Patent Publication Number: US-6904948-B2

Title: Cellular shade material for coverings for architectural openings

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a non-provisional application which claims the benefit of U.S. provisional application Ser. No. 60/383,346, filed May 24, 2002, which application is incorporated by reference herewith in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a fabrication apparatus and method for fabricating coverings for architectural openings. More specifically, the invention relates to a fabrication apparatus and method for fabricating cellular material from fabric tape for use in roller shade coverings. 
     2. Background Description 
     Roller shades are well known in the art and typically comprise a fabric shade material that hangs down from a roller and has a foot rail attached to its bottom edge. The roller is typically contained in a head rail that is attached to a vertical surface. As desired the shade material can be rolled up onto the roller to expose the architectural opening (typically, a window) beneath it. 
     In general, the shade material must be capable of being rolled up relatively tightly onto the roller so that the roller and the retracted shade can fit into the recesses of the head rail. It is possible that larger head rails could be utilized with a roller shade utilizing thick shade material, however, the head rail would likely be obtrusive and not aesthetically pleasing. Accordingly, the material used for roller shades is almost always flat. Typically, roller shade materials will be comprised of one or two layers of fabric. When two layers are utilized, a front fabric is typically specified for its aesthetic properties and the backing fabric for its light handling characteristics or its ability to withstand ultraviolet light without fading. 
     In the recent past coverings for architectural openings that utilize a cellular shade material have become very popular. The cellular shade material provides a measure of space between the back side of the shade and the front side. Like roller shade materials the backing fabrics may be specified for their light handling characteristics while the front fabrics may be chosen for aesthetic reasons. Cellular shades offer several advantages over roller shades. First, they handle light in a more aesthetically pleasing manner than two similar front and backing materials can when they are placed directly on top of each other. Second, the cells formed from the spacing between the fabrics create a dead air space that provides desirable insulating properties. 
     Cellular shades are typically expensive to manufacture, and in some instances the lift mechanisms require lift cords that are threaded through the interior of the cells. Conversely, roller shades do not utilize lift cords and have the entire lift mechanism contained within the roller. Fabrication of a roller shade typically comprises cutting the shade material to size, attaching a roller and foot rail to the material and attaching the roller to a head rail. 
     BRIEF SUMMARY OF THE INVENTION 
     An apparatus and method for fabricating a cellular roller shade material are described. 
     In a first embodiment, an apparatus for fabricating the cellular roller shade material includes one or more adhesive applicators that are configured to apply continuous adhesive beads to a fabric tape that is at least partially folded over onto itself along a longitudinal fold line. The one or more applicators are arranged such that the one adhesive bead is laterally spaced from the other adhesive bead. The apparatus further includes an elongated tubular surface on which the fabric tape is continuously wrapped in an overlapping arrangement perpendicularly to the longitudinal length of the surface. One or more drive motors are also provided for rotating the tubular surface at one speed while moving the tubular surface longitudinally at another speed, wherein the two speeds are proportional to each other in a predetermined ratio. 
     Variations of the first embodiment also include a roller biased against the tubular surface for compacting the fabric tape against the tubular surface and the section of fabric tape it overlaps. Another variation includes a folding guide for folding the fabric tape along the longitudinal fold line. In yet another variation, one or more spindles are provided on which roll(s) of fabric tape are placed. One variation includes another adhesive applicator and a pressure applicator, wherein two fabric tapes are joined together by an adhesive bead applied to one tape by the other adhesive applicator that is pressed against the other tape by the pressure applicator. When more than one fabric tape is utilized to make a single wider tape, one or more tensioning mechanisms may be provided to ensure that the tension levels between the constituent tapes are the same. 
     In another embodiment, an apparatus for fabricating the cellular roller shade material includes a mechanism for folding a fabric tape along a longitudinal fold line, a mechanism for positioning the folded tape onto another section of folded tape in a partially overlapping arrangement and a mechanism for joining the overlapping tapes together along two longitudinal seams. In variations of this embodiment, a supply mechanism and a second joining mechanism are provided to supply and join two constituent fabric tapes to form the fabric tape utilized by the folding and positioning mechanisms. 
     In another embodiment, a method for fabricating the cellular shade is described. First, a fabric tape is folded along a longitudinal fold line to form top and bottom sides. The folded tape is then positioned over another section of folded tape in an overlapping relationship and the two tapes are joined together. Typically, the top and bottom sides of one section of tape proximate the free longitudinal edges of the sides are both joined to either the top or bottom side of the other folded fabric tape section. In variations of the fabrication method, two constituent fabric tapes are joined together to create the fabric tape used in the above-described operations. 
     In yet another embodiment, a cellular shade material is described. The material comprises two or more adjacent, parallel longitudinally-extending folded fabric tapes. Each tape has a front side and a back side that are connected along a longitudinal fold line. Each side also terminates at a longitudinally-extending edge and has inside and outside surfaces. The back side of each tape has a lateral length that is greater than the lateral length of the front side. The inside surface of the backside of one fabric tape is joined to the outside surface of the backside of another adjacent tape along a longitudinally-extending seam that is located proximate the longitudinally-extending edge of the backside of the one fabric tape. Additionally, the outside surface of the front side of the one fabric tape is joined to the outside surface of the backside of the other fabric tape along another longitudinally extending seam that is located proximate the longitudinally-extending fold line of the other tape. In variations of the cellular shade material the seams include thermoplastic or thermosetting adhesives. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of the cellular roller shade material installed with a head rail roller attached to its top end and a foot rail attached to its bottom end. 
         FIG. 1   a  is a fragmentary side elevation of the cellular roller shade material shown in FIG.  1 . 
         FIG. 1   b  is an enlarged fragmentary section of a portion of the cellular shade material shown in  FIG. 1   a.    
         FIG. 1   c  is a fragmentary side elevation similar to  FIG. 1   a  with the cells of the shade material partially closed. 
         FIG. 1   d  is a fragmentary side elevation similar to  FIGS. 1   a  and  1   c  wherein the cells of the shade material are fully closed. 
         FIG. 1   e  is a side elevation of a front panel of a cell used in the shade material of FIG.  1 . 
         FIG. 1   f  is a side elevation of the rear panel of a cell used in the shade material of FIG.  1 . 
         FIG. 1   g  is a fragmentary side elevation of a second embodiment of the cellular material of the present invention with the cells in a partially closed condition. 
         FIG. 1   h  is a side elevation of a panel of material used to form the cell of the embodiment of  FIG. 1   g.    
         FIG. 2  is an isometric view of the cellular shade material rolled up onto a head rail roller. 
         FIG. 3  is an end view of the cellular shade material wound around a head rail roller taken along line  3 — 3  of FIG.  2 . 
         FIG. 4  is an isometric view of the cellular roller shade material fabrication apparatus. 
         FIG. 5  is a top view of the fabrication apparatus. 
         FIG. 6  is a partial isometric of the fabrication apparatus illustrating the supply and folding sections. 
         FIG. 7  is a top view of the supply section taken along line  7 — 7  of FIG.  4 . 
         FIG. 8  is a side view of the supply section taken along line  8 — 8  of FIG.  5 . 
         FIG. 9  is a side view of the supply section taken along line  9 — 9  of FIG.  5 . 
         FIG. 10  is a top view of a portion of the supply section taken along line  10 — 10  of FIG.  8 . 
