Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
139.31.
This invention relates generally to looms or weaving
machines, and particularly to a loom for weaving a continu-
ous length of tape for use as stringers or carriers in
slide fasteners. ~ore particularly, the invention concerns
a device for imparting progressively varying degrees of
tension to a series of warp yarns being woven by such a
loom into a continuous length of stringer tape, which is
thus biased to curve in its own plane.
As is well known, a continuous length of woven stringer
tape tshown ln Fig. 1 of the attached drawings) is, before ~ ;~
attachment of spaced groups of fastener elements or scoops
to its beaded or reinforced edge, curved in its own plane
with the beaded edge directed inwardly. The beaded edge
portion of the stringer tape is extended in length upon
attachment of fastener elements thereto, to such a degree
that -the complete stringer tape becomes straightened.
Conversely, should the stringer tape fresh from the
loom be straight, the tape would, upon mounting of fastener
elements thereon, become curved with its element-carrying
edge directed outwardly. If a slide fastener were formed
from a pair of such stringers, the complementary groups of
fastener elements when interengaged would form unsightly
corrugations along their length.
The common practice, therefore, is to tension a
series of warp yarns -to different degrees in interlacing
them with filling or weft yarns on a loom to form a continu-
ous length of stringer tape. The different degrees of
tension may be applied to~the successive warp yarns
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individually or to successive divisional groups of such
yarns. In this manner the yarns can be woven into the
desired stringer tape curved in its own plane.
One conventional measure~adopted for the above pur-
pose has been, at the time of warping, to wind a series
of warp yarns unwound from their respective payoff bobbins
upon a warp beam under different degrees o~ tension. The
warp yarns are woven under continued application of such
pressure. According to another known measure, a series
of warp yarns are wound on a pluraligy of warp beams under
the same degree of tension, and these warp beams are weighted
to different degrees to impart the correspondingly different
degrees of tension to the warp yarns being let oEf therefrom~
Common to these convention~al measures lS the drawback
that the degrees of tension to be applied to the warp yarns
must be adjusted individually, requiring complex means in
practice. In some cases, moreover, proper yarn tension
is difficult to regain upon breakage of one or more warp
yarns.
An Object oE this invention resides in the provision
of a materially simplified warp tensioning device whereby
a series of warp yarns on a loom can be subjected to ten-
sion which varies by constant degrees from the yarn on one
side of the series to the yarn on the opposite side, so
that the warp yarns can be interlaced with the filling
in the usual manner to provide a continuous length of
stringer tape whlch is constantly curved in its own plane.
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According to the present invention, a warp tensioning
device for a loom for weaving a continuous length of tape
for particular use as stringer tapes of slide fasteners,
wherein the loom is of the type including a shedding mecha~
nism disposed on a pa.th.àlong which a series of warp yarns
are fed in a predetermined direction to be woven into the
tape, comprises a tapered tension drum rotatably supported
on the path of the warp yarns in a positionlof the shedding
mechanism, the tension drum having its axis disposed at ;`~
right angles to the warp yarns, brake means for applying
a constant braking force to the tension drum, a irst
guide member over which the warp yarns are made to pass
before travelling over the tension drum, and a second guide
member over which the warp yarns are made to pass after
travelling over the tension drum. The first and the second -.~:
:: guide members are disposed parallel to the axis of the ; ~:
tension drum and coact to cause the warp yarns to pass
over the tension drum in sufficient frictional contact
therewith. As the warp yarns are forcibly fed in the
predetermined direction along the path, progressively ::~
varying degrees of tension are imparted to the successive
individual warp yarns by the tension drum.
The above and other objects, features and advantages
of this invention and the manner of attaining them will ~ ;
become more readily apparent, and the invention itself
will best be understood, from the following description
and appended claims taken in connection with the accompany-
ing drawings showing a preferred embodiment of the
inventionO
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Fig. l is a partial plan view of a length of curved ~;
stringer tape woven by a loom to which this~invention
pertains;
Fig. 2 is a schematic plan view of a needle loom
equipped with a preferred form of the warp tensioning device
in accordance with this invention, the view being expla-
natory, in particular, of the positional and functional
relationship between the warp tensioning device and some
working parts or mechanisms of the loom;
Fig. 3 is an elevational detail view of the warp
tensioning device of Fig. 2, shown together with means
for letting off a filling yarn and means for tensioning
a reinforcing cord to form the edge bead of the woven
stringer tape;
Fig. 4 is the right~hand side elevational view of
the showing~of Fig. 3; and
Fig. 5 is a perspective view of some essential
parts of the warp tensioning device, shown together with
a series of warp yarns being tensioned thereby.
