Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVENENTS IN OR RELATI~G TO THE HANDLING OF LIMP FABRIC
This invention relates to the handling of limp fabric in
manufacturing processes and in particular, to the stretching
and folding of such fabric prior to the performance of a
sewing operation thereon.
The fabrication of garments from fabric is currently a
labour-intensive process, principally because of the lack of
mechanical means for holding pieces of fabric as they are
sub~ected to various operations including transporting,
feeding through machines such as sewing machines, and folding.
It is an object of the present invention to provide a
method and apparatus for mechanically stretching and folding
a limp fabric piece to enable subsequent sewing of the folded
fabric piece to produce a garment.
The present invention is an improvement in and
modification of the method and apparatus disclosed and claimed
in applicant's earlier published patent application No.
PCT/AU86/00074.
The invention accordingly provides a method of stretching
and folding a limp fabric piece having a plurality of opposed
elastic bands extending therefrom comprising locating and
holding said fabric piece in an extend~d condition on a
platform having a foldable segment such that one half of said
fabric piece is located on said foldable segment and in a
position to enable subsequent folding of said fabric piece to
obtain the shape of the desired garment, applying suction to
said elastic bands in an axial direction thereto by suction
means, grippng said elastic bands relative to the suction
means, releasing the holding action on said fabric piece,
releasing the suction, stretching said fabric piece by axially
moving the suction means with the gripped (attached) elastic
bands away from said fabric piece, gripping the fabric piece
adjacent the elastic bands, associated with said foldable
segment,
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relative to the segment in the correct position to form the
garment with overlapping elastic bands when folded,
releasing the gripping hold on said elastic bands associated
with said foldable segment, folding said segment to form
5said garment with said elastic bands overlapping, pressing
and holding said garment adjacent said overlapping elastic
bands, releasing the grip on the elastic bands associated
with said (stationary) platform and said foldable segment
respectively, and returning said foldable segment.
The garment may then be held flat on said (stationary)
platform between said overlapping bands and moved along an
adjacent platform to a sewing station after releasing the
hold on said garment adjacent said overlapping elastic
bands.
The invention also provides apparatus for carrying out
the above method, comprising
a platform having a foldable segment,
means for folding said foldable segment relative to the
platform,
a limp fabric piece feeding plate for feeding said limp
fabric piece to said platform and holding said fabric piece
thereon in an extended condition and in a pre-determined
position to enable eventual folding of the fabric piece to
produce a garment,
means for moving said plate member horizontally or
vertically,
suction means located adjacent said platform for
applying suction to the elastic bands extending from the
fabric piece,
elastic band gripper means associated with the suction
means for gripping and holding the sucked-in elastic bands,
relative to said suction means,
means for moving said suction means relative to said
platform to stretch said fabric piece,
garment gripper means associated with said foldable
segment for gripping and holding the stretched fabric piece
at the correct position for folding said piece and
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garment pressing means associated with said (stationary)
platform for pressing and holding the folded garment
adjacent the overlapping elastic bands of said fabric piece.
Conveniently, the apparatus also includes a garment
feeding plate reciprocating horizontally adapted to be
superimposed on the garment between the points of contact of
said garment pressing means and moving said garment to a
sewing station after release of said garment pressing means.
Conveniently, the suction means comprises a plurality of
suction pipes, one adjacent each elastic band, connected to
an air-suction source. These air suction pipes are movable
relative to said platform by conventional pneumatic means so
as to stretch the fabric piece.
Advantageously, the elastic band gripper means may
consist of a clip mounted at the outer end of the suction
pipes for pivotal movement about said pipes and which clip
may be actuated by a link mechanism coupled to conventional
pneumatic means.
The garment gripper means may take the form of a pair of
horizontally, slidably mounted brackets which are
reciprocally movable to opposed positions above the fabric
piece adjacent to the elastic bands and are also mounted for
vertical movement to achieve gripping and release
respectively of the fabric piece relative to the foldable
segment. The aforementioned movements of the garment gripper
brackets may conveniently be actuated by conventional
pneumatic means.
Advantageously, the garment gripper means associated
with each leg elastic band is mounted separately to the
other (opposed) gripper means (associated with the waist
elastic band) and is associated with optical alignment means
to ensure alignment of the leg elastic bands to ensure in
turn alignment of these after folding (for subsequent sewing
operation).