         FIG. 11  is a cross sectional view of the adhesive applicator and the associated fabric tape as taken along line  11 — 11  of  FIG. 7   
         FIG. 12  is a cross sectional view of the fabric tapes passing through the nip rollers as taken along line  12 — 12  of FIG.  7 . 
         FIG. 13  is across sectional view of the second adhesive applicator as taken along line  13 — 13  of FIG.  16 . 
         FIG. 14  is a top view of the supply section similar to  FIG. 7 , wherein only a single roll of “doublewide” fabric tape is utilized in place of two rolls of fabric tape. 
         FIG. 15  is a side view of the supply section similar to  FIG. 8  except set up for a single roll of “doublewide” fabric tape. 
         FIG. 16  is a side view of the folding section of the fabrication apparatus as taken along line  16 — 16  of FIG.  5 . 
         FIG. 17  is a side view of one variation of the folding section taken along line  16 — 16  of FIG.  5 . 
         FIG. 18  is a cross sectional view of the joined fabric tape as taken along line  18 — 18  of FIG.  16 . 
         FIGS. 19A-E  are cross sectional views of the folding horn taken along lines A-E of FIG.  16 . 
         FIG. 20  is a backside view of the folding section as taken along lines  20 — 20  of FIG.  5 . 
         FIG. 21  is a similar view as  FIG. 20  with the idler wheels in their retracted positions. 
         FIG. 22  is a cross sectional view of the folded fabric tape as viewed along line  22 — 22  of FIG.  16 . 
         FIG. 23  is a cross sectional view of the folded tape with longitudinal adhesive beads applied as viewed along line  23 — 23  of FIG.  16 . 
         FIG. 24  is a cross sectional view of the folded tape illustrating one section overlapping another section as the folded tape is applied to the rotating drum. 
         FIG. 25  is a partial cross sectional view taken along line  25 — 25  of  FIG. 26  illustrating the contact between a roller and the surface of the tape on the rotating drum. 
         FIG. 26  is a view of the rollers of the pressurized roller assembly biased against the laid down tape as viewed along line  26 — 26  of FIG.  16 . 
         FIG. 27  is a cross sectional view of the small roller of the pressurized roller assembly in contact with the folded fabric tape on the drum as viewed along line  27 — 27  of FIG.  26 . 
         FIG. 28  is a cross sectional view of the drum taken along line  28 — 28  of FIG.  4 . 
         FIG. 29  is an end view of the drum taken along line  29 — 29  of FIG.  4 . 
         FIG. 30  is a flow diagram of a controller algorithm of the preferred embodiment. 
         FIG. 31  is an isometric view of the first alternative embodiment fabrication apparatus. 
         FIG. 32  is a top view of the first alternative embodiment fabrication apparatus. 
         FIG. 33  is a partial isometric of the first alternative embodiment fabrication apparatus primarily illustrating the supply and folding sections. 
         FIG. 34  is a side view of the folding section of the first alternative fabrication apparatus as viewed along line  34 — 34  of FIG.  32 . 
         FIG. 35  is a cross sectional view of the conveyor belt assembly taken along line  35 — 35  of FIG.  32 . 
         FIG. 36  is a side view of the conveyor belt assembly taken along line  36 — 36  of FIG.  32 . 
         FIG. 37  is a partial cross sectional view of the conveyor belt assembly and the pressurized roller assembly as taken along line  37 — 37  of FIG.  32 . 
         FIG. 38  is an isometric view of the second embodiment fabrication apparatus. 
         FIG. 39  is a top view of the second embodiment fabrication apparatus. 
         FIG. 40  is a side view of the second embodiment fabrication apparatus. 
         FIG. 41  is a side view of the folding horn and the adhesive applicator for the second embodiment fabrication apparatus as viewed along line  41 — 41  of FIG.  39 . 
         FIG. 42  is an end view of the adhesive applicator for the second embodiment fabrication apparatus as viewed along line  42 — 42  of FIG.  39 . 
         FIG. 43  is a cross sectional view of the folded tape from the second alternative embodiment illustrating one section overlapping another section as the folded tape is applied to the rotating drum. 
         FIG. 44  is a cross section of a folded tape with the adhesive beads applied to bottom surfaces proximate the open edges of the tape. 
         FIG. 45  is a cross sectional view of the folded tape of  FIG. 44  illustrating one section overlapping another section as the folded tape is applied to the rotating drum or a conveyor belt. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An apparatus and method for fabricating cellular fabric from fabric tape for use in roller shade coverings is described. As used herein fabric tape refers to both woven and non-woven fibrous fabrics as well as films. In a preferred embodiment, the fabrication apparatus adhesively joins two fabric tapes as supplied from separate rolls of tape together along overlapping longitudinal edges. Next, the resulting joined tape is folded longitudinally along a line offset a relatively small distance from the adhesive seam and the longitudinal centerline of the joined tape. Additional adhesive is then applied to the bottom side of the folded combined tape along two longitudinal lines. Finally, the bottom side of the folded tape is laid against a drum or a conveyor belt that is rotating or moving in a direction generally parallel with the longitudinal orientation of the folded tape. As the folded tape is being placed, the two adhesive beads are brought into contact with the top sides of a previously laid section of the tape proximate the open edges of the previously laid tape section, thereby longitudinally joining the tape with the previously laid section. The tape is continuously wrapped onto the drum or conveyor belt to produce a tube of cellular roller shade fabric comprised of the spiraling folded tape. Once a tube of sufficient length is created or the drum is substantially covered, the fabrication apparatus is stopped and the cellular shade material is cut transversely to the longitudinal orientation of the folded tape to create a flat sheet of cellular shade material. 
     After fabrication, the cellular shade material  12  is then trimmed to the desired size and one end of the shade material is secured to a head rail roller  14 , while the opposite end is secured to a weighted foot rail  16  as is shown in  FIGS. 1-3 . To complete the roller blind assembly, the head rail roller is secured into a head rail (not shown). The head rail typically includes a means for mounting the shade onto a vertical surface and a retraction mechanism that interfaces with the roller for lowering or raising the roller shade material. 
     As illustrated in  FIGS. 1-1   f , the shade material  12  is primarily comprised of a plurality of horizontally extending cells  18  with rectangular cross sections that are joined to other cells  18  along a partial top side  19  and a bottom side  20 . In one preferred embodiment of the roller shade material, the front side  22  of each cell comprises a decorative fabric as supplied by one of the two aforementioned rolls of fabric tape, and the back side  24  comprises another fabric (typically non-woven light diffusing fabric) supplied by the other roll of fabric tape. 
     The cellular shade material  12  provides several advantages when compared to single layer fabric shade material typically utilized in roller shade coverings. For instance, the dead air contained within the cells  18  provides a barrier to heat transfer, resulting in a roller shade covering with better insulating properties. Additionally, the light transmitted through a cellular shade can be better controlled to provide the desired effect. For example, the rear side  24  could comprise a fabric specified for the sole purpose of diffusing or blocking light, while the front side  22  could comprise a aesthetically pleasing fabric that if utilized in a single layer shade would not provide the desired light handling characteristics. 
     As illustrated in  FIGS. 2-3 , as the roller shade covering  12  is retracted and wound onto the roller  14 , the cells  18  collapse wrapping compactly around the roller. Accordingly, the need for an enlarged head rail that is potentially aesthetically displeasing to contain the shade material  12  when retracted is obviated. 
