Method of manufacture of expandable and collapsible single-panel shades of fabric

Single-panel pleated shades are created through an adaptation of methods used to create cellular shades. The cellular shades are created by known methods, and are then cut longitudinally to divide them into two single-panel pleated shades. Advantages of the invention include its enhanced appearance and low cost.

FIELD OF THE INVENTION 
This invention relates to a method of manufacture of an improved pleated 
window shade. Specifically, the invention relates to a method of 
manufacture of an expandable and collapsible material for a single-panel 
pleated window shade, by cutting in half a cellular window shade 
consisting of a number of horizontally-extending cells formed of fabric 
strips adhesively bonded to one another. 
BACKGROUND OF THE INVENTION 
Several processes are known for manufacturing window shades of folded 
material. Two basic varieties of these shades of relevance here are as 
follows. A first, pleated type consists of a single panel of corrugated 
material. The other is a more complex cellular type, where stacked folded 
strips form a series of collapsible cells. This latter type is known to 
have favorable thermal insulation properties, because of the static air 
mass which is trapped between the layers of material when the cells are in 
the expanded position. The single-panel type, on the other hand, is 
favored for its appearance in some cases, and is less expensive to 
manufacture. 
There is considerable difference in the method of manufacture of the 
single-panel and cellular shades. The former has heretofore been made by 
repeatedly folding the material across its width, so that it becomes 
pleated. Among the difficulties with this approach is the need to 
repeatedly make narrow parallel folds transversely across a wide sheet of 
material of continuous length. Unless highly exacting conditions are 
maintained, the folding process can fall out of alignment. Also, 
substitution of materials is cumbersome because sheets of material and not 
strips are involved. Further, single-panel shades are relatively weak, 
structurally, as compared to cellular shades. Retention of pleat shape is 
a significant problem with most single-panel shades, and is particularly 
severe where non-woven or sheer fabrics are used. Another disadvantage is 
the necessity of using multiple sheets joined at seams where large shades 
are desired. 
There are several methods for producing the cellular shades. Most similar 
to the pleated, single-panel method is the Anderson U.S. Pat No. 
4,685,986. This joins together two single-panel pleated lengths of 
material by adhesively bonding them together at opposing pleats. The 
adhesive bonding step limits the problem of pleat retention noted above 
with respect to pleated shades. Other methods depart from the Anderson 
Patent by joining together series of longitudinally folded strips, rather 
than continuous sheets of pleated material. Such methods are shown in 
Colson U.S. Pat. No. 4,450,027, and in Anderson U.S. Pat. No. 4,676,855. 
In the Colson Patent strips longitudinally folded into a U-shape are 
adhered on top of one another, whereas in the Anderson Patent these strips 
are Z-shaped and are adhered in an interlocking position. 
The strip joining method shown in the Colson patent has a number of 
desirable attributes, while providing a highly desirable thermally 
insulative shade. First, the alignment problems inherent in folding large 
sheets of material transversely to make pleated shades are largely 
avoided. Second, substitution of materials is easier because strips and 
not sheets of material are involved. Third, structural strength is 
increased, which gives greater pleat retention and allows for more 
lightweight materials to be used. Fourth, larger shades can be made 
without the need for seams. Finally, the speed of production of such 
cellular shades is at least as fast as that of single-panel pleated shades 
made by usual methods. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the invention to provide a method of 
manufacture of "pleated-look" shades of greater strength, and in 
particular, greater resistance to flattening of the pleats, than 
heretofore achieved by simply pleating a sheet of material. 
It is a further object of the invention to provide such a method which is 
useful with a wide range of materials, including non-woven and sheer 
materials. 
It is a further object of the invention to provide such a method whereby 
large shades may be produced without seams. 
It is a further object of the invention to provide such a method with rapid 
production speed and versatile material substitution. 
According to the invention a cellular shade structure, particularly as 
disclosed in the Colson patent discussed above, is created by the methods 
taught therein. Specifically, an initial creaser assembly is used in which 
a pair of spaced-apart sharp wheels are pressed into a strip of material 
to form uniform creases extending longitudinally along the strip. A 
folding assembly then folds the lateral edges at the creases, over the 
center portion of the strip, and a press assembly mechanically sets the 
folds. 
Generally, the process is carried out as follows. A drive assembly pulls 
the material through the folding assembly, and a positive displacement 
pump feeds a liquid adhesive through an applicator onto the surface of the 
folded material. The pump is driven from the material drive assembly so 
that the rate of deposition of the adhesive material on the film is always 
in direct relation to the rate at which the film moves through the 
apparatus. Successive lengths of material are stacked in uniform layers on 
a rotatable stacking bed with flat surfaces where they are adhered 
together to form the panel structures. 
A cutting blade is used to divide the shades lengthwise creating two 
single-panel shades of equal proportions. Because the cellular method of 
manufacture is as fast as the traditional pleated shade method, the 
present invention is nearly twice as fast in producing single-panel 
shades, while the adhesively bonded strips exhibit excellent pleat 
retention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As indicated above, single-panel "pleated-look" shades are produced 
according to the invention by essentially the same methods disclosed in 
the Colson U.S. Pat. No. 4,450,027, with the additional step of cutting 
the cellular shade obtained thereby into two essentially identical panels. 
