Tape laminator

A tape laying machine is disclosed carrying a tape laminator unit which forms in situ from individual strips of composite material. The strips are first spaced apart on a carrier sheet and next compressed to a relatively thin widened state where the widened strips are contiguous to one another, forming a unitary wide composite tape. The tape is conveyed to a tape laydown station where it is transferred from the carrier sheet and deposited on a work surface.

BACKGROUND OF THE INVENTION 
This invention relates to the field of fabricating structures through 
progressive layers of composite tape. 
Current composite tape laying equipment uses a fixed width, fixed 
thickness, pre-preg fabricated tape generally comprised, in part, of 
bundles of synthetic fibers or filaments known as "tows". The tows are 
bundled into a predetermined, untwisted grouping of fibers and are bonded 
with a material such as epoxy, which is B-staged or partially cured to a 
tacky state. The tape is dispensed by a tape laying head onto a mold 
surface, wherein successive plys of tape are utilized to build up a 
desired structure. After the structure is formed by the tape, the unit is 
thermally cured, often in a vacuum bag placed in an autoclave. 
In current equipment, the tape is cut at the end of a "lay-down" pass to 
match the angle formed at the edge of the part. There exists a problem in 
being able to selectively compact the angled end portion of the tape to 
the part structure without also compacting the mating angled portion 
(tail) of the tape remaining on the dispensing reel. Further, this tail 
must be retracted in preparation for laying the next ply, or course, of 
tape. The problem of handling the tail is particularly apparent when using 
wide tape and cutting a steep angle, since these conditions result in a 
long tail being formed. On conventional state-of-the-art tape heads, the 
angle on the leading edge of the tape will be the complement of the angle 
cut on the end of the previously laid piece of tape. If this is not the 
required starting angle for the next lay the tape will then have to be 
recut before starting, or else trimmed off after laying, resulting in 
considerable waste of very expensive material. 
Since conventional tape heads lay a constant width and constant thickness 
tape it is felt by the inventor that it would be an advantage to have a 
system where the thickness of the composite tape could be varied slightly 
to allow the tape to be feathered from a relatively thick section, for a 
highly stressed area, down to a thin section in a lightly stressed area. 
It is further felt that it would be desirable to have a tape laying head 
which can vary the width of the tape so that the tape may form openings or 
voids if desirable. 
Conventional tape laying heads require a critical setting for the depth of 
cut taken by the tape cutter, since the cutter or knife must be capable of 
cutting through the composite tape entirely without shearing the backing 
paper. The backing paper is required to transport the tape and is subject 
to breaking if scored across its width. 
Applicant has obviated the difficulties inherent in the conventional tape 
laying heads used in the field of composite tape structures, by means of a 
novel tape laminator which creates a predetermined quantity of relatively 
wide tape formed in situ on the machine from individually supplied 
relatively narrow bonded tows in the tape laying head. 
SUMMARY OF THE INVENTION 
The invention is shown embodied in a tape laying machine having a tape 
laminator for forming tape in situ on the machine from individual strips 
of composite material. 
The tape laminator has a housing which contains a spacing mechanism to 
space incoming strips, or ribbons, or composite material from one another. 
A release-surfaced carrier sheet is trained from a supply reel, through 
the housing and a compacting unit, around a laydown roller, and ultimately 
wound on a take-up reel. 
In the housing, the spaced-apart strips of composite material are deposited 
on the carrier sheet and cut to predetermined lengths. The sheet and 
strips are next passed through the compacting unit where at least one set 
of compacting rollers compress the strips on the carrier sheet to a 
thinned-out, widened, state where the ribbons are contiguous, thus forming 
a unitary wide composite tape on the carrier sheet. 
