Composite tape preparation and application

High strength composite tape is prepared for laying in side-by-side strips upon a work surface by precutting the strips to a predetermined length and mounting the strips upon a carrier belt in longitudinally spaced relation to one another, so that the pressure foot of the machine applying the tape to a work surface may press to the end of one tape strip without pressing the end of the following tape strip. Improved laying of the tape is achieved by stretching a strip of tape entirely across the area on which the tape is to be laid before pressing any part of the tape against the work surface, and then pressing the tape against the surface while the tape is stretched across and adjacent the work surface. The tape is held and stretched across the work surface on supply and take up reels on opposite sides of the work surface, so that the reels need not move along the tape with the moving pressure foot.

The present invention relates to the application of high strength composite 
tape and more particularly concerns methods and apparatus for laying of 
composite tape and for its off-line preparation. 
BACKGROUND OF THE INVENTION 
Composite fiber tape formed of high tensile strength fibers of materials 
such as boron, graphite, or glass, and impregnated with a matrix of a 
thermosetting resin, has been employed for a number of years in the 
manufacture of laminated composite structural shapes for aircraft and 
aerospace vehicles. Composite tape structural parts are commonly made by 
superposing many laminations with different tape orientations, each 
lamination made by laying down strips of composite tape in a side-by-side 
relation upon a pattern or form. The many laminations are placed in a mold 
and heated to cure the resin and provide the finished part. Much time, 
effort, and expense has been devoted to the fabrication of automatic 
machines for the laying of individual strips of tape. Examples of such 
tape laying machines are shown in U.S. Pat. Nos. 3,574,040; 3,775,219; 
3,810,805; 4,133,711; and 4,292,108. 
These machines generally involve an overhead gantry from which is suspended 
a laterally traveling tape laying head which often carries tape supply and 
take up reels, guiding mechanisms, cutting mechanisms, a heater, and a 
tape pressure foot. The tape laying head does all the tape preparation, in 
addition to pressing the tape upon a work surface. In the head mechanism, 
tape is withdrawn from a supply reel carried by the mechanism and cut into 
predetermined strip lengths as it is applied to a work surface. One part 
of a continuous tape length is often laid down before the trailing end of 
the tape is cut. The composite tape, having an exceedingly high modulus of 
elasticity, is stiff, inelastic, and difficult to handle. The tape head 
laying machine is massive, expensive, slow, and complex, and, in some 
cases, may comprise a structure in the order of one to two feet in 
diameter and four to six feet in height. All of this structure must be 
movably mounted on a gantry and controlled for guiding the tapes in 
precise, aligned side-by-side paths. 
In such prior machines, each cut made in a continuous tape defines both the 
trailing edge of one tape strip and the immediately adjoining leading edge 
of the next tape strip. Where the tape is to be cut at an angle, so as to 
closely follow the angulated boundary of a part that is being formed, the 
tape pressure foot or roller cannot press to the trailing end of one 
angularly cut strip without pressing at least part of the immediately 
adjoining leading edge of the following strip. This is undesirable, 
because the leading edge of the following strip must be positioned at a 
different location than the trailing edge of the first strip. Further, for 
smaller oblique angles of cut, the length of cut increases, and, 
accordingly, the force required to complete the cut increases, thus 
further adding to complexity and bulk of the prior art tape laying 
machine. 
An additional problem exists in the laying of tape upon a surface of 
compound curvature. To properly fit a compound curve, the individual tape 
fibers must slip longitudinally relative to one another, since those 
fibers extending over a path of greater curvature must have a greater 
length than adjoining fibers of the same tape strip that extend over a 
path of lesser curvature. However, where the tape supply reel is carried 
by the tape laying machine, and, in particular, where a long strip of tape 
is not cut until after a portion of the same strip has been laid, no 
relative slippage of tape fibers is possible. 
In prior machines, cutting of the tape, which is generally mounted upon a 
paper backing ribbon, is achieved either by first removing the paper 
backing to cut the tape without cutting the ribbon, or by cutting the tape 
with a carefully controlled cutter that does not sever the backing ribbon. 
Because in such systems further handling of the tape on the backing ribbon 
is required, it is necessary either to cut the tape without cutting the 
ribbon or to replace the tape upon the ribbon after the cutting. 
Imperfections in the manufacture of the tape, or damage to the tape during 
handling, can be discovered in prior art machines only after the tape has 
been pulled out of the tape laying machine and at least partly laid upon 
the work surface. Therefore, a damaged tape strip can be replaced only 
after it has been laid, a situation that increases cost and time of 
manufacture, particularly where a damaged strip of tape of many feet or 
many tens of feet in length must be removed after it has been laid. 
Accordingly, it is an object of this invention to avoid or minimize 
above-mentioned problems. 
SUMMARY OF THE INVENTION 
In carrying out principles of the present invention in accordance with a 
preferred embodiment thereof, composite tape is preassembled for use in 
the fabrication of a structural member formed of tape strips laid in 
side-by-side parallel rows by withdrawing tape from a tape supply station, 
cutting the tape in consecutive strips, and mounting the consecutive 
strips of cut tape on a carrier belt in longitudinally spaced relation to 
one another. An improved method of laying the tape comprises stretching a 
strip of tape adjacent a work surface between first and second boundaries 
of a pattern on the work surface, with one end of the strip at one 
boundary, and pressing one end of the strip against the surface along a 
pressure area of the tape strip. The pressure area is then moved along the 
tape strip while holding the strip stretched across and adjacent the work 
surface area. In a modification of this method, the tape pressure area is 
moved from an intermediate point of the tape outwardly toward opposite 
ends of the tape to facilitate laying the tape on a curved surface and to 
facilitate fiber slippage. 
