[0001] The present invention relates to a yarn carrier for weaving looms which is constructed
so as to allow more efficient supporting of the warp yarns and improved compensation
of the tension thereof, when the looms are equipped with a single beam or, respectively,
with several beams arranged alongside each other.
[0002] It is known that in weaving looms which produce double-width fabric, or, in any case,
in looms which are very long, the fabric may consist of two separate or attached pieces,
with the warp yarns which are unwound from two separate beams arranged alongside each
other, in which case the yarn-carrying cylinder essentially consists of a pair of
idle cylinders oscillating with respect to a fixed axis and supported in the middle
of the loom as well as on the two external shoulders. Alternatively, the fabric may
consist of a single piece, with the warp yarns unwound from a single beam, or two
"twin" beams arranged alongside each other, in which case the yarn-carrying cylinder
essentially consists of a single idle cylinder oscillating with respect to a fixed
axis and supported at the two ends of the shoulders of the weaving loom.
[0003] Moreover it is also know that the moment of inertia of the yarn-carrying cylinder
has a negative effect, which is proportional to the length of the loom or to the horizontal
distance between the two side levers supporting the cylinder itself, since with a
high moment of inertia it is not possible to limit the cylinder deflection induced
by the load of the yarns.
[0004] The yarn-carrying cylinders thus constructed, in accordance with the known art, therefore
have the defect of negatively influencing the weaving process by introducing, on the
warp yarns, tension peaks which cause continuous breakage of the yarns themselves
on account of the high moment of inertia both during rotation of the cylinders about
their longitudinal axis and during their oscillation with respect to their fixed axis.
[0005] It is therefore obvious that, in the case of a very "long" loom, the problem of the
moment of inertia of the yarn carrier becomes critical in the case of single-piece
fabrics if operation is being performed with a single-cylinder yarn carrier, whereas
it is less critical, although not entirely negligible, in the case of fabrics consisting
of two separate pieces, with a "split" yarn carrier.
[0006] The present invention now aims to solve the abovementioned problem by providing the
yarn carrier with a configuration which is extremely versatile for the purposes of
supporting the yarns and compensating the tension thereof and thus favouring uniform
intertwining between weft and warp over the whole length of the loom. In particular,
the invention relates to a yarn carrier which is suitable for a double-width and two-piece
loom, but may be adapted, if necessary, for the production of a single piece.
[0007] The invention solves the problem posed by means of a yarn carrier for weaving looms
over which the warp yarns supplied by one or more beams and directed towards the fabric
forming zone of the loom pass, characterized in that it consists of at least two adjacent
cylinders with the same diameter mounted idle on a respective support bar, the axis
of which is parallel to and at a distance from the fixed axis of oscillation of the
yarn carrier; in that said support bars are mounted oscillating on said axis by means
of pairs of levers which are pivotably mounted on fixed supports of the loom and in
that said support bars may be locked together in rotation.
[0008] In a suitable manner, elements for deviating the warp yarns at the adjacent ends
of said cylinders are also provided.
[0009] In a particular embodiment of the invention for a double-width and twin-beam loom,
the yarn carrier comprises a pair of cylinders which are respectively connected to
the resilient reaction system present on each side of the loon, the corresponding
support bars of which may or may not be locked in rotation by means of a removable
joint, preferably of the flanged type with a screw-type connection, which is located
in the middle of the loom.
[0010] The invention is now described in greater detail with reference to the accompanying
drawings, which illustrate a currently preferred embodiment thereof with a yarn carrier
consisting of two cylinders and in which:
Fig. 1 is a perspective view of the yarn carrier according to the invention applied
to a weaving loom consisting of two beams arranged alongside each other, said yarn
carrier being located above the beams themselves;
Fig. 2 shows a detail of a type of joint provided between the two cylinders of the
yarn carrier according to Fig. 1;
Fig. 3 shows a device for deviating the warp yarns in the region of said joint and
a variation of embodiment of the joint itself;
Fig. 4 shows the yarn carrier according to the present invention applied to a loom
which has two beams mounted alongside each other and illustrates the operation thereof;
and
Fig. 5 shows the yarn carrier according to the invention applied to a loom which has
a single beam mounted and illustrates the operation diagram thereof.