The warp tensioning device of this invention is
intended for use in or with a loom for weaving a continuous
length of stringer tape 10 shown in Fig. 1. The tape is
formed to include a reinforcing bead in the form of a ;`
cord 11 extending along one of its longitudinal edges~
Groups of fastener elements or scoops are to be attached
to this reinforced edge of the stringer tape 10, as repre-
sented by several phantom fastener elements 12. It will
be noted that the stringer tape 10 is constantly curved
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in its own plane, with its beaded edge directed inwardly.
In Fig. 2 the warp tensioning device of the invention ~:
is generally labelled 13 and i5 shown together, by way of
example only, with a needle loom for weaving the stringer
tape 10. The warp tensioning device 13 imparts progressive- :
ly varying degrees of tension to a series of warp ~arns
14 being interlaced with a filling yarn 15 by the loom to
form the stringer tape 10.
The needle loom includes a shedding mechanism 16
com~rising harnesses or heald framed which operate in the
well known fashion to create the shed of the warp yarns
14. The reinforcing cord 11 is disposed on one side of the
warp yarns 14, as an additional member of the warp, to form
the noted edge bead in the completed stringer tape 10.
The filling yarn 15 is passed through the shed of the warp
by a filling carrier 17, from one side to the other of
the warp, and is engaged by a latch needle 18. Shown at
19 is a battening reed which with each picking operation,
pushes or battens the filliny pick against the fabric tape
10 which has already been woven. The woven fabric tape ;
10 is fed by a pair of feed rolls 20 ~one seen) in the :~
arrow marked direction to suitable take-up means (not shown)~
The warp tensioning device 13 is disposed on the
path along which the warp yarns 14 are fed through the
lcom by the feed roll pair 20. The position of this warp
tensioniny device 13 precedes the position of the shedding
mechanism 16 of the loom with respect to the arrow-marked
travelling direction of the warp yarns 14 along the path.
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More detailed representations of the warp tensioning
device 13 are gi~en in Figs. 3 and 4. These figures show
a pair of such warp tensioning devices 13 and 13', along
with a pair of filling yarn let-off devices 21 and 21'
and a pair of reinforcing cord tensioning devices 22 and 22',
for combined use with a pair of juxtaposed needle looms
each configured as depicted in Fig. 2. These pairs of
devices 13 and 13', 21 and 21', and 22 and ~2' are all
mounted on a frame comprising a base pedestal 23, a plural-
ity of uprights 24 on the pedestal, and a table 25 atop
the uprights. The table 25 is formed to include a pair
of upstanding bearing arms 26.
Since the pair of warp tensioning devices 13 and
13', the pair of filling yarn let-off devices 21 and 21',
and the pair o reinforcing cord tensioning dèvices 22 and
22' are each identical in construction, except for some
parts shared by both devices of each pair, only one device
13, 21, 22 of each pair will be described in detail.
Further, the reference numerals used to designate various
parts of these exemplified devices 13, 21 and 22 will be
simply primed in the drawings to denote the corresponding
parts of the other devices 13', 21' and 22', it being
understood that the descriptions of the exemplified devices
13, 21 and 22 are applicable to the devices 13', 21' and 22'.
The exemplified warp tensioning device 13 comprises
a tapered tension drum or roll 27 fixedly mounted on a shaft
28 rotatably journalled at both ends in the pair of bearing
arms 26 on the table 25. The shaft 28 is disposed at right
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angles with the path of the warp yarns 14, which are made
to pass over the tension drum 27, as hereinafter described
in detail. Preferably, as shown in Fig. 5, the tension
drum 27 has a cover.ing 29 of felt or like material capable
of a~fording positive frictional contact thereo~ with the
warp yarns 14. A tapered pressure roll 30 is rotatably
mounted on another shaft 31 extending between the bearing
arms 26 in parallel rPlationship to the first recited shaft
28. This pressure roll 30 is intended to press the warp
yarns 14 against the tension drum 27.
For exertion of a constant braking force on the
tension drum 27, a brake band 32 is secured a.t one end 33
to a part of the frame and is wrapped around the tension
drum adjacent one end thereof. ~ weight 34 i.s secured to
the other end of the brake band 32.