Tape preparation apparatus embodying principles of the invention includes a 
cutting station having means for feeding tape from a source to the station 
and carrier belt supply and take up stations with a receiving station 
therebetween. Means are provided to pass the carrier belt through the 
receiving station and to feed tape from the cutting station to the 
receiviing station where the strips of tape are mounted to the carrier 
belt in longitudinally spaced relation. 
Tape laying apparatus embodying principles of the invention comprises an 
elongated support extending across a work table having supply and take up 
reel receiving devices mounted at opposite ends of the support. A tape 
laying pressure head is mounted on the support for motion between the 
receiving devices adjacent the work table, and includes means for pressing 
composite tape and its carrier belt against the work table while the head 
is driven toward the supply receiving device. 
According to another feature of the invention, the tape laying head of the 
apparatus includes a gripping and lifting roller, which may grip the tape 
while it is being pulled out to position, and which will separate the 
carrier belt or paper backing from the tape.

DETAILED DESCRIPTION OF THE INVENTION 
As shown in FIG. 1, an exemplary prior art machine involves a gantry 10, 
carrying an integral tape head laying machine 12, mounted for travel along 
the length of the gantry above a table 14 on which is to be laid a layer 
of tape strips 16 in a pattern, generally indicated as the trapezoidal 
FIG. 18. The table and gantry are relatively moved along the length of the 
strips 16 during the laying of each individual strip. To lay successive 
strips, the integral head 12 is shifted laterally with respect to the 
table along the gantry 10. As schematically shown in FIG. 2, the integral 
tape laying head includes a tape supply reel 20, driving rollers 22, a 
cutting station 24, a tape pressure roller 26, and take up reel 28 for 
winding up backing paper that is removed from the composite tape. Supply 
reel 20 stores a roll of composite tape mounted upon a paper backing 
ribbon. Tape and backing are drawn from the supply reel 20 and passed 
through and under the pressure roller 26, while the integral tape head is 
moved relative to the table and relative to the pattern in the direction 
of the arrows shown in FIGS. 2 and 3. Initially, the tape roller 26 is 
positioned over the end 32 of a first path 30 and will travel to the far 
end 34. At some time before reaching the far end 34, the trailing edge of 
the tape strip being laid on path 30 is cut at the required angle by the 
integral tape head cutters. Upon reaching the end of path 34, the integral 
tape head is raised, rotates 180.degree., and then proceeds in the 
opposite direction along the adjoining tape laying path 36. 
FIG. 4 illustrates strips of tape 38 and 40 which will be cut and laid by 
the integral tape head machine shown in FIGS. 1 and 2. The tape strips are 
shown in dotted lines below the continuous paper backing strip, which is 
shown in solid lines. With roller 26 moving in the direction of the arrow 
in FIG. 4, tape strip 38 is laid, being pressed down by the roller 
traveling to the trailing end 42 of the tape strip. The latter is cut at 
the indicated angle to conform to the edge of the end 34 of the part 
pattern illustrated in FIGS. 1 and 3. When the roller reaches the traling 
end 42 of strip 38, the following tape strip 40, which is still entirely 
carried in the integral tape head, has its leading edge immediately 
adjoining the just laid edge of strip 38 so that the roller 26 will 
necessarily also press against the adjoining edge of the strip 40, 
producing an overlapping pressure on adjoining ends of consecutive strips. 
It is undesirable to press the strip 40 down upon the work surface at this 
time, because the strip 40 must be moved laterally and turned 180.degree. 
as the tape head turns to begin the next laying course 36. Thus, the tape 
head will be lifted before it reaches the trailing end of an angularly cut 
strip, and this unpressed end will be pressed down at a later time. 
According to certain principles of the present invention, the problem of 
overlapping pressure on adjoining ends of consecutive cut tape strips is 
eliminated by preassembly of tape strips. This preassembly also has many 
other advantages, as will be discussed below. As illustrated in FIG. 5, 
the several tape strips for each of the successive tape paths (such as 
paths 30, 36, etc., of FIG. 3) are precut and laid down end-to-end in 
longitudinally spaced relation upon a carrier belt. The carrier belt, like 
the paper backing ribbon, may be slightly wider than the composite fiber 
tape. The assembly of precut tape strips on a carrier belt, when adapted 
for use with an integral head tape laying machine of the type illustrated 
in FIGS. 1 and 2, is generally in the configuration illustrated in FIG. 5, 
wherein precut tape strips 43, 44, 45, 46 and 47 all shown by dotted 
lines, are laid down upon a continuous carrier belt 50 (shown in solid 
lines). Both belt and tape strips are wound together and stored upon a 
composite strip supply reel 52. Adjacent edges of successive strips, such 
as edges 54, 55 of consecutive strips 44 and 45, are longitudinally spaced 
from each other by a distance sufficient to enable the roller 26 (or other 
pressure foot) to run to the very end of strip 44 without overlapping or 
pressing upon the adjoining end of strip 45. 
TAPE PREASSEMBLY 
Composing and preassembly of precut tape strips and carrier belt, 
illustrated in FIG. 5, may be employed for use with a machine of the 
integral head type illustrated in FIGS. 1 and 2, and may be prepared by an 
assembly apparatus of the type shown in FIGS. 6 and 7. As shown in these 
figures, manufactured composite tape 60, mounted on an inexpensive and 
readily disposable paper backing ribbon 62, is mounted on a supply reel 64 
at a supply station, withdrawn from the supply station past an inspection 
station 66, over a return roller 68, so that the paper backing, after 
separation from the tape, may be wound upon a take up roller 70 driven by 
a motor 72. If deemed necessary or desirable, the supply roller 64 may 
also be driven by a motor (not shown). 
Although the supply station is shown in FIG. 6 as comprising a reel of 
preformed and prewound tape and backing, it will readily be appreciated 
that the tape manufacturing system itself (which makes and aligns the tape 
fibers and impregnates them with resin) may form the supply station so 
that the tape is fed directly from the output of the tape fabrication 
system past the inspection station. In such an arrangement, the described 
preparation system will be located at the fabrication system (which is now 
the supply station), and it may be unnecessary to employ the paper backing 
62. 
