Note: Descriptions are shown in the official language in which they were submitted.
7~
This invention relates to a method and apparatus for '
producing a reinforced molding compound in a sheet form. More
particularly the invention relates to an improved compaction
section or wet out station to be used in forming the molding
compound.
In the past a number of devices have been used to
produce molding compounds in sheet form. Usually these devices
deposit a reinforcing material and a resinous material molding
compound in a pre-molded state between two carrier sheets. The
composite retained as a layer between the carrier sheets, is then
passed between two opposed compaction rolls or a series of
opposed compaction rolls that are in spaced apart relationship
to wet out the reinforcement and resln. However, the prior art
compaction rolls only supply force for a short period of time to
the composite and the reinforcements are not always completely
~: .
wet out by the resin. Also, when the composite is formed, there
is frequently air entrapped beneath the carrier sheets. When the
composite passes through the compaction rolIs the air is not
always forced from beneath these carrier sheets. After the
composite passes through the compaction rolls the composite
springs back and large air bubbles can be formed beneath the
~carrier sheets. These air bubbles can break the carrier sheets
leading to production line shut-down or cause non-uniformities -
when the composite is molded. In addition the unequal force
; applied hy the compaction rolls, the springiny back of the
composite a~ter it passes through the compaction rolls and the air
bubbles can cause the reinforcement in the composite to be
displaced or moved. When the reinorcement is displaced the
strength provided by the reinforcement may no longer be uniform
30 as the positioning of the reinforcement in the composite is no ,~
:;
76
longer uniform. Accordingly, the strength of an article molded
from the composite rnay not be as uniform as desired.
A complet~ wet out of the fibers of the composite is
essential to the quality of the ultimately molded product. The
difficulties heretofore encountered in achieving proper wet out
have resulted in limitations both in continuous process production
rates as well as in the restriction of fiber loading or weight
and thickness of the sheet molding compounds. When properly wet
out, the entire surface of each fiber within the resin matrix is
coated with resin. E~ailure to properly wet out a fiber or fibers
generally results in the presence of an internally disposed air
pocket or bubble representing a production defect.
In any event the non-uniformities that may be produced
by the compaction rolls can reduce the uniformity of the sheet
molding composite that is produced. 'rhis in turn can effect the
uniformity of articles molded from the composi-te. These non-
uniformities can also effect the reproducibility or uniformity of
composites that are produced at different times.
According to an em~odiment of the invention there i8
provided a method and apparatus defining a means for linearly
. advancing a sheet molding compound. A movable upper surface
formed by a helt passing around a series of driven rollers ig
adapted to contact the upper surface of the sheet molding
compound~ The belt of the upper surface is held in biased
relationship to the sheet molding compound.
An object of the invention is to provide an improved
method and apparatus Eor making sheet molding compound.
Another ob~ect of the invention is to provide an
improved method and apparatus for compacting and efEecting wet out
33 of the fibers of the sheet molding compound.
~,
- ~
76
,~
Additional embodiments o~ the invention are
further addressed to an apparatus and method for treating
sheet molding compound present as a composite of a molding
compound in a premolded state having reinforcing fibers
disposed therewithin ! the composite being retained as a
layer between the mutually inwardly disposed surfaces of two
continuous thin, supporting sheets. Both the composite and
supporting sheets are mo~ed along a production path through two
mutually facing continuous belts which preferably are steel mesh
.
belts under tension. By arranging the roller supports of the
belts appropriately, the composite and supporting sheets are ~;
caused to be not only compressed bu~ to flex in vertically
undulating fashlon to derive a ~ery high quality of wet out of
the fibers within the resin matrix. In one arrangementl one
belt is moved or driven at a fixed rate, while the belt adjacent
` thereto is driven at a rate continually oscillating a predeter-
mined amount above and below the aforesaid fixed rate. Such an
arrangement, particularly when combined with the noted undulatory
manipulation of the material, serves to considerably improve
production rates as well as afford a capability for producing
materials of greater thickness and fiber loadings, ultimately
deriving higher strengths. In another embodiment of the
invention, four continuous belts are utilized in the fashion
described, those adjacent helts positioned upstream along the
production path being arranged to assert a first wet out action
upon the composite and the next succeeding pair of belts assert-
ing another wet out action specific to the altered state of the
composite as it passes through the first pair of belts.
Additionally, the operator is afforded the opportunity to alter
the degree of compression exerted by any given pair of continu-
ous belts. A highly desirable flexibility thus is afforded the
3 -
--~.~.................................................................. .
S~ 76
opera-tor with the four belt system. ~y utilizing a steel mesh
bel-t of relatively coarse mesh configuration, larger composite
sizes can be treated initially without causing the resin
component to migrate away from the fibers or "squeeze out". In
effect, the resin is trapped in a myriad of pocke-ts to inhibit
such migra-tion at the upstream stage of treatment. The down-
stream pair of belts then can be provided having a finer mesh
configuration to effect the final and thorough wet out of all
fibers within the larger composite structure. As a consequence,
composite structures exhibiting considerably enhanced strength
and size can be produced where such production was heretofore
impossible at practical and economical production rates.
