Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
  • D03D47/40—Forming selvedges
  • D03D47/48—Forming selvedges by inserting cut end of weft in next shed, e.g. by tucking, by blowing

Definitions

• the present invention relates to webbing and in particular it relates to a device for forming a fabric recessed selvedge for shuttleless looms.
• 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.
• 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 .
• 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.
• 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 .
• 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.
• 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.
• 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:
• 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
• 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.
• 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.
• 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.
• 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 .
• 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 .
• Another object of the invention is to provide a device for forming a fabric recessed selvedge for shuttleless looms ⁇ which is able,.,_t.o__ 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.
• the device for forming fabric recessed selvedges 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.
• 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.
• the selvedge device 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 elastic -d-ispiacement—o ⁇ f ⁇ said fabric making line when the comb is ready for beating.
• 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
• FIG. 3 shows a partial exploded view of the device of figures 1 and 2, according to the present invention
• FIG. 4 shows a rear partial view of the device of figure 2, according to the present invention
• FIG. 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
• FIG. 9 shows a rear perspective view of the device of figure 8, according to the present invention.
• FIG. 10 shows a perspe_c_ti-ve—view—o-f—the—dev ee ⁇ "of _ figure 8, according to the present invention, in a second operating position.
• the device 100 for forming fabric recessed selvedges according to the invention substantially comprises:
• 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,
• 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.
• the rod 9 is able to slide longitudinally inside the sleeve 20; moreover, the rod 9, inside the sleeve 20, is shaped so as ⁇ ⁇ _c ⁇ ntjcOlcorethe ⁇ rotation while- ⁇ a3 ⁇ 4 ⁇ OTtf3 ⁇ 4cf 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.
• 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 .
• 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.
• 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' ' .
• the belt tensioner 24 is repositioned to restore the tension
• 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.
• 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.
• the hook or needle 5 actuated by the ro o- 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.
• 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.
• __ i_t ⁇ is unders andable—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.
• 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.
• 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 .

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Looms (AREA)
• Replacement Of Web Rolls (AREA)
• Vending Machines For Individual Products (AREA)
• Spinning Or Twisting Of Yarns (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=44993808

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (3)

Family Cites Families (7)

• 2011
  • 2011-09-22 IT IT000255A patent/ITVI20110255A1/it unknown
• 2012
  • 2012-09-21 EP EP12791279.8A patent/EP2800829B1/de active Active
  • 2012-09-21 WO PCT/IT2012/000292 patent/WO2013042158A2/en not_active Ceased

Non-Patent Citations (1)

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