Enclosing elastic in a fabric

Apparatus for securing an elastic band in a hem tunnel formed of garment fabric comprises a fabric folding device having an entry zone and an exit zone both of which are planar, the entry zone being inclined at an angle, conveniently between 30.degree. and 90.degree., preferably 45.degree., relative to the exit zone. A guide roller by which a band is guided to the entry zone is rotatable about an axis parallel with the entry zone and at right angles to the direction of feed of the band and fabric through the device. The apparatus facilitates the incorporation of draw-cord elastic into garment hem tunnels.

FIELD OF THE INVENTION 
This invention relates to enclosing of elastic in a fabric and especially 
to apparatus suitable for use in enclosing and securing an extensible 
elastic band within a hem tunnel formed in a length of garment fabric. 
BACKGROUND TO THE INVENTION 
Many garments have an extensible wearer-encircling portion such garments 
include for example track suits, casual jackets, ladies and means leisure 
trousers and the like. The wearer-encircling portion may be for example a 
waist band, a cuff band or an ankle band. 
In our Pat. No. GB 1406822 is described a method of securing and enclosing 
an extensible elastic band within a hem tunnel formed in a length of 
garment fabric and apparatus for securing and enclosing an extensible 
elastic band within a hem tunnel formed in the length of garment fabric. 
Apparatus generally similar to that described in our Patent Specification 
has been used successfully for enclosing an elastic band in a hem tunnel 
formed in a length of garment fabric in a wide variety of applications. 
One form of elastic band which is desirably included in some garments, for 
example the waist band of certain leisure trousers is commonly referred to 
as draw-cord elastic. Draw-cord elastic comprises a substantially 
inextensible cord extending lengthwise along a region of the elastic band. 
In use in a garment portions of the draw-cord ar appropriate positions are 
accessible to a wearer thus to draw the wearer-encircling portion of the 
garment tighter and secure it in the tightened position, for example by 
tying a suitable knot. Draw-cord elastic is produced by the applicant 
company and a draw-cord elastic is the subject of our Pat. No. GB 1406821. 
Apparatus described in our Pat. No. GB 1406822 comprises a folding device 
and the apparatus supplied by the applicant company has utilized a folding 
device which is about 16 cms in length and which comprises two parallel 
members through a gap in which the band and fabric travel in face contact, 
the members in the commercially supplied device, as in the device as 
described by way of example in our Pat. No. 1406822 twisting in their 
length through 180.degree.. Apparatus with a folding device of this length 
has been found suitable for use in enclosing many elastic bands within a 
hem tunnel but not altogether satisfactory for enclosing an elastic band 
including a draw-cord which has been found to show a tendency to collapse 
along the centre line: this has apparently occurred because of the degree 
of twist applied to the elastic band in a relatively short distance. 
In order to satisfactorily enclose a draw-cord elastic within a hem tunnel 
using apparatus generally as shown in our Pat. No. 1406822, a longer 
folding device has been found to be necessary having a length of about 30 
cms and again the folding members twisting in their length through 
180.degree.. The severity of the twist applied to the elastic band in such 
a longer machine is much reduced and with such a machine having a longer 
folding device the tendency of the band including draw-cord to collapse 
along its centre line has been substantially reduced so that it is 
virtually non-existent. 
The use of a longer folding device, however, is itself not altogether 
satisfactory (although the results obtained using draw-cord elastic are 
much improved) because the operator of the succeeding sewing machine to 
which the work is fed is necessarily further from the sewing machine 
making control of the sewing more difficult and thus being less 
ergonomically satisfactory. Furthermore, the longer folding device is 
necessarily more expensive. As far as production is concerned, the short 
system is easier and faster to use, thereby increasing productivity 
whereas the longer folding device leads to more scrap and greater wastage 
of elastic. 
OBJECTS OF THE INVENTION 
One of the various objects of the present invention is to provide improved 
apparatus suitable for use in securing and enclosing an extensible elastic 
band within a hem tunnel formed in a length of garment fabric and 
especially such apparatus suitable for use in securing an extensible 
elastic band including a draw-cord. 
SUMMARY OF THE INVENTION 
In one aspect the invention may be considered to provide apparatus suitable 
for use in securing and enclosing an extensible elastic band within a hem 
tunnel formed in a length of garment fabric comprising a fabric folding 
device for forming fabric into a hem tunnel, for example by folding a 
marginal strip of fabric protruding beyond an edge of an elastic band fed 
to the folding device with a first face of the band in contact with a 
first face of the fabric around said edge of the band to overlay a second, 
opposite face of the band and by folding the fabric about the other edge 
of the band to present said second face of the band, and the marginal 
strip, to the first face of the fabric whereby to present the fabric 
folded about the band on a substantially planar path to a mechanism for 
withdrawing the band and fabric from a planar or substantially planar exit 
zone of the folding device and for securing the band in the hem tunnel, 
the fabric folding device comprising a substantially planar entry zone at 
which the fabric and band are introduced into the folding device inclined 
at an angle relative to said exit zone, and the apparatus further 
comprising a guide roll by which a band is guided to said folding device, 
mounted for rotation about an axis parallel or substantially parallel with 
the plane of the entry zone but at right angles or substantially at right 
angles to the direction of feed of material through the folding device. 