[0011] With reference to the drawings, the yarn carrier according to the invention consists,
in the embodiment shown, of a pair of external cylinders 1a, 1b over each of which
the yarns F unwound from the beams 2a, 2b of the loom travel and which are operated
in a known manner by the unwinding device 3a, 3b. Each cylinder 1a, 1b of the yarn
carrier 3a, 3b is mounted idle on a respective support bar 4a, 4b mounted parallel
to and at a distance from the axis 7 of oscillation of the yarn carrier by means of
pairs of levers, 5a, 5b, on the outer sides of the loom and, 6a, 6b, close to the
middle of the loom itself, respectively. The support bars 4a and 4b are arranged alongside
each other and the levers 5a, 5b and 6a, 6b are pivotably mounted on the loom by means
of suitable supports. The support bars 4a, 4b are also connected to the resilient
reaction system 8a, 8b arranged on the sides of the loom, at the end of each support
bar 4a, 4b. The side levers 5a, 5b are pivotably mounted on the loom in a known manner,
whereas the levers 6a, 6b in the centre of the loom are mounted, oscillating about
the axis 7, on a support of the fixed structure of the loom and may be joined together
in a permanent or removable manner by means of a joint 10 (see Fig. 2). Said joint
may be provided, instead of between the levers 6a and 6b, as shown in Fig. 2, directly
between the support bars 4a and 4b, in accordance with the embodiment shown in Fig.
3: in this case the flanged solution with fixing screws is compact, with the advantage
of a smaller deviation of the yarns, which in any case must be provided, in accordance
with the invention, between each cylinder of the yarn carrier, i.e. in the example
illustrated, in the middle of the loom.
[0012] In this connection Fig. 3 shows how, in the region of the joint between the two adjacent
portions of the yarn carrier, deviation elements 11 for the yarns are provided integral
with the fixed structure of the loom or, alternatively, with the levers 6a, 6b.
[0013] Although illustrated and described above in connection with the embodiment consisting
of two cylinders, the yarn carrier according to the invention may comprise - as already
indicated - three or more adjacent cylinders, mounted idle on respective support bars,
which may be locked together in rotation, so as to transmit the twisting torque between
each bar and the adjacent bars.
[0014] The use of the yarn carrier according to the invention, which is constructed with
two or more cylinders which are detached, but can be joined together by means of the
joint 10 and are also supported by a series of intermediate levers, results in important
advantages.
[0015] Firstly, a yarn carrier formed by a series of modules, the transverse dimensions
of which are significantly smaller, is obtained: this allows a considerable improvement
in the performance of the yarn carrier itself, the inertia of which, thus greatly
reduced, tends to be uninfluential during the fabric forming steps.
[0016] In the case of a double-width loom, by simply connecting or disconnecting the joint
10, it is possible to adapt the yarn carrier so as to obtain the best operating performance
of the loom with a single beam (Fig. 5) or with a twin beam (Fig. 4), for the weaving
of one piece or two pieces (both separate and attached), thus resulting in effective
and rational compensation of the tension of the warp yarns in both cases: in the case
of a single piece, there being basically a single continuous yarn carrier operating
uniformly and, in the case of a double piece, two separate yarn carriers, one for
each piece, operating independently and as required for weaving of the two pieces.
[0017] It is understood that other embodiments of the yarn carrier for weaving looms, different
from those described, could be carried out. These embodiments obviously fall within
the scope of protection of the present invention.
1. Yarn carrier for weaving looms over which the warp yarns supplied by one or more beams
and directed towards the fabric forming zone of the loom pass, characterized in that
it consists of at least two adjacent cylinders with the same diameter (1a, 1b) which
are mounted idle on a respective support bar (4a, 4b), the axis of which is parallel
to and at a distance from the fixed axis of oscillation (7) of the yarn carrier; in
that said support bars (4a, 4b) are mounted oscillating on said axis (7) by means
of pairs of levers (5a, 5b and 6a, 6b) which are pivotably mounted on fixed supports
of the loom, and in that said support bars (4a, 4b) may be locked together in rotation.
2. Yarn carrier for weaving looms as claimed in Claim 1, wherein elements (11) for deviating
the warp yarns (F) are provided in the region of the adjacent ends of said cylinders
(1a, 1b).
3. Yarn carrier for weaving looms as claimed in Claim 1, of the double-width twin-beam
type, wherein the yarn carriers comprises a pair of cylinders (1a, 1b) respectively
connected to the resilient reaction system (8a, 8b) present on each side of the loom,
the corresponding support bars (4a, 4b) of which may or may not be locked together
in rotation by means of a removable joint (10), preferably of the flanged type with
a screw-type connection, located in the middle of the loom.
4. Yarn carrier for weaving looms as claimed in Claim 1, wherein said support bars (4a,
4b) are locked together in rotation by means of removable joints (10).
5. Yarn carrier for weaving looms as claimed in Claim 4, wherein said joints (10) operate
directly between the support bars (4a, 4b).
6. Yarn carrier for weaving looms as claimed in Claim 4, wherein said joints (10) operate
between said mounting levers (6a, 6b).