[0001] The present invention relates to webbing and in particular it relates to a device
for forming a fabric recessed selvedge for shuttleless looms.
[0002] More particularly, the invention concerns a selvedge device having a simple and compact
structure so as to achieve lightness and stiffness features that are needed for the
high working speed of the looms; specifically, the invention concerns a device which
is exclusively constituted by mechanical components, particularly suitable for forming
a recessed selvedge to the side edges of a fabric by using a method of folding the
tails of the weft within the mouth formed by the warp yarns in a shuttleless loom.
[0003] It is well known that the side selvedges of shuttle looms cannot be obtained in shuttleless
looms, because the weft thread is not continuous, but it is cut after each insertion.
The fabric has, therefore, the side edges consisting of fringes of free wefts which
may be partially interwoven with a certain number of additional warp yarns, forming
the so-called "leno selvedges"; alternatively, when the quality or the features of
the fabric require that the ends of the wefts are more firmly bound to the fabric,
the above-mentioned method of folding the weft tails is used.
[0004] In particular, the side edges of the fabric are obtained by reinserting the weft
tails into the shed soon after that the loom comb has beaten the weft, thereby forming
the so-called "tucked or recessed selvedge"; therefore, it is not necessary to reinforce
the fabric edges with mechanical systems for twisting and rotating additional warp
yarns, which are not very reliable.
[0005] The selvedges re-entering process is normally carried out by means of known selvedge
devices, which comprise means for gripping and cutting the weft yarn that is inserted
in the warp passage; in practice, the operation of said selvedge devices is based
on the fact that a needle is used to grasp the end of the cut weft thread, the so-called
"pigtail", to make it fit, folded, into the warp shed, as soon as the latter is opened
again for the next step, so as to be stretched again and beaten with the next weft,
thus creating a recessed selvedge.
[0007] In particular, the Italian patent
IT 1244762 describes a mechanism for selecting the movement of the movable members of a device
for forming a fabric recessed selvedge, which is constituted by a touch probe hinged
at one end on the device's casing; the mechanism is cooperating, through a spring,
with one of the cams actuating the control levers of the movable members, so as to
cause an oscillation of a bridge small castle, integral with said mechanism, from
a first to a second position.
[0008] In the first position, the bridge of the small castle interacts with the abutments
of the actuating levers in order to block them in a fixed position, while in the second
position there is no longer interaction and a metal anchor which is integral with
the touch probe is supported by an electromagnetic device.
[0009] However, such a known selvedge device is rather complex and requires accurate adjustments;
also, because of the remarkable overall dimensions of the yarn gripping and cutting
means, it is necessary to cut into several parts the loom's beating comb, when the
production of several fabrics on the same machine is required.
[0010] Furthermore, the known mechanical selvedge devices are suitable to work on looms
operating at few revolutions per minute and, for this reason, they are not easily
adaptable to the most recent looms, which are able to operate at a very high number
of revolutions per minute, because the needle and the weft yarn gripping and cutting
means are controlled by kinematic means that are very complex and bulky and therefore
they cannot operate at the high speeds that are reached by the modern looms.
[0011] It is also known to use selvedge devices that employ pneumatic or mechanical-pneumatic
recessed selvedge forming means, but, even in these cases, the technical solutions
are rather unsatisfactory and unreliable and have serious technical drawbacks.
[0012] For example, the Italian patent
IT 1251849 describes a device for forming a recessed selvedge in an air jet loom, comprising
devices for inserting the weft yarn inside the shed, a comb to beat the yarn when
inserted, and weft cutting means; the device also includes suction and cutting means,
which are moved with independent cyclical movements, so that said means are switched
from a first position to a second position and to a third position in the following
way:
- at the first position, the suction means are adjacent to the weft and to the comb
and the cutting means are in a rest position and do not interfere with the comb when
the latter is ready for beating,
- at the second position, the cutting means are near the weft so as to cut the yarn
and the suction means stay on the first position for sucking the free weft "pigtail",
while
- at the third position, the suction means are placed laterally to the open shed to
insert herein the sucked "pigtail", which is expelled by means of a flow reversal
action of the internal fluid, and the comb is far from the beating position.
[0013] Moreover, a device for forming a fabric recessed selvedge having the technical features
of the preamble of the appended claim 1 is known for example from
EP454238A1. A selvedge forming device with pulleys, a toothed belt and a belt tensioner is known
from
JP200100342.