In another aspect the invention may be considered to provide an attachment 
for a machine suitable for use in securing and enclosing an extensible 
elastic band in a hem tunnel formed in a length of garment fabric 
comprising a fabric folding device having a planar or substantially planar 
entry zone at which an elastic band and fabric to be folded thereabout can 
be introduced to the folding device and a planar or substantially planar 
exit zone from which the band with fabric folded thereabout can be 
presented to mechanism of a machine for securing the band within the hem 
tunnel, wherein the entry zone is inclined at an angle relative to the 
exit zone, the attachment further comprising a guide roller by which a 
band can be guided to the entry zone the guide roller being mounted for 
rotation about an axis parallel or substantially parallel with the entry 
zone and at right angles to the direction in which the band and fabric 
passes through the device in the use thereof. 
Preferably, in accordance with the invention, the axis of the guide roller 
and the entry zone are inclined at and angle of between 30.degree. and 
90.degree., more preferably about 45.degree. to the exit zone. Although an 
angle of about 45.degree. is preferred, it may be possible to position the 
guide roller and the entry zone of the folding device perpendicular to the 
exit zone of the folding device; for example, in a normal sewing machine 
the exit zone would be horizontal and the axis of the guide roller and the 
entry zone vertical. In this instance, the fabric may be supplied to the 
entry zone of the folding device through an L-shaped guide with the bulk 
of the fabric above the guide roll and the portion to be folded about the 
elastic band depending downwardly. 
Preferably the folding device defines the entry and exit zones. Suitably 
the folding device comprises two parallel members which define the entry 
and exit zones, and portions of the band and fabric travel between the 
members. Preferably a first of the members has a width equal to or greater 
than that of the band and the second of the members is narrower and 
located adjacent one edge portion of the first member. The members twist 
in their length through an angle of less than 180.degree. (the angle 
depending upon the angle of the entry zone relative to that of the exit 
zone). By reducing the angle by which the members twist in their lengths, 
it is possible to reduce the twisting force applied to the band by a 
folding device of a given length, and the tendency of a band including a 
draw-cord to collapse is thereby reduced. 
Apparatus in accordance with the invention preferably comprises a pair of 
metering rollers, at least one of which is driven, for forwarding the band 
at a predetermined linear speed to the guide roller. The mechanism for 
withdrawing the band and fabric from the folding device preferably 
comprises a pair of rollers so driven that the band and fabric are 
withdrawn from the folding device in the operation of the apparatus at a 
greater linear speed than that at which the band is forwarded by the 
metering rollers. 
The mechanism for drawing the band and fabric from the folding device and 
for securing the band in the hem tunnel in apparatus in accordance with 
the invention is preferably a sewing mechanism of known construction but 
other means of securing the band may be employed if desired, for example a 
heat seal adhesive material activated by the securing mechanism. 
Whereas apparatus in accordance with the invention may be integrally 
constructed to include a guide roller and folding device, conveniently the 
folding device and guide roller are included in an attachment e.g. for a 
sewing machine so that the attachment can be readily exchanged to deal 
with various different materials. An attachment in accordance with the 
invention may be secured to existing sewing machines in replacement for 
attachments including a longer folding device as used presently. 
In order that the currently available sewing machines may readily be used 
to enclose elastic with or without draw-cords in the most efficient 
manner, the sewing machines have been constructed with a readily 
detachable attachment carrying inter alia the folding device so that the 
attachment can readily be removed and replaced by an attachment 
appropriately to the work to be carried out.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The illustrative apparatus functions in a manner which is well known to 
those skilled in the art to wrap a part of the garment fabric around an 
elastic band to form a hem tunnel and to secure the elastic band within 
the hem tunnel utilising a sewing machine. The method is generally as 
described in our Pat. No. GB 1406822. 
The illustrative apparatus comprises a folding device 10 for forming fabric 
12 into a hem tunnel by folding a marginal strip 14 of fabric protruding 
beyond an edge of an elastic band 16 fed to the folding device 10, with a 
first face of the band in contact with the first face of the fabric 12 
around said edge of the band to overlay a second, opposite, face of the 
band 16 and by folding the fabric about the other edge of the band 16 to 
present a second face of the band and marginal strip 14 to the first face 
of the fabric. 
