Facing ply separator

Alternate facing plies in a single stack are separated by this apparatus into two separate piles. The apparatus of the invention includes means for differentiating each top layer from the feed stack and means for transporting the differentiated top layers alternately to a first location and to a second location. The differentiating means includes movable, rotating elements for curling back one or more of the edges of the top layer from the edges of the next underlying layer in the stack and thereafter lifting the layer with the curled edges away from the stack.

BACKGROUND OF THE INVENTION 
The invention relates to automatic apparatus for separating alternately 
facing fabric workpieces from a single stack into two separate stacks. 
It is often desirable in the garment fabrication industry to separate 
layers of stacked fabric workpieces from each other and to transport them 
to other work stations. Such prior art separating devices are described in 
U.S. Pat. Nos. 3,253,824 and 3,042,505. As pointed out in those patents, 
separating stacked fabric layers is extremely difficult since the layers 
of fabric, during cutting, tend to have their end threads interwoven and 
are thereby bonded together. It requires considerable ingenuity to 
separate each layer of fabric from this bonding interengagement of the end 
threads without simultaneously disrupting the placement of the layers in 
the stack. 
It is desirable not to disturb the placement of the layers in the stack in 
order that the workpieces may be accurately aligned with respect to the 
separating apparatus and so that after separation they can be transported 
to another work station with a predetermined orientation. If the fabric 
layers are misaligned, they will not be properly transported in an aligned 
relationship to the next work station, but, instead, will be 
mis-positioned upon reaching the subsequent work station. 
The mechanisms for separating such layers of stacked fabric workpieces are 
known in the trade as differentiators. The differentiators described in 
the above two referenced patents rely on a clamping member working in 
conjunction with a rotating friction member to peel back a layer of fabric 
while holding the remaining stack stationary. This type of differentiator 
has many disadvantages well known to the trade, among them, the problem 
that it does not easily adapt to different types of fabric, nor is it 
entirely effective in separating the layers without disturbing the 
underlying layers or picking up more than one layer of fabric at the same 
time. 
More suitable types of differentiators are described in U.S. Pat. Nos. 
793,009 (Miller) and 3,981,495 (Bijttebier) which disclose a pair of 
horizontal, rotatable cylinders having needles which project in opposite 
directions and which are lowered to rest on the top fabric layer of a 
stack of fabric workpieces. The cylinders are counter-rotated to drive the 
needles into the top layer and then are lifted to pull away the top layer 
from the stack. This type of differentiating head is more effective than 
other types of differentiating heads for some applications. However, it 
also suffers from a disadvantage in that unless the needles penetrate the 
fabric evenly when the cylinders are counter-rotated there may be a 
tendency to shift the top layer horizontally, thus causing it to be 
misaligned. 
In one garment industry operation, left and right pocket facings are cut 
simultaneously on a spreading table from a fabric stack having alternately 
face-up and face-down layers. The result is a plurality of smaller stacks 
of alternating left and right facing plies. It then becomes necessary to 
separate these left and right facing plies into two separate stacks of all 
left and all right facing plies. In order to do this automatically, it is 
not only necessary to effectively separate the alternate left and right 
facing plies from the stack without misalignment, as described above, but 
it is also necessary to detect whether the stack somehow contains two 
facing plies oriented in the same direction, that is, face-up or 
face-down. It is further necessary to detect whether one of the 
differentiated plies has been dropped by the differentiating head since 
this would cause one of the stacks to be short in the number of facing 
plies. 
SUMMARY OF THE INVENTION 
The above and other disadvantages are overcome by the present invention of 
an improved apparatus for sequentially separating into a plurality of 
stacks alternate layers of sheet-like workpieces from a single feed stack 
of sheet-like workpieces. The improved apparatus comprises means for 
differentiating each top workpiece layer from the feed stack and means for 
transporting the differentiated top workpieces alternately to a first 
location and to a second location. The differentiating means includes 
means for curling back one or more edges of the workpiece from the edges 
of the next underlying workpiece layer in the stack and thereafter lifting 
the workpiece with the curled edge away from the stack. In the preferred 
embodiment, the workpieces have differently colored plane faces in 
alternate layers and the differentiating means includes photo optic means 
for detecting whether each differentiated workpiece is turned face-up or 
face-down. 
In one preferred embodiment, the differentiating means simultaneously 
differentiates the topmost workpiece from the feed stack while releasing 
the previously differentiated workpiece at the first or second location. 
In one embodiment, the differentiating is accomplished by a pair of 
differentiating heads carried by the transporting means, which are 
alternately lowered onto the feed stack, raised, moved horizontally over 
one of the separated piles and lowered onto the separated pile. 
In another embodiment the differentiating heads are not carried by the 
transporting means but instead the differentiating head is movable and 
delivers the separated workpiece to a belt type transport which conveys 
the workpieces alternately to the first and second locations. 
In all of these embodiments, separation is achieved using two or more of 
the following principles in combination: (1) different lateral motion of 
the top workpiece with respect to the next underlying (second) workpiece 
in combination with a negative pressure or force applied to the underlying 
layer to release interlocking weaving patterns and edge threads, (2) 
bending the top workpiece around a small radius so that by the forces of 
inertia, gravity and the vacuum between the second and third layers the 
second layer, upon release of the interlocking weave and edge threads, 
tends to fall away from the top workpiece as it passes around the bend and 
(3) placing the stress of separation along a line which moves across a 
plane which is parallel to the planes containing the flat surfaces of the 
workpiece, as opposed to trying to separate along the whole surface at 
once. 