The garment pressing means may conveniently consist of a
pair of brackets pivotally mounted on a common axle, the
brackets being spaced such that contact with the garment is
made adjacent but on the outside of the point of contact of
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the fabric gripper means. Advantageouslyt these brackets
have pivotally mounted at the outer ends thereof, garment
contacting platelets for contacting and holding the folded
garment against the platform. Rotational movement about the
common axle is actuated by conventional electrical means.
Advantageously, additional stretching and aligning means
are provided on both sides of the stretched fabric piece
principally for the purpose of correctly aligning the two
halves of the fabric piece so that upon folding particularly
the respective areas of the fabric piece adjacent the
elastic bands are correctly superimposed. Conveniently, the
above additional means can take the form of gripping fingers
mounted on each side of the stretched fabric adapted to be
moved above and to grip and stretch opposed elasticised
portions of the fabric piece. In addition, the apparatus
may also comprise a plurality of brushes mounted abové the
elastic bands of the fabric piece for vertical movement and
horizontal movement along said elastic bands. The purpose
of the brushes is to align the elastic bands with the free
ends of the suction pipes to enable suction of the elastic
bands within said pipes.
Conveniently, the platform and adjacent platforms
serving the supply and removal of the limp fabric piece and
folded garment, respectively, are of low friction material
and the underside of said garment and limp fabric piece
feeding plates are of high friction material to facilitate
movement of said fabric piece and garment on the adjacent
platform.
Conveniently, the various method steps are carried out
by programmed electronic and sequential actuation of the
various components of the apparatus.
The invention will now be described and illustrated with
reference to a preferred embodiment depicted in the
accompanying drawings wherein:
Figures 1 and 2 show an overall view of part of the
method and apparatus according to the invention;
Figures 3 to 11 show the various method steps and
portions of the relevant apparatus used to carry out these
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steps; Figure 3a is a more detailed view of a pair of the
brushes mounted on their respective carriage;
Figure 12 shows a plan view of the limp fabric piece
feeding plate partially located on the foldable segment of
the platform;
Figure 13 shows one of the air suction and elastic band
gripper units associated with the apparatus of the
invention;
Figure 14 shows another view of the suction unit shown
in Figure 13;
Figure 15 shows one form of the garment gripper
mechanism associated with the apparatus of the invention;
and
Figures 16A, 16s and 16C show another, preferred form of
the garment gripper mechanism and associated optical sensing
mechanism.
Referring to Figures 1 and 2, a limp fabric piece 1 (in
the form of a blank for a brief) having four pairs of
elastic bands 12, 12~ 13, 13' extending therefrom is
transported from a previous work-station, (not shown) to a
platform 2 having a turning plate 3 such that one half (la)
of the fabric piece 1 is located on the turning plate 3, the
axle 3a thereof extending through the crotch portion lb of
the brief. Turning plate 3 is pivotable by means of
~5 rotatably mounted cylinder 4. Stoppers 14,15 mounted on
platform 2 are provided to stop a limp fabric piece feeder
plate 5 at the correct position.
Platform 2 and adjacent platforms 6,7 (which may be
integral therewith) are of low friction material whereas
feeder plate 5 has a bottom surface of high friction
material.
After the limp fabric piece 1 is stretched (described
hereinbelow) feeder plate 5 is lifted therefrom and returned
to an earlier work station (not shown). The fabric piece 1
is then folded by means of turning plate 3 to form a brief 8
which, after being held by garment pressing lever 11, is
then moved by means of a garment feeding plate 9 to a pair
of overlock sewing machines 10 for side seaming.
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Referring to Figures 3 to 11, each pair of elastic bands
12, 12' 13, 13' has located adjacent to them, a correspond-
ing pair of suction pipes 20 mounted on suction units
(described hereinbelow, not shown). Each suction pipe 20 has
at its outer end and located there within a pivotally
mounted clip 21 pneumatically actuated for gripping (and
releasing) the corresponding elastic bands (e.g. 13, 12')
and releasing same. Each of adjacent elastic band pairs 12,
12' has furthermore associated with it a pair of opposed
garment grippers 22 (described hereinbelow). The garment
grippers 22 are actuated to move to a position above the
fabric piece 1 in its stretched condition and to be raised
or lowered in relation to the fabric piece 1. A plurality
of stretcher fingers 70 may be brought into stretching
engagement at selected positions on both sides of the fabric
piece 1 associated with the stationary platform to properly
align said piece before folding said turning plate 3 with
the other half of said fabric piece 1 located on said plate
3.