The sheet is next passed under a roller or shoe at a laydown station where 
the tape is deposited on a work surface. In the preferred embodiment, the 
carrier sheet leaving the laydown station is gathered on a take-up reel.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, FIG. 1 depicts a tape laying machine 10 for 
producing composite parts. The machine 10 has a base structure 11 with 
elevated horizontal ways 12 for supporting a bifurcated gantry 13 movable 
in an "X" direction along the ways 12. The gantry 13 has horizontal ways 
14 extending at 90.degree. to the base ways 12 and a saddle 15 is carried 
on the gantry ways 14 for movement in a "Y" direction. The saddle 15 has a 
vertical way system 16 which carries a vertical slide unit 17 for movement 
in a "Z" direction. The vertical slide unit 17 carries a tape head housing 
18 which is rotatable on the vertical slide unit 17 about a "C" axis, i.e. 
around the vertical. The tape laying head 19 in the present invention 
comprises in part, a tape laminator 20 which, as will be described 
further, is a unit for forming a unitary wide tape in situ on the machine 
from individually-supplied bonded tows of composite material. 
FIG. 2 depicts the tape laminator 20 in elemental diagrammatic form, 
wherein the laminator 20 is comprised of the following main elements, all 
carried by the head housing 18: carrier dispensing reel 21; tape assembler 
unit 22; tape compactor unit 23; tape laydown roller 24; and carrier 
takeup reel 25. Certain details, such as bearing mounts for the tape 
laydown roller 24, carrier take-up reel 25, tape compactor unit, etc. have 
been omitted for purposes of clarity, but are deemed to be well within the 
ken of the ordinary machine designer. 
The carrier dispensing reel 21 is rotatably supported and allows a paper 
carrier strip 26, or sheet, to be routed through the tape assembler unit 
22. In the tape assembler unit 22 bonded tows, or "ribbons" 27, of 
composite material are received from overhead storage creels (not shown), 
and the ribbons 27 are deposited in predetermined spacings on the carrier 
strip 26. The carrier strip 26 and ribbons 27 continue from the tape 
assembler unit 22 into a tape compactor unit 23 which has a pair (multiple 
pairs, in some instances) of rolls 28,29, powered by a drive motor (not 
shown) and forming a nip 30 designed to receive and flatten the ribbons 27 
on the paper carrier strip 26, thus creating contiguous bands of composite 
material which, in effect, form a wide tape 31 on the paper strip 26. The 
tape 31 and carrier strip 26 exit from the compactor unit 23 and are 
trained over a tape laydown roller 24, which transfers the sticky tape 31 
to a part surface 32, or mold for building up a part surface. The carrier 
strip 26, once free of the composite tape 31, is gathered on a take-up 
reel 25. The rolls 28,29 are adjustably positioned with respect to one 
another to vary the opening at the nip 30. The rolls 28,29 may be adjusted 
by automatic means (not shown) so that tape 31 may be produced with 
varying cross-sectional thickness. 
Here it may be noted that while the preferred embodiment utilizes a carrier 
strip 26 coated with a release agent, other materials may be substituted 
therefor. Also, it should be noted that the composite ribbon 27 may have 
various cross-sections including, but not limited to: rectangular; round; 
and oval. 
FIG. 3 depicts the spaced ribbons 27 exiting the tape assembler unit 22. A 
plurality of ribbon spacing guide assemblies and a like number of 
corresponding cutter cam assemblies are located within the tape assembler 
unit 22 and will be discussed further in conjunction with FIGS. 5, 7 and 
8. 
The front view depicted in FIG. 4 shows the compacted ribbons 27 forming a 
wide tape 31 on the carrier strip 26. By proper sequencing of the start 
and stop points of the ribbon laydown on the carrier strip 26, angled 
profiles may be formed with the created tape 31 to facilitate 
edge-shaping, and custom-shaping of voids in the tape 31. 
Referring to FIGS. 5 and 7 taken through the tape assembler unit 22, the 
unit 22 has a basic frame comprised of upper and lower plates 33,34 
rigidly attached to end plates 35,36 and one side plate 37. The end plates 
35,36 have slots 38,39 machined therein, for the entry and exit of the 
carrier strip 26 across rear and front idler rollers 40,41 respectively. 