According to one aspect o the presen invention, then, there is
~- provided an apparatus for treating a o~q~ite present as a moldingloo~pound
; in a pre-molded state having reinforcing fibers disposed there-
within, said composite being retained as a layer between the
mutually inwardly disposed surfaces of two continuous, thin
supporting sheets, comprising conveyor means including a belt
exhibiting an upwardly disposed continuous movable surface and
having a width at least co-extensive with ~he width of said
composite for supporting said composite by contact with the
lowermost one of said supporting sheets and effecting the movement
thereof along a path, a plurality of spaced, serially disposed
rollers mounted for supporting said belt at points of tangency
with the underside of said upwardly disposed surface, means for
driving said conveyor means belt at a predetermined rate to effect
said continuous surface movement, wet out stage means including
a continuous belt under tension positioned above said conveyor
means belt, having a width at least co-extensive with the width
of said composite, having a downwardly disposed surface extending
,< '~
~5~6
over a substantial lengthwise portion thereof and including a
plurality of spaced rotatable serially disposed rollers support-
ed for contact with said tensioned belt at spaced points of
tangency with the upwardly disposed surace thereof and urging
said downwardly disposed surface thereof into con~inuous com- :
pressi~e contact with the uppermost one of said supporting
`sheets, so as to effect a sub:stantial wet out of the surfaces of
said fibers by said compound to deri~e an intimate bond there-
between when molded.
: ",
~ 10 According to a further aspect of the present invention,
there is pro~ided a ~ethod for treating a composite present as
a moldin~ compound in a pre-molded state ha~ing reinforc:ing ~:
~ "
fibers disposed therewithin, said composite being retained as a
- layer between the mutually inwardly disposed surfaces of two
'::
continuous, thin supporting sheets, comprising the steps of
providing a continuous first moving:belt in tension having an
upwardly disposed surface movable along a predetermined produc-
tion path, providing a continuous second moving belt in tension
having a downwardly disposed surface of substantial len~thwise
extent in substantial adjacency with said first belt upwardly
disposed surface; and passing said supporting sheets and
; enclosed composite along said production path between said down-
wardly disposed continuous belt surface and said upwardly dis-
posed surface of said convenyor belt to efEect the compression
thereof while, simultaneously, causing said adjacent belt surface
to ~lex in a vertically undulatin~ fashion.
Accordin~ to another aspect of the present invention,
there is further provided a method of wetting out fibers in an
: indefinite length layer of resinous material, comprising: pro-
viding a first mesh surface movable along a predetermined path;
~ _ 5 _
,~
~:~2~ 76
providing a second mesh surface opposite the first surface
movable along the path; compressing a layer containing resin and
fibers between the first surface and the second surface along
the path; moving the first surface along the . path at a first
rate; and moving the second surface along the path at a second
rate; the second rate continuously varying within a predetermined
: range of rates above and below the ~irst rate.
Embodiments of the invention will now be described with
; reference to the accompanyiny drawings in which:
Figure 1 is a side elevation view o the apparatus for
producing sheet molding compound.
~ 5a -
~ir
5~
Figure 2 is a top view of the apparatus for producing
sheet molding compound~
Figure 3 is a side elevation view of the compaction
section or wet out sta~e used to produce the sheet molding
compound.
Figure 4 is a partial side elevation view of the
compaction section or wet out stage shown .in Figure 3 where the
compaction section is compacting sheet molding compound.
Figure 5 is a side elevation view of another embodiment .
; 10 for apparatus serving to treat sheet molding compound.
Figure 6 is a top view of the apparatus of Figure 5.
Figure 7 is an upstream end view of the apparatus of
Figure 5.
Figure 8 is a partial sectional view of the apparatus
of Figure 5 taken in a downstream direction through the plane 8-8
in that figure.
Figure 9 is a schematic elevation view of the drive
arrangement of the apparatus of Figures 5 and 6.
Figure 1~ is a side elevation view of still another
embodiment for apparatus serving to treat sheet molding compound.
The invention will be more fully explained in the
following descriptive material with reference made to the attached
drawings. Figures 1 and 2 show apparatus for producing a
reinforced resinous molding compound in sheet form. The apparatus
has a movable conveyor 1 that is supported on a series of rollers
2. At each end on the conveyor there is a large drive roll 3 for
supplying movement to the conveyor. Any conventional drive means
can be used to drive or rotate the drive rolls 3 to advance the
conveyor. As the conveyor passes around the drive rolls it
forms a continuous closed loop around the drive rolls~
- 6 -
76
At one end of the conveyor a first roll 5 of thin
material is located. The sheet material 7 can be unrolled from
the roll S onto the upper surface of the conveyor. The sheet
material will be of a width that it will extend across the
entire width of the conveyor. Although a number of materials
can be used for the sheet material, it has been Eound that a thin
vinyl material works very satisfactorily.
Located along the conveyor is a reservoir 11 for
holding a flowable resinous material 12. The reservoir 11 has
four sides that define the container but there is no bottom wall
in the reservoir. The reservoir is positioned so that it is
spaced apart Erom the upper surface of the sheet material 7 on
the conveyor.
Positioned next a~ong the conveyor is a chopper 15 for
chopping rein~orcing material ~S to a certain length. The chopper
contains a rotatable resllient cot roll 17 and a rotatable
chopping roll 19. Positioned around the periphery of the chopping
roll is a series of blades 21. The blades 21 strike the cot roll
as the chopping roll is rotated. Positioned above the cot roll is
- 20 an idler roll 23 that is in contact with the cot roll.
~ . . .
The b-ades 21 on the chopping roll extend across the
width of the chopping roll. Also, the blades are spaced apart
a distance that is substantially the same as the desired length
for the chopped reinforcing material.
A second roll of thin sheet material 51 is located after
the chopper along the path of the conveyor. The sheet material
53 from this roll passes beneath a resin reservoir 55, around a
rotatable roll 57 and onto the surface of the conveyor. The
; resin reservoir 55 is substantially the same in construction and
is located substantially the same distance above the sheet
material as the previously described resin reservoir 11.
~'
~'
.~ :
A series of freely rotatable compaction rolls 61 are
positioned above the conveyor. A belt 62 passes around the
compaction rolls in a continuous closed loop. The compaction
rolls and belt extend across the entire width of the conveyor.
he compaction rolls are positioned so that the belt is in contact
with the upper surface of the second sheet of material on the ;~
conveyor. The belt should be positioned around the compaction
rolls so that the belt is ~ept in a taut or tensioned condition.