In some of these embodiments, such separation of the topmost layer is aided 
by one or more separating rods which are movable horizontally and press 
against the topmost layer during its separation form the stack to thereby 
produce a moving bend in the topmost layer. This bend helps to disengage 
the threads and weave of the top layer from the threads of the next layer 
in the feed stack. In other embodiments the moving bend is produced by 
using small diameter rotatable elements which wrap the topmost workpiece 
about themselves to achieve separation. 
In the preferred embodiments, each differentiating head includes a frame, a 
pair of rotatable elements, and means for horizontally mounting the 
rotatable elements parallel to each other and at opposite ends of the 
frame. Needles are mounted on curved surfaces of the rotatable elements 
and are pointed in a direction away from the center of the frame. In some 
embodiments the frame carries at least one separate needle mounted 
stationary in the frame so as to project beneath the frame and normal to a 
hypothetical plane lying tangent to corresponding portions of the curved 
surfaces of the rotatable elements. Means are provided for selectively 
rotating one or more of the rotatable elements with respect to the other 
to engage the needles with the top workpiece of the feed stack and then 
release the differentiated workpiece over one of the separated piles, 
depending upon the direction of rotation. In some embodiments, both 
elements are simultaneously counter-rotated to engage and disengage with 
the topmost workpiece. 
The frame is so dimensioned that the rotatable elements are spaced apart by 
only slightly less than the width of the fabric workpieces, so that upon 
rotation in a direction which engages the element needles in the topmost 
workpiece, at least one edge of the topmost workpiece is thereby curled 
upwardly along with the needles and away from the corresponding edge of 
the next underlying workpiece. The edges of the next underlying workpiece 
do not curl up with the topmost workpiece edges because they are held 
stationary by the force of the interengaged threads with the underlying 
workpieces in the remaining portion of the stack. The bond thus holding 
the topmost workpiece to the remaining portion of the stack is thus broken 
before the workpiece is even lifted free of the stack. 
The purpose in having the single stationary needle located between the two 
rotatable elements is to prevent the topmost workpiece layer from being 
misaligned as the needles are caused to engage with it. In some 
embodiments, the rotatable element needles are mounted so as to project 
beneath the frame by a distance which corresponds to the thickness of the 
fabric workpiece. In this way, they do not engage with the next succeeding 
workpiece layer at the same time as they engage with the topmost layer of 
the single feed stack. 
At the first and second locations, the differentiated workpiece layers are 
received onto separate elevators which index downwardly by the thickness 
of each ply as it is released onto the stack carried by the elevator. 
Simultaneously, the central single feed stack is also carried by a 
separate elevator which indexes upwardly by the thickness of each 
workpiece which is removed by the differentiating heads. 
Photocells positioned on opposite sides of the single feed stack detect 
whether the underside of each ply is light or dark colored to determine if 
it is properly a left or a right facing ply. Photocell detectors are also 
used to control the height of the stacks on the feed and receiving 
elevators. 
It is therefore an object of the present invention to provide apparatus for 
sequentially separating alternate layers of web-like workpieces from a 
single stack into a plurality of stacks. 
It is still another object of the invention to provide a fabric ply 
separator which automatically detects whether the separated fabric plies 
are face-up or face-down. 
It is still a further object of the invention to provide an apparatus for 
sequentially separating alternate layers of fabric workpieces from a 
single stack while simultaneously not causing the separated workpiece or 
the remainder of the stack to become misaligned. 
The foregoing and other objectives, features and advantages of the 
invention will be more readily understood upon consideration of the 
following detailed description of certain preferred embodiments of the 
invention, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now more particularly to FIG. 1, the single feed stack of 
alternating facing fabric workpieces 10 (shown in dashed-line fashion for 
clarity of illustration) is carried by a single feed elevator 12 mounted 
for vertical movement in a frame 14. The details of the elevator mechanism 
12 will be described further in a subsequent portion of this application. 
On the left and right sides of the feed elevator 12 are positioned 
additional vertical elevators 16 and 18, respectively. The elevators 16 
and 18 are also mounted in the frame 14 for vertical movement. Whereas the 
elevator 12 is mechanized to make upward adjustments as the layers of 
garment workpieces 20 are removed from the stack 10, the elevators 16 and 
18 are mechanized to index downwardly by a distance corresponding to the 
thickness of one workpiece. The actions of the elevators 12, 16 and 18 
will be described in greater detail hereinafter. 
Positioned above the elevators 12, 16 and 18 is the differentiating 
mechanism comprised of a horizontal bar 22 which carries separate 
differentiating heads 24 and 26 at its right and left ends, respectively. 
The differentiating heads 24 and 26 are each capable of removing the 
topmost workpiece 20 from the stack 10 without disturbing the remaining 
portion of the stack 10. The manner in which this is done will be 
described in greater detail at a later portion in this application with 
particular reference to FIG. 7. 
The horizontal bar 22 is carried on the lower end of a vertical pipe 28 
which is flexibly attached to a horizontally movable carriage 30 by means 
of a pair of flexible horizontal straps 32. A second, vertical, hollow 
pipe 34 is also attached to the horizontal bar 22 by means of a bracket 36 
which is also attached to the first vertical pipe 28. The pipe 34 can be 
connected to a vacuum source (not shown) in some embodiments or it can 
simply serve as a conduit for air lines 38 which activate the 
differentiating heads. 