The composite fiber tape 60 is mounted on the upper side of the backing 
paper ribbon 62 as the tape and ribbon are withdrawn from the supply reel. 
The resin that impregnates the tape fibers is relatively rigid at the 
preferred temperature (40.degree. F. or below) of this tape preparation 
operation. Accordingly, the tape is much stiffer than either its paper 
backing or the carrier belt. As the paper is bent around the return reel 
68, the fiber tape 60 is lifted by its own lack of flexibility from the 
bending paper backing to which it is but loosely and lightly secured 
initially, and continues in a straight path to and over the upper surface 
of a cutting anvil 74. The anvil 74 is part of a tape cutting station 
having a tape cutter blade 76 carried by a blade driving and rotating 
mechanism 78, which rotates the blade 76 about a vertical axis to a 
desired angular position and drives it downwardly against the anvil to cut 
the interposed tape. 
The anvil extends for a short distance past the cutting blade and 
terminates adjacent the entrance of a receiving station 80 formed, in 
part, by the beveled flanges 82, 84 of a receiving station roller 86. A 
carrier belt supply reel 88 has wound upon it a supply of a relatively 
high quality, reusable, and preferably nondisposable continuous strip of 
carrier belt 90, which is drawn from the supply and trained over the 
receiving station roller 86. The belt then passes through a pair of 
gripping rollers 92, 94 driven by a motor 96, to be wound upon a carrier 
belt take up reel 98, which is driven by a motor 100. Ahead of the drive 
or gripping rollers 92, 94 and the receiver roller 86 is provided a pair 
of upstanding tape guide flanges 102, 104. 
Although FIG. 6 illustrates relatively short pieces of cut tape strips 60a, 
60b, 60c, it will be readily understood that many, if not the majority of 
the strips, will be of considerably greater length, depending, of course, 
upon the size and configuration of the part to be made. In any event, for 
the assembly of the precut strips and carrier belt of the arrangement 
illustrated in FIG. 5 (for use with an integral head machine), tape is 
withdrawn from the supply reel 60, past inspection station 78, and past 
the cutting station where, at this time, the blade 76 is raised. Paper 
backing 62 is wound upon the take up reel 66, while the stiffer fiber tape 
passes unbent along the anvil 74, and over the end of the anvil between 
lateral guides 102, 104 having beveled entrance edges. From the anvil and 
guides the tape passes to and between the adjacent outwardly beveled 
flanges 82, 84 of receiver roller 86 and to be captured between pick up 
rollers 92, 94. The latter press the tape against the carrier belt 90, 
which is being driven by motor 100 through the supply station from the 
supply reel 88 to take up reel 98, while the fiber tape 60 is being driven 
from the cutting station into the receiving station 80. The tape is 
withdrawn from supply reel 64 at the same rate that the belt 90 is driven 
through the receiving station. 
When the point at which the tape 60 is to be cut reaches the cutting 
station, all motion of tape, belt, and all reels and drives is stopped and 
the cutting blade is activated to cut the tape. Thereafter, the cutter 
blade is raised and the carrier belt supply and take up systems, together 
with the pick up rollers, are started to continue to withdraw the now cut 
trailing end 95 of one tape strip 60a from the cutting station while the 
supply of tape 60 from supply reel 64 is temporarily and momentarily 
stopped. After the cut end 95 of tape strip 60a has traveled a distance 
equal to the desired longitudinal spacing between adjacent tape strips on 
the carrier belt, take up reel motor 72 is started and tape is again 
withdrawn from the supply reel 60 in synchronism with the driving of the 
belt through the receiving station. The drive of all reels and rollers 
continues until the point of the next cut reaches the cutting station, at 
which point, all drives are stopped for the cut, the carrier belt drives 
are again started, and, after a delay, the withdrawal of tape from supply 
60 is also started. In this manner, the continuous carrier belt is wound 
upon the take up reel 98 with precut and longitudinally spaced strips of 
composite tape pressed upon a surface of the carrier belt. In effect, the 
carrier belt and tape withdrawal are operated together at the same rate to 
ensure that long strips of tape will be properly mounted on the belt, but 
the withdrawal is slowed or stopped momentarily (while belt drives 
continue) to provide the desired longitudinal spacing of tape strips. 
In order to handle small precut strips of tape, a transfer station is 
interposed between the cutting station and the receiving station. The 
transfer station includes a vacuum-operated transfer head 112 carried on 
an arm 114, which, in turn, is mounted to a rotary lever 116 of a support 
118 that is arranged to move the vacuum head 112 up and down, toward and 
away from the tape bearing surfaces, and also to shift the arm and the 
vacuum head to and from each of the transfer station and the receiving 
station. To pick up a small piece of tape, after its trailing edge has 
been cut at the cutting station, lever 116 is operated to move the vacuum 
head 112 downwardly into contact with the tape on the output end of anvil 
74. Vacuum is applied to the head via a vacuum line 120, and lever 116 is 
rotated about an axis 122 to move the vacuum head and small tape strip 
upwardly and toward the right (as illustrated in FIG. 6) and then 
downwardly to position and lightly press the tape down upon the surface of 
the carrier belt, which will then carry the tape to the pickup rollers 92, 
94. 
The described arrangement of tape preparation apparatus illustrated in FIG. 
6 will prepare a precut assembly of carrier belt and spaced tape strips 
for use with the bidirectional tape laying integral head of FIGS. 1 and 2. 