~ he belt 62 could be constructed of almost any material.
10 ~owever, ln practice it has been found that a steel mesh belt ;
works most satisfactorily.
At the end of the conveyor is located a rotatable co~let
65 that is supported by framework 67. The collet is located at
approximately the same height as the upper surface of the conveyor
and the material formed on the conveyor lS collected as a wound
package on the collet. A motor (not shown) is attached to the
coIlet for rotating the collet at substantially the same speed
as the advancing conveyor.
The operation of this invention will be more fully
understood by referring to Figures 1 and 2 in conjunction with
the following description. The conveyor 1 is caused to move by
any suitable drive means (not shown). As the conveyor advances
a layer of the supporting sheet material 7 is p~aced on the
upper surface of the conveyor so that the sheet material is
carried along with the moving conveyor.
As the sheet material advances it passes under a resin
reservoir 11 positioned along the path o the conveyor. A layer
of resinous material 63 which is a molding compo~md in an
unmolded state, is deposited onto the upper surface of the sheet
material by the resin reservoir. The front edge 64 of the resin
` ~ '
~ - 8 -
,
76
reservoir acts as a metering blade to control the thickness of
the layer of resin that is deposited onto the sheet material.
Next the sheet material is advanced under the reinforce-
ment chopper 15. At the chopper, strands of reinforcing material
~5 are fed between the cot roll 17 and the rotating chopping roll
19 and the blades 21 on the chopping roll break the reinforcing
material into a plurality of short lengths of reinforcing material
69. The short lengths of reinforcing material are deposited onto
the layer of resin 63 on the upper surface of the advancing sheet
material.
Positioned next along the advancing conveyor is a
second roll of supporting sheet material 51. The sheet material
53 from the roll is passed under a resin reservoir 55 and a layer
of resin 79 is deposited onto the upper surface of the sheet
material. The resin reservoir works substantially simi~ar to the
previously described resin reservoir 11. The resin coated sheet
material passes around rotatable roll 57 and advances down to the
conveyor. The resin layer 79 on the sheet material comes into
contact with the chopped reinforcement and resin that are already
being advanced along the conveyor. Thus, the resin and chopped
reinforcements are sandwiched between two thin sheets of material.
Next the composite 81 of the resln, reinforcing material
~ sandwiched with two sheets of supporting material passes under
- the belt 62 and compaction rolls 61. As the composite 81 advances
it will usually cause the belt 62 to advance around the rotatable
compaction rolls. The belt and compaction rolls exert a downward
force or a compaction force on the composite. l'his compaction
force pushes the resin and reinforcing material together so that
the reinforcing is wet out by the resin. ~he compaction force
also assists in removing entrapped air from the composi-te. In
5~76
between the compaction rolls 61 the weight and tautness of the
belt 62 continues to exer-t a compaction force on the composite.
Thus, the composite is kept under a compaction force for an
extended residence interval, i.e. during the entire time it is
under the belt 62. This compaction force is also uniform across
the èntire width of the belt and serves to exert a shear-type
force across the resin-fiber composite simultaneously with the
noted compression thereof inasmuch as belt 62 is not directly
motor driven.
;~ 10 After passin~ under the belt 62 the composite advances
alon~ the conveyor to a collet 65. The collet 65 is rotated at
substantially the same speed as the advancing composite and the
composite with supportin~ thin sheets is wrapped around the
collet to form a wound package.
; Figures 3 and 4 show an additional embodiment of
compaction section or wet out stage that can be used to produce a
reinforced resinous molding compound. In these figures the
composite sandwich 81 is produced as previously described; then
the composite is advanced to a separate compaction section or
wet out stage 100. The compaction section has a stationary lower
member 105 having a series of rotatable rollers 107 mounted
therein and a movable upper member 109 having a series of
rotatable rollers 111 mounted therein. A movable belt 115 is
positioned around the rollers 107, an idler roll 117 and a drive
roll 119 to form a continuous closed loop around the lower member.
On the upper member a movable belt 125 is positioned around the
rollers 111, and idler roll 127 and a drive roll 129 to form a
continuous closed loop. The idler roll 117 and idler roll 127
are slidably mounted on lower and upper members respectively.
The idler rolls can move in a radial direction with respect to the
- 10 -
76
adjacent drive roll due to the sliding moun-ting arrangement for
the idler rolls. A biaslng means 118 is positioned on idler roll
117 and idler roll 127. The biasing means supplies a constant
force to the idler rolls and act to urge the idler rolls in a
generally downward direction against the upper and lower belts.
The biasing means can be a spring, weight or other suitable mPans.
A double sprocket 120 is located on the lower drive roll
119 and sprocket 130 is located on the upper drive roll 129. A
chain 133 connects the double sprocket 120 to sprocket 135 located
10 on the drive motor 137. Chain 139 connects double sprocket 120
to sprocket 130. Therefore, sprockets 120 and 130 are both
connected to the drive motor by chain 133 and chain 139.
A rotatable idler sprocket 141 is positioned on the
upper member 109 and is in contact with the chain 139. The axle
or support 145 for the idler sprocket is slidably mounted in slot
147 in the upper member. A spring or air cylinder 149 is
; positioned in the slot and the spring pushes against the axle 145
of the idler sprocket to urge the idler sprocket to move towards
the chain. The spring 149 usually urges the idler sprocket to
move in a direction that is the same as the direction of advance-
ment of the composite material.
.
At each end of the upper member 109 there is located an
air cylinder 155 serviny, in effect, as a compaction actuator,
that is used to vertica]ly position the upper member~ The air
cylinders can be used to either raise or lower the upper member.