[0014] The main object of the present invention is, therefore, to obviate the above mentioned
drawbacks of the prior art, by making an improved device for forming a fabric recessed
selvedge, that is entirely adaptable to the modern shuttleless looms.
[0015] Another object of the invention is to provide a device for forming a fabric recessed
selvedge for shuttleless looms, which guarantees high precision and functional, mechanical
and technological reliability, when the weft ends ("pigtails") go back into the warp
mouth or shed.
[0016] Another object of the invention is to provide a device for forming a fabric recessed
selvedge for shuttleless looms, which includes yarn processing units that are able
to perform repeatable instantaneous movements.
[0017] A further object of the present invention is to provide a device for forming a fabric
recessed selvedge for shuttleless looms, which has a simple and compact structure
in order to achieve lightness and stiffness features that are needed for the higher
working speeds of the modern looms.
[0018] Another object of the invention is to provide a device for forming a fabric recessed
selvedge for shuttleless looms, which is able to minimize the length of weft ends,
resulting in a narrow fabric recessed selvedge, and which is able to eliminate, at
the same time, the need for a comb cutting when central recessed selvedges are provided.
[0019] These and other objects, which will become clear in the following, are obtained by
making a device for forming a fabric recessed selvedge for shuttleless looms, according
to the attached claim 1; additional technical features are mentioned in the dependent
claims. Advantageously, the device for forming fabric recessed selvedges (selvedge
device) according to the present invention allows to obtain a remarkable functional
reliability when the weft ends re-enter the warp mouth; this is due to the accuracy
and repeatability of the movements of the yarn processing units.
[0020] Furthermore, said device has a simple and compact structure, thereby achieving lightness
and stiffness features that are needed for the high working speeds of the modern shuttleless
looms; in particular, the size of the group including a leg and a shear, which are
able to process the yarn, are extremely compact and suitable for minimizing the length
of the re-entering weft ends, resulting in a suitably narrow fabric recessed selvedge.
[0021] Finally, the selvedge device according to the invention allows operation without
interference with the group consisting of the leg and the shear and with the comb,
when the comb is ready for beating, thus avoiding a comb cut when central recessed
selvedges are provided and thus allowing to make horizontal adjustments of the leg-shear
group and the hook group that are perpendicular to the fabric making line, depending
on the "recovery" given by the elastic displacement of said fabric making line when
the comb is ready for beating.
[0022] Further technical characteristics and advantages of the device for forming a fabric
recessed selvedge in shuttleless looms, according to the present invention, will appear
more clear from the following description that refers to preferred embodiments of
the invention and from the attached drawings, in which:
- figure 1 shows a perspective view of a first embodiment of the device for forming
a fabric recessed selvedge in shuttleless looms, according to the present invention,
in a first working position;
- figure 2 shows the device of figure 1 without the outer casing;
- figure 3 shows a partial exploded view of the device of figures 1 and 2, according
to the present invention;
- figure 4 shows a rear partial view of the device of figure 2, according to the present
invention;
- figure 5 shows an enlarged detail of figure 2, according to the present invention,
in a first operating position;
- figure 6 shows the same enlarged detail of figure 5, according to the invention, in
a second operating position;
- figure 7 shows a perspective view of a further embodiment of the device for forming
a fabric recessed selvedge in shuttleless looms, according to the present invention,
in a first operating position;
- figure 8 shows the device according to figure 7, without the outer casing;
- figure 9 shows a rear perspective view of the device of figure 8, according to the
present invention;
- figure 10 shows a perspective view of the device of figure 8, according to the present
invention, in a second operating position.
[0023] Referring to the attached figures 1-6, the device 100 for forming fabric recessed
selvedges according to the invention substantially comprises:
- an external containment casing 1',
- a leg-shear group 1, which is provided for grasping and cutting the tail of the weft
yarn 2, which protrudes from the edge of the fabric 3,
- a hook group 4 with a hook or needle 5, around which the weft yarn 2 is wrapped and
then is dragged and folded towards the center of the fabric 3 between the warp yarns
6, which are arranged for a subsequent insertion of the weft yarn 2,
- two parallel rods 7, 8 that are moved with reciprocating translational movements so
as to control the movements of the leg-shear group 1,
- a further rod 9, which is parallel to the rods 7, 8 of the leg-shear group 1 and which
is moved with reciprocating translational and rotational movements so as to control
the movements of the hook group 4.
