US3229725A - Weaving machines - Google Patents

Weaving machines Download PDF

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Publication number
US3229725A
US3229725A US341928A US34192864A US3229725A US 3229725 A US3229725 A US 3229725A US 341928 A US341928 A US 341928A US 34192864 A US34192864 A US 34192864A US 3229725 A US3229725 A US 3229725A
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weft
nozzle
yarn
air
drum
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Saito Hifumi
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    • 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
    • D03D47/28—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed
    • D03D47/30—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed by gas jet
    • D03D47/3026—Air supply systems
    • 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
    • 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
    • D03D47/28—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed
    • D03D47/30—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed by gas jet
    • D03D47/3006—Construction of the nozzles
    • 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
    • D03D47/28—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed
    • D03D47/30—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed by gas jet
    • D03D47/3026—Air supply systems
    • D03D47/306—Construction or details of parts, e.g. valves, ducts
    • D—TEXTILES; PAPER
    • D03—WEAVING
    • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
    • D03D49/00—Details or constructional features not specially adapted for looms of a particular type
    • D03D49/60—Construction or operation of slay

Definitions

  • This invention relates to so-called jet looms or weaving machines in which weft or filling yarns are picked by jets of fluid under pressure.
  • Previously known air jet looms employ relatively high air pressures giving rise to explosive sounds when jets are formed and are generally unable to weave into fabric fine yarns, particularly, single yarns comprising short fibers and yarns comprising rayon, acetate or other long fibers.
  • Water jet looms are capable of weaving tine yarns but are hardly capable of weaving raw yarns which are hydrophilic or of weaving fabrics which employ warp yarns to be perfectly sized. After all, the fact is that there are many kinds of Woven fabric which cannot be formed by any of existing air or water jet looms.
  • the present invention is concerned particularly with jet looms employing air as pressure lliuid and proposes to ernploy extraordinarily low air pressures to make it possible to weave those kinds of fabric which it has previously been impossible to weave with jet looms as well as fabrics of the kind previously weavable thereon.
  • Use of low air pressures is also advantageous in that it reduces cost of air and eliminates occurrence of explosive sounds upon jet formation and warp damage due to jet currents, as will readily be understood from the following description.
  • Extension of the duration of air ejection means that the ejection is started earlier at the time when the shed is still very small and the filling yarn must be inserted while avoiding its contact with the warp yarns as far as possible. Moreover, the picking operation must be effected in such a manner as to reduce or eliminate any shock, resistance or obstacle to the filling yarn being inserted.
  • the present invention has solved all of the above problems previously met with yjet looms.
  • F'IG. 1 is a diagrammatic rear View of a jet loom embodying the present invention
  • FIG. 2 is a fragmentary perspective rear view illustrating the mechanism for moving back and forth the air nozzle for weft insertion
  • FIG. 3 is a side elevation of the mechanism shown in FIG. 2;
  • FIG. 4A is a fragmentary schematic view illustrating the relative position of the shed and the air nozzle according to the present invention at the start of air ejection;
  • FIG. 4B is a View generally similar to FIG. 4A illustrating the position of the air nozzle conventionally secured to the reed frame at the same instant as in FIG. 4A;
  • FIGS. 5C and 5D are fragmentary plan views illustrating the relative position of the air nozzle for weft insertion with its yarn inlet and the mechanism for furnishing yarn thereto;
  • FIG. SC illustrates the air nozzle secured to the reed frame for movement therewith
  • FIG. SID illustrates the air nozzle arranged not only for movement with the battening motion of the reed but also for movement relative to the plane of the reed frame; in these gures, reference characters C-I and D-1 represent the nozzle position when the shed is at its Imaximum and reference characters C-Z and D-2 represent the nozzle position when the weft yarn has been pushed against the formed portion of the fabric;
  • FIGS. 6E and 6F are schematic plan views showing the relationship between the auxiliary blast arrangement and the path of weft yarn being ejected through respective air nozzles int-o which the weft is introduced in different ways;
  • FIGS. 6E-1 and 6F-1 are cross-sectional views taken along the line X-Y in FIGS. 6E and 6F, respectively;
  • FIG. 7 is a fragmentary perspective view of the weft measuring device
  • FIG. 8 is a side view of same showing the operation of the pay-out roller
  • FIG. 9 illustrates two forms of annular belt to be fitted over the measuring drum to vary its effective diameter
  • FIG. 1() is a vertical cross-sectional View of another basic form of weft measuring device
  • FIG. 11 is a front View of the essential part of the weft measuring device of FIG. 10;
  • FIGS. 12 and 13 are a diagrammatic vertical crosssectional view and a front view, respectively, of a further form of weft measuring device
  • FIG. 14 is a front view of yet another form of weft measuring device
  • FIG. 15 is a perspective view of the weft nipper device
  • FIG. 16 is a side view showing the manner in which the weft nipper device operates
  • FIG. 17 is a fragmentary transverse cross-sectional view of the auxiliary blast arrangement
  • FIG. 18 is a fragmentary longitudinal cross-sectional View of same.
