Improvements in Stretching and Tentering Woven Fabrics, and in Apparatus therefor.
Year: 1895

page_text: Date of Application, 20th Aug., 1895
Complete Specification Left, 13th May, 1896-Accepted, 15th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in Stretching and Tentering Woven Fabrics, and in
Apparatus therefor.
We, FRITZ CHWALLA and GUSTAV CHWALLA, both of Appollogasse 4,
Vienna VII, Austria, Manufacturers, do hereby declare the nature of this
invention to be as follows:-
This invention relates to an improved mode of stretching and tentering fabrics,
that is to say, holding the same in a transversely stretched condition and at the
same time shifting the weft so as to bring the same into oblique positions
alternately in opposite directions after treating them with dressing and while they
are passing over the tentering machine for drying. The invention consists mainly
in effecting the alternate advance of one side of the fabric relatively to the other
side, by alternately accelerating and retarding the forward motion of the tentering
chains by means of excentrics at the end of the machine, which excentrics are
shifted 90° relatively to each other and are connected to the sliding bearings of
the wheels over which the tentering chains pass, so that as the chains travel
forward, the one excentric draws say the right hand wheel and tentering chain a
certain distance in advance of the left hand one, thereby bringing the weft threads
into an oblique position, whereupon the left hand excentric draws the corresponding
chain forward, while the right hand one moves back again, whereby the weit is
first brought back to the original position at right angles to the length of the
fabric; and are then brought into the opposite oblique position, and so on, the
weft of the fabric being thus continuously shifted from one oblique position to
the opposite one during its travel, whereby any cementing together of the threads
by the dressing as it dries is effectually prevented.
The fabric is made to travel with the tentering chains round to the underside of
the loop, which is so arranged as not to partake of the alternate acceleration of the
upper part, so that the weft is there maintained in its normal position at right
angles to the warp, and is delivered from the chains in that condition.
The wheels over which the tentering chains pass at the feeding end of the
machine do not partake of the above described to and fro motion of the wheels at
the other end; it follows therefore that the upper sides of the endless tentering
chains have to be alternately extended and shortened in length, while still always
remaining taut. In order to enable this to be effected, the lower sides of the
chains have loops formed in them at the feeding end of the machine which loops
are kept stretched by means of weighted rollers carried by pivotted arms, so that
when the one chain has its upper side extended as described a corresponding length
thereof is drawn up from the said loop over the wheels at the feeding end and when
it is shortened again a corresponding length is drawn into the loop again by the
weighted roller. The drawing of the weft into alternate oblique positions would
have the effect of injuriously stretching the threads; in order to avoid this, the
beams that carry the two tentering chains are made to alternately approach
towards and recede from each other as the weft pass from the straight to the
oblique position and back again. For this purpose, according to one arrangement,
a shaft driven by gearing from the excentric shaft imparts motion by a crank and
connecting rod to a toothed rack gearing with a pinion on a spindle having right
and left handed screw threads screwing through the two chain beams, so that as the
excentrics bring the weft into the oblique position, the crank and rack are moved

page_text: so as to turn the screw spindle in one direction so as to screw the two beams with
the tentering chains nearer together, while when the excentrics bring the weft into
the straight position, the rack turns the screw spindle in the contrary direction so
as to move the beams and chains apart again.
Similar spindles with right and left handed threads are arranged along the whole
length of the chain beams, and are geared to the first described one either by bevil
gear on a longitudinal way shaft, or by other suitable means, so as to cause them
all to turn alternately in opposite directions, simultaneously with the first one, thus
causing the entire length of the beams and chains to partake of the above described
movement. The eccentrics are also moved laterally on their shaft in a corresponding
manner, by providing the chain beams with projecting arms having forks that
engage with collars on the bosses of the eccentrics, these being arranged to slide
with a key and feather on their shaft; or the latter may be made of a square
section for the purpose.
According to another arrangement for effecting the said approaching and receding
motion of the beams and chains, the beams are mounted on divided spindles of
which the two halves are arranged so that they can slide telescopically on each
other.
The outer ends carry collars with which engage the forked ends of levers on
longitudinal way shafts on which are other downward projecting levers the lower
ends of which are connected to the rods of eccentrics on a shaft extending
longitudinally along the centre of the lower part of the machine, and receiving
motion by gearing from the shaft carrying the first described eccentrics.
Thus the last described eccentrics are made to alternately turn the longitudinal
way shaft through a certain angle in opposite directions whereby the upper levers
thereon are made to move the transverse spindles carrying the beams and chains
so as to cause these to alternately approach and recede from each other.
The said way shafts also have levers that act in a like manner on the tentering
eccentrics so as to move these to and fro laterally on their shaft in a corresponding
manner.