The carriage 30 travels on a pair of vertically spaced apart horizontal, 
parallel rails 40 mounted in a frame 43 over the area where the stacks of 
fabric workpieces are located. The carriage slides on the rails 40 by 
means of sleeve bearings 42 and roller wheels (not shown). A motor driven 
sprocket chain 44 trained around sprocket gear wheels 46 at opposite ends 
of the rails 40 provides the moving force for reciprocating the carriage 
30 back and forth on the rails 40. The carriage 30 is attached to the 
drive chain 44 by means of a pair of links 48 pivoted at one end to the 
top and bottom of the carriage 30 and at their other ends to separate 
vertices of a triangular member 50. The third vertex of the triangular 
member 50 is rotatably attached to the sprocket chain 44. In this way, no 
nontensional forces are imparted to the drive chain 44 or to the sleeve 
bearings 42 of the carriage 30. A roller 52 projects outwardly from the 
vertex of the triangular member 50 at the point where it attaches to the 
sprocket chain 44 and is captured by a rectangular bracket 54. The 
rectangular bracket 54 is mounted on one end of a shaft 56 which is 
rotatably mounted in a boss 58 attached to the carriage 30. 
At the opposite end of the shaft 56 a crank mechanism is mounted. The crank 
mechanism 60 is attached to the vertical pipe 28 to raise and lower the 
vertical pipe 28, and hence the differentiating heads 24 and 26, each time 
the roller 52 passes around the ends of the sprocket gears 46. The manner 
in which this carriage transfer mechanism operates is explained in greater 
detail in the applicant's co-pending patent application entitled 
Intermittent Drive and Transfer Assembly, filed Feb. 2, 1976 and assigned 
Ser. No. 654,705. 
The sprocket gears 46 are spaced apart by a distance corresponding roughly 
to the distance between the central feed stack and one of the receiving, 
separated ply stacks. The length of the horizontal arm 22 is also equal to 
the distance between the central feed stack 10 and one of the separated 
ply stacks. In this way, as best viewed in FIG. 6 in hidden-line fashion, 
when the carriage 30 is at the extreme right hand end of travel as viewed 
in FIG. 6, the differentiating head 24 will be positioned over the 
receiving elevator 18 and the differentiating head 26 will be positioned 
over the central feed stack elevator 12. At the extreme left hand end of 
the travel of the carriage 30, as viewed in FIG. 6, the differentiating 
head 26 will be positioned over the receiving elevator 16 and the 
differentiating head 24 will be positioned over the central feed stack 
elevator 12. As will be explained in greater detail hereinafter, the 
differentiating heads 24 and 26 are operated to engage the topmost 
workpiece 20 of the central feed stack 10 on the elevator 12 at the same 
time that the other differentiating head, positioned over one of the 
receiving elevators 16 or 18, is releasing a previously differentiated 
workpiece. 
Referring now more particularly to FIG. 3, the apparatus for raising and 
lowering the stack elevators will be described in greater detail. In the 
following description, only the single stack feed elevator 12 will be 
described, however, it should be understood that this description is 
equally applicable to the elevators 16 and 18 except that whereas the 
elevator 12 is indexed upwardly by the thickness of each layer which is 
differentiated, the elevators 16 and 18 are indexed downwardly for each 
differentiated layer which is placed on top of the stack. 
The elevator 12 has a leg 62 which is a horizontal platform for carrying 
the single feed stack and a vertical portion 64 intregal therewith, which 
has an annular slide bearing 66 for slidably mounting the elevator 12 on a 
vertically extending rod 67 mounted in the frame 14. The elevator platform 
12 is prevented from rotating in a horizontal plane by a pair of rollers 
68 which straddle a vertically extending rail 70 spaced behind the rod 67, 
as viewed in FIG. 4. The rollers 68 are attached to the vertically 
extending portion 64 of the elevator 12 by means of an integrally mounted 
boss 72 on the vertical portion 64. 
The elevator platform 12 is raised and lowered by means of a vertically 
extending sprocket chain 74 which is trained around a sprocket pulley 76 
mounted on a horizontal shaft 78 at the base of the elevator and around a 
sprocket 80 rotatably mounted on a horizontal shaft 82 at the top of the 
elevator. The horizontal shafts 78 and 82 are rotatably mounted in bosses 
or brackets attached to the frame 14. The lower sprocket pulley 76 also 
has a drive chain 84 trained around it which is driven by an electric 
motor 86. It is to be understood that the motor 86 includes suitable 
reduction gearing (not shown). The lower sprocket pulley 76 is not pinned 
to the shaft 78 and rotates freely about it. It is to be understood that 
each of the elevators 12, 16 and 18, has an independent motor drive. 
In order to completely stabilize the platform 12 in the horizontal plane, a 
pair of vertically extending rods 88 and 90 are positioned on either side 
of the elevator platform near the front, as best viewed in FIG. 4. The 
vertical rod 90 is on the right side of the platform and the vertical rod 
88 is on the left side of the platform as viewed in FIG. 4. Separate 
rollers 92 and 94 mounted on the underside of the horizontal portion 62 of 
the elevator bear against the rods 88 and 90, respectively. The vertical 
rod 88 is mounted on a horizontal swinging arm 96 which is pivoted on the 
frame 14 toward the rear of the horizontal platform 62 at a point 98. This 
allows the vertical rod 88 to be swung open from the platform elevator 12 
when the feed stack is placed on top of the platform 62. The rod 88 is 
thereafter swung closed to prevent the stack from being removed from the 
elevator 12. 