     A Preferred Embodiment 
     A first embodiment of a fabrication apparatus for producing roller shade material  12  is illustrated in  FIGS. 4-12  and  14 - 16 . The fabrication apparatus includes a fabric tape supply section (supply section)  100 , wherein fabric tapes  104  are unwound from rolls  102  and the tape is orientated for a subsequent folding operation. One or two rolls  102  of tape can be utilized. As shown in  FIGS. 4 and 5 , two fabric tapes  104  are unwound from separate rolls  102  and adhesively joined together for subsequent operations. One tape  104 A forms primarily the front side  22  of the cells  18  of the resulting cellular shade material  12  and the other tape  104 B forms primarily the back side  24  of the cells. The supply section  100  can also be configured with a single tape  104 , wherein the tape forms both the front and back sides of the cells. The configuration and operation of the supply section is discussed in detail below. 
     After exiting the supply section, the joined tape  106  is passed into the folding and adhesive application section (folding section)  200  of the fabrication apparatus. In FIGS.  4  and  5  the inner workings of the folding section are hidden behind a pair of access doors  202 .  FIG. 6  illustrates the inner working of the folding section  200 , which will be described in detail below. Briefly, the joined tape  106  is folded along a longitudinal fold line that is offset from the longitudinal center axis of the joined tape. Next, parallel longitudinal lines of adhesive are applied to the overhanging portion of the folded tape  106 . 
     The adhesive-laden folded tape  106  is then passed to the bonding section  300  to be longitudinally joined via the parallel adhesive lines to a section of the continuous folded tape that has been previously circumferentially wrapped around a rotating drum  302 . As shown, the drum  302  also moves in its longitudinal direction at a specified rate of speed so that the amount of overlap between adjacent circumferentially wrapped folded tape sections is precisely controlled to create uniform cells  18  in the resulting cellular shade material  12 . The configuration and operation of the bonding section  300  is described in detail below. 
     The various sections comprise a variety of servo motors and sensors that are controlled and utilized by a computerized controller  400 . The controller helps ensure the tape is maintained at a constant tension as it passes through the fabrication apparatus and is deposited on the drum in a manner that results in a cellular shade material  12  comprised of uniformly-sized cells  18 . 
     Once the folded tape  106  is circumferentially wrapped around substantially the entire surface of the drum  302 , the fabrication apparatus is stopped. The cellular shade material  12  is then cut along the entire length of the drum  302  along a cut line that is substantially perpendicular to the longitudinal axis of the wrapped folded tape. It can be appreciated that the longitudinal axis of the tape will be canted slightly relative to the circumferential direction of the drum. Accordingly, the cut line will be slightly acute (approximately 1 degree in a preferred embodiment) relative to the longitudinal axis of the drum. The rectangular cellular shade material is then stacked on a layout table  500  pending subsequent operations to cut the material to size, affix a head rail roller  14  and a foot rail  26  to the material  12  and assemble it into a complete roller shade covering. 
     The Supply Section 
     The fabric tape supply section  100  configured for two rolls of fabric tape  104  is illustrated in  FIGS. 6-12 , and a supply section configured for one roll of fabric tape is illustrated in  FIGS. 14-15 . The supply section typically includes (i) similar first and second fabric tape supply assemblies  108 A and B; (ii) an adhesive applicator  110 ; and (iii) a nip roller assembly  112 . 
     Referring to  FIGS. 6-12 , each fabric tape supply assembly  108  includes a turntable  114  with a center locking spindle  116  over which the hollow center of a roll  102  of fabric tape is fixedly secured. The turntable also comprises a collar  118  (best seen in  FIG. 8 ) that is set to a vertically-orientated axle  120  that passes through the center of the turntable. By loosening the collar  118 , the turntable can be moved vertically to adjust its positioning on the axle  120 . At its bottom end, the axle  120  is coupled with an electric servo motor  122 A or B, wherein the servo motor is adapted for turning the turntable  114 . The servo motor is electrically coupled to the controller  400 , which controls the operating speed of the motor. An ultrasonic sensor  124  is attached to the framework of the supply section  100  pointed towards the center of the turntable. The sensor  124  measures the distance between the sensor and the surface of the roll  102  of fabric tape contained on the turntable. This information is utilized by the controller to calculate the diameter and circumference of the roll for reasons that will become apparent in the controller section. The sensor  124  also determines through the controller when the roll  102  of tape is nearly exhausted so that the fabrication apparatus can be shut down to change the roll of fabric tape. 
     As the fabric tape  104  is unwound from the roll  102 , it is pulled around a tape tensioning mechanism  126  comprising three spindles  128 ,  130  and  132 . Each spindle is typically fabricated from a low friction material such as polyethylene, Derlin or Teflon. Each spindle has upper and lower flanges that both help to retain the tape  104  on the spindle and position the tape at a correct vertical height. Each spindle is rotatably secured to a steel shaft  134  by way of a pair of collars  136  that are attached to bearing assemblies (not shown). The bearing assemblies are configured to provide a measure of rotational friction, whereby the spindle does not spin freely about its associated steel shaft (for example, by packing the bearings with a high viscosity grease). The fabrication apparatus has been found to operate better when the spindles do not turn in unison with the fabric tapes passing around them. Ideally, the rotational speed of the surface of the spindles as the tape passes over it is 10% slower than the linear speed of the tape. In other words, the tape both slips on the surface of the spindles, as well as, causing the spindles to rotate. The collars  136  permit the spindles to be adjusted up and down to vertically position the tape passing around it. 
     The steel shafts  134  associated with the first and third spindles  128  and  132  of each of the fabric tape supply assemblies  108 A and  108 B is immovably fixed to the framework of the supply section  100  and are either horizontal or vertically aligned with each other (as viewed in FIG.  7 ). The steel shaft associated with the second spindle  130  is coupled with a linear slide table  138  permitting a measure of movement in a direction substantially perpendicular to the direction of alignment of the associated first and third spindles  128  and  132 . The second spindle is also typically centered between in the first and third spindles in the alignment direction. 
     Referring primarily to  FIG. 10 , the moveable portion  140  of the linear slide table  138  is connected to the shaft of a pneumatic cylinder  142  at one end and a linear position transducer  144  at the opposite end. The pneumatic cylinder, which is coupled with a pressurized air source through a regulator (neither shown), biases the second spindle  130  away from the first and third spindles  128  and  132 , thereby tensioning the tape  104  passing around it. The linear position transducer  144  measures the position of the second spindle in the slide table  138  and sends this information to the controller  400 . The controller uses this information to adjust the speed of the turntable servo motor  122 A or B as necessary to maintain the spindle  130  near the middle of the table  138  as is discussed in greater detail in the controller section below. 
     Referring to  FIGS. 6 and 7 , from the third spindle  134 , the tape  104  is pulled through a pair of nip rollers  146  and  147  of the nip roller assembly  112 . The nip rollers comprise two vertically orientated elongated cylinders that are covered in a resilient material such as rubber or silicone. Each nip roller is mounted to a steel shaft  148  or  149 . The steel shaft  148  of the left roller is rotatably mounted to the framework of the supply section through a pair of bearing assemblies. The steel shaft  149  of the right nip roller is rotatably mounted proximate its ends to a pair of arms  150  by way of two bearing assemblies  151  (as best seen in FIG.  9 ). The other end of the arms are connected to a shaft  152  which is pivotally fixed to the framework by one or more bearing assemblies. As best seen in  FIGS. 9 and 10 , a pivot arm  154  is affixed to and extends from the shaft  152 . The other end of the pivot arm is pivotally attached to the shaft of a pneumatic cylinder  156  by way of a clevis  158 . The opposite end of the pneumatic cylinder  156  is pivotally attached to the framework. Operationally, the surface of the second nip roller  147  can be moved against the surface of the first nip roller  146  to apply pressure therebetween. Alternatively, the second roller may be moved away from the first to facilitate the threading of the fabric tapes  104 A and B therebetween during fabrication apparatus setup. 