Figure 4 shows the position the upper member would normally be in
with respect to the lower member, during actual use of the
compaction section. In this figure it can be seen that the
rotatable rollers 107 in the lower member and the rotatable rollers
111 in the upper member are positioned so that the arc of the
rollers that contacts the composite will fit in the space provided
~Z5~7~
.
between the adjacent two rollers on the opposite member. Thus,
the lower belt 115 and the upper belt 125 de~ine a generally
undulating or sinusoidal path when upper and lower members are
in the operating position shown in Figure 4.
In operation the compaction section 100 will be placed
in the normal operating position by activating air cylinders 155
to lower the upper member 109 to the general position shown in
Figure 4. This movement of the air cylinders will also provide
a downward or compaction force to the upper member. When the
upper member is properly positioned, the drive motor 137 is
actlvated and this causes sprocket 135 to rotate. Chain 133
transfers the rotation of sprocket 135 to double sprocket 120 and
chain 139, which connects double sprocket 120 and sprocket 130,
causes sprocket 130 to rotate. Thus, drive roll 119 and drive
roll 129 are caused to rotate, by the rotation of sprocket 120
and sprocket 130 respectively, when the drive motor is activated.
It should be noted that sprockets 120 and 130 are substantially
the same diameter and that drive roll 119 and drive roll 129 are
also substantially the same diameter. Accordingly, the circumfer-
ential speed of the drive roll 119 and drive roll 129 will be
substantlally the same. -
As the drive roll 119 rotates it causes the belt 115 to
advance around the rollers 107 and idler roll 117. At the same
time drive roll 129 is rotating and causing belt 125 to advance
around rollers 111 and idler roll 127. Since drive rolls 119
and 129 are rotating at substantially the same speed, belt 115
and belt 125 will also be advanced at substantially the same
speed. The two belts will be driven so that they are advanced
over the rollers 107 and 111 in the same direction as the
composite is being advanced. The speed of drive motor, drive rolls
- 12 -
5~7~
and sprockets should be selected to advance the belts at ~ .
substantially the same speed as the composite is ~eing advanced~ ~ .
As the two belts advance; the biasing means 118 on idler
roll 117 and idler 127 will force the idler rolls in a generally
downward direction against the belts with a cons~ant force. The
constant force from the idler rolls will keep a constant tension
on the upper and lower belts as the belts are advanced. Also
the idler sprocket 141 is urged against chain 139 with a constant
force supplied by spring 149. The force from the idler support
10 keeps the chain at the proper tension. Sinee the idler sprocket :
ean slide in slot 147, the idler sprocket can keep tension on the .
chain 139 even though the upper member is moving in a vertical
direction.
Figure 4 shows the composite 81 with supporting sheets
as i-t passes through a portion of the eompaetion section. Once
: - ~
the composite comes into contact with the belts, the advancing
belts grip the composite and advance the composite through the
. compaction section. In the eompaetion seetion the eomposite is
foreed to follow a generally undulatin~ path that is formed as
20 the belts pass over rollers 107 and rollers 111.
. . b
The downward or compaetion ~orce supplied to the upper .
member by the eompaetion aetuators or air eylinders 155 will be
transferred to the belts through rollers 107 and rollers 111. The
eompaetion force will aet on the eomposite primarily when the ::
: eomposite is passing between the nip region formed by opposing
rollers on oppos.ite members. The eompaetion foree will cause the
eomposite to de~orm and eompaet. When the eomposite is in the
peaks 160 and valleys 165 formed between adjaeent rollers on a
member/ the eompaetion force supplied by the air eylinder and the
weight of the eompaetion seetion will not be as great. However,
- 13 -
~: .
7~
the composite must displace the upper and lower belts to move
through the compac~ion section. Since the biasing means 118 on
the idler roll 117 and idler roll 127 supplies a constant tension
to the belts, the composite must overcome the force of this
tension to displace the belts. Thus, the biasing means 118 keeps
a level of tension on the belts that also exerts a compaction
force on the composite. ~ccoxdlngly, as the composite moves
through the compaction section, the composite will always be
under a compaction force~
10The compaction force, shear and related phenomena on
the composite will push the resinous material and rein~orcing
material together to wet out the reinforcin~ material. The
undulating path formed by the compaction section or wet out stage
causes the composite to be cycled in an up and down or vertical
direction and this movement improves the flowing together of the
reinforcing material and resinous material and therefore improves
- the wet out of the reinforcing material. The compaction force
also forces entrapped air out of the composite. Since the
composite is kept under continual compression in the compaction
section large air bubbles do not have a chance to form. Further,
the continual force supplied by the compaction section discoura~es
any movement by the reinforcing material in the composite.
The air cylinders used to position the upper member 109
can he operated independently of one another. Therefore, the air
cylinder at the entrance end of the compaction section can he
exerting a different force on the upper member than the air
cylinder at the exit end of the compaction section. Thus, the
compaction force supplied by the air eylinders can be different
along the length of the compaction section by havin~ the air
cylinders supplying different forces at each end of the upper
member.
- 14 -
5~376
In the previously described embodiments a chopped
rein~orcing material has been used. In practice it has been
found that glass fibers work very well as this reinforcing
material. Also the glass fibers could be continuous fibers, the
glass fibers could be chopped fibers that have been deposited
with the longitudinal axis of the fibers being substantially
parallel to one another, or other well known forms of glass fiber
reinforcements could be used in the composite.
Almost any resinous material that is normally used to
make a molding compound in sheet form could be used in this
invention. However, thermosetting resins and particularly
polyester resins have been found to work most satisfactorily.
As described hereinabove in connection with the
embodiment of Figures 3 and 4, the wet out stage 100 combines
.
a continuous compression over the composite 81 in combination with
the imposition of a shear effect thereon occasioned from a
verticaIly undulating manipulation. This combination of activities
imposed upon the composite achieves such a high degree of wet
out that thicker composites and higher fiber loaded products can
be produced at advantageously higher production rates. Further
improvements are available with the wet out stage embodiment
: .
represented in Figures 5-8, composite 81 being fabricated as
described in Figures 1 and 2.