The frame 14 includes a top horizontal working space 100 which has a 
cut-out portion 102 to accommodate the horizontal platform 62 of the 
elevator 12. It has similar cut-out portions to accommodate the other 
elevators as well. A pair of photo-optic sensors 104 are placed on 
opposite sides of the cut-out space 102 to detect the presence or absence 
of the top layer of material in the stack carried by the elevator 12. 
These photo-optic sensors lead to a control panel (not shown) which 
control the indexing motion of the motor 86 which raises the elevator 12 
by a distance corresponding to the thickness of one ply of fabric in the 
stack as it is removed by the differentiating heads. A second pair of 
photo-optic sensors 106 are mounted on top of the horizontal platform 100 
of the frame 14 and are directed upwardly to detect the contrast of the 
underside of the fabric workpieces carried by the differentiating heads 24 
and 26. This contrast is due to the fact that the twill denim fabric from 
which the pocket facings are made, has a blue tint on the one side and a 
white line striped pattern on the opposite side. The white striped side 
reflects more light and thus can be sensed by the sensors 106. The sensors 
106 additionally provide information as to whether or not a pocket facing 
has been dropped by one of the differentiating heads which also would 
throw off the sequencing of the differentiation process. 
The controls for the operation of the carriage transfer 30 and the control 
for the differentiating heads 24 and 26 will not be described in detail 
since such sequential controls are well known to those skilled in the art. 
They basically involve a timing disc mounted to rotate in synchronism with 
the drive for the carriage transfer. The timing disc includes sensor means 
for actuating pneumatic valves and the drive motors in a properly timed 
sequence. 
Referring now more particularly to FIGS. 1, 2 and 7-9, the operation of the 
differentiating heads will be described. Although the description relates 
particularly to the differentiating head 26, it will be understood that 
the description is equally applicable to the differentiating head 24. 
The differentiating head 26 includes a pair of spaced apart rectangular, 
horizontal frame members 108 and 109 mounted on the horizontal bar 22. 
Separate groups of cylindrical elements 110 and 112 are rotatably mounted 
on the frame members 108 and 109, respectively. The cylindrical elements 
are eccentrically mounted to rotate with shafts 114 and 116, respectively. 
The shaft 114 is more or less centered through the lower right hand 
quadrant, as viewed in FIG. 7, of the circular cross-section of the 
cylindrical elements 110. The shaft 116 is more or less centered through 
the lower left hand quadrant of the cross-section of the cylindrical 
elements 112. The cylindrical elements 110 and 112 as well as the shafts 
114 and 116 are all parallel to each other. The frames 108 and 109 are 
adjustably mounted on the bar 22 by brackets 111 so that the cylindrical 
elements 110 and 112 can be spaced apart by slightly less than the width 
of any given group of fabric workpieces 10. As best viewed in FIG. 10, the 
cylindrical elements 110 are adjustably spaced apart along the shaft 114 
and the elements 112 are adjustably spaced apart along the shaft 116. 
Each cylindrical element 110 and 112 has at least a pair of needles 120 
threadably mounted in the cylinder so as to project slightly beyond the 
cylindrical surface of the cylinders and at an acute angle to the 
cylindrical surface (see FIG. 8). The needles 120 are each mounted in a 
threaded screw 121 which is screwed into a threaded bore 123. The needles 
of the cylinder 110 are mounted so as to be inclined to the cylindrical 
surface taken in the counterclockwise direction. The needles of the 
cylinder 112 are mounted so as to be inclined to the cylindrical surface 
in the clockwise direction. Thus, the needles of the cylinders 110 and 112 
are directed towards the ends of the topmost fabric layer 20. 
Each cylinder 110 and 112 has an outer cylindrical layer of foam 122 
through which the needles 120 project by a distance which is adjusted to 
be slightly less than the thickness of one layer of fabric in the stack 
10. In this manner, when the horizontal arm 22 with the differentiating 
head 26 is lowered onto the top of the stack 10 of the fabric layers, the 
needles 120 will penetrate only into the top layer 20 of fabric. In order 
to counter-rotate the cylinders 110 and 112, with respect to each other, 
the shaft 116 of the cylinder 112 is provided with a crank arm 124 which 
is pivotally connected to the shaft 126 of a pneumatic actuator 128. Upon 
the application of a proper pressure differential to the actuator 128 by 
means of air hoses 130, the shaft 126 may be made to withdraw into the 
cylinder 128 or extend from it. When it is withdrawn into the actuator 
128, the reaction is to rotate the cylinder 112 in a clockwise direction, 
as indicated in dash-line fashion in FIG. 8. A similar actuator is 
disposed on the opposite side of frame 108 to operate the shaft 114 and 
thus simultaneously rotate the cylinder 110 in the opposite direction from 
the direction of rotation of the cylinder 112. 
Between the frames 108 and 109, a second needle 132 is mounted in a 
downwardly extending portion 131 of the frame so as to project beneath the 
frame and normal to a hypothetical plane lying tangent to the 
corresponding portions of the curved surfaces of the cylinders 110 and 
112. A block of foam 134 surrounds the needle 132. 
The adjustability of the spacing between the cylindrical elements, such as 
the elements 110, along their axis of rotation allows workpieces of 
different shapes and sizes to be accommodated. 