This head may be termed bidirectional, because a first tape strip is laid 
in the path 30 with the machine moving in a first direction, and the 
adjoining tape strip is laid in path 36 with the machine moving in the 
opposite direction relative to the work surface. Such a bidirectional 
machine may conveniently employ a single cut to separate consecutive 
strips (where non-right angle cuts are made), because the two cut edges 
are geometric supplements, and when one is turned through 180.degree., the 
supplementary end is now properly oriented. If, however, the tape is to be 
laid by a machine which lays the tape in only a single direction from one 
side of a part to another and then returns to the starting side to lay a 
second strip in the same direction (such a macine will be described 
below), a pair of successive cuts must be made, one for the leading edge 
of a first strip and a second cut at a different angle for the adjoining 
trailing edge of the next strip. For example, and with reference to the 
pattern of FIG. 3, using such a unidirectional tape laying machine, a 
first tape strip would be laid down on path 30 starting with a leading end 
32 and finishing with a trailing end 34. A strip on the following path 36 
would also be laid down in the same direction, starting with its leading 
end 33 and finishing with its trailing end 35. Before cutting the two tape 
strips, the leading end 33 of the strip on path 36 will be close to and 
following the trailing end 34 of the leading strip on path 30. However, 
ends 34 and 33 are necessarily cut at different angles, and thus two cuts 
will be required, with an ensuing waste of the costly composite fiber 
material between the two cut strips. 
To enable the use of a unidirectional tape laying process and apparatus 
while making only a single cut and avoiding the waste between two 
successive cuts, the tape preparation apparatus of FIG. 6 is arranged to 
mount a first series of alternate strips cut from tape 60 upon a first 
carrier belt and to mount the remaining strips cut from the same length of 
tape 60 upon a second carrier belt. 
Accordingly, the described carrier belt composing and preassembly system, 
including supply and take up reels 88, 98, pick up rollers 92, 94, and the 
receiving station 80, including the receiving roller 86, are all mounted 
on one side of a rigid slide plate 124. Slide plate 124 is formed of a 
horizontal beam 125 having fixed upstanding arms 126, 127, and 128 upon 
which are respectively mounted reels 88 and 98, rollers 92 and 94, and 
receiver roller 86. The slide plate is mounted for lateral sliding motion 
by means of guide rods 129, 130 under control of a bidirectional driving 
air cylinder 132. Air cylinder 132 and guide rods 129, 130 are fixedly 
mounted in a support structure (not shown). A second carrier belt 
composing and preassembly system, including a supply reel 88a, take up 
reel and drive motor therefor 98a, 100a, receiving roller 186a, pick up 
rollers 92a and 94a, and pick up motor drive 96a, are all arranged and 
positioned in the same manner as are the similar components of the first 
carrier belt composing and preassembly system, but on the opposite side of 
the slide plate 124. The slide plate is driven laterally between first and 
second positions by air cylinder 132, so that in its first position the 
first carrier belt system, including reels 88 and 98 and receiving roller 
86, are aligned with the tape 60 coming from supply 64 and the cutting 
station. In the laterally shifted second position of the two carrier belt 
composing and preassembly systems, the second system, including supply and 
take up reels 88a and 90a and associated system components, are all 
aligned with and will receive the tape 60 coming from the cutting station. 
The systems are operated, as previously mentioned, so that alternate cut 
strips are fed to, and mounted upon, respective ones of the carrier belt 
composing systems. In other words, a first strip is fed to, and mounted 
upon, the carrier belt of one system, and then the two side-by-side 
carrier belt systems are laterally shifted so that the next strip cut and 
fed from the cutting station is mounted upon the other carrier belt 
system. The system continues to cut strips and shift belt systems. 
A sequence of operations is as follows for this dual carrier belt composing 
and preassembly system with the system positioned as shown in FIGS. 6 and 
7. The graphite or fiber tape is fed from the supply reel 64 past the 
inspection station, past the cutting station, and into the receiving 
roller 86 of the first carrier belt system 88, 98, to be wound upon the 
take up reel 98. During operation of the first carrier belt system, the 
second carrier belt system, including reels 88a, 98a, its receiving 
roller, and pick up rollers, are all stopped. The first carrier belt 
system 88, 98 and the supply and take up reels 64 and 70 are stopped for 
the cut when an appropriate point on the tape is reached. 
After cutting the tape, carrier belt system 88, 98 is restarted to begin to 
withdraw the cut end 95 of the tape from the cutting blade. After the cut 
trailing end 95 has traveled a short distance, being pulled from the anvil 
(and from the still stopped tape 60) by rollers 92, 94 and the driven 
carrier belt, the take up motor 72 of reel 70 is restarted to again 
withdraw tape from supply reel 69. When the trailing edge 110 of the first 
cut strip leaves the cutting station anvil 74, the leading edge of the 
next strip is spaced rearwardly because of the delay in restarting take up 
motor 72. Air cylinder 132 is energized at this point to shift the slide 
plate and all of the components mounted thereon downwardly, as viewed in 
FIG. 7, so as to displace the first system 88, 98 laterally of the cutting 
station, and to move the second carrier belt system 88a, 98a and receiving 
roller 186a into alignment with the cutting station and the tape fed 
therefrom. 
Now, or after a short delay to allow trailing edge 95 to approach rollers 
92, 94, the first system 88, 98 is stopped, and when the leading edge of 
the next strip has passed the end of the anvil and entered the receiving 
station through a predetermined distance, so as to have attained a 
predetermined spacing from the trailing edge of any strip that was 
previously laid upon the belt of the second carrier belt system, the 
latter is started to drive its carrier belt and pick up rollers. Thus, the 
tape strip that has just entered the receiving station of the second belt 
system is driven past the pick up rollers to be wound upon the take up 
reel 98a. Continued operation of take up reel 70 will drive the leading 
edge of the tape strip to the pick up rollers 92a, 94a. When the end of 
the strip being wound upon the system 88a, 98a reaches the cutting 
station, all systems are stopped, the cut is made, the preassembly or 
composing system 88a, 98a is restarted, and the supply system 64, 70 is 
restarted after a suitable delay. When the end of the most recently cut 
strip leaves the lateral guides at the end of anvil 74, the two 
preassembly and composing belt systems are laterally shifted back to the 
first position, the first system 88, 98 is restarted, and the second 
system 88a, 98a is stopped. 