     In one variation of the preferred embodiment of the fabrication apparatus, both fabric tape supply assemblies  108  are threaded with fabric tape  104 A and B. Typically, the tape from one assembly forms the back side of the cells of the resulting roller shade material and the tape from the other assembly forms the front side of the cells. It can be appreciated that a more expensive and more aesthetically pleasing tape may often be used for the front side and a less expensive material such as a light diffusing non-woven mat may be used for the back side. 
     As mentioned above, the two tapes  104 A and B are adhesively joined to form a single joined tape  106  that is almost twice as wide as the constituent tapes  104 A and B. An adhesive applicator  110  is provided between the third spindle  132  of the fabric tape supply assembly associated with the fabric tape  104 B that forms the back side of the cells and the nip roller assembly  112  in the path of the fabric tape  104 B. As shown in  FIGS. 7 and 11 , a longitudinal bead  160  of thermoplastic (or hotmelt) adhesive is applied to the rightward facing side of the tape  104 B proximate its bottom edge as the tape passes by the adhesive applicator  110 . 
     Referring to  FIG. 12 , the tapes  104 A and  104 B from both tape supply assemblies  108  converge at the nip rollers  148  and  149  with the leftwardly facing side of one tape  104 A proximate its top edge overlapping the rightwardly facing side of the other tape  104 B at the adhesive bead  160 . Typical overlap is about 0.125″ and is set by adjusting the vertical heights of the turntable  114  and spindles  128 - 32  of each tape supply assembly  108  so that the tape  104 B that forms the rear side  24  of the cells  18  is disposed vertically above the tape  104 A that forms the front sides  22  except for the overlapping portions. As the tapes  104 A and B are pulled through the nip rollers, the resilient roller coverings are deformed around the overlapping portion of the tapes, thereby applying pressure to the bondline. The adhesive bead  160  is pressed against and into both tapes joining them together as the adhesive cools and re-solidifies. The resulting joined tape  106 , which has a width that is slightly less than twice the width of either of its constituent tapes  104 A and B, is pulled from the rollers into the folding section  200 . 
     Referring to  FIGS. 14 and 15 , the supply section  100  can also be set up with a single roll of “doublewide” fabric tape  104  for fabricating roller shade cellular material  12  in which the front and back sides  22  and  24  of the cells  18  are comprised of the same material as illustrated in  FIGS. 1   g  and  1   h . As shown in  FIG. 14 , the single roll of tape  104  is secured to a turntable  114  of one of the tape supply assemblies  108  and the tape is threaded around the associated first, second and third spindles  128 - 32  and passed through the nip roller assembly  112 . The other tape supply assembly and the adhesive applicator  110  are not utilized with this configuration. 
     The Folding Section 
     The folding section, wherein the joined tape  106  or “doublewide” tape  104  is folded longitudinally and twin adhesive lines are applied to one side of the folded tape, is illustrated in FIGS.  6  and  16 - 21 . Referring primarily to  FIG. 16 , after exiting the nip rollers  148  and  149 , the joined tape  106  (as shown in  FIG. 18 ) is pulled through a folding horn  204 . As the tape  106  is pulled through the horn  204 , it is folded along a longitudinal line parallel to but offset a short distance from the longitudinal center axis of the joined tape. Additionally, the orientation of the tape is changed from vertical to horizontal. 
     As best illustrated in  FIGS. 19A-E , the horn  204  comprises a pair of substantially parallel plates  206  and  208  joined at their ends by top and bottom sides  210  and  212  respectively that form a slot  214  through which the joined tape  106  passes. As shown in  FIG. 19A , a cross section of the horn  204  at its left end, the slot  214  is initially straight and substantially vertically orientated. The width of the slot is at least slightly greater than the thickness of the adhesively-joined overlapping section of the joined tape  106 . The vertical height of the slot is slightly longer than the width of the combined tape such that the proper positioning of the tape is ensured when it enters the horn.  FIGS. 19B-E  illustrate the cross sections of the horn as it extends from the left to the right. As can be seen, the plates  206  and  208  forming the left and right sides of the slot begin to bend over onto themselves about a fold line that is located above the central longitudinal axis of the tape. Finally, near the right end of the horn the inside plate  208  of the slot terminates and the sides of the remaining outside plate  206  close in upon themselves to create a folded fabric tape  106  as shown in FIG.  19 E. It is of importance to note that the bottom side  216  of the folded tape overhangs the upper side  218  by an amount substantially equal to the distance the longitudinal fold line is offset from the central longitudinal axis of the tape. A cross sectional view of the folded tape  106  is illustrated in FIG.  22 . 
     From the right edge of the horn, the folded tape  106  is pulled to the right by a pair of drive wheels  220  that flank a second adhesive applicator  222 . The drive wheels  220  are cylindrically shaped and have a recessed portion on their surface (as shown in FIG.  6 ), wherein the width of the recessed portion is slightly greater than the folded width of the tape  106 . Accordingly, the drive wheels help ensure proper front to rear alignment of the tape as it passes over the adhesive applicator  222 . The drive wheels are each attached to a drive shaft  224  through a center passage. The drive shafts  224  are each coupled with a servo motor (as shown in FIG.  20 ). Like the servo motors in the supply section  100 , these servo motors  226  are coupled with the controller  400 , which controls their operational speed. 
     Referring back to  FIG. 16 , an idler wheel  228  is disposed vertically beneath each of the two drive wheels  220 . Each idler wheel is cylindrically shaped (as shown in  FIG. 6 ) having a longitudinal length similar to the length of the recessed portion of the associated drive wheel, wherein each idler wheel nests in the recessed portion of the associated drive wheel helping to ensure the proper front to rear positioning of the folded tape  106  as it passes between each drive wheel and the associated idler wheel. 
     Referring primarily to  FIGS. 16 ,  20  and  21 , each idler wheel  228  is connected with a pneumatic cylinder  230  through several lever arms and associated pivotal connections for moving the wheels  228  between a nested position and a retracted position, wherein the tape can be threaded between the drive and idler wheels. Both idler wheels  228 A and  228 B are rotatably connected to one end of a generally horizontal lever arm  232  through a first axle member  234 . The opposite end of each horizontal lever arm is fixedly secured to a second axle member  236 . Each second axle member  236  passes through a bore in the vertically orientated framework of the folding section  200  that permits pivotal movement of the second axle therein. On the other side of the framework, each axle  236  is fixedly secured to one end of a generally vertical lever arm  238 . The other end of each vertical lever arm  238  is pivotally attached to the end of a shaft of a pneumatic cylinder  230 . The other end of each pneumatic cylinder is pivotally attached to the folding section framework. When either pneumatic cylinder is in its retracted position, the associated idler wheel  228 A or  228 B is in its normal position partially received in the recess of the drive wheel  220 . When cylinder  230  is activated as shown in  FIG. 21 , the horizontal and vertical lever arms  232  and  238  pivot about the second axle member  236 , thereby lowering the idler wheel  228 A  228 B away from the drive wheel  220 . 