  • FIGS. -191 and 19] are fragmentary vertical crosssectional views of the shielding device when the shed is at its maximum and when reduced.
  • the weft or filling yarn being fed from a spool 1 is measured by the measuring device 2 and then directed into the main nozzle 3 to be inserted into the shed by a jet of air under pressure formed through the main nozzle and jets of air under pressure formed through auxiliary nozzles 8, 8', which are fed through conduit 57.
  • the weft is subsequently battened and cut by scissors 62.
  • jet loom of the present invention is arranged so that the air nozzle for weft insertion is not only moved back and forth of the loom with the movement of the reed but also the axis of the air nozzle is moved relative to the plane of the reed during the back and forth movement with the reed.
  • the conventional back and forth movement of the air nozzle is desirable in that the timing for ejecting weft yarn is adjustable to a more or less extent as desired and that, where auxiliary blast means are provided, weft yarns can be inserted under favorable conditions with the main and auxiliary air jets arranged substantially along a straight line.
  • the duration of air ejection cannot be extended to any substantial extent with the arrangement in which the main air nozzle is movable only with the reed.
  • the nozzle outlet since the axis of the air nozzle is ordinarily spaced more or less from the reed plane, the nozzle outlet must assume a position where the two groups of warp yarns forming the shed are spaced apart from each other only an extremely limited distance if the duration of air ejection were to be extended. This apparently would increase the tendency for the warp yarns to be damaged and for the yarns ejected to be caught by the warp yarns. Accordingly, with such arrangement, weft yarns must be ejected after a substantial shed has been opened, though the duration of air ejection is limited to that extent. According to the present invention, the arrangement for air ejection is made so that the ejection can be started when the shed is only partly opened.
  • the nozzle is positioned at the start of ejection in a position immediately adjacent the reed plane and immediately displaced to an optimum position more or less spaced from the plane of the reed.
  • a wheel member 37 is tted over a rock shaft 38, which is driven through a crank mechanism to rock in direct proportion to the crank member.
  • a chain sprocket Wheel 56 is also mounted on the rock shaft to effect the same rotary movement as that of member 37 to drive another sprocket wheel 36 so that shaft 54 secured to the slaysword 39 is rocked in direct proportion to the crank member.
  • a cam 45 is mounted on the shaft 54.
  • the air nozzle 3 is secured to one extremity of a rod 41, which is fulcrumed at 42 on the slay-sword 39 and formed integral with a lever 43.
  • the remote end of the lever 43 is held in sliding contact with a cam by a spring 44.
  • Reference numerals 6 and 6 indicate the bottom and top frames of the reed 9, respectively.
  • the nozzle 3 In operation, when the raised portion of the cam 45 is out of contact with the lever 43, the nozzle 3 is closely adjacent to the plane of the reed and a filling yarn is being picked with the air ejection through the nozzle 3 interrupted. As the raised portion of the cam 45 starts to actuate the lever 43, the nozzle 3 starts to move forwardly of the reed while initiating weft ejection. When the cam 45 has nearly ceased to act, the weft ejection also comes close to its end.
  • FIG. 4A illustrates the relative position of the warp shed and the air nozzle arranged for movement according to the present invention at the start of ejection
  • FIG. 4B illustrates the position of a conventional air nozzle secured to the reed frame for movement therewith when the warp shed is in the same condition as in FIG. 4A.