The folding device 10 comprises an entry zone 18 and an exit zone 20 both 
of which are substantially planar. The folding device 10 comprises two 
parallel members 22, 24 between which portions of the band and fabric 
travel along the folding device 10. A first of the members 22 has a width 
substantially equal to that of the band 16 and a turned over marginal 
portion 23 for folding the strip 14 round the edge of the band. The second 
of the members 24 is much narrower than the member 22 and located adjacent 
one edge portion of the first member 22. The members twist in their length 
through an angle of less than 180.degree.. 
The apparatus further comprises a first guide roller 26 by which the band 
16 is guided to the folding device 10. The guide roller 26 is mounted for 
rotation about an axis A which is parallel with the plane F of the entry 
zone of the folding device 10 but at right angles with the direction D of 
feed of material through the folding device 10. A guide 28 is positioned 
adjacent the guide roller 26 against which an edge portion of the fabric 
12 may be guided when feeding the fabric 12 into the folding device 10. A 
retaining member 30 is mounted on spring means conveniently a leaf spring 
32 to aid in retaining the folded fabric in position as it leaves the 
folding device 10; the spring mounting of the member 30 permits it to 
yield thus to allow bulky seams to pass unrestricted, the spring 32 
returning the member 30 to its normal position. 
Folding device 10, the retaining device 30 and the guide roller 26 are all 
mounted on an attachment which is readily removable from a sewing machine 
34 adapted to secure the band in the hem tunnel. 
Existing machines supplied by Automatic Braiding Limited include 
attachments mounting inter alia long or short folding devices as outlined 
above, the members of which twist through 180.degree. in the length of the 
device. The attachments of the existing machines are commonly 
inter-changed dependant on whether or not the elastic to be incorporated 
in the hem tunnel is a draw-cord elastic. The attachment of the 
illustrative machine is constructed to likewise be readily exchangeable 
with the existing attachments. 
As can be seen from the drawings, the sewing machine comprises a needle bar 
36 carrying needles 38. The sewing machine further comprises a pair of 
feed rollers 40, 42, being so driven that the band and fabric, passing 
between the rollers are withdrawn from the folding device in known manner. 
The illustrative sewing machine further comprises a metering device, viz 
pair of metering rollers (not shown), at least one of which is driven, for 
forwarding the band at a predetermined linear speed over an idler roller 
46 to the guide roller 26. The metering rollers are of known construction. 
The idler roller 46 is also carried on the attachment for the sewing 
machine, as is the guide roller 26; however the metering device is carried 
on the frame of the sewing machine and is utilized with other attachments 
carrying folding devices which may be mounted on the sewing machine. In 
known manner, the feed of the material by the feed rollers 40, 42 is 
co-ordinated with the reciprocation of the needle bar 36 and movement of 
the feed dog (positioned beneath the foot of the sewing machine) and the 
feed rollers 40, 42 and feed dog are driven at such a speed that the band 
and fabric are withdrawn from the folding device 10 at a greater linear 
speed than that at which the band 16 is forwarded by the metering rollers 
so that the band 16 is in a tensioned condition as it is secured within 
the hem tunnel. 
In the drawings, the band 16 is shown extending through the machine; 
however, a piece of garment fabric 12 is shown in a position where it is 
about to enter the entry zone of the folding device. 
FIGS. 2 to 5 show the folding device 10 at various positions along its 
length. FIG. 2 is a view at the entry zone 18 while FIG. 5 is a view at 
the exit zone 20. The exit zone 20 is substantially planar and horizontal, 
as indicated by the chain dot line P which is also parallel with the 
planar path of the material leaving the folding device 10. The plane P is 
shown on each of FIGS. 2 to 5. ln FIG. 2 the plane of the entry zone 18 is 
indicated by the chain dot line F and as can be seen from FIG. 2 this is 
inclined at an angle X to the plane of the exit zone P. The axis A of the 
guide roller 26 is parallel with the plane F. In the apparatus the angle X 
is about 45.degree. but this may be varied in other apparatus in 
accordance with the invention, generally similar to the illustrative 
apparatus, as desired. 
As the length of the folding device 10 is about 16 cms, corresponding with 
the length of the short folding devices of the known machines supplied by 
the applicant company, whilst the angle through which the member 22 twists 
along the length of the folding device is only about 135.degree., the 
severity of the twisting force applied to the band 16 is less than would 
be the case were the standard folding device to be used and the tendency 
of drawcord elastic to collapse is substantially eliminated. The 
illustrative apparatus is easier for an operator to use when inserting 
draw-cord elastic than the existing apparatus utilising a longer folding 
device and can be run at a faster speed due to the reduced resistance. 
Furthermore, the illustrative attachment is less expensive than the known 
attachments for dealing with draw-cord elastic satisfactorily and a 
reduction in scrap can also arise.