This sequence continues so that a first cut strip is mounted upon the belt 
of the first system, and the next cut strip is mounted upon the belt of 
the second system with alternate cut strips being mounted alternately on 
the first and second belt systems. Thus, with reference to FIG. 8, a strip 
130x is cut first and mounted on the first carrier belt 90. The cut is 
made at a trailing edge 132 of the strip 130x. This same cut forms the 
leading edge 134 of the following strip 130y which is mounted on the 
second carrier belt 90a. The trailing edge 136 of the second strip 130y is 
formed by a cut which also forms the leading edge 138 of the third strip 
140x to be mounted on the belt 90. The trailing edge 142 of strip 140x is 
formed by a cut which also forms the leading edge 144 of a fourth strip 
140y which is mounted on the second belt 90a. Accordingly, alternate 
strips 130x and 140x are all mounted on belt 90, whereas the intermediate 
alternate strips that are cut between strips 130x and 140x are all mounted 
on the second belt 90a. In effect, the strips 130x, 140x, etc., on the one 
belt 90 are all similarly oriented with respect to one another, insofar as 
their angularly cut ends are concerned. From one point of view, and for 
the purposes of this discussion, they may be deemed to be of the same 
"handedness". Likewise, strips 130y and 140y, and similar strips, all 
mounted on the other belt 90a have their angularly cut ends all oriented 
in the same direction (assuming substantially linear edges of a part being 
laid), and all may be considered, for the purposes of this discussion, to 
be of the same handedness, which is opposite that of the strips 130x, 
140x, etc., on the belt 90. 
With these arrangements of the preassembled and precut strips on the two 
belts, each reel 98 and 98a may be employed as a supply reel for laying 
strips for the same part in a unidirectional laying machine. The assembly 
on reel 98 may be used to lay parts in a first direction, whereas the 
assembly of reel 98a may be used to lay strips for the same part but in 
the opposite direction (either from the other side of the part or with the 
part turned 180.degree.). The use and orientation of these reels will be 
described in further detail below. 
Although the continuous tape has been shown on the upper side of the 
withdrawn paper ribbon, and is thus wound on reel 64 with the tape 
inwardly of the ribbon, it is also common to wind the tape outwardly of 
its paper backing or with backing on both sides of the tape. It is desired 
to maintain all bends of the tape in the same direction. Thus, if the tape 
is wound inwardly on supply reel 64, the cut strips will be wound inwardly 
of carrier belts 90 and 90a on reels 98, 98a. If the tape is wound 
outwardly on the supply reel, the cut strips will be wound outwardly on 
reels 98, 98a. If paper backing is placed on both sides of the tape, when 
wound on supply reel 64, both backings will be removed before cutting. 
Whether the tape is wound inwardly or outwardly of its backing or carrier 
belt, it is always withdrawn for laying with the backing or carrier belt 
between the pressure roller and the fiber tape. 
FIG. 6 shows the use of two tape strip composing systems to enable 
alternate cut strips to be all properly oriented for use in a single 
direction tape laying machine. To lay all cut strips in like orientation 
on a single carrier belt, thus eliminating one of the two composing 
systems, all of the composing systems ahead of (to the left of, as viewed 
in FIGS. 6 and 7) the cutting station, including supply reel 64, roller 
68, take up reel 70, and inspection station 66, may be mounted for 
180.degree. rotation in unison about an axis extending longitudinally of, 
and lying in the plane of, the tape 60. The rotatable components are then 
rotated through 180.degree. each time that a trailing edge of a cut strip 
leaves the cutting anvil. If necessary, the tape 60 may be withdrawn a 
short distance after each cut to facilitate the tape rotation without 
interference with the anvil. 
TAPE PULLING AND LAYING APATUS 
Illustrated in FIGS. 9 through 15 is a unidirectional tape apparatus which 
embodies supply and take up reels that are fixed relative to a given tape 
strip path and a shuttle-type tape head which reciprocates back and forth 
between the reels across a work surface. The apparatus can use 
conventionally prepared composite tape, but is best adapted for use with 
composed and preassembled tape strips as shown in FIG. 8. 
A rotatable work table 150 is mounted on a fixed based 152 beneath a 
traveling gantry 154, the ends of which are slidably mounted in transverse 
tracks 156, 158 at opposite sides of table 150. The gantry is driven 
laterally of the table 150 and along the length of tracks 156, 158 by a 
motor 160 driving an endless chain 162 via a gear box and sprocket 164, 
the endless chain being connected at its opposite ends to opposite sides 
of the end of the gantry 154. A similar motor and chain drive 161, 163, 
165 for the other end of the gantry is provided and synchronized with the 
drive of the first end. 
Mounted at one end of the gantry is a supply reel 166 which may include a 
composed preassembly of carrier belt and precut, longitudinally spaced 
tape strips, such as reel 98 or 98a, illustrated in FIG. 8. The tape and 
belt are wound with the tape relatively inwardly and the belt relatively 
outwardly, so that the winding of the belt helps to maintain the much 
stiffer tape in its wound condition. Tape from supply reel 166 is drawn 
off over a low mass, light-weight, curved tensioning spring 168 and fed 
through a cutting station 170, which may be employed if precut tape strips 
are not used for supply reel 166. The tape cutter is preferably arranged 
to precisely limit blade travel so as to cut through the tape but not its 
backing. A disposable backing of a conventionally prepared continuous and 
uncut tape requires use of such a cutter, whereas the above described 
composed and preassembled tape and carrier belt needs no cutter on the 
tape laying apparatus. When withdrawn, the tape faces downwardly, being 
positioned between the belt and the work surface. The wound tape or, more 
specifically, the carrier belt upon which the tape is wound, is passed 
through a shuttle type tape laying head 172 which is slidably mounted for 
reciprocation along the length of gantry 154, and thence past a clamp 174 
at the other end of the gantry. From the clamp, the carrier belt extends 
around a second low mass, light-weight, curved tensioning spring 176 to be 
wound upon a take up reel 178 mounted at the other end of the gantry. The 
supply and take up reels are driven by bidirectional drive motors 167, 
179, respectively. 