  • the nozzle With the nozzle positioned as in FIG. 4B, ejection of air is impossible with any satisfactory results. It will be evident that the positioning of the nozzle 3 in FIG. 4A has many advantages over that in FIG. 4B though the shed or opening between warp groups 10 and the reed position are the same in the two illustrations.
  • FIG. 5C illustrates the battening position of the reed on conventional jet looms in which the air nozzle is movable with the reed
  • FIG. 5D illustrates the battening position of the reed according to the present invention.
  • reference characters C-1 and D-1 indicate the nozzle position when the warp yarns are opened to the maximum
  • reference characters C-2 and D-2 indicate the nozzle position at the time when the weft yarn has been battened.
  • the weft yarn 4 is flexed at the nozzle position C-2 in FIG. 5C to a larger extent than at the nozzle position D-Z in FIG. 5D, and such yarn flexure occurs in most cases after the weft yarn has been interlaced with the warp yarns and thus causes an excessive tension in the weft.
  • Separate means may apparently be provided for feeding an appropriate additional length of weft yarn to compensate for such tension, but this renders the loom structure complicated to that extent. It is also to be understood that in some instances it is structurally desirable to have the nozzle positioned adjacent to the reed plane at the time when the weft is pushed against the formed portion of the fabric.
  • the nozzle is carried in a back and forth movement on a rod fulcrumed on the slay-sword
  • the nozzle can be arranged in various ways as long as the nozzle is movable back and forth in a manner so that the axis of the nozzle is displaced relative to the reed plane to vary the distance therebetween.
  • a further important feature of the present invention is the relationship of the nozzle structure with the yarn feed to the nozzle and with the auxiliary blasts.
  • the weft ejecting nozzle according to the present invention is constructed so that when ejected through the nozzle, the weft yarn is carried along a path displaced toward the reed from the nozzle axis.
  • the weft yarn leaves the nozzle exit along a line offset from the nozzle axis to the reed side and thus tends to be deflected away from the axis of the main jet toward the reed. This mode of flight of weft yarns is advantageous in various ways.
  • the weft yarn effectively prevented from engagement with warp yarns even if the shed is limited since the weft yarn when ejected through such shed starts to fly along a path adjacent to the reed surface, never deviating toward the Weaving end of the fabric.
  • the weft yarn can be blown straight forwardly by the cooperation with the main air jet of auxiliary air blasts which are formed adjacent to the reed surface in the direction of the weft flight so as to be effective to keep the weft from contacting the reed, as shown in FIGS. 6E and 6F. With this arrangement, the weft yarn can pass freely through the shed along the reed surface without contacting the latter. It will be apparent t-o 4those skilled in the lart that the same :effect can he obtained with the nozzle arrangement in which the main nozzle is not movable relative to the reed during the battening operation.
  • the main nozzle 3 has a yarn inlet aperture 11 formed in its side adjacent to the reed and the auxiliary nozzles have respective exit openings at 8.
  • the position of the yarn 4 in the exit opening of the main nozzle 3 is illustrated in the cross-sectional view of FIG. E-l.
  • FIGS. F and F-l illustrate in plan and in cross section, respectively, a modified form of main air nozzle operable tto the ysame effect as rthe nozzle in FIGS. E and E-l.
  • weft is fed to the nozzle from a point located rearwardly of the weft inlet to the nozzle in its rearmost or retracted position, or it is fed to the nozzle, which moves back and forth, from a point behind one extension of the reed plane, as clearly shown in FIGS. l, 5C and 5D.
  • reference characters C-l and D-l illustrate the relative position of the reed 9 and nozzle 3 to the yarn exit 17 from the measuring device when the nozzle is in its rearmost position or when the warp shed is at its maximum.
  • the yarn exit 17 is arranged rearward of the nozzle position indicated by C-l or D-l.
  • This arrangement is highly advantageous in that it facilitates supply of weft yarn to a nozzle which has a yarn inlet aperture on its side adjacent to the reed as shown in FIG. 6E and that the weft yarn is directly fed from the measuring device into the nozzle inlet with no yarn guides arranged therebetween which may provide resistance to the yarn.
  • a further advantage of this arrangement is that because of the yarn feed to the nozzle from behind, the yarn is automatically drawn back as the nozzle is advanced.