The tubular idler rollers 40,41 have end hubs 42 journalled for free 
rotation on shafts 43 held in the end plates 35,36. The rollers 40,41 have 
spaced hub flanges 44 for guiding the carrier strip 26. The carrier strip 
26 passes between a given ribbon spacing guide assembly 45 and its 
respective cutter cam assembly 46. It can be seen that multiple assemblies 
are required, i.e. one set of ribbon spacing guide assembly 45 and cutter 
cam assembly 46 is required for each ribbon 27 of composite material. In 
the present embodiment, nine ribbons 27 of composite material have been 
depicted, but it may be appreciated that the amount of ribbons 27 may be 
increased or reduced to suit the particular application. 
Ribbon Spacing Guide Assembly 
The ribbon spacing guide assembly 45 has a clevis-type carrier bracket 47 
which has downwardly-extending walls 48,49 and a central web 50 joining 
the walls 48,49. An access hole 51 is machined through each wall 48,49. 
The walls 48,49 have a pair of rollers 52,53 journalled for rotation 
therewith, and forming a nip 54 between the rollers 52,53. FIG. 9 shows 
that the rear roller 53 has an annular groove 55 to guide the ribbon 27. 
The rear of the web 50 has a rectangular boss 56 extending upwardly. The 
front of the web 50 has a vertical bore 57 journalled on a shoulder 
bushing 58 and a fixed pin 59 received in the top plate 33. The pin 59 has 
a threaded stud portion 60 received in the plate 33, and secured with a 
lock nut 61, and has a slightly increased shoulder diameter 62 extending 
from the plate 33 to a collar portion 63 located intermediate the plate 33 
and the bushing 58. The shoulder diameter 62 of the pin 59 journals a 
pivotal, straight link bar 64. The rearward boss 56 of the bracket 47 has 
a pilot hole 65 in which is received a pin 66 stationarily held in the top 
plate 33. A second pivotal link bar 67 is journalled around the pin 66 and 
prevented from axial movement by virtue of washers 68 and a collar 69 
integral with the pin 66. The pins 59,66 serve to keep the assembly 45 
aligned with the carrier strip 26. 
A two-legged equalizing bracket 70 is received on the journal pin 71 for 
the front roller 52 received between the side walls 48,49. One leg 72 of 
the equalizing bracket 70 carries a rotary wheel 73 which bears against 
both composite ribbon 27 and a back-up anvil portion 74 of a cutter cam 
assembly 46. The other leg 75 of the equalizing bracket 70 has a 
stationary pin 76 with a torsion spring 77 thereon to keep tension against 
a ribbon 27 riding on the roller 52 and to prevent back motion of the 
ribbon 27 after cutting. 
A ribbon 27 of composite material is first received through a vertical slot 
78 in the top plate 33, and extends downward through a vertical slot 79 in 
the web 50 of the bracket 47, passing into the nip 54 of the two rollers 
52,53. The ribbon 27 then wraps around the front roller 52 and extends 
across and under the wheel 73 of the equalizing bracket 70. The center 
ribbon spacing guide assembly 45 of the middle side-by-side trio of guide 
assemblies 45 shown is the only one securely attached to the top plate 33. 
In the remaining offset trios of guide assemblies 45, only the link bars 
80,81,82,83 are held in a fixed relationship with the top plate 33, by 
respective short-headed pins 84,85 at the front 80,81 and rear 82,83 link 
bars. All of the remaining spacing guide assemblies 45 depend from their 
two link bars respectively of a given trio set of guide assemblies 45, as 
shown in FIGS. 11, 12, 13. 
Cutter Cam Assembly 
The cutter cam assembly 46 is comprised of a bracket 86 having a bottom 
plate 87 attached to an upwardly-extending anvil portion 74 which 
terminates at the carrier strip 26. A pair of side walls 88,89 are affixed 
to the bracket 86 and the side walls 88,89 carry a horizontal pin 90, upon 
which is journalled a cutter cam unit 91. 
Each cutter cam unit 91 has a rotary cam 92 supported between the side 
walls 88,89 of the bracket 86. The cam 92 has a radial slot 93 receiving a 
transverse portion 94 of a torsion spring 95. The spring 95 has coils 96 
at each side of the bracket journalled on the pin 90. The spring coils 96 
each have a horizontal leg 97 joining with the transverse portion 94, and 
a vertical section 98 is hooked over the top of the bracket 86, to bias 
the cam 92 in a counter-clockwise direction. A set screw 99 received in 
the anvil portion 74 of the bracket 86 extends into a wide circumferential 
slot 100, or relief, to limit the bidirectional movement of the cam 92. 