In operation, the differentiating head 26 is lowered by means of the 
carriage transfer mechanism, as described in greater detail above, onto 
the top layer 20 of the stack 10 of fabric pieces on the elevator 12. The 
foam 122 on the cylinders 110 and 112 as well as the foam block 134 are 
slightly compressed and the pneumatic actuator 128 and its corresponding 
counterpart on the opposite side of the frame, 108, are actuated to 
counter-rotate the cylinders 110 and 112 so as to drive the needles 120 
into the topmost fabric layer. Because of the eccentric mounting of the 
cylinders 110 and 112 on the shafts 114 and 116 a more favorable orbit of 
motion for the needles is thereby obtained than if the cylinders were 
centrally mounted. This eccentric needle movement gives a more favorable 
angle of penetration, i.e., nearly perpendicular to the top layer 20 by 
the needle 120. The needle 120 is also swung with less vertical 
displacement when it is nearly parallel with the stack layers thereby 
providing a hooking action. 
Because of the location of the cylinders 110 and 112, being adjusted to be 
close to the edges of the fabric layer 118, the counter-rotation of the 
cylinders tends to curl up the edges of the topmost layer, thereby 
breaking the bond of interlocking threads which would otherwise hold it to 
the next most fabric layer. The effect is a stretching of the topmost 
layer in addition to curling the edges. The purpose of the stationary 
needle 132 is to prevent any misalignment of the topmost fabric layer as 
it is being differentiated. Once the interlocking thread bond is broken by 
the action of the needles, 120, the differentiating head 24 is raised to 
carry away the topmost layer. After the differentiating head is positioned 
and lowered onto the stack on the appropriate receiving elevator 16, the 
actuators, such as actuator 128, are operated in the reverse direction to 
extend their shafts 126, thereby counter-rotating the cylinders 110 and 
112 in the reverse direction from the previous operation to thereby 
withdraw the needles 120 from the topmost layer 20 of fabric and release 
it. At this point, the resiliency of the foam layers 122 and 134 aids in 
separating the fabric from the needles and releases the topmost layer 20 
onto the top of the stack carried by the elevator 16. As mentioned 
previously, upon the removal of the topmost layer 20 from the stack 10 
carried by the elevator 12, the photo cells 104 will cause the stack to 
index upwardly by a distance equal to approximately the thickness of one 
layer of the fabric. The photo cells 104 which control the positioning of 
the elevator 16 will cause the elevator to index downwardly by the 
distance approximately equal to the newly deposited topmost layer 20 
released by the differentiating head 26. 
The control of the differentiating head actuators 128 is done by the timing 
disc mechanism referred to above (but not shown). It should be understood 
that in other embodiments other types of controls may be used, such as 
contacting switches and photo-optic sensors. 
Referring now more particularly to FIG. 11, the facing ply separator of the 
invention when used in conjunction with an assembly line garment 
manufacturing system is illustrated. In this application, the facing ply 
separator is used to feed alternately facing plies to the input to the 
assembly line system as well as providing a stack of plies all of which 
are of one type. This is in contrast to the apparatus described above in 
reference to FIG. 1 in which the single main feed stack was divided into 
two separate stacks of same type plies. As shown in FIG. 11, the facing 
ply separator apparatus 136 of the type described above, differentiates 
the topmost layer of the main feed stack 10 and sequentially and 
alternately places the differentiated topmost layer onto the stack carried 
by the receiving elevators 16 and onto a registration table 142. The 
registration table 142 is, in effect, a transparent glass, horizontal 
plane carried by a servo mechanism 138. Stationary photo-optic sensors 
(not shown) control the servo mechanism 138 to position the table 142 such 
that the workpiece 140 deposited by the facing ply separator 136 onto the 
table 142 is precisely positioned with respect to a vacuum transfer 
mechanism 144. The transfer mechanism 144 then reciprocates horizontally 
to place the separated piece 140 at one input to the assembly line 
apparatus, the remainder of which is not shown in FIG. 11. The 
registration table 138 and the carriage transfer mechanism 144 are not 
described in detail since such mechanisms are generally well known. See, 
for example, U.S. Pat. Nos. 3,548,196 and 3,442,505. By this manner of 
placing one ply into a separate stack and the other ply onto the feeding 
means of a processing machine directly restacking of the one half of the 
separated material is thereby avoided. 
Referring now more particularly to FIGS. 12A-12H, inclusive, a modification 
of the differentiating head depicted in FIGS. 7-10 is illustrated. Similar 
elements have been assigned corresponding reference numerals, primed. The 
basic differentiating head depicted in the modified embodiment is 
essentially the same as that depicted in FIGS. 8-10, with the exception of 
the center needle 132'. The center needle 132' is for the purpose of 
fixing the position of the topmost layer 20 with respect to the rotatable 
cylinders 110' and 112' during the separation process, thereby preventing 
any misalignment of the topmost layer 20 either during separation or 
during its release upon the separated workpiece piles. 
The center needle 132' in the modified embodiment is mounted on the end of 
a shaft 202 which projects from a vertical arm 200. The arm 200 may be 
attached to the frame 22 (see FIG. 8) or it may be independently mounted. 
In any case, the arm 200 is raised and lowered simultaneously with the 
rotatable cylinders 110' and 112' during the separation process. A 
stripper 204 is coaxially mounted about the shaft 202 and is slidable on 
the shaft 202 between a first position in which the needle 132' is 
unsheathed so that it can penetrate the topmost layer 20 and a second 
position, shown in FIG. 12H, in which the needle 132 is covered by the 
lower end of the stripper 204. The action of the stripper 204 may be 
either by simple gravity and inertia or it may be air cylinder actuated or 
spring loaded. 