  • the picked weft is drawn back by the advance of the main nozzle, as observed in FIGS. 5C and 5D.
  • the length of the yarn leg between the yarn exit I7 of the measuring device to the yarn inlet aperture 11 in the air nozzle when the warp shed is at its maximum differs from that when the inserted yarn has been beaten up.
  • This length difference substantially corresponds to the amount of back draw of the weft.
  • the weft is drawn back relatively smoothly in correspondence to the battening speed and is made straight without any quiver at the yarn end.
  • the weft yarn is subjected to no resistance inherently provided by yarn guides.
  • weft yarn can be smoothly inserted through the shed of warp yarns by means of a jet of air at extraordinarily low pressure without adversely affecting the short-fiber single or long lament forming the weft yarn.
  • a jet of air at extraordinarily low pressure
  • Such feature is based upon a principle similar to that of kite-frying, in which the kite swings when the wind is too strong or the string is suddenly pulled and falls down when the string is made too loose.
  • any known backdraw device may be combined with the above arrangement if desired for some kinds of yarn without detracting from the advantages of the inventive arrangement including the reduction inamount of the back draw and in pressure of air forming jets.
  • the yarn measuring device In general, that portion of the weft yarn inserted which extends between a point close to the selvage adjacent to the main air nozzle and the measuring device is subjected to an unusually high tension after the weft has been closely interlaced with warp yarns. To avoid this, the weft yarn is usually cut with scissors before it is tensioned, or is drawn back in advance so as to be freely battened. In some cases, the measuring device is designed so that the weft can Slip over the periphery of the measuring drum. These known measures, however, are all not entirely satisfactory.
  • the time of scissor cutting cannot be freely advanced because of the type of loom, kind of fabric, timing of the beat-up operation, or other factors.
  • the drawing back of the inserted weft involves some problems in the other aspects of the weaving operation, as described hereinbefore. Weft slippage on the measuring device tends to detract from the measuring accuracy. In case the weft yarn is cut under substantial tension, there is a danger that the cut end portion of the weft be retracted excessively into the nozzle to the extent normal nozzle pressure will not recover the weft and necessitating an additonal pressure for the subsequent picking operation.
  • any required weft increment is taken from the measuring device without causing any excessive tension in the weft and without use of any means causing resistance to the flight of the next weft.
  • the measuring device according to the present invention is of the general type including a rotating drum about which weft yarn is wound for measurement, but the feature is that the rotating drum is constructed to have different diameters along its axial length.
  • one form of the inventive measuring device includes a shouldered rotating drum having cylindrical sections of different diameters and a plurality of pressure rollers operable to engage the respective drum sections in a timed relation to each other to deliver a length of weft yarn required to form a pick, as will be described hereinafter in detail.
  • This form of measuring device is advantageous in that it enables adjustment of the yarn feed within a limited range and that it makes constant the rate at which yarn is paid out from the cone and the tension under which it is wound about the measuring drum, alleviating the need for any substantial accuracy in the configuration and nature of cones.
  • the measuring drum 2 is continuously driven from the main drive shaft of the loom and is shouldered to dene cylindrical sections 2x and 2y, one of which sections 2x having a circumference larger than that of the other section 2y.
  • Small rollers 14 and I4 are arranged to engage the respective drum sections 2x and 2y in any desired timed relation to each other to deliver weft yarn 4.
  • the yarn 4 is paid out from the cone 1 to pass through a yarn guide 16 and between one of the drum sections 2x and roller 14 and further through yarn guides 15 and 16' to pass between the other drum section 2y and associated roller 14.
  • the yarn then passes through a further yarn guide 15 to be wound about the drum by engagement with a retractable pin 12.
  • FIG. 8 illustrates the manner in which rollers 14 and 14" are disengaged from the respective drum-sections 2x and 2y.
  • the roller 14 is carried on a lever 19 fulcrumed at 18.
  • the lever 19 is biased in a counterclockwise direction as viewed in FIG. 8 by a spring 23 into contacting engagement with a cam 20 as at 22.Y
  • the cam 20 has a raised portion 21 and is driven by the main shaft of the loom for rotation in direct proportion with the crank motion. As the cam 20 rotates, its raised portion 21 actuates the lever 22 so that roller 14 thereon is disengaged from the drum section 2y.