Looking to Figures 5 and 6, as in the embodiment 100,
the wet out stage 180 includes an upper member or carriage
assembly 181 formed generally having side beams or supports 182
and 183 which, as revealed in Figure 8, are retained in spaced
apart relationship by cross beams, one of which is revealed as 184.
As in the earlier embodiment, assembly 181 supports a continuous
belt 185 which, preferably, is present as a meta] mesh or weave
~:: . .. .. , :
~L;25~6
belt capable of being driven in tension. Belt 185 extends about
a drive roll 186, the surface of which is formed having a flexible
or rubberized material assuring a positive drive contact with the
underside of belt 185. At the forward or production upstream end
of carriage assembly 181 there is positioned a freely rotating end
roll 187 over which belt 185 is passed. Roll 187 serves to
maintain belt 185 in a tension predetermined by the operator by
virtue of the journaled connection of its axle 188 within opposed
slideable supports 189 and 190. As shown in Figure 5, each
support as at 189 is mounted for horizontal manipulation by
slideable engagement with two horizontally disposed beams 191 and
;-~ 192. Supports 189 and 190, respectively, are maneuvered
~; horizontally in consequence of their engagement with the movable
piston of hydraulic cylinder assemblies 193 and 194 As in the
earlier embodiments, assembly 181 also supports a plurality of
spaced, rotatable, serially disposed rollers, certain of which
are identified, for example at 195. The supports for these
rollers 195 are coupled to the bottom flanges of oppositely
disposed side beams 182 and 183.
~;~ 20 Shown in its lowered operational orientation, the
carriage assembly 181 is selectively movable vertically, ~or
example, to an orientation earlier described in connection with
Figure 3, by four pneumatic cylinders 196-199. The upwardly
disposed ends oE the piston rods extending from pneumatic
cylinders 196-199 are each joined to a connector block as shown
respectively at 200-203, each of which is fixed to an associated
side beam 182 or 183. Serving as compression ac-tuators, pneumatic
cylinders 196-199 may be utilized to adjust the vertical position
of carriage assembly 181 and the consequent compressive stress or
compaction of the composite passing through the wet out stage 180.
Z5~376
Cylinders 196 and 197 are connected to the side beam
204 of a lower assembly represented generally at 205. As shown
in Figure 8 r the corresponding side beam 206 serves to support
the oppositely disposed pneumatic cylinders 198 and 199. That
figure also reveals the pressure of one cross beam 208 o~ an
arrangement thereof serving to provide the support of and lateral
~ spacing of beams 204 and 206. The entire stage 180 is supported
~ above floor level by leg members 209 and 210 connected, ~.
respectively, to side beams 204 and 206 (see additionally Figures
-` 10 7 and 8). : -
~ .
Formed in substantially similar fashion as carriage
: assembly 180, lower assembly 205 incorporates a drive roll 211
mounted for rotation at the downstream end thereof, as well as
an end roll 212 at the upstream end thereof~ The axle 213 of
.. . .
roll 212 is jou.rnaled for rotation within slideable supports 214
` and 215 (see Figures 5 and 7). Supports 214 and 215, in turn, are
: :i
,~ ~ mounted upon respective beams 204 and 206 by slideable connection
~'~ with horizontally disposed guide beams, two of which are revealed
at 216 and 217 in Figure 5 as associated with support 213.
Adjustment of the horizontal position of roll 212 is provided by
pneumatic cylinder 243 and 244 in similar fashion as provided for
end roll 187. Similar to the arrangement of end roll 187 of
carriage assembly 181, end roll 212 serves to impart a predeter-
mined tension upon a continuous belt 218 passing additionally over
drive roll 211 and a plurality of spaced, rotatable, serially
; dlsposed rollers certain of which are identified at 219. Rollers
219 are supported across the upward flanges of side beams 204 and
206. Additi.onal support for belt 218 is provided along the under-
side of assembly 205 by supplementary support rolls 220 and 221
30 which span across respective leg members 209 and 210 as shown.
- 17 - :
S~7~
As in the case of the embodiment of Figures 3 and 4, rollers 219
are spaced with respect to rollers 195 of upper car~iage assembly
181 such that the points of tangency of rollers 195 with the
upwardly disposed surface of belt 185 fall intermediate the
corresponding points of tangency of rollers 219 with the downwardly
disposed surface of belt 2180
Looking additionally to Figures 5 and 6, upper carriage
assembly 181 is provided having a leveling.system constituted by
four leveling assemblies shown generally at 222-225. Each of the
latter assemblies is formed having a pair of adjacently disposed
upstanding racks 226 and 227. The racks 226 and 227 of assemblies
:~ 222 and 223 are adjustably bolted to side beams 204, while the
.
corresponding racks 226 and 227 of assemblies 224 and 225 are
adjustably bolted to side beam 206. Racks 226 each face inwardly
toward the center line of the assemblage, while corresponding
;~ racks 227 face outwardly in alignment with the lengthwise
orientation of upper carriage assembly 181. The inwardly facing
racks 226 of assemblies 222 and 223 are associated by corres-
ponding pinions 228 which are enmeshed therewith and are fixedly
journaled over the opposite ends of an elongate rod 229. Rod 229,
in turn, is rotatably mounted between two spaced bearing
assemblies 230, each of which is connected to the upwardly
disposed portion of side beam 182. In identical fashion, as
shown in Figure 6, spaced pinions 231 are associate~ with racks
226 of assemblies 224 and 225. Pinions 231 are fixedly iournaled
to an elongate rod 232 which, in turn, is rotatably mounted upon
beam 183 by spaced bearing assemblies 233. With the arrangement
thus far described, upper carriage assembly 181 is restrained
from tilting away from a horizontal orientation along -the length-
wise extent of stage 180.