The operation of this modified embodiment is depicted in the sequence of 
drawings in FIGS. 12A-12H. In FIG. 12A, the differentiating head has been 
lowered onto the topmost layer 20 and the needle 132' has penetrated the 
topmost layer 20 and the stripper 204 has been lifted to its uppermost 
position by the force of the fabric 20 against the lower edge of the 
stripper 204. In FIGS. 12B and 12C, the rotatable cylinders 110' and 112' 
have been counter-rotated to engage the topmost layer 20 and to curl its 
outer edges up and away from the corresponding edges of the next 
succeeding layer in the stack 10. The rotatable cylinders 110' and 112' 
are lifted upwardly with respect to the arm 200 which causes the topmost 
layer 20 to bend around the projecting needle 132', thereby further aiding 
the separation of the topmost layer 20 as best shown in FIG. 12D. 
In FIG. 12E the differentiating head has separated the topmost layer 20 and 
moves it to either the first or the second location in the manner 
described above for the primary embodiment. 
In FIG. 12F, the differentiating head has deposited the topmost layer 20 
onto one of the receiving elevators 16 or 18 and is about to disengage the 
rotatable cylinders 110' and 112'. The disengagement of the rotatable 
cylinders 110' and 112' is accomplished by counter-rotation as is shown in 
FIG. 12G. The differentiating head is then lifted clear of the receiving 
elevator and the inertia of the stripper 204 causes it to slide to its 
lowermost position on the shaft 202 thereby forcing the topmost layer 20 
clear of the needle 132' to complete the differentiation process. 
It should be apparent that in other embodiments the stripper 204 may be 
stationary with respect to the arm 200 and the shaft 202 may be 
withdrawable up into the arm 200. It is the sheathing and unsheathing of 
the needle 132' which the applicant regards as his invention. 
Referring now more particularly to FIGS. 13A-13F, still a further 
modification of the embodiment depicted in FIGS. 12A-12H is illustrated. 
In this embodiment, the differentiation of the topmost layer is aided by a 
pair of separating rods 206. The separating rods 206 are mounted parallel 
to the rotatable cylinders 110' and 112'. The rods 206 can be supported by 
a lever arm or simply can extend through horizontal slots 208 in a pair of 
horizontal members 210 positioned at opposite ends of the cylinders 110' 
and 112' so as to straddle the cylinders, as best shown in FIG. 13G. The 
frame members 210 are attached to the differentiating head frame 22. Thus, 
the separating rods 206 are slidable horizontally in the slots 208 in a 
plane which is parallel to the topmost workpiece 20. The separating rods 
206 are biased toward their outermost positions, as best shown in FIG. 
13G, by tension springs 212 which are attached to the frame members 210. 
A further difference from the embodiment depicted in FIGS. 12A-12H is that 
the rotatable cylinders 110' and 112' are movable vertically somewhat 
independently of the center needle 132'. To accomplish this, the vertical 
rod 200 which carries the needle 132' forms the end of a plunger in a 
hydraulic or pneumatic actuator 213 which, in turn, is attached to the 
frame 22 of the differentiating head. The operation of this modified 
embodiment is best depicted in FIGS. 13A-13F. The differentiating head is 
first lowered onto the topmost layer 20 of the feed stack as viewed in 
FIG. 13A. The rotatable cylinders 110' and 112' are then counter-rotated 
to engage the needles 120' in the workpiece 20. The differentiating head 
is then raised vertically slightly while the actuator 213 is caused to 
extend the needle 132' downwardly so as to remain in contact with the 
layer 20 on top of the stack 10. Simultaneously with the raising of the 
rotatable cylinders 110' and 112', the workpiece 20 is caused to bend 
around the separating rods 206 and to thereby exert a force inwardly 
towards the needle 132' on the rods 206. As this process continues, the 
rods 206 are drawn toward the center of the workpiece 20 and the needle 
132', as best shown in FIGS. 13D and 13E. All during this time, the 
actuator 213 causes the needle 132' to press the center of the workpiece 
20 against the topmost layer of the stack 10. Ultimately, the 
differentiating head lifts the cylinders 110' and 112' together with the 
center needle assembly 132' and the workpiece 20 free of the stack 10 as 
shown in FIG. 13F. 
The differentiating head releases the separated workpiece 20 on one of the 
receiving elevators 16 or 18 by simply reversing the above described 
process. As in the embodiments depicted in FIGS. 12A-12H, when the needle 
132' is withdrawn from the topmost workpiece 20 after its release the 
stripping member 204, either by inertia or by spring force, strips the 
workpiece 20 from the end of the needle 132' to aid in the separation. 
Referring now more particularly to FIGS. 14A-14F, still another variation 
of the embodiment depicted in FIGS. 12A-12H is illustrated. The primary 
difference between this embodiment and the embodiment depicted in FIGS. 
12A-12H is that the rotatable cylindrical elements 110' and 112' not only 
are counter-rotated to engage or disengage the topmost workpiece 20, but 
they are simultaneously moved closer or further away from each other 
during engagement and disengagement with the workpiece 20, respectively. 