The said telescoping spindles carrying the beams and chains have right and left
screw threads screwing through the beams, and are capable of being turned by
hand so as to adjust the normal distance apart of the beams and chains, for
regulating the transverse tension put on the fabric in the first instance, the
spindles are all connected by pitch wheels and chains so that by turning one by
hand, all the others, including one acting on the tentering eccentrics, are
simultaneously adjusted.
The fabric is carried by the tentering chains round the wheels that are acted
upon by the eccentrics as first described, and is carried a certain distance along
the under side of the chain, to a point where the tentering hooks are automatically
disengaged therefrom and whence the fabric is then passed first over a heated
drying roller and then to a winding beam.
It will be seen that owing to the provision of the before mentioned loops in the
chains which compensate for the alternate lengthening and shortening of the upper
sides thereof the undersides of the tentering chains will not partake of the above
described relative to and fro movement of the upper side, but will travel uniformly
forward to the before mentioned loops, so that the fabric is delivered from such
underside with the weft perfectly straight, at right angles to the fabric.
In order to feed the fabric properly into the tentering chains while these have
the before described relative to and fro motion, it is passed first over an overhead
guide roller down to a second guide roller, level with the tentering chains, which
second roller is so mounted and actuated from the tentering machine that its axis
is made to vibrate horizontally through opposite angular positions corresponding
with the oblique positions of the weft on the tentering chains.
Dated this 20th day of & wenst 1205
ABEL & IMRAY,
Agents for Applicants.

page_text: Improvements in Stretching and Tentering Woven Fabrics, and in
Apparatus therefor.
We, FRITZ CHWALLA and GUSTAV CHWALLA, both of Appollogasse 4,
Vienna VII Austria, Manufacturers do hereby declare the nature of our said
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to an improved mode of stretching and tentering fabrics
that is to say, holding the same in a transversely stretched condition and at the
same time shifting the weft so as to bring the same into oblique positions
alternately in opposite directions after treating them with dressing and while
they are passing over the tentering machine for drying. The invention consists
mainly in effecting the alternate advance of one side of the fabric relatively to
the other side, by alternately accelerating and retarding the forward motion of
the tentering chains by means of eccentrics at the end of the machine such
eccentrics being shifted 90° relatively to each other and connected to the sliding
bearings of the wheels over which the tentering chains pass.
As the chains travel forward, therefore, the one eccentric draws say the right
hand wheel and tentering chain a certain distance in advance of the left hand one,
thereby bringing the weft threads into an oblique position, whereupon the left
hand eccentric draws the corresponding chain forward, while the right hand one
moves back again. The weft is thus first brought back to the original position at
right angles to the length of the fabric, and then into the opposite oblique position,
and so on, the weft of the fabric being othus continuously shifted from one oblique
position to the opposite one during its travel, whereby any cementing together of
the threads by the dressing as it dries is effectually prevented.
The fabric is made to travel with the tentering chains round to the underside
of the loop, which is so arranged as not to partake of the alternate accelera-
tion of the upper part, so that the weft is there maintained in its normal
position at right angles to the warp, and is delivered from the chains in that
condition.
The wheels over which the tentering chains pass at the feeding end of the
machine do not partake of the above described to and fro motion of the wheels at
the other end; it follows therefore that the upper sides of the endless tentering
chains have to be alternately extended and shortened in length, while still always
remaining taut. In order to enable this to be effected, the lower sides of the
chains have loops formed in them at the feeding end of the machine which loops
are kept stretched by means of weighted rollers carried by pivotted arms, so that
when the one chain has its upper side extended as described, a corresponding
length thereof is drawn up from the said loop over the wheels at the feeding end
and when it is shortened again a corresponding length is drawn into the loop
again by the weighted roller. The drawing of the weft into alternate oblique
positions would have the effect of injuriously stretching the threads; in order to
avoid this, the beams that carry the two tentering chains are made to alternately
approach towards and recede from each other as the weft pass from the straight to
the oblique position and back again.
Referring to the accompanying drawing
:-
Fig. 1 is a longitudinal sectiou through the machine;
Fig. 2 is a like view on a larger scale of part of same.
Fig. 3 shows a plan view of the machine;
Fig. 4 and 5 are side and sectional views respectively of a
construction.
modified
As shown in Fig. 1, the fabric to be dressed is fed from any part, for instance,

page_text: from the dressing apparatus a, where it is saturated in the usual manner with
dressing and then advanced in the direction, shown by the arrow, over the ordinary
stretching device for being dried and finally reaches the machine proper.