- 18 -
5.~6
Leveling control in a direction transverse to the noted
lengthwise extent is provided by a similar association of pinions
234 as enmeshed with corresponding racks 227 of spaced assemblies
224 and 222 at the upstream end of assembly 180. Pinions 234 are
fixedly journaled to the ends of an elongate rod 235 which~ in
turn, is supported for rotation by spaced bearinq assemblies 236
and 237 which are fixed, xespectively, to the upper flanges of
beams 182 and 183 (see Fiqure 7). Similarlyf toward the down-
stream end of staqe 180, pinions 237 are enmeshed with corres-
-;.,
~` 10 ponding racks 227 of spaced assemblies 223 and 225. Pinions 238
are fixedly journaled to the oppositely disposed ends of elongate
, rod 239 which is rotatably supported by spaced bearing assemblies
240 and 241. Assemblies 240 and 241 are fixed to the upwardly
disposed flanges of respective side beams 182 and 183. Each of
-" ~ ~
s~ the leveling assemblies 222-225 also incorporates a retainer ~ ~
~ ~, .: .
arrangement including a freely rotatable roller 242 which rides
against the smooth outwardly disposed surface of a corresponding ~ `
rack 2260 With the arrangement thus described, upper carriage
assembly 181 is retained in a horizontal orientation while being
permitted vertical adjustment between open and closed orientations.
The wet out stage embodiment of Figures 5-8 particularly
is characterized by the technique of treatment of the composite
81 as it progresses from the upstream through the downstream end
of the apparatus. This direction is indicated in Figure 5 by
an arrow above a schematic representation of composite 81. In
addition to the extended and continuous compression as well as
the vertical undulation of the material, a third shear inducing
factor is produced from the drive system itself. Initial drive
for the system is provided by a motor 250 which delivers a
rotative output through a sprocket 251. Looking additionally to
-- 19 --
~5~76
Figure 9, sprocket 251 is seen coupled through chain 252 in
driving relationship with a sprocket 253. Sprocket 253, in turn,
is journaled over and fixed to the axle 25~ associated in driving
relationship with drive roll 211 of lower assembly 205.
Accordingly, drive roll 211 is rotated from the abvve described
~; linkage. Note, however, that a second sprocket 255 also is
~- journaled and flxed to axle 254. This sprocket communicates via
- chain 256 to a sprocket 257 rotatable about axle 258 and ~
positioned within a drive system housing 259. Sprocket 257 ~ ~-
imparts rotational driv~ to a coaxially mounted sprocket 260.
Sprocket 260, in turn, imparts drive to a chain 261 which extends
upwardly and is driveably enmeshed with the teeth of a sprocket
262. From this engagement with sprocket 262, chain 261 extends
about guide sprocket 263 which is rotatable about axle 2640 From
guide sprocket 263, chain 261 extends over an idler sprocket 265,
freely rotatable about axle 266. From idler sprocket 265 chain
261 returns to engagement with sprocket 260. Axle 266 is mounted
so as to be pivotally movable about an arc and is biased in an
upward direction by a conventional sprlng arrangement (not shown).
Sprocket 262 is eccentrically mounted upon an axle 267
and imparts drive thereto. Axle 267, in turn, is driveably
connected to the center of a sprocket 268 and the latter sprocket
imparts drive through a chain 269 to a drive sprocket 270.
Sprocket 270, in turn, is journaled over and fixed to axle 271
and through that axle imparts drive to drive roll 186 of upper
carriage assembly 181. It will be apparent that double sprockets
may be utilized in combining sprockets 253 and 255,sprockets 257
and 260 and sprockets 262 and 268, depending upon the desires of
the apparatus designer.
With the drive system thus described, it may be observed
- 20 ~
~L25~ 76
that the drive imparted through sprocket 253 to drive roll 211 of
~ the lower assembly 281 is at a uniform fixed rate. Elowever, the
`` eccentric mounting of sprocket 262 imparts a drive through
-~ sprockets 268 and 270 to drive roll 186 of upper or carriage
assembly 181 at a rate which continually oscillates a predeter-
~ mined amount above and below the fixed rate of drive imparted to
- lower as~embly drive roll 211. As a consequence, a further
oscillatory shear action is imparte~ through the top of composite
: 81. This activity has been observed to enhan~e the wet out of the
:~: 10 composite 81 and permit the fabrication of thicker composites ~~
.
` as well as composites having higher fiber loadings~ The biased :.
arcuate movement of ldler sprocket Z65 may be observed to perform
the necessary function of taking up slac~ within chain 261 in ~:
j
~; the course of the eccentric rotation of sprocket 262~ An exemplary ~.
. .
; altered orientation of sprocket 265 is represented in Figure 10 ~;~
at 265', while the corresponding alteration of the orientation
of chain 261 is represented in dashed line fashion at 261'. ~ -
Note, that with the embodiment as described, comp~site 81 is
subjected to a continuous compression coupled with a vertical
-. 20 undulation as well as a lengthwise induced shear due to the
~- - oscillatory drive emanating from drive roll 186. Note further,
. ~.
that the average rate of movement of chain 185 is equal to the
fixed rate of movement oE lower chain 218. As a consequence,
the integrity of composite 181 is maintained throughout its
passage along wet out stage 180.
Referring to Figure 10, another embodiment for a wet
out stage is revealed generally at 280. As before, composite 81
is fabricated as described in connection with Figures 1 and 2
prior to introduction at the upstream end of stage 280. This end
3~ is located at the production flow directional arrow positioned
- 21 -
76
above the schematic representation of composite 81 in the figure.