     Referring back to  FIG. 16 , the second adhesive applicator  222  is located between the two drive wheels  220  in the folding section  200 . The adhesive applicator is coupled to the vertical framework of the folding section by way of a vertical adjustment mechanism  248 , wherein the vertical position of the adhesive applicator&#39;s nozzles can be moved up and down by turning an adjustment knob  250  on the vertical adjustment mechanism. The second adhesive applicator  222  includes two spaced nozzles  252  positioned underneath and in contact with the bottom side  216  of the folded tape  106  as best seen in FIG.  13 . The nozzles each apply a longitudinally orientated hotmelt adhesive bead  254  and  256  respectively to the folded tape. One adhesive bead  254  is located on the back side of the tape proximate the fold line, and the second adhesive bead  256  is spaced a short distance from the other. A cross sectional view of the tape  106  with the longitudinal adhesive beads applied to it is illustrated in FIG.  23 . It is to be appreciated that the portion of the folded tape located between the longitudinal adhesive beads substantially forms the top or bottom side  20  of one cell  18  and the other of the top or bottom side of an adjacent cell  18 . 
     Referring back to  FIG. 16 , a backing plate  258  is provided above the adhesive nozzles  252  against which the top side  218  of the folded tape  106  is positioned as it is pulled towards the bonding section  300 . The plate  258  supports the tape as the adhesive beads  254  and  256  are applied to it to help ensure that the beads are longitudinally continuous. In a preferred embodiment, the backing plate  258  has a downwardly facing convex arcuate surface, wherein the lowest portion of the surface is located vertically below the vertical most portion of the idler wheels  228 A and B over which the folded tape passed. Accordingly, the folded tape  106  is biased upwardly against the backing plate. 
     Referring to  FIG. 16 , after the adhesive beads are applied to the folded tape, the tape is pulled to the right by both the second drive wheel and the rotating drum  302 . It is to be appreciated that in certain embodiments the surface of the second idler wheel  228 B may include recesses proximate the location of the adhesive beads  254  and  256  to ensure that the beads are not compacted against the second idler wheel as it passes over the second idler wheel. From the second drive wheel  220 , the tape is pulled into the bonding section. 
       FIG. 17  illustrates a variation of the folding section  200 . As illustrated, the pneumatic cylinders  230  and lever arms  232 ,  238 ,  240  and  246  used with the idler wheels  228 A and B to move the idler wheels away from the drive wheels  220  have been replaced with linear adjustment mechanisms  260  similar to the one described above with reference to the second adhesive applicator. By turning the knobs  262  on the vertical adjustment mechanisms, the idler wheels can be lowered away from the drive wheels  220 . It is to be appreciated that the time necessary to move the idler wheels using the vertical adjustment mechanism is much greater than using a pneumatically controlled mechanism as illustrated in  FIG. 16 ; accordingly, the pneumatic mechanism is typically preferred for production environments. 
     The nozzles of the adhesive applicator in the  FIG. 17  variation are offset to the right of the backing plate  258 , wherein the folded tape  106  is not backed by the plate at the location of the nozzles  252 . The tension of the folded tape in the vicinity of the nozzles  252  is enhanced by the use of the backing plate  258  which is sufficient to maintain good contact between the bottom side  212  of the tape and the nozzles. It is to be appreciated that many variations in the manner in which the fabric tape is folded and the manner in which longitudinal adhesive beads are applied to the tape are contemplated, and that the illustrated embodiments are therefore merely exemplary. 
     The Bonding Section 
     The bonding section as shown in  FIG. 4  comprises (1) the rotating drum  302  for receiving the folded tape  106 ; (2) a screw drive mechanism  304  for propelling the drum in its longitudinal direction at a prescribed rate; (3) a tensioning mechanism  306  for maintaining the tension of the folded tape as it is wrapped onto the drum; and (4) a pressurized roller assembly  308  for compacting the longitudinal adhesive beads  254  and  256  on the folded tape against a section of the continuous tape that was laid on the drum in the previous rotation. The bonding section is best illustrated in  FIGS. 4-6 ,  16 ,  17  and  FIGS. 24-29 . 
     Referring primarily to  FIG. 16 , after exiting the folding section, the folded tape  106  with the parallel adhesive beads  254  and  256  deposited thereon is pulled both downwardly and to the right under and against a roller  310  of the tensioning mechanism  306  and then upwardly and to the right from the roller onto the surface of the drum  302 . The roller  310  is rotateably coupled to a vertically orientated slide table  314  by way of an axle and bearing assemblies. The slide table  314  is mounted to a downwardly extending framework beam  318 . A shaft  320  of a pneumatic cylinder  322  located on the beam above the slide table  314  is coupled to the moveable portion of the slide table, whereby pressurizing the pneumatic cylinder  322  biases the shaft  320  downwardly, encouraging the bottom of the roller  310  against the folded tape  106 . A linear position transducer  324  is also attached to the moveable portion of the slide table for determining the linear position of the roller. The linear transducer is electrically coupled to the controller  400 , which uses the positioning information to adjust the speed of the servo motors connected with the drive wheels  220  of the folding section  200  to maintain a uniform tape speed through all sections of the fabrication apparatus. The operation of the controller is discussed in greater detail in the controller section below. 
     From the tensioning roller  310  the rotation of the drum  302  pulls the tape  106  onto its surface. The drum also moves linearly in a direction along its longitudinal axis, i.e., in the direction perpendicular to its direction of rotation, at a speed that is both synchronized with and proportional to the rotational speed. As the tape is wrapped onto the drum, the portion of the tape with the longitudinal adhesive beads applied to it overlaps and is laid on top of a portion of the folded tape laid on the drum in the previous rotation. The configuration of the folded tape as it is laid onto the roller overlapping the previously laid section of tape is illustrated in FIG.  24 . As shown, the adhesive bead  254 , which is closest to the folded edge, overlaps and is placed against the top side  218  of the previously laid section, whereas the other adhesive bead  256  is placed over the overhanging flap of the bottom side  216  of the previously laid tape section. 
     As the drum  302  is rotated clockwise, the adhesive beads are compacted against the overlapped tape section by way of the pressurized roller assembly  308 . In a preferred embodiment, as shown in  FIG. 16 , a two stage pressure roller assembly is specified, wherein a first roller  326  compacts both adhesive beads and a second roller  328  that compacts only the adhesive bead overlapping the flap portion of the previously laid tape section as illustrated in FIG.  25 . Both the wider first roller  326  and the thinner second roller  328  are preferably fabricated of an elastomeric material, like rubber or silicone, that conforms to the surface of the drum  302  and the fabric tapes  106  contained thereon. The first roller  326  is rotatably attached to the right end of an arm  330  extending from the moveable portion  332  of a linear slide table  334 . The other end of the moveable portion is secured to the shaft  336  of a pneumatic cylinder  338  with the cylinder&#39;s body being fixedly secured to the framework of the fabrication apparatus. In operation, the cylinder is pressurized to a specified level to bias the first roller against the overlapping portions of the tape as is shown in  FIGS. 25 and 26 . 