Referring specifically to Figures 3a to 3c, there are
shown a pair of brushes 60 co-operating with a correspond-
ing pair of elastic bands 13,12' sweeping the bands towards
the open end of suction pipes 20. The brushes 60 depend b~
means of a rod assembly from a carriage 80, there being
provided one such carriage 80 on each side of each half of
the fabric piece 1. The brushes 60 are mounted on the
carriages 80 for vertical and horizontal movement so that
they are capable of being moved down onto and along the
elastic band pairs 12,12',13 and 13' to sweep the bands into
the respective suction pipes 20. Carriage 80 is mounted for
horizontal movement on a rod (not shown) which also carries
a second identical carriage (not shown) supporting the other
pair of brushes (not shown) for co-operation with elastic
bands 12 (not shown) and 12' (Figure 3a). srushes 60 are
mounted via rods 61,62,63,64 and 65 on carriage 80, rods 65
heing moveable in a vertical direction relative to carriage
80 to lower or raise brushes 60 relative to the elastic
bands 12,12',13 and 13'. Actuation of carriage 80 (for
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horizontal movement) and rods 65 (for vertical movement) is
by well-known pneumatic means (e.g. as shown at 66).
Specifically, with reference to Figure 10, there is
shown a garment pressing unit 30 which comprises a pair of
garment pressing levers 31 mounted on a common axle 32
actuated for rotation by an electric motor 33. The ends of
each lever are provided with a pivctally mounted platelet 34
which has the function, upon the garment pressing levers 31
being in the operative position, of aligning themselves with
the folded fabric piece or garment 8.
Referring to Figure 11, a garment feeding plate 9
reciprocates between the position adopted by the folded
fabric piece or garment 8 to a position adjacent the two
overlock sewing machines 10 (see Figs. 1 and 2). The plate
has a lower contact surface of high friction material which
is designed to frictionally hold the garment 8 when the
garment is moved along the low friction platform 7.
The se~uence of operations in relation to the limp
fabric piece is as follows:
The fabric piece 1 is transported in an extended
condition with the aid of the fabric piece feeding plate 5
to the location on platform 2 described herein before.
Vacuum is then applied by means of the air suction unit
(described hereinbelow) and the air suction pipes 20 to the
elastic bands 12, 12', 13, 13' whereby they are sucked into
each of the pipes 20 with the aid of the brushes 60. The
elastic bands 12, 12', 13, 13' are then gripped relative to
the pipes 20 by means of the elastic band gripper clips 21
which are moved into the gripping position shown in Figures
5 and 6. The suction pipes 20 are then moved axially away
from the platform 2 in order to stretch the fabric piece and
the garment grippers 22 associated with elastic bands 12 and
12' are then actuated to move into engagement with the
fabric piece 1 adjacent these elastic bands by moving the
grippers 22 to a position above and then down upon the
fabric piece 1 (cf. Figure 8). Stretcher fingers 70 are
then actuated to stretch and align the fabric piece 1
associated with the stationary platform with the other half
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of the fabric piece 1 to be folded.
The turning plate 3 is then actuated by means of
cylinder 4 such that it overlaps platform 2 with the two
halves of the fabric piece 1 being superimposed and forming
the garment 8 (cf. Fig 9).
The garment pressing levers 31 are then actuated to
engage the garment 8 on the inside of the garment grippers
22 whereafter the garment grippers 22, stretcher fingers 70
and the elastic band grippers 21 associated with elastic
bands 13 and 13' are released (cf. Fig. 11). The turning
plate 3 is then returned and the garment feeding plate 9 is
moved and located above the garment 8 between the garment
pressing levers 31(cf. Fig. 10). Levers 31 are then released
and the garment is moved along platform 7 to a pair of
overlock sewing machines 10 for seaming.