[0024] Each rod 7, 8, 9 is secured to a respective gear 10, 11, 12, which is driven, in
turn, during its linear translation motion, by a respective pair of conjugated cams
13, 14, 15, which act on the corresponding touch probes 13', 14', 15', while the rotary
oscillation motion of the hook group 4 is controlled by a suitable pair of conjugated
cams 16, which acts, through the touch probes 16', on a L-shaped lever 18, which,
through a tie rod 19, is able to rotate the sleeve 20.
[0025] The rod 9 is able to slide longitudinally inside the sleeve 20; moreover, the rod
9, inside the sleeve 20, is shaped so as to control the rotation while allowing an
axial sliding (as shown in detail in the attached figure 4), thus being able to control
the rotation of the needle 5; in particular, said rod 9 can be shaped as a shackle
member or can be replaced with generic grooved couplings.
[0026] The structure of the above mentioned mechanical control units is particularly simple
and effective, as well as the movable units of the device according to the invention
are rather light, easy to assemble and stiff, so as to guarantee precision and repeatability
for handling the weft ends also at working high speeds of the looms.
[0027] The three conjugated cams 13, 14, 15 which drive the translation of the rods 7, 8,
9 and the conjugated cam 16 which drives the rotation of the rod 9 are all mounted
on the drive shaft 21, driven by a toothed pulley 22, which is in turn connected,
through a toothed belt 23 having a belt tensioner 24, to a second toothed pulley 25,
mounted on the shaft 25', which protrudes from the gear casing able to take its motion
from a command underlying the fabric 3.
[0028] The loosening of the belt tensioner 24 provided on the toothed belt 23 allows a longitudinal
sliding, in a direction perpendicular to the comb 40, of the entire device 100 in
an advanced or retracted position with respect to the support plate 1".
[0029] Therefore, it is possible to bring near or move away the leg-shear group 1 and hook
group 4 from the fabric formation edge as a function of the characteristics and requirements
of the same fabric 3.
[0030] Once the desired operation is carried out, the belt tensioner 24 is repositioned
to restore the tension needed for a proper functioning of the toothed belt 23. With
particular reference to the attached figures 5 and 6 and making reference to the functioning
of the device for forming recessed selvedges, which is the object of the present invention,
a "selvedge re-entering" cycle may be summarized as follows.
[0031] The leg-shear group 1 is maintained in a vertical position to receive the weft 2;
in this position (shown in detail in the attached figure 5), the shear 27 is open
and the grasping foot 28 is kept open and lowered by a suitable cam 29, which acts
on the top of the stem 28' of the foot 28 and which is mounted on the rod 9 of the
hook group 4, while the needle 5 is maintained in a raised position, outside the warp
6, by actuating the rod 9.
[0032] Then, once the weft yarn 2, after having beaten by the comb 40, has entered the foot
28, said foot 28 is closed with a partial rotation of the needle's 5 axis (as shown
in detail in the attached figure 6). Furthermore, the two driving rods 7, 8 of the
leg-shear group 1 may move and translate synchronously to push forward or backward
the whole leg-shear group 1 or may translate at different distances so as to rotate
the portion 33 of the group 1 around the pivoting pin 30 and to obtain the fabric
weft cutting through the shear 27 and the winding of the weft yarn 2, held by the
foot 28, around the needle 5.
[0033] Then, the hook or needle 5, actuated by the roto-translating motion of the driven
rod 7, engages the weft yarn 2 and drags it inside the warp shed, where it is beaten
by the comb 40 together with the weft which is inserted subsequently the weft yarn
2.
[0034] It should be noted in particular that the opening of the grasping foot 28, which
is carried out by the hook group 4, takes place while the leg-shear group 1 is steady,
that is to say without movements for opening or closing said group 1 (as instead realized
in other known devices), thus minimizing the overall dimension of the leg-shear group
1 (as well as the functional spaces), so that when it devices for forming central
recessed selvedges (such as the device shown in the attached figures 7-10), that are
used when several fabrics are made with a same loom, are needed, it is not necessary
to cut the comb 40 in the space between two adjacent fabrics, thus making more versatile
the use of the combs.
[0035] Finally, the rotation of the leg-shear group 1 around the pin 30 is obtained by differentiating
the displacements of the two rods 7, 8, so that the slide 31, connected to the rod
7, is able to push, through the connecting link-block 32, the upper portion 33 of
the leg-shear group 1, thus making it rotate around the pivoting pin 30, which is
placed in the lower portion 34 of the group 1 that is connected to the rod 8.