     It is appreciated that the adhesive bead  254  located in the thicker portion of the overlapping tapes (i.e. the bead overlapping the folded section of the previously applied tape) will have a greater amount of pressure applied to it than the other bead  256  located in the thinner portion of the overlapping section despite a degree of deformation of the elastomeric roller material. Accordingly, to help ensure the proper amount of pressure is applied to the other adhesive bead  256 , the smaller second roller  328  is utilized. The second roller is attached to the shaft  342  of a second pneumatic cylinder  342  of the pressurized roller assembly  308 . The body of the cylinder is mounted to the slide table  334 . Pressurization of the pneumatic cylinder causes the smaller second roller  328  to be pressed against the adhesive bead  256  disposed over the flap portion of the bottom side  216  of the previously laid tape as shown in  FIGS. 26 and 27 , thereby ensuring a good bond between the newly laid tape and the previously laid tape. 
     In an alternative embodiment, as specifically shown in  FIG. 17 , only a single roller  326  is in the pressure roller assembly to compact the adhesive bead against the previously laid tape. A roller made of an elastomeric material with a low durometer is utilized to ensure the roller deforms sufficiently to apply bond pressure to both adhesive beads despite the height differences between where the two adhesive beads are disposed on the overlapping portion of the previously laid tape. The configuration of the single roller pressure roller assembly is substantially the same as the dual roller assembly save for the absence of the second roller and the pneumatic cylinder associated with the second roller. 
     As described above, the folded tape  106  is continuously wrapped around the drum  302  from one longitudinal end to the other. The drum is typically a relatively large diameter cylinder that is long enough to fabricate shade material that is long enough to cover most architectural openings over which it might be utilized. The diameter is typically large enough such that the width of the shade material fabricated (as measured by the drum&#39;s circumference) is at least as wide as the widest architectural opening over which the shade material may be utilized. 
     Further, the diameter must be large enough so that the differences in the length of the top side  218  of the folded tape  106  and the bottom side  216  of the folded tape is negligible when circumferentially wrapped a complete rotation around the drum. The length of the bottom side  216  of the folded tape is substantially equal to the product of diameter of the drum and Pi; whereas, the length of the top side  218  is substantially equal to the diameter of the drum plus twice the thickness of the bottom side of the folded tape times Pi. For tape material of a given thickness, it can be appreciated that the relative difference in length between the top and bottom sides of the tape increases as the diameter decreases. Large relative length differences can effect the appearance of the finished shade material. In the preferred embodiment, a drum  302  having a diameter of about 5′ 3″ and a length of about 9′ is utilized. 
     The drum  302  may be fabricated from any number of suitable materials, although the drum must be uniformly round along its entire surface and it must be stiff enough to resist sagging longitudinally. In the preferred embodiment, as shown in  FIGS. 28 and 29 , the drum is fabricated from a plurality of spaced circular spoked steel plates  344  onto which a rectangular steel plate  346  is wrapped and welded. A Teflon coated fabric may be placed over the surface of the drum to help prevent the shade material from sticking to the surface due to any wayward adhesive material. A steel axle  348  extends down the length of the drum through the center of each of the spoked plates to which it is secured. The axle extends from each end of the drum, wherein each end is received in a bearing assembly  350  that permits the drum to rotate. Each bearing assembly is secured to one side of a wheeled platform  352 . The wheeled platform supports the drum through the axle and bearing assemblies at either end of the drum. 
     Referring to  FIGS. 4 and 28 , the drum&#39;s axle  348  extends through the bearing assembly  350  at the right side of the wheeled platform  352  and is coupled to a servo motor  354 , which rotates the drum. The drum servo motor  354 , like the other servo motors, is coupled with the controller  400 , which controls the speed and operating parameters of the motor. In the preferred embodiment, the drum servo motor serves as the master servo motor, wherein the speed of all the other servo motors are adjusted to synchronize with it to ensure the even flow of tape material through the fabrication apparatus. 
     The wheels  356  of the wheeled platform  352  rest on a pair of rails  358  of a base platform  360  as best shown in  FIGS. 28 and 29 . The wheels  352  are orientated to permit movement of the wheeled platform  352  and the drum  302  along the rails  358  in the longitudinal direction of the drum. To facilitate the controlled longitudinal movement of the wheeled platform, a screw drive  304  is utilized. The screw drive comprises an elongated screw  362  rotateably attached to the base platform that extends underneath the wheeled platform parallel to the drum. The screw  362  is coupled with the wheeled platform by way of a tab  364  that extends downwardly from the wheeled platform, wherein the screw passes through a threaded bore in the tab. By turning the screw the wheeled platform is encouraged to move one way or the other depending on the direction of the screw&#39;s rotation. A servo motor  366  is coupled with one end of the screw  362  to rotate the screw. The screw servo motor  366  is also coupled to the controller  400  and like the other servo motors  122  and  226  is synchronized with the drum servo motor  354  so that the wheeled platform and the drum move only a specified longitudinal distance amount for each rotation of the drum. 
     Controller Operation of the Fabrication Apparatus 
     Up to five servo motors  122 ,  226  and  354  are utilized to feed the tape material from the fabric rolls  102  to its final position on the drum  302  as part of the cellular roller shade material  12 . Another servo motor  366  is provided to move the drum linearly to ensure so that the folded tapes  106  overlap properly as they are laid onto the drum. It is imperative to the proper operation of the fabrication apparatus that the servo motors are all synchronized properly to ensure even tension is maintained on the tape(s) throughout the various sections of the fabrication apparatus. The computerized controller  400  acts to constantly monitor the operation of the various sections of the fabrication apparatus and adjust the various speed of the servo motors as necessary. 
     Ideally, the tension applied to the tapes as they are pulled through the fabrication apparatus is held at the lowest possible levels that are sufficient to facilitate: (1) the proper and continuous application of adhesive to the tape  104 B, which forms the rear sides  24  of cells  18 , prior to bonding to the tape  104 A, which forms the front sides  22  of the cells  18 ; (2) the straightness of both tapes  104 A and  104 B as they are joined so that no folds or creases are introduced into the joined tape  106 ; (3) the continuous application of the longitudinal parallel adhesive beads  254  and  256  to the folded tape  106 ; and (4) the flat lay down of the folded tape  106  on the drum  302  without introducing any anomalies that could affect the uniformity of the finished cellular shade material  12 . It is to be appreciated that too much tension can cause problems such as elastic and plastic stretching of the fabric tapes that result in unevenness of the cells when the tension is released by removing the shade material  12  from the drum  302 . 
     To help maintain a constant tension throughout the fabrication apparatus, several tension mechanisms  126  and  306  are provided. As described in detail above, each tensioning mechanism generally comprises a spindle or roller that is moveably attached to a linear slide table and have a pneumatic cylinder attached to them to provide the necessary tensioning force. The slide table allows the spindle or roller to move in response to small changes in the speed of the servo motors without causing the tension level throughout the fabrication apparatus to change. It can be appreciated that if the slide tables are allowed to be fully extended to either of their ends, the tension in the system could change to levels above or below the preferred level resulting in a degradation of the resulting roller shade material  12 . Accordingly, linear position transducers are provided at each of the tensioning mechanisms. The transducers are coupled to the controller  400  and provide the controller with position information that the controller utilizes to adjust the speed of the various servo motors to help maintain the spindle or roller attached to a tensioning mechanism near the middle of the associated linear slide table&#39;s range of travel. 
     To complicate matters, as the tape material is unwound from either roll  102  of fabric tape, the amount of fabric tape  104  unwound for a given servo motor speed decreases with the change in circumference of the roll. Accordingly, the associated servo motors&#39; speeds must be constantly increased to continue to supply the fabric tapes  104  at constant rates. As mentioned above, ultrasonic sensors  124  are provided to measure the distance between the sensors and the surface of the associated rolls  102 . The computer controller utilizes this information to determine the circumference of the rolls so that it can adjust the speed of the associated servo motors  122  to maintain the unwind rate at the same rate at which the folded tape  106  is deposited on the drum  302 . 