FIGS. 1 through 4 illustrate steps used in the basic method for 
manufacturing cellular shades. A continuous strip of shade material 10 is 
drawn through a series of steps which result in its edges 12 being folded 
over the central portion 13, so that they approach each other closely near 
the middle of the strip. As FIG. 1 shows, a pair of spaced-apart creaser 
wheels 14 are pressed against the shade material 10 as it is drawn around 
a roller 16. The creaser wheels are mounted on an axle 17 which is itself 
mounted on a pivotal arm assembly 18, and are kept pressed against the 
shade material by a spring 19 which exerts force against the arm assembly. 
The initial creasing prepares the shade material for the folding process 
shown in FIGS. 2 and 3. After creasing, the material 10 is drawn through 
rollers 20, 21 which are used to bend the edges 12 of the shade material 
inwardly, as shown in FIG. 2. The edges 12 are then folded in, over the 
central portion 13 of the shade material 10, by being drawn through a 
folding die 22, as shown in FIG. 3. 
Once folded, adhesive material 30 is applied to the shade material, as 
shown in FIGS. 4 and 5, to bond layers of the shade material together. 
Generally, as the shade material 10 is drawn around a roller 32, adhesive 
material 30 is dispensed from an applicator 34 onto the shade material 10. 
Motor-driven belts 36 may be used to drive the roller 32 to assist in 
drawing the shade material 10. Preferably, the adhesive 30 is dispensed at 
a rate proportional to the speed at which the shade material 10 is drawn 
past, so that a like amount of adhesive 30 is applied regardless of the 
manufacturing rate. 
FIGS. 4 and 5 show two preferred modes of adhesive application which result 
in two different embodiments of the invention shown in FIGS. 9 and 10, 
respectively. In the FIG. 4 embodiment, two beads 30a of adhesive 30 are 
continuously dispensed one each onto the edges 12 of the shade material 
10. The strips of material 10 are then stacked as shown in the Colson 
patent, so that the strips 10 are bonded to one another. According to the 
invention, these bonded strips are subsequently cut to create two 
single-panel shades 40 of the type shown in FIG. 9. 
A second embodiment of the invention, varying from that of FIG. 4 in the 
way in which adhesive 30 is dispensed, is shown in FIG. 5. Instead of the 
two beads of adhesive, two pairs of parallel beads 30b are applied. When 
the stacked strips are subsequently cut, creating two single-panel shades, 
those shades are of the type shown in FIG. 10. 
As noted above, after the application of adhesive material, the shade 
material 10 is stacked so that the folded edge portions 12 of one strip 
are adhesively bonded to the central portion 13 of the next strip. 
According to the methods disclosed in Colson U.S. Pat. No. 4,450,027, the 
strip material is wound upon a rotating elongated mandrel. The stacked 
assembly of strips thus curves around the ends of the mandrel. When the 
assembly is complete, the curved ends of the assembly are cut off, leaving 
two shade panels on either side of the mandrel. 
The present invention adds the additional step of cutting he stacked 
material longitudinally down its central portion 13, between the folded 
side portions 12, yielding two pleated panels 40. See FIG. 6. The 
preferred method of cutting the cellular stack 42 to obtain two panels 40 
employs a rotating, circular knife blade 44, as shown in FIG. 6. However, 
any basic cutting tool could be used, even a simple hand-held knife. These 
pleated panels are then used in the usual way to make finished shade 
products. That is, they may be joined to a top slat 50 and a bottom slat 
52, as shown in FIGS. 7 and 8, in order to give the panel 40 structural 
rigidity. Conventional cords 60, pulleys 62, and related hardware, as 
shown schematically in FIGS. 9 and 10, may be added to provide a means for 
expanding and contracting the panel 40. 
As noted above, in the FIG. 9 embodiment, one bead of adhesive 30a is used 
to bond each strip to the next. Typically, holes 64 are drilled so that 
the cords 60 for expanding and contracting the shade 40 are visible from 
the side of the shade meant to face into a room, as shown. In the FIG. 10 
embodiment, holes 64 are drilled so that the cords 60 are typically 
disposed between the beads of adhesive 30b provided. In this embodiment, 
the cords 60 for expanding and contracting the shade 40 are not visible 
from the side of the shade meant to face into a room. 
Two other embodiments representing variations on the manner of adhesive 
bonding are shown in FIGS. 11 and 12. Both of these use two beads of 
adhesive dispensed onto the strip of shade material, as in the FIG. 9 
embodiment. In the FIG. 11 embodiment, however, the holes 64 for the cords 
60 are drilled behind the adhesive bonds 30c so that the cords 60 for 
expanding and contracting the shade 40 are not visible from the side of 
the shade meant to face into a room. According to the embodiment of FIG. 
12, the adhesive bonds 30d are relatively wide and the holes 64 for the 
cords 60 are drilled through the bonds. This also yields a product where 
the cords are not visible from the side of the shade meant to face into a 
room. 
It should also be noted that the adhesive material used, while usually 
liquid adhesive, may be of other varieties such as double-sided contact 
tape. 
Finally, while the preferred mode of the invention is to employ the 
processes disclosed in Colson U.S. Pat. No. 4,450,027, adding the cutting 
step according to the invention, and including the steps of drilling the 
assembly for cords and the like at specific locations with respect to the 
glue bond locations as needed, the invention may be used generally to 
divide cellular shades produced by other methods to yield two single-panel 
pleated shades. These other methods include all those employing different 
ways of creating cellular arrays of folded strips of material which are 
stacked and bonded to form the shade. 
While preferred embodiments of the invention have been disclosed and 
discussed in detail, they are not to be considered as limitations on the 
invention, but only exemplary thereof. Accordingly, the invention should 
not be limited by the above disclosure, but only by the following claims.