[0036] As already mentioned in the above, the attached figures 7-10 show respective views
of a device 101 for forming fabric central recessed selvedges; the device 101 is made
by introducing within a same casing 101', similar to the casing 1' of figure 1, two
twin similar groups having the same functionality as that of the lateral group described
above; in particular, in the attached figures 7-10, the elements having structural
and functional characteristics that are similar or equal to the characteristics of
the elements shown in the attached figures 6-10 are indicated with the same reference
numbers.
[0037] Based on the foregoing, it is understandable how the device for forming a fabric
recessed selvedge in shuttleless looms, which is the object of the present invention,
achieves the intended aims and advantages previously mentioned.
[0038] In particular, the shape and dimensions of the device according to the invention
allows to minimize the inevitable bending and/or vibrations of the leg-shear group,
ensuring the repeatability of the movement and positions with respect to the yarn
and/or to the weft end.
[0039] Furthermore, the action of the cam 29, which is applied to the hook axis and which,
through the rotation of said axis, provides for opening the leg to house the weft
yarn and for closing the leg to hold it in a following step when it is wounded around
the hook without any movement of the leg-shear group, allows to reduce the size of
said leg-shear group in a direction perpendicular to the comb, so as not to interfere
with said comb when it is ready for beating; according to the prior art, in fact,
the leg is usually opened by the reciprocal actions that take place between the different
portions of the leg-shear group, which must also perform wide translations and rotations
to carry out the yarn cutting and the yarn wrapping around the hook.
[0040] Finally, according to the invention, it is also possible to suitably adjust the device
according to the compactness features of the fabric (with respect to the specific
load factor of said fabric) and to the elastic displacement of the fabric making line
when the comb is ready for beating.
[0041] The invention thus conceived is however susceptible of numerous modifications and
variations, all falling within the scope of the claims; furthermore, all the details
may furthermore be replaced with other technically equivalent elements.
[0042] Where the features and techniques mentioned in any claim are followed by reference
signs, those reference signs have been included for the sole purpose of increasing
the intelligibility of the claims and accordingly said reference signs do not have
any limiting effect on the interpretation of each element identified, by way of example,
by said reference signs.
1. Device (100, 101) for forming a fabric (3) recessed selvedge on shuttleless looms
comprising substantially
- a taking and cutting group (1), consisting of at least one foot (28) and at least
one cutter (27), which is held upright in order to take and cut to size at least one
tail of a weft yarn (2) protruding from one edge of a fabric (3),
- at least one hooking group (4), which includes at least one hook or needle (5),
said tail of the weft yarn (2) being wrapped around said hook or needle (5) and being
dragged and folded toward the center of the fabric (3), between the warp yarns (6)
arranged for the insertion of the weft tails (2),
- at least two first rods (7, 8), parallel to each other and moving according to an
alternate translational motion, which are able to drive said taking and cutting group
(1),
- at least one second rod (9), parallel to said first rods (7, 8) and moving according
to a rotational or translational motion, which is able to drive said hooking group
(4),
wherein each of said first (7, 8) and second (9) rods is linked to a respective carriage
(10, 11, 12), driven in turn to linearly translate by means of at least one respective
pair of first combined cams (13, 14, 15), which act on corresponding first probe means
(13', 14', 15'), while said hooking group (4) is driven according to an oscillating
rotary motion by means of at least one pair of second combined cams (16) acting, through
second probe means (16'), on at least one lever (18), which drives in rotation at
least one sleeve (20), said second rod (9) being longitudinally inserted into said
sleeve (20),
wherein said first (13, 14, 15) and second combined cams (16) are mounted on at least
one drive shaft (21),
characterized in that said drive shaft (21) is driven by at least one first toothed pulley (22) of the
device (100, 101), which is connected, via a toothed belt (23) equipped with a belt-tensioner
(24) of the device (100, 101), with at least one second toothed pulley (25) of the
device (100, 101), which is mounted on a shaft (25') coming out a gearbox able to
take the motion from a command placed below said fabric (3), and
characterized in that said belt-tensioner (24) is movable so as to allow sliding of said taking and cutting
group (1) with respect to a support plate (1") of the device (100, 101).