The fabric is now caught by the endless tentering chains as a arranged on the
beams a₁ a, and is carried by same above and below the latter; it is then
automatically released at any suitable place, for instance, at as, whence it passes
over a steam-heated drum a, and winds on to a roller a, mounted in a travelling
frame a
The chains as a, are both driven at the same speed by belt b and toothed
transmitting wheels b₂ b₁ (Fig. 1), and thus the fabric held by such chains
travels at a uniform rate, the weft being at right angles to the direction of
movement.
In order to bring about the accelerating and retarding motion and to move the
weft so that same is not cemented together by the dressing and so that the fabric is
not stiffened thereby, chain-dises c₁₂ (Figs. 1, 2, 3) are arranged in addition to the
stationary discs c₁₁ c₂' (Fig. 1) the former being mounted in slides d₁ d. The latter
slide in the beams a, a, and are connected to eccentrics e, e, by connecting-rods e
such eccentrics being set at an angle of 180° to each other and whose eccentricity
is preferably adjustable. These eccentrics (Fig. 1) are preferably driven from the
main shaft by means of belts fif, and wheels f8f8
The movements to be imparted to the fabric will be best understood by following
a complete revolution of the eccentrics from the position shown in Figs. 2 and 3.
It will be seen that the fabric is stretched at the right side, this being effected as
follows:-
The disc c (or the part of the chain on same) is in its outermost position, while
the disc (2 is in the innermost position.
If, now,
the eccentrics e₁ e, are turned 90° further in the direction of the arrow
(Fig. 2), the slides d₁ d, the discs, together with the corresponding parts of
the chain, come exactly opposite each other at the end of such movement, and
thus the weft of the fabric takes up its normal position again.
On continuing to turn the eccentrics from 90°-180°, the fabric commences to
be stretched (by reason of the movement of the slides d₁ d) in opposite directions,
until, at the end of such movement, the weft has taken up its outermost position to
the left.
At the end of the movement from 180°-270°, the fabric is again returned to its
normal position in consequence of the simultaneous return of the slides d₁ d,; and
during the further part-revolution from 270°-360°, the weft of the fabric is again
stretched to the right in the manner before described.
During each revolution of the eccentrics, therefore, the fabric takes up two
extreme, and two normal positions, because during such movement each tentering
chain advances and recedes once; or, in other words, because the continuously
advaucing movement of the upper runs of the chains are alternately accelerated
and retarded, the lower runs not participating in such movement but always
advancing uniformly.
It is therefore evident that such alternate advancing and receding notion of the
chains would stretch the weft; such is, however, prevented by the chain-beams a₁ a
being made to approach each other when the fabric is passing from the normal to
the extreme position.
The accompanying drawings show two arrangements for effecting the latter
purpose, the one in Figs. 2 and 3 comprising an eccentric or crank g₁ keyed outo a
shaft g, such crank imparting a to and fro motion to the rack gs (Fig. 2, 3 & 3ª)
by means of connecting rod g,. Said rack operates a toothed-wheel h, (preferably
arranged so as to couple with h.) keyed on to one of the spindles h, which latter
are provided with right and left-handed screw threads screwing through the two
chain beams a₁ ag.
The latter are connected along their whole length by a series
of such spindles h and hence, on the wheel coupling with h³, by reason of the
movements imparted to the rack 9, by the eccentrics, the screw spindles h are

page_text: turned, and thus the beams a, a, caused to approach and recede from each other
accordingly. The spindles h are geared to the first by means of chains or, as
shown in the drawing by bevel-gear ht through a shaft, and thus the motions
of the first spindle are simultaneously imparted to the others.
In order to always maintain the connection between the eccentrics е, e, and the
slides d₁ de (which latter also participate in the transverse movements of the chain-
beams a, a,) either the eccentrics, connecting rols and the slides must have a suitable
joint connection, or the eccentrics may be coupled with the chain-beams so that
they can participate in the lateral movements of the latter. According to the
construction shown in Figs. 2 and 3, the eccentrics are mounted on a square
shaft e and coupled to the beams a₁ a, by means of rails or arms my my which
engage with collars on the bosses of the eccentrics, without interfering with the
ordinary movements of the latter. The beams a₁ a₂ are preferably provided with
rollers (Fig. 2) for facilitating the lateral movements of same in the manner
above described.
According to the arrangement shown in Figs. 4 and 5 the spindles h having
right and left handed screw threads are not destined to effect the approaching and
receding motion of the chain beams as before described, but only for adjusting the
latter in accordance with the width of the fabric to be treated.
For this purpose each spindle is composed of two parts h, h (Fig. 5) and is
provided, for instance, with a collar 10, so that the parts can be slid tele-
scopically on each other and this without interfering with their ordinary rotary
movements.
