IMPROVED STRETCHER IN CALENDERS FOR TUBULAR KNITTED FABRICS

TENDEUR PERFECTIONNE POUR CALANDRES DE TRAITEMENT DE TRICOTS TUBULAIRES

English Abstract

The invention relates to a stretcher for tubular knitted fabrics comprising
two separate stretcher arms (5, 6) bearing pulleys (23) in contact with belts
(22) for carrying fabric (4), driven by drive wheels (11A, 11B) borne by
supports (8) suitable to horizontally move in opposite directions and bearing
pairs of support rolls (19, 20) with angled axle (21), each pair (19, 20)
supporting on the opposite sides a ring (17) which has a particular profile,
is idle on each arm (5, 6) and is in contact with each drive wheel (11A, 11B),
wherein the above-mentioned pairs of rolls (19, 20) are motor-driven.

French Abstract

Tendeur pour tricots tubulaires, comportant deux bras tendeurs indépendants (5, 6) portant des poulies (23) qui se trouvent au contact de courroies (22) assurant le transport du tissu (4) et étant entraînées par des roues d'entraînement (11A, 11B) montées sur des supports (8) aptes à se déplacer horizontalement dans des sens contraires et portant des paires de rouleaux d'appui (19, 20) à axe incliné (21), chacune de ces paires (19, 20) portant de l'autre côté une bague (17) présentant un profil particulier, laquelle est montée libre sur chaque bras (5, 6) et vient au contact de chaque roue d'entraînement (11A, 11B), lesdites paires de rouleaux (19, 20) étant entraînées par un moteur.

Claims

- 8 -
CLAIMS
1. Stretcher in calender for tubular knitted fabrics
comprising: two stretcher arms (5, 6) substantially
vertical and horizontally moving in opposite
directions, each arm provided with pulleys (23)
connected to a belt (22) for carrying the tubular
fabric (4) and two support devices, each support
device comprising a pair of support rolls (19, 20);
a shaped ring (17) idle on each stretcher arm (5,
6) and in contact with a rotating drive wheel (11A,
11B), the circumferential shaped external surfaces
of the support rolls (19, 20) with angled axle (21)
engaging with the surfaces of the shaped ring (17),
the tubular fabric being carried between said
circumferential shaped surfaces of said support
rolls (19, 20) and the shaped surfaces of said
shaped rings (17), characterized in that the
support rolls (19, 20) are driven through own
driving means.
2. Stretcher according to claim 1, characterized in
that an elastic drive belt (24) connects said
support rolls (19) to the drive wheels (11A, 11B)
for rotating them, and a second elastic drive belt
(24') connects said support rolls (20) to said
drive wheels (11A, 11B).

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3. Stretcher according to claim 1 and 2, characterized
in that the drive wheels (11A, 11B) have a convex
peripheral surface, both in contact with the
concave external surface of the shaped ring (17).
4. Stretcher according to the preceding claims,
characterized in that the support rolls (19, 20)
are borne by mountings (18) consisting of fork
brackets (26) for the adjustment of the
working-angles of the arms (5 and 6).
5. Stretcher according to the preceding claims,
characterized in that a sole crossbar (7) bears the
two stretcher arms (5, 6) which are suitable to
move along said crossbar (7).
6. Stretcher according to the preceding claims,
characterized in that the two support devices (19,
20) are placed on both sides of an actuating shaft
(16) which moves the two stretcher arms (5, 6), and
that the drive wheels (11A, 11B) are mechanically
connected together, whereby only the drive wheels
(11A) are driven by a single rotating grooved bar
(10) .

Description

.
WO 96115303 - 2 2 0 1 7 0 ~ 17~
"IMPROV~n ST~T~ IN C~T~D~S FOR TUBU~
F~R~ICS"
Subject of the present invention is a stretcher for
tubular knitted fabrics, in particular a stretcher to
be applied in calenders or other machines for the
treatment of tubular fabrics.
As it is known, during the finishing operations of
tubular knitted fabrics, stretchers are used to spread
out and stretch the tubular element in order to enhance
the finishing operations. Thus in calendering, which
usually is the last finishing operation, it is
necessary to use a stretcher to achieve a uniform
vaporization and to adjust the height of the tubular
element to the desired value.
Known stretchers or expanders are provided with
means placed between the stretcher arms, such as for
example pantograph devices or telescopic tubes. These
stretchers are provided in two or more sizes
corresponding to the different heights of the tubular
fabric. In these conditions there is the disadvantage
that, in order to change a height range, it is
necessary to replace the stretchers, so that the
machine must be shut down for fitting the new stretcher
in and the tubular fabric portions must be unstiched
and restiched.

WO96/15303 2 2 0 1 7 0 4 ~ /00178
-- 2
The present invention is applied to stretchers of
the prior art in order to improve them; in particular,
reference is made to the European Patent N 0267880 in
the name of the owner of the present invention. This
patent relates to a stretcher for tubular knitted
~abrics comprising two stretcher arms horizontally
moving in opposite directions, each arm provided with
pulleys, whereby at least one of them is in contact
with a drive wheel for carrying the tubular fabric and
a support device integral with a support for the drive
wheel which bears a shaped ring idle on each stretcher
arm and in contact with the drive wheel, thus making
said support integral with the stretcher arm.
Main object and technical problem of the present
invention is to provide a stretcher in calenders for
tubular knitted fabrics wherein the drive homogeneity
of the carrying of the fabric, the centering of the
stretcher arm and the adjustmerLt of the work-angles are
improved, and the stretcher is sturdy enough to have a
practically inflexible bar on which the arms run with a
high drive easiness for the motion of the stretcher
arms.
The features, the advantages and the solution of
the above mentioned technical problem of the invention
will become apparent from the following detailed