2. Device (100, 101) as claimed in claim 1, characterized in that, internally to said sleeve (20), said second rod (9) is shaped so as to rotate and
axially slide, said second rod (9) being also able to drive in rotation said hook
or needle (5).
3. Device (100, 101) as claimed in at least one of the preceding claims, characterized in that means are provided to longitudinally slide said taking and cutting group (1) in a
direction which is perpendicular to a comb (40) of the loom, so as to bring the taking
and cutting group (1) near a fabric (3) formation edge or to send it away said fabric
(3) formation edge.
4. Device (100, 101) as claimed in at least one of the preceding claims, characterized in that said foot (28) of the taking and cutting group (1) is driven by a relative cam (29),
which acts on the top of a stem (28') of said foot (28) and which is mounted on said
second rod (9) of the hooking group (4), said second rod (9) being able to drive said
hook or needle (5) in a raised position outside the warp (6) of the fabric (3) or
in a lowered position on said warp (6) of the fabric (3).
5. Device (100, 101) as claimed in at least one of the preceding claims, characterized in that said first rods (7, 8), which drive said taking and cutting group (1), are able to
push forward or back said taking and cutting group (1) or shift by different lengths,
so as to rotate at least one portion (33) of said taking and cutting group (1), in
order to cut the fabric (3) weft (2) by means of said cutter (27) and to wrap said
weft tail (2), which is retained by said foot (28) of said taking and cutting group
(1), around said hook or needle (5), said hook or needle (5) being able to bring said
weft tail (2) inside the warp mouth, where a comb (40) of the loom is provided for
beaten the weft tail (2) together with the following weft.
6. Device (100, 101) according to claim 4, characterized by the fact that said hooking group (4) drives the opening of said foot (28) of the
taking and cutting group (1), while said taking and cutting group (1) is stationary.
1. Vorrichtung (100, 101) zum Bilden einer vertieften Webkante eines Gewebes (3) an schützenlosen
Webmaschinen, wobei die Vorrichtung im Wesentlichen Folgendes umfasst:
- eine Aufnahme- und Schneidgruppe (1), die aus mindestens einem Fuß (28) und mindestens
einem Schneidwerkzeug (27) besteht, das aufrecht gehalten wird, um mindestens ein
Ende eines Schussfadens (2), der aus einer Kante eines Gewebes (3) herausragt, aufzunehmen
und zuzuschneiden,
- mindestens eine Hakengruppe (4), die mindestens einen Haken oder eine Nadel (5)
aufweist, wobei das Ende des Schussfadens (2) um den Haken oder die Nadel (5) gewickelt
ist und in Richtung des Zentrums des Gewebes (3) zwischen den Kettfäden (6), die zum
Einsetzen der Schussfadenenden (2) angeordnet sind, gezogen und gefaltet wird,
- mindestens zwei erste Stäbe (7, 8), die parallel zueinander angeordnet sind, sich
gemäß einer alternativen Translationsbewegung bewegen und die Aufnahme- und Schneidgruppe
(1) antreiben können,
- mindestens einen zweiten Stab (9) parallel zu den ersten Stäben (7, 8), die sich
gemäß einer Dreh- oder Translationsbewegung bewegen, die die Hakengruppe (4) antreiben
kann,
wobei jeder der ersten (7, 8) und zweiten (9) Stäbe mit einem jeweiligen Schlitten
(10, 11, 12) verbunden ist, der angetrieben wird, um seinerseits mittels mindestens
eines jeweiligen Paares von ersten kombinierten Nocken (13, 14, 15), die auf entsprechende
erste Sondenmittel (13 ', 14', 15 ') wirken, eine lineare Translationsbewegung auszuführen,
während die Hakengruppe (4) gemäß einer oszillierenden Drehbewegung mittels mindestens
eines Paares von zweiten kombinierten Nocken (16), die durch ein zweites Sondenmittel
(16') auf mindestens einen Hebel (18) wirken, angetrieben wird, der mindestens eine
Hülse (20) in Drehung versetzt, wobei der zweite Stab (9) in Längsrichtung in die
Hülse (20) eingesetzt ist,
wobei die ersten (13, 14, 15) und zweiten kombinierten Nocken (16) an mindestens einer
Antriebswelle (21) angebracht sind,
dadurch gekennzeichnet, dass die Antriebswelle (21) von mindestens einer ersten Zahnscheibe (22) der Vorrichtung
(100, 101) angetrieben wird, die über einen Zahnriemen (23), der mit einem Riemenspanner
(24) der Vorrichtung (100, 101) ausgestattet ist, mit mindestens einer zweiten Zahnscheibe
(25) der Vorrichtung (100, 101) verbunden ist, die auf einer Welle (25') montiert
ist, die aus einem Getriebe herauskommt und die Bewegung von einer Führung annehmen
kann, die unterhalb des Gewebes (3) angeordnet ist, und
dadurch gekennzeichnet, dass der Riemenspanner (24) beweglich ist, um ein Gleiten der Aufnahme- und Schneidgruppe
(1) gegenüber einer Trägerplatte (1) der Vorrichtung (100, 101) zu ermöglichen.