  • the yarn limb on the drum extending between yarn guides 15 and 16 is slackened to sag as indicated by the broken line 4.
  • This slack yarn can readily be fed forwardly by moving the roller 14' apart from the drum section 2y.
  • the weft yarn inserted through the warp shed can be kept free from any excessive force and hence from recoiling when cut under such tension, if the roller 14 is only released, when the weft yarn is tensioned upon battening, to allow the slack weft 4 to be drawn forward as required, and the picking operation can thus be effected eiciently without any mispick even by use of a jet of air at low pressure.
  • the roller 14 is continuously held in pressure Contact with the drum while roller 14 is released therefrom at an appropriate time during each cycle of machine operation, ⁇ the weft yarn around the drum is at all times held in a slack state between the yarn guides 15 and 16'.
  • any desired length of yarn can be measured by arranging so that .the weft yarn is initially delivered solely under the action of roller 14 with roller 14 held apart from the drum and then solely under the action of roller 14 with roller 14 held apart from the drum.
  • the measured length of yarn can be finely adjusted within a limited range simply by controlling the timing of engagement and disengagement of the two rollers with the measuring drum independently of each other.
  • the measuring purpose can be attained by use of either roller 14 or 14 alone if only separate means are provided to release the tension of the pick for the battening operation.
  • the shouldered configuration of the measuring drum is intended to enable control of the yarn length measured for each pick, as will be readily understood.
  • reference nuameral 101 denotes a hollow rotating drum having a conically shaped peripheral surface; a feed roller 102 arranged to engage the drum end portion having a larger diameter; and a retractable operating pin 103 arranged in the other drum end portion to extend radially outwardly through the adjacent peripheral wall of the drum.
  • a hollow bearing boss 104 is secured to the adjacent end wall of the drum in alignment therewith and journaled in the machine frame (not shown) by way of a bearing 105 to allow the drum to rotate freely.
  • a gear 106 is rsecured to the boss 104 and is'in mesh with another gear 103 mounted on a rotative shaft 107, which is driven from the main shaft of the loom.
  • the ratio of the number of teeth of gear 106 to that of gear 107 is l to 2 so that the drum 101 driven at a rotative speed twice as high as that of the main shaft of the loom.
  • a bracket 109 is secured to the inside of the adjacent end wall of the drum in the vicinity of the operating pin 103 and pivoted to the bracket is a bellcrank lever 110 one end of Which is pivotally connected to the inner end of the operating pin.
  • the other end of the bellcrank lever 110 is pivotally connected to the inner end of a rotative shaft 111 extending through the boss 104.
  • a lever 112 is fulcrumed intermediate its ends as at 113 to the machine frame and carries at opposite ends balls 114 and 115, which are fitted in respective grooves formed in annular members 114' and 115 secured to the rotative shafts 107 and 111.
  • the width of the groove formed in the annular member 114 is considerably larger than the associated ball 114, which is held at all times in contact with one side wall of the groove under the bias of a spring 116 secured at one end to the lever 112.
  • a cam 117 is formed on one side wall of the groove, in annular member 115 to act upon the ball 115 thereby to rock the lever 112 against the bias of spring 116 and move the shaft 111 axially to the left.
  • the operating pin 103 is withdrawn by bellcrank lever 110 to the inside of the drum wall.
  • the lever 112 and associated parts are restored to their normal position under the bias of spring 116 causing the operating pin 103 to project beyond the peripheral wall of the drum.
  • the operating pin 103 is held in this advanced position until the cam 117 comes again into engagement with the ball 115.
  • Weft yarn 4 coming from the cone 1 passes through yarn guides 122 and 123 and between the roller 102 and the adjacent drum surface and, turning about the drum periphery comes into engagement with the operating pin.
  • the yarn further proceeds through a yarn guide 125 to be fed into the air nozzle 3 as air is ejected therethrough.
  • the drum 101 is continuously driven at an angular velocity twice that of the main shaft of the loom, as described hereinbefore, and the roller 102 is continuously held in pressure contact with the drum so that the weft yarn extending therebetween is pulled out from cone 1 to be wound about the peripheral surface of the drum.