~'he warp tensioning device 13 further comprises
guide means for causing the warp yarns 14 to pass over
the tension drum 27 in contact therewith through a suitably .
great angle. The guide means is shown to comprise first
35 and second 36 guide rolls rotatably mounted on the table
25 in parallel relationship to the ~xis of the tension
drum 27. A positioning reed 37 is fixedly mounted adjacent
the fi.rst guide roll 35. Released from suitable let-off
means (not shown), the series of warp yarns 14 are made
to pass through the positioning reed 37, then under the
first guide roll 35, then o~er the tension drum 27, and ~;
then under the second guide roll 36, on their way to the
shedding mechanism 16 of the loom.
Disposed next to the second guide roll 36 and fixedly
mounted on ~he table 25 is an open-top reservoir 38 contain-
ing a suitable lubricant. A coating roll 3g is rotatably
mounted within the reservoir 38 so as to partly project
upwardly therefrom. The coating roll 39 is connected via ~ :~
belt-and-pulley arrangement 4Q to the tension drum 27 for
simultaneous rotation therewith~ The warp yarns 14 pass
in contact with the coating roll 39 on their way from the
second guide roll 36 to the shedding mechanism 16.
The exemplified filling yarn let-off device 21 is
shown to comprise a pair of filling cheeses 41 pivotally
mounted on a cheese stand 42 secured to the base pedestal
23. The filling yarn 15 from the let-off device 21 is
threaded through a guide disc 43, compensa-tor 44 and guide
hole 45 and is made to pass in contact wi.th the coating :.;
roll 39 along with the warp yarns 14.
~he exemplified reinforcing cord tensioning device
22 includes a tension disc 46 rotatably mounted on a hori-
zontal shaft 47 supported by two adjacent ones of the up-
rights 24. The tension disc 46 has a pair of parallel
grooves formed in its periphery, one of which grooves
receives a brake band 48 carrying a weight 49 on.one end
and secured at the other end to a cross member 50 extending
between said two adjacent ones of the uprights 24. The;~.
weighted brake band 48 is effective to apply a constant
braking force to the tension disc 46. : :
Delivered from suLtable let-off means ~not shown), -.
the reinforcing cord ll is first threaded through a hole
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51 in a guide bar 52 also extending between said two adjacent
ones of the uprights 24. The reinforcing cord 11 is then
wrapped around the tension disc 46 and is then passed under
a guide rod 53 extending between the other two adjacent
ones of the uprigh-ts 24, on its way to the shedding mecha~
nism 16. The reinforcing cord 11 wrapped around the tension
disc 46 is received in the other of its no-ted two peripheral
grooves.
In operation, as the pair o~ feed rolls 20 of the
loom rotate to feed the woven fabric tape 10 toward the
unshown take-up means with each shedding, picking and
battening operation, the series of warp yarns 14 are pulled
in the same direction. The warp yarns 14 are in frictional
contact with the tension drum 27, so that the latter is
rotated in a clockwise direction, as viewed in Figs. 3 and
5~ ln opposition to the constant braking force applied
thereto by the weighted brake band 32.
Since the tension dr~n 27 is tapered, and since its
axis is disposed paxallel to the first 35 and second 36
guide rolls, the successive warp yarns 14 arranged on the
dr~n from its large to small diameter end are fed to pro-
gressively smaller extents toward the shedding mechanism
16 with each rotation of the feed rolls 20 and of the
drum. Thus, provided that the warp yarns 14 are arranged
at unvarying spacings on the tension drum 27, the warp
yarn portions extending between the drum and the feed rolls
20 are individually tensioned to constantly increasing
degrees from the endmost yarn passing ov~r the large diameter
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end of the drum to the other endmost yarn passing over its
small diameter end.
The reinforcing cord 11 is separately tensioned by
its own tensioning device 22 to a degree determined in
accordance with the tension imparted as above to the
adjoining endmost one of the warp yarns 14. Tensioned
in this manner to progressively varying degrees, the warp
yarns 14 and reinforcing cord ll are interlaced as aforesaid
with the filling yarn 15 into the continuous length of '
stringer tape 10 which is constantly curved in its own
~: plane, with its reinforced edge directed inwardly.
Although this invention has been particularly shown
and des.cribed with reference to a preferred embodiment : :
thereof, it will be understood that various changes in
form and detail may be made without departing from the
spirit and scope of the invention.
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