Thus, as best shown in FIGS. 14B-14E, after the differentiating head is 
lowered onto the topmost workpiece 20 the cylinders 110' and 112' are 
counter-rotated to engage the needles 120' in the topmost workpiece 20 
while at the same time the cylinders are rolled closer to each other 
toward the center of the workpiece 20 at the needle 132'. When the 
cylinders 110' and 112' have reached a predetermined spacing immediately 
adjacent to the needle 132', the differentiating head lifts up with the 
workpiece 20 having its opposite ends rolled around the cylinders 110' and 
112'. The mechanism by which the cylinders 110' and 112' are moved and 
simultaneously rotated is illustrated in FIG. 14F. It should be understood 
that this is simply an example of one suitable mechanism for moving and 
rotating the cylinders and numerous other types of mechanisms will 
undoubtedly be apparent to those having ordinary skills in the art. It is 
the type of movement of the cylinders 110' and 112' which the applicant 
regards as his invention rather than the specific mechanism for carrying 
out this movement. 
As shown in FIG. 14F, the cylinders 110' and 112' are mounted on symmetric, 
axial shafts 114' and 116', respectively. It will be noted that the shafts 
114' and 116' are not mounted in the cylinders 110' and 112' eccentrically 
as is disclosed in the primary embodiment. A modification to allow an 
eccentric rotatable mounting would be apparent to those skilled in the 
art, however, it will be omitted for the sake of clarity in this 
description. The shafts 114' and 116' are carried in a horizontal slot 214 
in a horizontal frame member 216 which is attached to the differentiating 
head 22. It will be appreciated that a frame member 216 is positioned at 
each end of the shafts 114' and 116' in order to support the cylinders 
110' and 112'. 
A gear 218 is mounted at one end of each of the shafts 114' and 116'. Each 
gear 218 engages a separate rack member 220 which is attached to the end 
of a plunger of a separate pneumatic actuator 222 mounted on one of the 
frame members 216. The pneumatic actuators 222 are two-way acting. When 
they are caused to retract, the rack members 220 move toward the center of 
the workpiece 20, that is toward the member 200 which is centered between 
the cylinders 110' and 112'. The actuators 222 are simultaneously operated 
to thereby simultaneously counter-rotate the cylinders 110' and 112' and 
roll them towards each other. In order to disengage the cylinders 110' and 
112' from the workpiece 20, of course, the actuators 222 are operated to 
extend their rack members 220 and thereby counter-rotate the cylinders 
110' and 112' away from each other. As mentioned above, it will be 
apparent that numerous other modifications for accomplishing the same 
objective will be readily apparent to those skilled in the art and the 
applicant makes no claim of invention to the particular mechanism for 
carrying out this operation. 
The cylinders 110' and 112' shown in FIG. 14F are of exaggerated size for 
aid in the illustration. In actual practice, the cylinders 110' and 112' 
would be of a relatively small diameter to allow the workpiece 20 to be 
rolled thereon. 
Referring now more particularly to FIGS. 15A-15F, still another embodiment 
of the invention is illustrated. Heretofore, the differentiating head was 
moved by a transfer carriage mechanism in order to sort the differentiated 
workpieces into two separate piles. In the next series of embodiments, 
including the embodiment depicted in FIGS. 15A-15F, the differentiating 
head remains in relatively close proximity to the feed stack 10. The 
separated workpieces are transferred sequentially to the first and second 
locations by means of a conveyor type belt. Such a belt may have a gripper 
thereon or may be a vacuum operated belt of the type which is well known 
to those skilled in the making of automated, garment manufacturing 
devices. 
In this embodiment, the differentiating head has a single rotatable 
cylindrical element 224 having a projecting needle 120'. The cylindrical 
element 224 is positioned at one edge of the fabric ply stack 10. A 
separating rod 226 is located immediately adjacent to the cylinder 224 on 
the side opposite to the edge. During separation the cylindrical element 
224 is rotated, as for example, in a clockwise direction shown in FIG. 15B 
to engage the needle 120' in the edge of the topmost fabric workpiece 20. 
This curls up the edge of the workpiece 20. A clamp 228 is rotated in a 
clockwise direction to hold down the remaining edges of the feed stack 10. 
The cylindrical element 224 is then caused to move in an arc, as shown in 
FIG. 15C, up and over the separating rod 226 and then passes horizontally 
across the top of the feed stack 10. The separating rod 226 can be mounted 
in a framework similar to that shown in FIG. 13G so that the separating 
rod 226 is spring biased against the drawing force of the workpiece 20. 
Causing the workpiece 20 to bend around the separating rod 226 and to move 
the separating rod 226 across the fabric stack aids greatly in the 
separation by producing a movable bend in the fabric which disengages the 
threads of the workpiece 20 from the underlying layer. It will be apparent 
that the movement of the separating rod 226 is one half the speed of the 
movement of the rotatable cylinder 224 in traveling across the top of the 
fabric stack. 
The rotatable cylinder 224 delivers the curled up end of the workpiece 20 
to a vacuum transfer belt 230 positioned above and to one side of the 
fabric stack 10. The vacuum grips the workpiece 20 through holes 232 in 
the belt in the manner well understood by those skilled in the art as the 
cylinder 224 is simultaneously rotated counterclockwise to disengage its 
needles 120' from the workpiece. On the return stroke of the cylinder 224, 
it presses the workpiece 20 up and in contact with the vacuum belt 230. 
Simultaneously the separating rod 226 returns to its original position by 
the force of the spring attached to it. While a particular type of 
transfer belt is illustrated, it should be apparent that other suitable 
types of transfer belts may be utilized such as belts having cam operated 
grippers thereon. 