The bracket 86 is carried in a rotary slip-fit on a forward vertical pin 
101 which extends through a bearing set 102 located in the bottom plate 
34. A second pin 103 extends through a second bearing set 104 in the 
bottom plate 34 and is fitted into a rear vertical hole 105 in the bracket 
86. The intermediate portion of the forward pin, between the bracket 86 
and the lower plate 34, is affixed by a screw 106 to a first rigid link 
bar 107 extending sideways as shown in FIGS. 5 and 11. A second link bar 
108 is journalled for rotation on the rear pin 103, between a shoulder 109 
of the pin 103 and the bracket 86, and the link bar 108 extends 
transversely to the two side brackets 86(a)(b), shown in FIG. 5. Here it 
should be noted that the front and rear pins 101,103 extend into the 
bracket 86 of only the centermost cutter cam assembly 46 of the middle 
side-by-side trio of assemblies 46, whereas all remaining assemblies 
46(a)-(h) are pinned to respective front and rear link bars 
110,111,112,113, alone, and not into the lower plate 34. 
The front and rear link bars 110,111,112,113 of the remaining trios of 
cutter cam assemblies 46(c)-(h) are journalled for rotation with their 
respective journal pins 114,115,116,117 in the lower plate 34. There are 
no upper extensions from the lower plate journal pins 114-117 (see FIGS. 
7, 12 and 13). The remaining side assemblies 46(a)(b) of the central trio 
of assemblies 46 are journalled for rotation on hollow pins 150 received 
in the linkage bars and secured with set screws 118 having dog points 119 
(FIG. 8). The outboard ends of the upper and lower linkage bars 64,107 
(FIG. 11, 12 and 13) are tied together by a post 120 having end screws 121 
so they will move in unison. The lower extensions of the journal pins 
103,114,116,117 received in the lower plate 34 are affixed to gears 
122,123,124 drivingly connected to one another. A driven sprocket 125 is 
affixed to the first gear 122 by screws 126, and is connected through a 
cog belt 127 to a drive sprocket 128 affixed to the shaft 129 of a drive 
motor 130 received on a bracket 131 mounted to the lower plate 34. The 
center gear 124 is affixed to the center forward vertical pin 101 by a 
screw 132. 
FIG. 6 depicts an idler sprocket freely journalled on a threaded stud 134 
which is radially movable in an elongate clearance slot 135 in the bottom 
plate 34 to adjust tension on the cog belt 127. 
In the assemblies shown in FIGS. 5, 7, and 8, it can be seen that rotation 
of the drive sprocket 128 causes the gears 122,123,124 to rotate their 
respective link bar assemblies, which are in fact four bar linkages, 
creating parallelograms of ribbon spacing guide assemblies 45 on top of 
the tape 31 and cutter cam assemblies 46 below the tape 31, so that the 
assemblies 45,46 remain parallel even though shifted sideways to vary the 
spacing of the ribbons 27 as shown in FIG. 10. 
The forward vertical pin 101 of the central bracket 86 is hollow, and has 
an adapter flange 136 affixed to its bottom portion by a set screw 137. 
The adapter flange 136 carries the coil 138 of a solenoid actuator 139 by 
studs 140 and locknuts 141 received with the flange 136. The solenoid 
armature 142 extends into the pin 101 and supports an actuator rod 143, 
which is slidably supported and extends from the top of the pin 101. The 
armature 142 has a bottom plate 144 biased in a downward direction by a 
conical compression spring 145. 
Referring to FIG. 8, the sectional view shows the motor mounting bracket 
131 secured to the bottom plate 34 by screws 146. The bracket 131 carries 
bearings 147 which support the drive sprocket 128, and a coupling 148 ties 
the sprocket 128 to the motor shaft 129. A side opening 149 is provided 
through the bracket 131 so that the cog belt 127 may be trained over the 
drive sprocket 128 and the drive sprocket 125. 