As is apparent from the figure, the instant emhodiment
incorporates components somewha-t similar to or identical to the
embodiment described above in connection with Figures 5-9. In
: this regard, note that the stage 280 includes a lower assembly
281 having spaced elongate and parallel side beams, one of
which is revealed at 282. The assembly is supported above floor
: level by leg members as at 283 and includes a drive roll 284
- at the downstream terminus thereo~O This drive roll preferably
is provided having a surface texture suited for frictionally
~ engaging a continuous belt 285. Such texture may be provided
:~` through the utilization o~ rubberized coatings or the like. As
in the earlier embodiments, belt 285 has a width at least
coextensive with composite 81 and the upwardly disposed portion
thereof is situated such that its downwardly disposed sur~ace
extends over a pl~rality of spaced, ~reely rotatable, serially
disposed smooth surface rollers, certain of which are identified : :
at 286. Rollers 286 extend across the assembly 281 in the same
fashion as in the embodiment of Figure 6, however, roller 287
of the grouping positioned farthest upstream in the production
path is located at about the midpoint of lower assembly 281.
Upon passing over roller 287, belt 285 extends angularly down-
stream to pass over an idler roll 288 arranged in parallel with
rollers 286 and 287, but, attached to the lowermost :Elange of
the side beam of assembly 281. Upon passin~ over roll 288, belt
2fl5 is introduced to one side of an equalizer assembly 289.
Within assembly 289, belt 285 extends over a roll 290 having an
axle 291 journaled for rotation within spaced slideable supports,
one of which is revealed at 292. From roll 290, belt 2~5
extends in con-tinuous fashion to drive roll 284. As in the
- 22 -
~5~7G
earlier embodiments, drive to the assemblage is provided from a
motor 293 having a rotative output at sprocket 294 which is
: imparted through chain 295 to sprocket 296 which is coupled in
driving relationship with roll 284 through axle 297.
Positioned within lower assemhly 281 upstream of belt
285 is another continuous belt 300. Belt 300 extends over an
: end roll 301 and thence in a downstream direction over a plurality
of spaced, rotatable, serially disposed rollers/ certain o~ which
: are identified at 302 and which are mounted upon the upper flange
of the side beams of lower assembly 201. It may be noted that
~ belt 300 is supported by rolls 302 at an elevation coplanar with
the corresponding upwardly disposed portion of downstream belt
285. Upon passing the downstream roller 303 at about the
midpoint o~ assernbly 281, belt 300 is directed angularly upstream
to an idler roll 304 attached to the lower :Elanges of the side
beams as at 282 of assembly 281. From idler pulley 304, belt
300 is directed into equalizer assembly 289, whereupon it passes
over a drive-type roll. 305 supported upon transverse axis 306.
A~le 306 is journaled for rotation within slideable supports,
one o~ which is revealed at 307. Tension is imparted to belt 300
through end roll 301 by a pneumatic arrangement identical to
the embodiment of Figure 5I that arrangement including slideable
supports, one of which is revealed at 308 through which the axle
309 is journaled for rotation and which is actuated for horizontal
manipulatiorl to adjust tensioning by pneumatic cylinder 310.
Equalizer assembly 289 is conventional in the art and
provides a dual operat:Lonal ~unction. Eirst, the assembly
-transfers synchronous rotative drive ~rom driven belt 285 through
roll 290 and to roll 305. Roll 305 then serves as the drive ~or
continuous belt 300. Additionally, through providing a co-action
- 23 -
5~76
between slideable supports as at 307 and 292, the tensioning
: adjustment provided from pneumatic cylinder 310 additionally is
asserted into continuous belt 285.
The upper carriage assembly of stage 280 is represented
generally at 320 in an orientation wherein it i5 elevated for
purposes of servicing or set up. The assembly is formed
similarly to the corresponding assembly of the embodiment of
Figure 5, including a rectangular frame incorporating side beams, .
one of which is revealed at 321. Elevating carriage assembly 320
is carried out in a manner identical to that described in
connection with Figures 5-9, including pneumatic cylinders such
as those depicted at 314 and 315. Note that the respective
piston rods 316 and 317 of the cylinders are extended to elevate
the upper assembly to the orientation shown. Stage 280 also
includes a leveling arrangement identical to the embodiment of
Figures 5-9, two of the four assemblies being revealed in general
at 318 and 319.
The assembly is structured having two discrete
continuous belts, the downstream belt 322 extending around drive
roll 323. As before, the surface of roll 323 is textured with
rubberized material or the like so as to provide adequate
frictional driving engagement with belt 322. Upon passing roll
323, belt 322 extends beneath a plurality of spaced, rotatable,
serially disposed, smoothly surfaced rollers, certain of which
are represented at 324 and the furthest upstream of which is
represented a-t 325. From gene:rally centrally located roller 325,
belt 322 extends angularly downstream to pass over an idler
roller 326 attached to the top flange of the side beams as at 321.
From idler 326 belt 322 is introduced into an equaliæer assembly
327 within which it is passed cver roll 328 and returns above
carriage assembly 320 for engagement with drive roll 323.
- 24 -
5~7~i -
The upstream continuous belt of carria~e assembly 320
is represented at 334 and is depicted passing over end roll 335,
~; whereupon it is directed in a downstream direction beneath a
plurality of spaced, rotatable~ serially disposed, smoothly
surfaced rollers, certain of which are revealed at 236. At about
the center of the assembly 320, belt 334 is passed over downstream
roll 337 and directed angularly in an upstream direction to pass :
over an idler roll 338~ From idler roll 338, the belt is
introduced to equalizer assembly 327 within which it is passed
over roll 339.