2. Vorrichtung (100, 101) nach Anspruch 1, dadurch gekennzeichnet, dass der zweite Stab (9) in der Hülse (20) so geformt ist, dass er sich dreht und axial
verschiebt, wobei der zweite Stab (9) ebenfalls den Haken oder die Nadel (5) in Drehung
versetzen kann.
3. Vorrichtung (100, 101) nach mindestens einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass Mittel vorgesehen sind, um die Aufnahme- und Schneidgruppe (1) längs in einer Richtung
zu schieben, die senkrecht zu einem Kamm (40) der Webmaschine verläuft, um die Aufnahme-
und Schneidgruppe (1) nahe einer Formkante des Gewebes (3) zu bewegen oder sie von
der Formkante des Gewebes (3) wegzubewegen.
4. Vorrichtung (100, 101) nach mindestens einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Fuß (28) der Aufnahme- und Schneidgruppe (1) von einem Relativnocken (29) angetrieben
ist, der auf die Oberseite eines Stiels (28') des Fußes (28) wirkt und auf dem zweiten
Stab (9) der Hakengruppe (4) montiert ist, wobei der zweite Stab (9) in der Lage ist,
den Haken oder die Nadel (5) in eine angehobene Position außerhalb des Kettfadens
(6) des Gewebes (3) oder in eine abgesenkte Position auf dem Kettfaden (6) des Gewebes
(3) zu bewegen.
5. Vorrichtung (100, 101) nach mindestens einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die ersten Stäbe (7, 8), die die Aufnahme- und Schneidgruppe (1) antreiben, in der
Lage sind, die Aufnahme- und Schneidgruppe (1) vorwärts oder rückwärts zu schieben
oder um unterschiedliche Längen zu verschieben, um mindestens einen Abschnitt (33)
der Aufnahme- und Schneidgruppe (1) zu drehen, um den Schussfaden (2) des Gewebes
(3) mit dem Schneidwerkzeug (27) zu schneiden und das Schussfadenende (2), das durch
den Fuß (28) der Aufnahme- und Schneidgruppe (1) gehalten wird, um den Haken oder
die Nadel (5) zu wickeln, wobei der Haken oder die Nadel (5) das Schussfadenende (2)
in die Kettfadenöffnung bringen kann, wobei ein Kamm (40) des Webstuhls vorgesehen
ist, um das Schussfadenende (2) zusammen mit dem folgenden Schussfaden zu schlagen.
6. Vorrichtung (100, 101) nach Anspruch 4, dadurch gekennzeichnet, dass die Hakengruppe (4) die Öffnung des Fußes (28) der Aufnahme- und Schneidgruppe (1)
antreibt, während die Aufnahme- und Schneidgruppe (1) stationär ist.