Tape head 172, more particularly illustrated in FIGS. 11-15, carries 
movably mounted and driven pressure roller 180 and belt lifting roller 
182. These rollers are driven to three different positions (FIGS. 11, 12, 
and 13) for operation of the tape head in three different modes. In each 
mode the belt 90 and the tape strip 130x, for example, pass through the 
tape head, below the pressure roller 180, and above the lifting roller 
182. In pass mode, illustrated in FIG. 13, the pressure roller is raised 
to a distance above the surface 184 of worktable 150. Lifting roller 182 
is also raised, but is considerably below the pressure roller so that the 
tape and belt, or more specifically, the belt alone, can be readily passed 
between the two rollers. The pass mode is used for initially (manually) 
loading the tape which is first drawn from the supply reel 166, around the 
tension spring and through the cutting station 170, if any, and then 
threaded between the two rollers 180, 182, as illustrated in FIG. 13, to 
be attached to and initially wound upon take up reel 178. 
In the pass mode, the leading section of the belt (which has no tape) is 
manually pulled between the two rollers until the leading edge of the 
first tape strip 130X is directly beneath the pressure roller 180. Assume 
that successive strips of tape are to be laid between boundaries 186 and 
188 that define two sides of a pattern 190 upon worktable 150 with the 
tape to be laid in parallel strips from boundary 186 to 188 (FIG. 9). The 
head initially is positioned somewhere to the left of the first or lead 
boundary 186. The head will first pull out and position a first tape strip 
and then will move from the first boundary 186 along a predetermined path, 
defined by the gantry position, to the second boundary 188 during the tape 
laying operation. With the leading edge of the fiber tape strip 130x 
positioned initially on the carrier belt somewhere to the left of the 
pattern 190, the tape head is moved in the pass mode until the pressure 
roller 180 is directly over the leading edge of tape strip 130x, at which 
time the head is moved into the pull mode (FIG. 11) in which the lifting 
roller 182 is pivoted upwardly relative to the pressure roller (which 
remains above the worktable). The lifting roller in pull mode is pressed 
against a clamp 192 (with belt 90 interposed), and the tape head is moved 
to the right, while the take up reel is driven to wind up the carrier 
belt, and the supply reel is driven to unwind the supply of belt and tape. 
In pull mode, the tape head is moved to position the leading edge of the 
cut tape strip directly above the first boundary 186 and the tape head 
then is driven to its lay mode (FIG. 12) in which the pressure roller 180 
is driven downwardly to press against the carrier belt, thereby to press 
the underlying tape at its leading edge against the surface of the 
worktable precisely at the first boundary 186. The lifting roller 182 in 
lay mode is still below the carrier belt, but is above the lowered 
pressure roller. Thus, the carrier belt is bent relatively sharply about 
the pressure roller to thereby facilitate the separation of the belt from 
the relatively stiff and inflexible composite tape as the head moves 
toward the second boundary 188 in lay mode. Clamp 174 (FIG. 10) at the 
take up end of the gantry now grasps the carrier belt, and the tape head 
in lay mode is driven to the left to press the tape against the work 
surface at a pressure area, which pressure area moves relative to the 
stationary tape toward second boundary 188 as the tape head moves toward 
the left, as viewed in the drawings. As the tape head moves toward the 
second boundary, pressing the tape upon pattern 190 on the work surface, 
the raised lifting roller continues to lift the carrier belt and separate 
it from the composite tape. This motion continues until the trailing edge 
of the composite tape is pressed to the work surface at the second 
boundary 188. Then the tape laying head is moved to its pull mode (FIG. 
11) in which the carrier belt (but not the composite tape) is clamped in 
the tape head, and both rollers are raised to lift the assembly of carrier 
belt and leading edge of the next tape strip. The tape head is then moved 
back toward the first boundary, pulling the belt and tape, and the gantry 
is shifted laterally to the next tape laying position. Thus, the belt and 
tape are first pulled out and stretched entirely across the area of the 
work surface to be covered by the tape, with the opposite ends of the tape 
positioned at the pattern boundaries. After so stretching and positioning 
the precut tape strip, the strip is progressively laid upon and pressed 
against the work surface pattern. 
TAPE HEAD STRUCTURE 
Opposite ends of an endless driving chain 200 (FIG. 14) are connected to a 
carriage 202 that carries the tape laying head and rides in tracks in the 
gantry 154. Chain 200 is driven through a gear box and sprocket 204 (FIG. 
10) from a motor 206 in a manner similar to the motor, gear box, and drive 
for the gantry ends. 
In order to ensure precision positioning, direction and steering of the 
tape as it is being laid, the tape laying carriage carries a vacuum 
tensioning shoe 208 mounted on an arm 210 carried by the carriage and 
having a vacuum line 212 connected thereto and leading back to a vacuum 
source (not shown). It will be noted that the tape and carrier belt are 
drawn from and to the supply and take up reels (see FIG. 10) at points 
well above the surface of the worktable so that when the tape is being 
laid and the pressure roller presses the tape against the table, both the 
belt, and the combination belt and tape strip, extend from the point of 
pressure contact of the pressure roller upwardly toward the take up reel 
and toward the supply reel. The upward inclination of the tape and belt 
portion between the tape laying head and the supply reel allows the 
tension head 208 to firmly grasp the belt and tape and to tension the belt 
and tape between the pressure roller and a point ahead of the pressure 
roller motion. Because the tension shoe is securely mounted to the tape 
laying carriage, and the latter is precisely guided by the gantry track, 
the tension shoe will precisely position the tape to be laid. The tape 
that is immediately ahead of the pressure roller, that is, the portion of 
the tape that is just about to be laid, is stretched ahead of the roller 
in the proper direction and, accordingly, precisely steered along the 
laying path. 