~ Looking to the drive aspects of the dual belted assembly: 320, an arrangement identical to that described in connection
with Figure 9 is provided. In this regard, a drive sprocket 342
is journaled over and fixed to axle 297 so as to be rotated
therefrom. Sprocket 342 drives a chain 343 which introduces
- rotative drive to the sprockets contained within a drive system :~:
~ housing 344, the latter retaining components identical to those
: described in connection with Figure 9. The output from housing
344 is provided at chain 345 which extends around sprocket 346
.'' - ~-: . - '
. 20 ~fixed,.in turn, to the axle 347 coupled to drive roll 323. Chain
- . . 345 serves the same function as earlier-described chain 269 and
: provides a rotative drive at a rate which oscillates evenly above
and below the fixed rate imparted to lower assemblage drive roll
28~. The drive imparted to chain 322 is transferred through
equalizer assembly 326 to upstream continuous belt 344 by virtue
of the geared or chain driven association of roll 339 with roll
328. Also similar to the embodiment described in connection with
Figures 5-9, the axle 348 o~ end roll 335 is coupled through
a pair of oppositely disposed slideable supports, one o~ which is
revealed at 349. Supports as at 349 may be adjusted horizontally
- 25 -
~5~7~ ~
through their connection with the piston rod of a pneumatic
cylinder as at 350. The tensioning derived through actuation of
cylinder 350 is transferred from belt 334 to belt 322 through
:~ equalizer assembly 327. In this regard, note that the axles 351
and 352 of respective rolls 339 and 328 a.re rotatably journaled
within slideable support members, two of which are revealed
respectively at 353 and 354. Through interconnection of these
support members, tension is transferred from roll 339 to roll 328.
To impart an appropriate vertically undulating motion
to composite 81 as it passes through wetting stage 280, it may be
noted that the points of tangency of rolls 336 with the upwardly
disposed surface o ~elt 334 reside intermediate the points of
tangency of rolls 302 with the lower disposed surface of belt
300. Similarly, the points of tangency of rolls 324 with the
upwardly disposed surface of belt 322 lie intermediate the
corresponding points of tangency of rolls 286 with the underside
of belt 285. Accordingly, when pneumatic cylinders 314 and 315
and their counterparts on the opposite side of stage 280 are
appropriately actuated to lower upper carriage assemhly 320,
composite 81 will be caused to flex in a vertically ~mdulating
fashion~ As this form of shear activity is carried out under
the effect of compression, a third effect is induced through the
oscillation of the rate of travel of the upwardly disposed belts.
In addition to the above-noted three aspects of the
physical treatment of the composite ~1, it is apparent that the
embodiment of Figure 10 provides an enhanced latitude of material
manipulation for the designer. For example, the apparatus can be
arranged to provide a difference in the extent of compression Eor
the upstream belts as opposed to the downstream belts. In many
instances it may be desirable, for example, to provide a lesser
- 26 -
~ 5976
degree of compression in the upstream belts as opposed to the
downstream belts. Such an arrangement may serve to avoid the
transverse migration of resinous matrix material through the sides
of the thin supporting sheets within which it is sandwiched. This
differential of compression also is available with the embodiment
shown in Figures 5-9, sufficient latitude of tolerance being
available in the leveling system of the upper carriage asser~ly
of each of the embodiments.
As indicated above, the preferred type of continuous
belt utilized with the apparatus of the invention is a weave or
mesh belt. Such belts, for example as produced by Ashworth Bros.,
Inc., Winchester, ~irginia, are available in a broad variety of
weave configurations as well as in a variety of materials. For -
example, the belts are fabricated in a full range of ferrous,
non-ferrous and nlckel chrome alloys. Preferably, a steel mesh
belt is utilized with the apparatus of the instant invention.
A particular aspect of belt usage is concerned with the
embodiment of Figure lQ. Where thick composites as at 81 are
prepared, a phenomenon wherein the resin matrix migrates trans-
versely, as discussed above, may be encountered. ~his phenomenonsometimes is referred to as "squeeze out". It is necessary,
.
therafore, to achieve some form of initial compression through
the upstream pair of belts without developing the noted transverse
resin migration~ By selecting a coarser mesh weave for the
continuous belts at 33~ and 300, the resin becomes entrapped in
pockets created within the openings of the mesh, those pockets
being created by resin pressure upon the thin vinyl supporting
sheets described earlier. As a conse~uence, the resin matrix in
the starting material is trapped and cannot transversely migrate
during initial compression. As the composite then moves from the
- 27 ~
5~376
upstream pair of belts, it encounters the downstream belts as at
322 and 285. After the initial treatment, these latter belts inay
be provided having a finer weave to achieve a final high quality
wet out of the relatively thick composite 81.
~ he improvement achieved with the invention may be
considered somewhat significant~ For example, before the
utilization of the instant wet out stages, production was limited
to relatively thin composites of thickness of about one-fourth
inch. Normally, this material would be produced at a speed of
about 20 to 25 feet per minute and at a maximum weight of about
16 ounces per square foot. With the introduction of the device
described in Figures 1 and 2, a fifty percent increase in the
speed of production was recognized and composites having a -twenty
to twen-ty-five percent increase in weight per square foot were
available with the pnx~ss. Further, with the development of the
embodiments of Figures 3 and 4, materials weighing about 40 ounces
per square foot could be produced at the higher speeds achieved
wlth the embodiment of Figures 1 and 2, i.e., about 30 feet per
minute.
Still another embodiment will readily occur to the
art-skilled in connection with the instant invention. For example,
the dual belt arrangement of upper carriage assembly 320 shown
in Figure 10 may be combined with a singular belt at the lower
assemblage or vice-versa.
Having described the invention in detail and with
reference -to the drawings, it will be understood that such
speciications are given for the sake of explanation. Various
modifications and substitutions other than those cited carl be made
without departing from the scope of the invention as defined by
the following claims.
- 28 -
~
.. = , ~,