       FIG. 30  is a flow chart illustrating the operation of the controller for a preferred embodiment of the invention. It is understood that other algorithms can be utilized to accomplish the result of maintaining the even flow of tape through the system at a constant tension and that the illustrated algorithm is therefore merely exemplary. 
     Referring to block  3010 , the rate that the folded tape  106  is laid down on the drum  302  is determined. The lay down rate is a function of the circumference and rotational speed of the drum. The rotational speed of the drum can be determined using a photovoltaic sensor  368  that is triggered each time the drum completes a rotation or the speed of the fifth servo motor can be utilized to determine the drum&#39;s rate of rotation. 
     In block  3020 , the distance between each ultrasonic sensor  124  and its associated roll  102  of fabric tape  104  is determined. Based on a known distance between each sensor and the center of the associated turntable  114 , the radius, diameter and circumference of the tape rolls are determined. 
     In block  3030 , using the circumference of the tape rolls and the rotational speed of the associated servo motors  122 , the unwind rates of the rolls of fabric tape are determined. 
     In block  3040 , the unwind rate of both rolls  102  are compared to the lay up rate of the folded tape  106  on the drum. Both unwind rates should be the same as the lay up rate. As necessary, the rotational speeds of the servo motors  122  are adjusted. Typically, the speed of the servo motors  122  are increased to account for the decrease in diameter of the associated rolls  102  of fabric tape. 
     It is to be appreciated that the rotational speeds of folding section drive wheel servo motors  226  and the screw servo motor  366 , which all operate a speed proportional to the drum servo motor  354 , may also be determined and adjusted as necessary. In general, however, when the fabrication apparatus is at full operational speed (250-300 ft/min), adjustment to the speeds of screw servo motor is rarely needed, and necessary adjustments to the speed of the drive wheel servo motors are typically very small and are based on the position of the tensioning roller  310  of the tensioning mechanism  306  as described below. However, when the fabrication apparatus is ramping up to operational speed during startup or slowing down as the fabrication apparatus is being shut down, the speed of the servo motors  226  and  366  will be adjusted to maintain proportionality with the drum servo motor. 
     Referring to block  3050 , the positions of the spindles  130  of the supply section tensioning mechanisms  126  are determined based on the position of the moveable portion  140  of the linear slide tables  138  as measured by the linear position transducers  144 . It can be appreciated that adjustments to the speed of either turntable servo motor  122  based on the circumferences of the respective rolls  102  of fabric tape as performed in block  3040  are relatively coarse being dependent on the tension at which the fabric rolls were originally wrapped, the uniformity of the fabric tapes, and the roundness of the rolls. Due to the coarseness of the speed adjustment based only on the circumference of the rolls, too much or too little tape may be unwound from the fabric tape rolls causing the spindles  130  to move in the linear slide tables  138  to maintain a constant tension. 
     More precise adjustments to the speed of the servo motors are necessary to account for these variations. The controller  400  is directed to maintain the spindles  130  of the tensioning mechanisms  126  near the center of the linear slide tables  138 . Accordingly, in block  3060 , the speed of the turntable servo motors  122  are adjusted to move the spindles back towards their center position. For example, if the circumference of a roll was determined using the ultrasonic sensor to be slightly larger than it actually was, less material would be unwound from the tape roll than necessary to maintain an unwind rate identical to the lay up rate. This will cause the spindle  130  to move in the direction of the stationary spindles  128  and  132  of the associated tensioning mechanism  126  providing the necessary extra tape to maintain the uniform tape tension. As the spindle  130  moves away from its center position, the movement is registered by the controller through the linear position transducer  144 , and the controller increases the rotational speed of the associated servo motor  122  slightly to cause the spindle  130  to move back towards its center position. 
     Referring back to block  3050 , The position of the tensioning roller  310  in the bonding section&#39;s tensioning mechanism  306  is measured by the associated linear position transducer  324 . Movement of the roller  310  can be caused if either of the drive wheel servo motors  226  are pulling the folded tape through their associated drive wheels  220  at a rate that is different than the lay up rate on the drum  302 . As mentioned above, the speed of these servo motors  226  does not typically need much adjustment, however, small variations in the rate at which the tape is pulled through the drive wheels  220  may result due to slippage of the folded tape  106  in-between the drive and idler wheels  228  caused by small variations in the composition and dimensions of the folded tape. As necessary, the speed of the drive wheel servo motors  226  is adjusted to cause the roller  310  to move back to its normal position at the middle of the slide table  314 . 
     As indicated by line  3055 , the position of the spindles  130  and the roller  310  is continuously monitored and speed adjustments are continuously made to the servo motors based on the positions of the spindles and the roller in their respective slide tables  138  and  314 . Further as indicated by line  3015 , the lay down speed of the folded tape  106  at the drum  302  and the circumferences of the tape rolls  102  are continuously monitored with speed adjustments being made to the turntable servo motors  114  as necessary. 
     A First Alternative Embodiment 
     A first alternative embodiment of the fabrication apparatus is illustrated in  FIGS. 31-37 . As shown in  FIGS. 31-34 , the supply and folding sections  100  and  200  of the first alternative embodiment are substantially the same as the similar sections described above with reference to the preferred embodiment. The first alternative embodiment differs from the preferred embodiment primarily in the use of a conveyor belt assembly  402  in place of the drum over which the folded tape  106  is assembled into cellular shade material  12 . 
     Referring to  FIGS. 31 ,  32 ,  35  and  36 , the conveyor belt assembly  402  typically comprises a tubular belt  474  of reinforced fabric that is tensioned about a pair of parallel spaced elongated cylinders  476 . The cylinders are rotateably attached to the ends of a wheeled platform  452 . The wheeled platform includes a substantially planer support plate  478  located between the two cylinders just beneath conveyor belt  474  to provide support to the belt when the belt is subjected to downwardly-directed forces such as those imparted by the rollers  426  and  428  of the pressure roller assembly  408  (as shown in  FIGS. 31 ,  37  and  38 ). As illustrated in  FIG. 37 , cooling lines  480  for circulating water or another cooling fluid may extend beneath the support plate  478  to facilitate the cooling and solidification of the hot melt adhesive after sections of the folded tape  106  are joined together. 
     Referring to  FIG. 31 , a belt drive motor  454  is attached to the axle  482  of one of the cylinders to rotate the cylinder and cause the conveyor belt  474  to move in the indicated direction. Like the drum servo motor  354  of the preferred embodiment, the belt drive motor (also a servo-type motor) is coupled with the controller, which controls its operating speed. Also, like in the preferred embodiment, the speeds of the other servo motors of the fabrication apparatus are all synchronized relative to the speed of the belt drive motor  454 . In this regard, the operation of the controller is substantially the same as described above for the preferred embodiment. 
     Referring to  FIGS. 35 and 36 , the wheels  456  of the wheeled platform  452  rest on a pair of rails  458  facilitating linear movement in a direction substantially perpendicular to the direction of rotation of the conveyor belt  474 . A screw drive mechanism  404  similar to the mechanism described in the preferred embodiment is provided for controlling the linear movement of the wheeled platform along the base platform&#39;s rails. A servo motor  466  that is synchronized to the drive motor  454  of the conveyor belt  474  is attached to the screw  462  to move the conveyor belt at a certain rate to ensure the proper overlap of the consecutive sections of the folded tape  106 . 