This transverse to and fro movements of the spindles are effected by the
eccentrics K, K preferably set at 180° to each other and to which rotary motion is
imparted (in the direction shown by the arrows) by rods k¹ k¹, levers and the
way shafts 1,7 extending longitudinally along the whole length of the machine and
carrying at the required points levers having forked ends, which latter, by means
of their parts, engage with the collars mounted on the outer ends of the
spindles ; these motions are thus imparted to the latter and to the chain
benms a, a, respectively.
The spindles may be adjusted by hand, during working, by turning the square
heads by means of a lever or key, such motions being likewise imparted
to all of the spindles by chain-wheels and chains 7, or other suitable
arrangements.
As shown in Fig. 4 the arrangement just described is in connection by means of
arms m', m² with the eccentrics, in order that the lateral movements of the beams.
are imparted to the latter, and in order that such eccentrics may be adjusted
during working, for which purpose the spindle carries a toothed wheel 4° rotated
by chain. By means of this construction, the strain on the arms m₁ mg is
reduced, while the parts cannot jam or in any way interfere with the operation of
the machine. It will also be evident that an arrangement similar to that shown in
Fig. 2 and may be employed for causing the eccentrics to slide on shaft e
in accordance with the lateral movements of the beams.
The tentering-chains a₁ ag, which are caused to advance and recede according to
the position of the eccentrics e₁ eg, must be constantly held under tension to avoid
any irregularities in the working; the device for keeping such chains under
tension must also be capable of fulfilling its functions irrespective of the
simultaneous accelerating, retarding and lateral movements of the chains.
As shown in Fig. 1 the device for holding the one chain under tension and
forming a loop in same consists of a chain-roller n, preferably arranged behind the
wheel and carrying a weight n¹; the latter thus constantly tends to press down
the suspended wheel nie. to tighten the chain, and is raised when the latter is
extended by the eccentrics. In order, however, to ensure the loops being properly
formed in the lower run of the chains and to keep the latter under proper tension,
it is preferable to mount the weighted roller n in arms n³ hinged either in the
chain-beams, or to a stationary pedestal.

page_text: As shown in Fig. 1 and 1ª a guide roller o is provided for ensuring the fabric
being properly fed to the machine. Such roller must follow the movement of
the fabric to be dressed, for which purpose it is mounted so as to vibrate
horizontally on a pivot o₁ connected by levers P₁ P: 91 9, and rods r, s,t to a slide d'
or d. The motions of the latter are thus transmitted to the guide roller o, which
then follows the oblique positions taken up by the weft on the tentering chains.
It will be evident that in place of such arrangement, rods, levers, cords or
chains may be made to connect the slides or the weight n¹ either directly or
indirectly with the guide-roller o.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. A mode of stretching and tentering dressed woven fabrics in which the fabric
is held in a transversely stretched condition by the upper run of continuously
advancing endless tentering-chains (as a) such upper runs being alternately
accelerated and retarded or respectively increased and decreased in length by the
action of eccentrics (e, e,) on slides (d, d) and also being made to approach and
recede from each other by means of spindles (h), the lower runs of such chains not
participating in such movements, but being kept taut by weighted rollers,
substantially as described and shown in the drawings.
2. In a machine for carrying out the mode of operation set forth in Claim 1,
beams (a₁ as) connected by screw-spindles (h) and supporting the tentering
chains (a, a) and receiving the slides (d₁ d,) such slides carrying discs (c, c₂)
over which said alternately-accelerated chains run and being operated by
eccentrics (e₁ es) substantially as described and shown in the drawings.
3. In combination with the machine set forth in Claim 2, the mechanism for
causing the beams and tentering chains to alternately approach and recede from
each other, comprising a series of spindles (h) having right and left handed screw
threads and screwing through the chain-beams (a₁ as), rack (93) moved to and fro
by levers (9, 9) aud coupling wheel (¹), substantially as described and shown in
the drawings. (Figs. 2 and 3.)
4. In combination with a machine as set forth in Claim 2, divided spindles (h, h)
with or without left and right handed screw threads and sliding telescopically on each
other, longitudinal way shafts (1, 1), levers (1, 1) and collars (he h₁) for imparting
transverse oscillating motion to the chain beams (a₁ as) substantially as described
and shown in the drawings (Figs. 4 & 5).
5. In combination with the machine set forth in the foregoing claims, the device
for forming loops in, and thus keeping taut, the tentering chains, consisting of
rollers (n) having weights (n₁) and mounted in hinged-arms (n,) or freely
suspended, substantially as described and shown in the drawings.
6. In a machine as set forth in Claim 2 a horizontally vibrating guide-roller (o)
connected by means of rods and levers (r, P₁ Pas 71 92 t), cords, or chains to the
chain weight (n), substantially as described and for the purpose shown and set
forth.
Dated this 13th day of May 1896
ABEL & IMRAY,
Agents for the Applicants.