  • the time when an appropriate length of weft yarn has been wound about the drum is approximately the same as the time when au appropriate shed or funnel of warp yarns has been formed to allow the nozzle to eject pressure fluid.
  • cam 117 comes into engagement with the ball 115 to retract the operating pin 103 into the drum allowing the weft wound about the drum to be released therefrom to be fed into the air nozzle 3.
  • FIGS. l2 and 13 Another form of measuring device shown in FIGS. l2 and 13 has means for adjusting the amount of slack yarn.
  • the peripheral wall of the drum has an axially elongated slot 130, through which pin 103 extends.
  • Slotted bars 131 and 132 are secured to the adjacent inner wall surface of the drum and the upper arm of the bellcrank lever 110, respectively, by screw means.
  • the pin 103 is pivoted at its bottom to one of the slotted bars 132 and extends through a small aperture formed in the other slotted bar 132 to project beyond the drum surface.
  • the yarn guide 124 is carried on a rod which is secured to the machine frame by way of a slotted adjusting piece 133, as shown in FIG. 13.
  • the slack of weft yarn is excessive, it can be reduced by displacing slotted bars 131 and 132 and hence pin 103 toward the base end of the conical drum by an appropriate distance to increase the radial dis tance of the drum surface adjacent to the pin 103 so that the latter rotates at an increased peripheral speed while engaging the weft.
  • the yarn guide 124 also is shifted toward the base end of the conical drum by means of the adjusting piece 133. Contrarily, if the pin 103 and yarn guide 124 are shifted toward the reduced end portion of the drum, the peripheral speed of the drum surface adjacent to the pin is reduced thereby to increase the amount of slack.
  • FIG. 14 illustrates a modification of the measuring drum, which includes a cylindrical section 101' for engagement with the feed roller 102 and the remaining section which is frusto-conical.
  • This form of measuring drum with the roller 102 mounted on an axis parallel to the axis of the drum affords some manufacturing convenience but is substantially the same in functional effect as the previously described forms.
  • the same principle may also be applied to the measuring device of the present invention having a conically shaped measuring drum by employing a feed roller adjustable in position along the drum surface for varying the yarn feed or the measured length of yarn to be fed to the air nozzle.
  • the measuring device which has been illustrated in various forms, is advantageous in that there exists at all times a tendency of the weft yarn on the drum to slack between the feeding region of the drum surface contacting the feed roller and the operating pin projecting radially outwardly beyond the drum surface, enabling the device tomeasure weft smoothly without subjecting it to any excesssive tension when it is wound about the drum and released therefrom.
  • the slack of yarn is effective to alleviate any excessive tension of the weft otherwise occurring when it is beaten up and to impart a proper tension to the weft when cut thereby to completely prevent problems caused by the recoiling of the cut end of weft.
  • a further feature of the present invention is a nipper device arranged between the weft ejecting nozzle and the scissors, as at 5 in FIG. 1.
  • the provision of the device has a great influence upon the pressure of air used for weft ejection.
  • the exit of the nozzle should be located considerably close to the selvage-forming warp, that is, the length of the weft end extending forwardly of the nozzle immediately before it is inserted should have an appropriate limited value.
  • the present invention employs a nipper Vdevice between the nozzle and scissors which operates to grip the weft immediately before it is eut and release it immediately before ejection is started so that the weft extends forwardly of the nozzle opening over a predetermined distance at all times immediately before ejection is started.
  • the nozzle and the nipper or clamp device are arranged to move back and forth and the former further moves back and forth at weft ejection. With this arrangement, the nipper is not required to open wide since it does not interfere with the ejection of air if effected in a position slightly ⁇ apart from the clamp device.
  • the clamp device is not necessarily required to clamp the yarn so firmly depending upon the type of yarn used.
  • This nipp-er device has an additional advantage that it eliminates any delay in weft flight due to misfunctioning of the scissors.
  • the nipper device according to the present invention is arranged to retract with the end of the weft cut and gripped therein to completely clear the passage for the next flight of weft so that insertion of the weft can be effected satisfactorily even with low pressure air.
  • Weft gripping means have frequently been used on previous shuttleless looms, but such means have included a structure which appears simple but actually involves various difficulties.