As best seen in FIGS. 14 and 15, the tape head carriage 202 is formed with 
a pair of laterally disposed longitudinally extending guide slots 216, 218 
slideably receiving legs 220, 222 of the generally C-shaped track 224 of 
the gantry. Endless chain 200 is fixedly connected at one end to one end 
of the carriage and at its other end to the other end of the carriage. A 
tape head housing comprising top and side walls 226, 228 and 230 is 
fixedly mounted to the carriage and rotatably carries a pair of tape 
laying pressure plates 232, 234 mounted for pivotal motion about a shaft 
236 carried by the housing sides 228, 230. Plates 232 and 234 are fixedly 
interconnected by an L-shaped cross bar 238, having a depending vertical 
leg 239 that carries an air cylinder 240 having a shaft 242. The cylinder 
shaft is connected to a yoke 294 that is pinned to an arm 246 which in 
turn is pivoted to a cross bar 248. Cross bar 248 extends between and is 
fixed to upper ends of each of a pair of spaced bell crank levers, each 
including arms 250 and 252. 
Lower arms 252 of the bell cranks rotatably mount tape lifting roller 182. 
The two bell cranks are pivotally mounted on a pivot shaft 254 carried by 
the pressure plates 232, 234. Shaft 254 also rotatably mounts the pressure 
roller 180. Side walls 228, 230 carry fixed brackets 256, 258 that fixedly 
mount pressure roller air cylinders 260, 262 on opposite sides of the tape 
head. The air cylinder pistons are pivotally connected to a transverse 
drive rod 264 extending through relatively large apertures 268 in the side 
walls 228, 230 and mounted in the pressure plates 232, 234. 
Accordingly, it will be seen that simultaneous operation of air cylinders 
260, 262 will pivot the pressure plates 232, 234, together with all the 
structure supported thereon (including both rollers 180 and 182) about the 
pressure plate pivot shaft 236 so as to raise or lower the pressure roller 
180, bell cranks 250, 252, and roller 182. Operation of air cylinder 240 
will rotate the bell cranks 250, 252 about the pivot axis of shaft 254 to 
raise or lower the lifting roller 182 relative to the pressure roller 180. 
If deemed necessary or desirable, a lateral guide shoe 266 is mounted to 
the underside of vacuum tension head support arm 210 at a point 
considerably closer to the pressure roller 180 so as to help steer the 
tape ahead of the pressure roller and tape head motion. 
TAPE LAYING METHODS 
It will be recalled that the tape preparation apparatus described above 
provides first and second substantially "opposite hand" assemblies of 
carrier belt and precut tape strips, such as indicated at reels 98 and 98a 
of FIG. 8. In the use of the tape pulling and laying apparatus of FIGS. 
9-15 for the laying of a part pattern 216 (see FIG. 16), reel 98 is used 
as supply reel 166 at the left side of the part as shown in FIGS. 9 and 
16. When located on the left side of the part pattern 216, the composed 
and preassembled tape strips and carrier belt on reel 98 are positioned so 
that the leading edge 218 (leading in withdrawal of tape from the reel) of 
each precut tape strip will conform to the angular orientation of the 
first boundary 186, and the trailing edge 220 will conform to the second 
boundary 188. In laying tape with reel 98, using the pull out and lay down 
apparatus of FIGS. 9 and 10, the tape is pulled out from left to right and 
laid down on motion of the tape head from right to left, as viewed in FIG. 
16. The tape and belt are withdrawn from supply reel 98 with the tape 
below the belt, as indicated in FIG. 16. 
In order to use the "opposite hand" reel 98a, formed by the tape 
preparation apparatus, for manufacture of the same part 216, the reel 98a 
is mounted as a supply reel on the opposite or right-hand side of the tape 
laying apparatus so that the leading edge 222 of tape withdrawn from reel 
98a will conform to the angular orientation of boundary 188 and the 
trailing edge 224 of the tape strip will conform to the boundary 186. In 
use of the supply reel on the right side of the part being fabricated, 
pull out and stretching of the tape across the work surface is from right 
to left and tape lay down is from left to right. FIG. 16 shows (solely for 
purposes of exposition) use of both reels 98 and 98a as supply reels for 
making the same part. Obviously, only one of these reels will be used for 
any one part. 
Alternatively, as seen in FIG. 17, the "opposite hand" end reel 98a may 
also be used on the left-hand side of the machine in the position of 
supply reel 166 of FIG. 9. Part 216 is rotated 180 degrees about a 
vertical axis, as by rotation of the worktable 150 upon its support 152. 
This positions the part 216 with boundary 188 at the right side and 
boundary 186 at the left side, as viewed in FIG. 17. This arrangement is 
presently preferred over that shown in FIG. 16 for use of reel 98a. 
The apparatus of FIGS. 9 and 10 is readily adapted to mount the supply and 
take up reels interchangeably on either end of the gantry. Clamp 174 is 
also mountable on either end. Similarly, the tape laying head may be 
merely remounted at 180 degrees to its illustrated position for laying 
tape from a supply reel 98a positioned on the right side of the machine. 
The described tape laying apparatus, as illustrated in FIGS. 9 through 15, 
has a number of advantages as compared with prior art integral tape laying 
heads. The head is considerably smaller, lighter in weight, and easier to 
maneuver, drive, guide and align. The tape can be inspected before it is 
laid down, after pulling it out and stretching it across the work area, so 
as to avoid the laying down of possibly damaged or unacceptable tape which 
then must be removed. Improved tension control is also provided. 
