined heat-reflective, light-transmissive, thermal insulating shade which discriminates between direct radiation and diffused radiation emanating from a source which gives off both heat and light radiation comprising a substantially flat pleated sheet of light-transmitting resilient material having a heat and light reflective coating situated on both sides of the pleated sheet covering only the show area of each pleat, the underlay area of each pleat being uncoated, said shade, when expanded, presenting a formation having coated and uncoated areas in spaced relationship.

5. A combined solar heating and thermal insulating shade comprising a substantially flat pleated sheet of light-transmitting resilient material having a first coating of heat and light reflective material situated on one side of said pleated sheet, the coating covering only the show area of each pleat, and a second coating of heat-absorbing material situated on the other side of said pleated sheet, the second coating covering only show area of each pleat, the underlay area of each pleat being uncoated, said shade, when expanded, presenting a formation having coated and uncoated areas in spaced relationship.

6. A combined solar heating and thermal insulating shade comprising a substantially flat pleated sheet of light-transmitting resilient material having a first coating of heat and light reflective material situated on one side of said pleated material, the coating covering only the show area of each pleat, and a second coating of heatabsorbing material situated on the other side of said pleated material, the coating covering only the show area of each pleat, the underlay area of each pleat being uncoated, said shade, when expanded, presenting a formation having coated and uncoated areas in spaced relationship.

7. The shade of any one of claims 1, 2, 3, 4, 5 and 6 wherein said coating of heat and light reflective material is metallic.

8. The shade of any one of claims 5 and 6 wherein said second coating of heat-absorbing material is also lightreflective.

9. The structure of any one of claims 1, 2, 3, 4, 5 and 6 wherein said pleats are box pleats.

10. The structure of any one of claims 1, 2, 3, 4, 5 and 6 wherein said pleats are side pleats.

References Cited UNITED STATES PATENTS 10 FOREIGN PATENTS 13,955 1852 Great Britain. 838,819 5/1952 Germany.

JULIA E. COINER, Primary Examiner.

US. Cl. X.R.

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