     Referring primarily to  FIG. 34 , the pressurized roller assembly  408  of the first alternative embodiment is similar to the same assembly in the preferred embodiment except the assembly of the first alternative embodiment is canted downwardly so that the small and large rollers  426  and  428  impact the conveyor belt when the belt is substantially horizontal as it exits the first cylinder. As previously mentioned, the support plate  478  provides support to ensure the pressure applied by the rollers is effective in compacting the adhesive beads  254  and  256  and forming a suitable bond. 
     A Second Alternative Embodiment 
     The second alternative embodiment is substantially different from both the preferred and first alternative embodiments and is illustrated in  FIGS. 38-42 . Essentially, the second alternative embodiment is a simplified fabrication apparatus compared to the other two embodiments, wherein only two motors are utilized and no complex computer control system is necessary to fabricate the cellular shade material  12 . The second alternative embodiment includes (1) a tape deposition cart  502  with implements for folding the fabric tape  106  and applying adhesive beads  554  and  556  to join the tape to previously laid sections of tape; (2) a rotating elongated cylindrical drum  504  for receiving the adhesive-laden folded tape; and (3) a base  506  on which the drum and cart are received including a drive motor  508  for rotating the drum and parallel recessed tracks  510  and a rack  512  with gear teeth gear for controlling the linear movement of the tape deposition cart. 
     Referring to  FIGS. 38 and 39 , the cart comprises: (1) a wheeled base  514 ; (2) a vertically projecting spindle  516  for rotationally receiving a roll of fabric tape material  518 ; (3) a tape folding horn  520  connected to the base by a generally horizontally extending arm  522 ; (4) an adhesive applicator  524  mounted at the end of the arm in front of the folding horn; and a drive motor  526  with an associated pinion gear  528  for moving the cart in a linear direction parallel to the drum. The prejoined tape  530  from the roll  518  extends from the vertical spindle to the folding horn. The folding horn is similar in construction to the horn described in reference to the preferred embodiment. The horn folds the vertically oriented tape along a fold line parallel to but offset from the longitudinal center line of the tape  530 . Upon exiting the horn, the folded tape is horizontally disposed with a portion of the bottom side of the folded tape extending beyond the free edge of the top side. 
     Next, referring to  FIG. 42 , the nozzles  548  of the adhesive applicator apply one adhesive bead  550  to the top surface of the overhanging portion of the folded tape and one bead  552  to the bottom side of the folded tape. This is in contrast to the previously described embodiments, wherein both adhesive beads are applied to the bottom side of the folded tape proximate the folded edge. 
     Finally, the tape is deposited onto the rotating drum, wherein the tension of the tape combined with the downward direction of the drum after the tape is applied pushes the bead into contact with the previously laid section of tape.  FIG. 43  illustrates how the folded tape  530  overlaps the previously laid section of tape to create the cellular shade material. 
     It is to be appreciated that despite the different points of application of the adhesive beads in the preferred embodiment versus the second alternative embodiment, the resulting cellular shade material is substantially the same. It can also be appreciated that the adhesive may also be applied to other locations on a folded tape and still create the cellular shade material  12 . For example, as shown in  FIGS. 44 and 45 , the fabric tape  530  is flipped in orientation when compared to the preferred embodiment with the overlapping flap on the top side. In this example, one bead of adhesive  554  is applied to the bottom surface of the flap and another adhesive bead  556  is applied to the bottom surface of the bottom side proximate the bottom side&#39;s open edge. The adhesive beads are laid against the folded edge of a previously laid section as shown in  FIG. 46 , resulting in a cellular shade material substantially the same as created using the adhesive applicators of either the preferred or second alternative embodiments. 
     The elongated drum  504  is best shown in  FIGS. 38 and 39 . The drum includes a central portion  532  with a surface onto which the folded tape  530  is laid to form the cellular shade material  12 , and two end caps  534  that have a greater diameter than the central portion. The circumferential edges of the end caps support the drum against two elongated rollers  536  of the base  506  as the drum is rotated. In one variation of the second embodiment, the drum includes a center axle through which the drum is supported in bearing assemblies above the bottom surface of the base. 
     The base  506  is best shown in  FIGS. 38 ,  39  and  40 . The base has a pair of parallel recessed tracks  510  that extend substantially the entire length of the base in a direction parallel to the drum  504 . The wheels  538  of the wheeled base  514  of the cart  502  are received in the tracks  510 , which guide the cart as it moves along them. In-between the tracks, the rack  512  is secured to the base. The rack  512  interfaces with the pinion gear  528  of the cart&#39;s drive motor  526  and provides the mechanism by which the cart propels itself from one end of the drum to the other. As mentioned above, two elongated roller cylinders  536  are rotateably mounted on the base  506  at their axles  540 . One of the axles of one of the roller cylinders has a pulley  542  attached to it. A drive belt  546  extends from the axle pulley  542  to a pulley  546  connected to the drive shaft of a drum drive motor  508  used to rotate the drum at a predetermined speed. 
     In one variation of the second alternative embodiment, the relationship between the speed of rotation of the drum and the linear speed of the cart is controlled mechanically based on the operating speeds of the respective drive motors  508  and  526 , as well as, the gearing utilized with both motors. Accordingly, the fabrication apparatus can be configured such that the cart moves a certain linear distance for every rotation of the drum, thereby ensuring the proper overlap of the folded tapes  530 . In another variation, both drive motors are coupled to a computerized controller that varies the speed of one drive motor based on the speed of the other in a proportional relationship necessary to apply the tape with the proper overlap. By using a controller that keys the speed of the cart drive motor to the speed of the drum drive motor, proportionality can be maintained during startup and slowdown. 
     Alternative Embodiments and Other Variations 
     It is to be appreciated that any number of variations to the fabrication apparatus can be made without deviating from the scope or intent of the invention. In this regard the illustrated and described embodiments are merely exemplary and not intended to limit the scope of the appended claims. For instance a bonding section  100  may be utilized that comprises only a single tape supply assembly for use with either rolls of previously joined fabric tape or “double wide” tape. In another variation springs may be utilized in place of the pneumatic cylinders in the tensioning mechanisms of the various sections. Further, the actual locations and the configurations of the tensioning mechanism might vary as would be obvious to one of ordinary skill in the art. In other variations, a servo motor other than the drum or conveyor belt servo motors may serve as the master utilized by the controller to synchronize the other servo motors. In yet another variation, the holt melt adhesive may be replaced with a thermoset adhesive with a curing device such as a heat gun or ultraviolet light source being provided somewhere on the apparatus to cure the adhesive. It is be appreciated that many other variations would be obvious to one of ordinary skill in the art given the benefit of this disclosure. 
     Throughout this specification and appended claims, directional terms such as, but not limited to, “front,” back,” “rear,” “top,” “bottom,” “lateral,” “longitudinal,” “left,” “right,” “vertical,” and “horizontal” have only been used to explain the relative relationships between various components and elements of the apparatus and the shade material and should be interpreted accordingly. For example, if apparatus of  FIG. 1  was vertically disposed along a wall instead of on a ground surface, the directional relationships between the components of the system would be retained even though in an absolute sense certain elements such as the spindles  128 - 130  would no longer be vertical.