The three cutter cam units 91 and brackets 86 shown typify the mounting of 
the assemblies 46 of all but the center one shown in FIG. 7. The brackets 
86 are supported for translatory movement on their respective link bars 
107,108,110,111,112,113. The brackets 86 are journalled on hollow forward 
vertical pins 150 secured to the link bars 107,110,112. The pins 150 
depend from the link bars 107,110,112 and extend through clearance slots 
151,152,153 in the bottom plate 34. 
In a similar fashion to the vertical pin 101 of the central bracket 86, 
each pin 150 carries a relatively stationary coil 138 of a solenoid 
actuator 139 at its lowermost end. The movable armature 142 of the 
solenoid actuator 139 supports an actuator rod 143 which is slidable in 
the hollow pin 150. 
The cam 92 of the cutter cam unit 91 is generally flat and D-shaped, with 
the chordal surface being the base 154. An alternate radial slot 155 is 
provided to increase the spring force, if desired. The cam has a central 
radial slot 156 extending upward from the base 154, and an elongate knife 
157 is slidably received in the slot 156. The knife 157 has a chisel point 
158 at the top and a circular surface 159 at the bottom in contact with 
the tapered end 160 of the actuator rod 143. A relief 161 is provided at 
the right of the surface 159. An elongate slot 162 in the knife 157 
permits movement of the knife 157 on the horizontal pin 90 of the bracket 
86. A compression spring 163 received on the knife 157 reacts against the 
cam base 154 and a knife shoulder 164 to bias the knife 157 in a downward 
direction. 
The cam profile is comprised of two radii. The major radius "R" is 
generated from the pin 90 and extends to the right of center (relative to 
the knife slot 156). The radius "R" is sized to urge paper carrier strip 
26 upward against the composite ribbon 27 and roller 52. The minor radius 
"r" is also generated from the pin 90 and extends to the left of center 
(relative to the knife slot 156). The radius "r" is sized to clear the 
carrier strip 26 as the cam 92 is rotated. 
Cutter Cam Operation 
FIG. 8 shows three cutter cam assemblies 46 in different modes of 
operation, which have been labeled from left-to-right: "Assembling"; 
"Cutting"; and "Standby". 
In the "Assembling" mode, the solenoid actuator 139 is de-energized, and 
the cam 92 is biased in a CCW direction, urging the carrier strip 26 
upward against the roller 52 and composite ribbon 27. The ribbon 27 and 
strip 26 then pass across the anvil portion 74 of the bracket 86. 
In the "Cutting" mode, the solenoid actuator 139 is energized, forcing the 
actuator rod 143 and knife 157 upward thereby puncturing the strip 26 and 
severing the composite ribbon 27. Continued movement of the paper strip 26 
during the "Cutting" mode causes rotation of the cam 92 in a CW direction. 
When the knife relief 161 reaches the end 160 of the actuator rod 143, the 
knife 157 will snap downward under the influence of the knife biasing 
spring 163. At this point the clearance radius "r" is under the paper 
strip 26, and the solenoid actuator 139 is still energized. the roller 52 
ceases rotation since the incoming ribbon 27 is out of contact with the 
moving carrier strip 26. 
To restart ribbon movement, the solenoid actuator 139 is then de-energized, 
thereby causing the cam 92 to rotate in a CCW direction under the 
influence of the torsion spring 95. When returned thusly to the 
"Assembling" position, the major radius "R" of the cam 92 will deflect the 
strip 26 upward against the composite ribbon 27 and roller 52, reattaching 
the sticky ribbon 27 to the paper strip 26. 
The individual ribbons 27 can be served and restarted at will, independent 
from one another, to form various tape profiles which will pass from the 
tape assembler unit 22 and into the taper compactor unit 23. 
After leaving the tape compactor unit 23 the tape 31 continues to the tape 
laydown roller 24 at a tape laydown station which is substantially the 
same as that in conventional type laying machines. The carrier strip 26 
exiting the tape laydown station is gathered on a take-up reel 25. 
While the invention has been shown in connection with a preferred 
embodiment, the invention is not limited to such embodiment, but rather 
the invention extends to all designs and modifications as come within the 
scope of the appended claims.