2201 704
WO96/15303 .~ D178
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description of a preferred but not exclusive embodiment
of the present stretcher, shown for a merely
illustrative and not limiting purpose in the attached
drawings wherein:
FIGURE 1 is a front view of the stretcher,
FIGURE 2 is an enlarged view of a partial
horizontal section of the stretcher along line II-II of
figure l, and
FIGURE 3 is a view of a detail of the stretcher.
lO Referring to the figures, the aforesaid calender
consists of stands l and 2 containing the calender
control and drive mechanisms not shown in the figure.
These stands support the known vaporizer 3 wherein the
tubular fabric 4 is introduced after having been passed
through the stretcher according to the present
invention.
Said stretcher consists of stretcher arms 5 and 6
which are supported by support devices described
afterwards. A guide bar 7 fastened to stands l and 2
bears the two supports 8 relevant to each arm 5, 6 and
supports 8 bear a bevel gear set 9 which is driven by a
grooved bar lO and drives the upper drive wheels llA.
The sole guide bar 7, having an appropriate size,
is useful for giving a better strength to the stretcher
so that the bar is practically inflexible.

WO96115303 2 2 0 1 7 0 4 1~ s;~olJ~
-- 4
Threaded bushings 12 and 13 are integral with
supports 8, said bushings being engaged with opposite
handed threads 14 and 15 respectively which are
provided on actuating shaft 16. Bar 10 and shaft 16 are
driven by known means contained in stands 1 and 2 and
not shown in the figure. When shaft 16 rotates, the two
opposite handed threads 14 and 15 move in opposite
directions bushings 12 and 13, supports 8 and therefore
stretcher arms 5 and 6.
Upper drive wheels llA are connected to the similar
lower wheels llB by means not shown in the figure, such
as ch~; n~, toothed belts or similar.
As it is clearly shown in figures 1 and 2,
stretcher arms 5 and 6 bear idle rings 17, suitably
shaped, which are in contact with the convex portion
11' of drive wheels llA and llB. These wheels bear
mountings 18 which support the aforesaid support
devices consisting of pairs of support rolls 19 and 20
with angled axle 21. Said rolls 19 and 20 support arms
5 and 6 by engaging their peripheral portion with the
circular profile 17' of rings 17, thus aligning them in
parallel. This parallel alignment is kept thanks to the
sets of rolls 19 and 20 with angled axle which are two
for each arm 5 and 6, whereby each set is engaged with
drive wheels llA and llB and placed on both sides of

220 1 704
actuating shaft 16. Tubular fabric 4 is carried by
means of belts 22 wound on a line of pulleys 23 which
are idle on arms 5 and 6, and along the shaped surfaces
o~ drive wheels llA and llB and o~ rings 17.
According to the main ~eature of the present
invention, as can be clearly seen in figures 2 and 3,
both support rolls 19 are motor-driven because they are
connected together by an elastic belt 24 which is wound
on drive wheels llA and llB and on idle pulleys 25.
Similarly, support rolls 20 are motor-driven
because they are connected to drive wheels llA and llB
by means of an elastic belt 24'.
Said motorization advantageously improves the
carrying o~ the fabric. There~ore, the convexity 11~ o~
wheels 11A and llB carries out a better centering o~
arms 5 and 6 and improves the working-angles thereo~.
In particular, mountings 18 consist of ~ork
brackets 26 for the adjustment o~ the working-angles o~
arms 5 and 6.
The velocity o~ the rolls 19l 20 must be carefully
choosen having regard to the velocity of the driving
wheel llA or llB on each support, so that the device
works properly and the fabric does not break.
Operation is as follows: tubular fabric 4, which
usually consists o~ several tubular pieces knitted
together, is introduced from the bottom, as it is shown
in figures 1 and 2, between rolls 19, 20 and ring 17
and between ring 17 and wheels llA and llB of each arm,
so it is carried to the top in the direction of arrow A
~N~
. .

WO96tl5303 2 2 0 1 7 0 4 ~ /00l~8
-- 6
by rotating drive wheels llA and llB engaged with rings
17 and pulleys 23 mounted on arms 5 and 6, which are
kept in position and are supported by the aforesaid
sets of rolls 19 and 20 with angled axle 21. In order
to increase the tubular height, shaft 16 is rotated by
drlving means not shown in the figure, so that threads
14 and 15 move arms 5 and 6 in the settled position,
corresponding to the desired tubular height. The
minimum height corresponds to the position of arms .5'
and 6' shown with dotted lines in figure 1.
When a greater height of the tubular fabric is
desired, shaft 16 is rotated in the opposite direction
so that arms 5 and 6 move away from each other up to
reach the m~mllm distance as shown with full lines in
figure 1.
As it is apparent, the stretcher can take any
position from a minimum to a maximum distance without
changing the stretcher, i.e. without shutting the
machine down and therefore without removing the tubular
fabric from the stretcher.
Furthermore, as described above, thanks to this
invention the carrying of the fabric, the centering of
the stretcher arms, the adjustment of the working-
angles and the strength of the stretcher are improved,
the bar on which the arms run is practically inflexible

. W096/15303 22 0 ~ 704 ~ ,00l78
and the stretcher is easy to control.
Practical or application-orlented variations can be
made to the embodiment details of this invention
without exceeding the scope thereof, as claimed below.
=7A~ 4

Representative Drawing