1. Dispositif (100, 101) pour former une lisière creuse en tissu (3) sur des métiers
à tisser sans navette comprenant sensiblement
- un groupe de saisie et de coupe (1), constitué d'au moins un pied (28) et d'au moins
un organe de coupe (27), qui est maintenu verticalement afin de saisir et couper à
dimension au moins une queue d'un fil de trame (2) faisant saillie à partir d'un bord
d'un tissu (3),
- au moins un groupe de crochetage (4), qui comprend au moins un crochet ou une aiguille
(5), ladite queue du fil de trame (2) étant enroulée autour dudit crochet ou de ladite
aiguille (5) et étant tirée et pliée vers le centre du tissu (3), entre les fils de
chaîne (6) agencés pour l'insertion des queues de trame (2),
- au moins deux premières tiges (7, 8), parallèles entre elles et se déplaçant selon
un mouvement de translation alternée, qui sont aptes à entraîner ledit groupe de saisie
et de coupe (1),
- au moins une seconde tige (9), parallèle auxdites premières tiges (7, 8) et se déplaçant
selon un mouvement de rotation ou de translation, qui est apte à entraîner ledit groupe
de crochetage (4),
dans lequel chacune desdites premières (7, 8) et seconde (9) tiges est liée à un chariot
respectif (10, 11, 12), entraîné lui-même pour se déplacer en translation de façon
linéaire au moyen d'au moins une paire respective de premières cames associées (13,
14, 15), qui agissent sur des premiers moyens de sonde correspondants (13', 14', 15'),
alors que ledit groupe de crochetage (4) est entraîné selon un mouvement de rotation
oscillant au moyen d'au moins une paire de secondes cames associées (16) agissant,
au travers de seconds moyens de sonde (16'), sur au moins un levier (18), qui entraîne
en rotation au moins un manchon (20), ladite seconde tige (9) étant insérée de manière
longitudinale dans ledit manchon (20),
dans lequel lesdites premières (13, 14, 15) et secondes cames associées (16) sont
montées sur au moins un arbre d'entraînement (21),
caractérisé en ce que ledit arbre d'entraînement (21) est entraîné par au moins une première poulie dentée
(22) du dispositif (100, 101) qui est reliée, via une courroie dentée (23) équipée
d'un tendeur de courroie (24) du dispositif (100, 101), à au moins une seconde poulie
dentée (25) du dispositif (100, 101), qui est montée sur un arbre (25') sortant d'une
boîte de vitesses apte à saisir le mouvement à partir d'une commande placée sous ledit
tissu (3), et
caractérisé en ce que ledit tendeur de courroie (24) est mobile de manière à permettre le coulissement
dudit groupe de saisie et de coupe (1) par rapport à une plaque de support (1") du
dispositif (100, 101).
2. Dispositif (100, 101) selon la revendication 1, caractérisé en ce que, à l'intérieur dudit manchon (20), ladite seconde tige (9) est formée de manière
à tourner et à coulisser axialement, ladite seconde tige (9) étant également apte
à entraîner en rotation ledit crochet ou ladite aiguille (5).
3. Dispositif (100, 101) selon au moins une des revendications précédentes, caractérisé en ce que des moyens sont prévus pour faire coulisser longitudinalement ledit groupe de saisie
et de coupe (1) dans une direction qui est perpendiculaire à un peigne (40) du métier
à tisser, de manière à approcher le groupe de saisie et de coupe (1) d'un bord de
formation de tissu (3) ou à l'éloigner dudit bord de formation de tissu (3).
4. Dispositif (100, 101) selon au moins une des revendications précédentes, caractérisé en ce que ledit pied (28) du groupe de saisie et de coupe (1) est entraîné par une came relative
(29), qui agit sur la partie supérieure d'une tige (28') dudit pied (28) et qui est
montée sur ladite seconde tige (9) du groupe de crochetage (4), ladite seconde tige
(9) étant apte à entraîner ledit crochet ou ladite aiguille (5) dans une position
levée en dehors de la chaîne (6) du tissu (3) ou dans une position baissée sur ladite
chaîne (6) du tissu (3).
5. Dispositif (100, 101) selon au moins une des revendications précédentes, caractérisé en ce que lesdites premières tiges (7, 8), qui entraînent ledit groupe de saisie et de coupe
(1), sont aptes à pousser vers l'avant ou l'arrière ledit groupe de saisie et de coupe
(1) ou à décaler de différentes longueurs, de manière à faire tourner au moins une
partie (33) dudit groupe de saisie et de coupe (1), afin de couper la trame (2) de
tissu (3) au moyen dudit organe de coupe (27) et d'enrouler ladite queue de trame
(2), qui est retenue par ledit pied (28) dudit groupe de saisie et de coupe (1), autour
dudit crochet ou de ladite aiguille (5), ledit crochet ou ladite aiguille (5) étant
apte à amener ladite queue de trame (2) à l'intérieur de la foule de chaîne, où un
peigne (40) du métier à tisser est prévu pour battre la queue de trame (2) conjointement
avec la trame suivante.
6. Dispositif (100, 101) selon la revendication 4, caractérisé par le fait que ledit groupe de crochetage (4) entraîne l'ouverture dudit pied (28) du groupe de
saisie et de coupe (1), alors que ledit groupe de saisie et de coupe (1) est fixe.