One feature of this embodiment which is not disclosed in the embodiments 
described heretofore, is that while the workpiece 20 is separated from the 
stack 10 it is also inverted. The delivery of the separated and inverted 
workpiece to one of two locations by the belt 230 is under separate 
control. The vacuum on the belt over the first and second locations is 
alternately and sequentially closed off to cause the pieces to be dropped 
in succession at the first location and then the second location. 
Still another embodiment which both separates the topmost workpiece and 
inverts it, is illustrated in FIGS. 16A-16F. In this embodiment, the 
rotatable cylindrical elements 110' and 112' are mounted on separate swing 
arms 234 and 236, respectively. The swing arms, in turn, are each attached 
at one end to separate horizontal rotatable shafts 238 and 240. The 
mechanism for rotating the rotatable cylinders 110' and 112' can be those 
shown in the previously described embodiment depicted in FIGS. 8-10. 
Alternatively, the cylinders may be rotated by separate servo motors. The 
shafts 238 and 240 can be rotated by means of pneumatic actuators 
operating through cranks or they may be operated by still further servo 
motors or pneumatic actuators. Since the mechanism for accomplishing these 
various movements would be obvious to those skilled in the art, a more 
detailed description of them will be omitted. 
In operation, the cylinders 110' and 112' are rotated by means of the lever 
arms 234 and 236 and the shafts 238 and 240. Initially the cylindrical 
elements 110' and 112' are positioned on top of the topmost workpiece 20. 
The cylinder 110' is then rotated counterclockwise to curl up the edge of 
the topmost workpiece 20. A clamping hook 229 is then caused to bear down 
against the edge of the next underlying workpiece. Thereafter, the 
cylinder 110' is rotated in a clockwise direction to disengage its needle 
120' from the edge of the workpiece 20. Simultaneously, the cylindrical 
element 112' is also rotated clockwise to engage its needle 120' in the 
opposite edge of the workpiece 20, thereby curling it up and away from the 
edge of the next underlying layer. 
As shown in FIG. 16D, the cylinder 112' is then raised upwardly by means of 
the lever arm 236 and the cylinder 112' continues to rotate in the 
clockwise direction. This causes the workpiece 20 to be pulled up and 
around the cylindrical element 112' and to pass over a projecting 
horizontal support 42 positioned immediately underneath the overhead 
vacuum type conveyor transfer belt 230. The workpiece 20 is gripped by the 
vacuum of the belt 230 and is thereafter carried away as the cylindrical 
element 112' is returned to its original position by means of the lever 
arm 236, all as shown in FIGS. 16E and 16F. This process may then be 
repeated or, alternatively, the sequence of operations may be reversed. 
Thus, for example, the cylinder 112' would be rotated in the clockwise 
direction to curl up the edge of the next underlying workpiece and the 
clamp 228 would then be brought to bear against the top of the stack 10. 
The cylinder 110' would then be rotated in a counterclockwise direction 
and simultaneously raised to pull the next underlying workpiece up and 
over a horizontal support 244 corresponding to the support 242. At this 
time, the belt 230 would be driven in the opposite direction from that 
shown in the figures to convey the separated workpiece to a second 
location. This allows the topmost workpieces to be not only 
differentiated, and inverted from face to face, but also to be inverted 
from end to end and removed alternately to two separate locations. 
In this embodiment, the belt 230 is cyclically driven in synchronism with 
the above described operation. 
A variation of this same embodiment is depicted in FIGS. 17A-17D where 
separation is aided by means of a separating bar 246 which passes 
underneath the separated workpiece 20 once the edge is curled up by the 
rotating cylindrical element 112' or 110'. The mechanism by which the bar 
246 is propelled across the top of the stack is optional and may be, for 
example, a pneumatic actuator pulling the bar. The framework in which the 
bar 246 is supported can be similar to that depicted in FIG. 13G. 
Referring now more particularly to FIGS. 18-20, a modification of the basic 
embodiment of the differentiating head depicted in FIGS. 7-10 is 
illustrated. The purpose of the modification is to provide positive 
stripping means for the cylindrical element needles 120. 
To this end, a stationary stripping wedge 250 is mounted on a cylinder 
portion 252 which is rotatably mounted on the shaft 116 by means of a 
bearing race 254. The cylinder portion 252 and wedge 250 are prevented 
from rotating about the shaft 116 by a stub member 256 which projects from 
the cylinder portion 256 upwardly into engagement with a horizontal shaft 
258 mounted in the frame 22 parallel to the shaft 116. 
As best noted in FIGS. 18 and 20, the wedge 250 is located on the 
circumferential portion of the cylinder 252 which is between the cylinders 
110 and 112 and is spaced by a radial distance from the shaft 116 which is 
less than the radius of the cylinder 112. 
In operation, when the cylinder 112 is rotated counterclockwise, as viewed 
in the figures, to disengage the needles 120 from a workpiece, the needles 
120 are rotated to a plane which is higher than the plane containing the 
bottom of the wedge 250 to thereby forcibly strip the workpiece from the 
needles 120. 
It will be understood that a corresponding stripper is mounted about the 
shaft 114 to cooperate with the needles 120 of the cylinder 110. 
The terms and expressions which have been employed here are used as terms 
of description and not of limitations, and there is no intention, in the 
use of such terms and expressions, of excluding equivalents of the 
features shown and described, or portions thereof, it being recognized 
that various modifications are possible within the scope of the invention 
claimed.