The described tape laying apparatus most advantageously employs a composed 
preassembly of carrier belt and precut tape strips made by the apparatus 
and methods described in connection with FIGS. 6 and 7. The preparation 
arrangement also allows for inspection prior to lay down. A higher quality 
backing or carrier belt may be used since the belt will be reusable and 
need not be disposable as in prior systems. Thus, the backing can be 
provided with improved tape sticking and non-sticking qualities on its 
opposite surfaces and also can be provided with sprocket holes for easier 
control and greater precision of registration and positioning. Provision 
of sprocket holes in the original paper backing tape would excessively add 
to the cost of this disposable material. Having precut the tape in the 
preparation system, improved speed of tape lay down is available because 
there is no need to stop for cutting of the composite tape. On parts 
having narrow portions, many relatively short length tape strips are 
required and many stops must be made for the cutting of many small pieces. 
The disposable backing paper is separated from the fiber tape for cutting 
in the described preparation system so that there is no need to 
temporarily remove the backing and replace it, nor is there any need to 
cut the tape with the paper backing applied with the precision required to 
avoid cutting of the backing. It is not desired to cut the paper backing 
since the latter must be used to handle and position the fiber tape. 
Another significant advantage of the tape preparation system is that 
operations of the preparation can be carried out at a considerably lower 
temperature, such as a temperature of about 40.degree. F. or less, for 
example, where the resin impregnated tape is considerably easier to handle 
and easier to cut. Because of its stiffness and to obtain better adhesion 
to the work surface, the fiber tape must be applied at a higher 
temperature, on the order of 74.degree.-76.degree. F., for example. 
However, the impregnating resin is tacky, sticky and harder to handle at 
the higher temperature, and will more rapidly build up in unacceptable 
quantities on the cutting blade. 
The vacuum tension shoe 208 that is affixed to and ahead of the tape laying 
carriage, not only ensures proper tension of a portion of the tape ahead 
of the pressure roller, but in addition, ensures that the tape is 
positioned close to and at the proper relatively small angle with respect 
to the work surface. The tension head will maintain this angle of 
inclination of the portion of the tape ahead of the pressure roller at a 
fixed value as the tape laying head progresses along its laying path. 
Because the supply roll is above the work surface, the tape and belt 
extend at an angle from the supply roll to the point of pressure. This 
angle will increase as the pressure roller moves toward the supply roll. 
The provision of the tension roller will avoid this change in angle and, 
moreover, will hold the tape ahead of the pressure roller at a fixed 
distance closer to the work surface. The vacuum tension shoe 208 may be 
caused to apply tension to the belt and tape merely by using the 
bi-directional drive of the supply reel to tension the entire length of 
tape after the pressure roller has been dropped to press the tape against 
the work surface, thereafter causing the tension shoe to grasp the tape 
and then slightly releasing the tension applied by the supply reel. The 
low mass, light-weight, curved springs at the supply and take up reels, 
permit increased speed of operation so that the tape and belt can be 
started and stopped more rapidly without imposing excessive acceleration 
and deceleration forces on the tape. The springs will absorb such 
excessive forces upon sudden starting or stopping of the tape and will 
help at all times to maintain tension on the tape and belt so as to enable 
proper positioning as the tape and belt are stretched across the 
worktable. 
The described tape pull out and laying machine can readily be adapted for 
laying of precut strips of tape on a surface so contoured in two 
directions so as to require slippage of tape fibers relative to one 
another particularly if the tape fibers extend longitudinally of the tape, 
rather than transversely or obliquely) as the tape is laid down. 
Preferably, for such a contouring operation, the tape is first stretched 
entirely across the workpiece with its precut ends positioned at opposite 
boundaries of the path along which the tape is to be laid. Pressure areas, 
for laying upon compound curvature surfaces, are to be applied from the 
center of the stretched tape strip outwardly toward opposite ends. 
Therefore, both tape and belt will be entirely below both rollers of the 
tape laying head. In fact, lifting roller 182 need not be used at all for 
laying such a precut tape on a compound curvature contoured surface. After 
the tape has been positioned and stretched across the pattern, the 
pressure roller is lowered to press against the belt at the center of the 
tape strip and then moved toward a first boundary to move the pressure 
area to one end of the tape. Thereafter, the pressure roller is moved back 
to the center and the pressure area is then moved from the center toward 
the other boundary. Moving the pressure roller from the center outwardly 
toward each end of the precut tape strip significantly enhances the 
ability of the tape fibers to slip relative to one another. Thus, another 
advantage of the tape preparation method and apparatus described above is 
its use for application of tape to a contoured surface as, for example, in 
laying the tape directly into a mold of compound curvature. The tape 
filaments, being inelastic, will stretch only a negligible amount and, 
thus, the pre-cutting of both ends of a tape allows the several filaments 
to behave relatively independently of one another for longitudinal 
slippage as the tape strip is pressed downwardly from its center and 
outwardly in both directions toward both ends. The described tape laying 
head will accommodate a certain amount of elevation change of the work 
surface, such as will be encountered in laying tape upon a curved surface. 
Additional elevation change may be readily handled by connecting the 
housing 226, 228, 230, and the parts supported thereby, to the carruage 
224 for continuous vertical adjustment under control of a suitably 
programmed motor. 
Although the various motors for driving the several parts of the tape 
laying machine and the tape preparation stations can be operated 
individually, independently and manually if necessary or desirable, it 
will be readily appreciated that a suitably programmed digital computer 
may be employed to send out the appropriate signals in the desired 
sequence for the operation of the various motors and drives. Conventional 
types of position sensors, such as shaft position encoders and 
photoelectric devices may be employed for monitoring and control of 
position, as well known to those skilled in the art. 
The foregoing detailed description is to be clearly understood as given by 
way of illustration and example only, the spirit and scope of this 
invention being limited solely by the appended claims.