Referring to Figure 12, the fabric piece feeding plate 5
consists of a metallic plate having a configuration such
that the fabric piece 1 protrudes beyond the edges 5a of the
plate 5, the latter having opposed raised surfaces 5b for
guiding a plurality of rollers concerned with a previous
work-station (not shown) involved with the seaming of the
corresponding opposed edges of the fabric piece 1. The plate
5 has a plurality of recesses 5c in order to minimise the
weight thereof. The plate 5 also has a pair of opposed pins
5d which enable appropriate grippers to attach themselves to
said pins 5d for lifting, lowering and moving said plate 5.
Referring to Figures 13 and 14, the air suction unit,
generally indicated as 40, comprises a pair of air suction
pipes 20 connected to a suction source (not shown) by means
of manifold 23 and hose 24. The air suction unit 40 is
mounted on a rod 25 extending through a collar 26 to which
the air suction pipes 20 are attached. The air suction unit
40 is slidable along rods 25 for horizontal movement
re~ative to the platform 2, such movement being actuated by
a piston 27 connected to air cylinder 28.
An elastic band gripper in the form of a rectangular
clip 21 is pivotally mounted on the inside of each pipe 20,
pivotal movement of the clip 21 being actuated by air
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cylinder 29 and piston 29a connected to said clip 21 throuqh
a link 29b.
Referring to Figure 15, a pair of opposed garment
grippers 22 are slidably mounted on rod 50 and are pivotally
connected by a pair of arms 51 to a pin 52 attached to
piston block 53 mounted on piston 54 associated with air
cylinder 55. Pin 52 moves within a slot 56 in a plate 57 one
end 58 of which has piston 54 extending therethrough. This
enables sliding movement of the garment grippers 22 on rod
50 consequent upon vertical movement of the pin 52 actuated
by air-cylinder 55 and piston 54.
Rod 50 is supported by collar 59 to which is attached
the other end of plate 57 which in turn is attached to a
further collar 61, these being rigidly secured together to
allow vertical movement of collar 61 on upright post 62
extending therethrough actuated by piston 63 and associated
air cylinder 64. This enables vertical movement of the
garment grippers 22 relative to the platform 2.
Referring to Figure 16A, there is shown the mechanism
shown in Figure 15 but modified to actuate only one garment
gripper 22 to co-operate with only one elastic band, i.e.
the waist band.
Referring to Figure 16s, there is shown another garment
gripper mechanism (unit) for co-operation with the other
elastic band, i.e. the leg band. The unit is comprised of
two main activating sub-assemblies, viz. a pulse motor
sub-assembly (generally indicated as 100) to effect
horizontal movement of the overall unit including the
garment gripper 90, and a garment gripper positioning and
clamping sub-assembly (generally indicated as 101) for
effecting vertical movement of garment gripper 90 via
pneumatic means.
Sub-assembly 100 comprises essentially a pulse motor 94,
controlled by switch 95, which actuates a driven threaded
shaft 93 to move the whole unit (including gripper 90)
horizontally along carrier slider shaft 92 to a selected
position over the leg elastic band (not shown).
Sub-assembly 101 comprises essentially air cyclinder 91
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which by means of piston rod 96 and bracket 97 actuates
garment gripper 90 for vertical movement over the leg
elastic band to clamp said band in the selected position.
Referring to Figure 16C, there is shown an optical
sensing mechanism (of which several are used in connection
with the unit shown in Figure 16B). The mechanism (unit)
comprises a fibre optic sensor 108 mounted on a carrier
block 107 driven by air cylinder 105 and slidably mounted on
shaft 106.
The movement of both sub-assemblies 100 and 101 is
co-ordinated by signals from a central processing unit (not
shown) which obtains its data from the optical sensing
mechanism shown in Figure 16C.
The units shown in Figures 16B and 16C are located in
separate locations. The unit shown in Figure 16B is mounted
on the lower side of turning plate 3 while the optical
sensing unit shown in Figure 16C is fixed in position to the
main frame of the overall machine. Co-ordination between
these two units ensures that the alignment of the elastic
leg bands of the garment is as is required to enable
accurate sewing of the side seams thus guaranteeing ideal
assembly appearance of the finished garment.