  • Most of previous nipper devices have included a pair of members adapted to abut against each other to grip yarn therebetween under the resilience of a spring or like means and thus -have not been fully reliable because of the wear of the gripping members, vibration and ishock upon inter-engagement therebetween, and other factors.
  • FIG. 15 illustrates the gripping structure of the inventive device
  • FIG. 16 illustrates the manner in which it operates.
  • reference character G indicates the position of the nipper device when the pick 1.1... is beaten up; and H its position when the shed of warp yarns is close to its maximum.
  • a pair of nipper lingers 25 and 26 are formed of hard materials such as steel and hard nylon land are perfectly finished by face-to-face grinding. Fingers 25 and 26 are mounted on a pin 28 secured to a bracket 24 and are pressed against each other and against the adjacent face of the bracket 24 by a spring 27.
  • One of the fingers 26 carries a lug 29, on which a sleeve 30 is moun-ted to freely rotate.
  • a lever 31 has a bifurcated end formed to loosely embrace the sleeve 30 and is rockable back and forth ⁇ to swing the lingers 25 and 26 relatively to each other so that they cooperate to grip and release the weft extending from the nozzle 3.
  • the lever 31 is fulcrumed as at 32 to the slay-sword 39 'and is held at the bottom in pressure lContact with a cam 35 under the bia-s of a spring 34.
  • the cam 35 is driven at a speed directly proportional to the rotation of the loom crank.
  • this clamp fingers 25 and 26 can readily be arranged to operate to engage the yarn at any required instant and remain effective for a required period of time by use of a cam 35 having a suitable proboard and a proper operational timing.
  • the spring 27 should have a suitable spring rate in accordance with the ⁇ type of yarn and the speed of loom operation.
  • the opposing edges of the clamp lingers 25 and 25 should obviously be slightly rounded so as not to form any sharp cutting edge.
  • either one or both of clamp fingers may take the form of a magnet so that they are held at all times in sliding contact with each other. In this case, however, the strength of the magnet should be adjusted in .accordance with the type of yarn and the operational speed of the loom.
  • the clamp device of the present invention is not based upon the principle of collision and hence is completely free from shock.
  • Use of clamp fingers 25 and 26 formed of hard material ⁇ and operable to lslide over each other is effective to eliminate friction and make the gripping action smooth and accurate, since the clampY fingers are held in close contact with each other for extended service life even if some friction exists therebetween.
  • This clamp device is durable and reliable so that it is also usable for gripping the free end of the inserted weft at ⁇ a point adjacent the selvage remote from the air nozzle with ext-reme effectiveness.
  • the device can take an important role of stabilizing the free end of the inserted weft to control its tension, or making it possible to locate in the vicinity of the clamp -a suitable weft detector which is operable upon the basis of such weft tension.
  • Such applications of the clamp device are not illustrated as they will be appa-rent to those skilled in lthe art.
  • a measure is known for releasably holding the weft end in front of the nozzle before ejection is started for the purpose of forming a loop of weft, which is effectively acted upon by the pressure of air ejected; the weft end being subsequently released.
  • This measure is entirely different in principle from the present invention and is rather detrimental to the inventive arrangement, in which weft is ejected into the shed of warp yarns when it is still narrow, as pointed out hereinbefore.
  • auxiliary blasts at points along the width of fabric.
  • This can be realized in various ways, which may be broadly classified into two groups.
  • 4one group air pressure is ejected in a continuous fashion, and in the other group it is ejected intermittently each time when required.
  • the former group involves a number of problems in addition to the excessive loss of energy.
  • it causes the weft to tremble to the last moment when it is beaten up, for example, when it is extremely small or is a twisted long fiber yarn, and the marginal portion of the fabric remote from the ejecting nozzle often has a con-struction including weft slacks.
  • the air pressure upstream of the valve must have a value a number of times as high as the pressure level required at the nozzles, and this apparently results in an enormous energy loss.
  • the valve must be located in the region of the reed frame. This valve arrangement has great advantage from the manufacturing standpoint since slight leakage of air through the valve is permissible. Under this condition, it is apparently easy to obtain a valve operable at high speed.
  • the auxiliary blast arrangement according to the present invention will next be described with reference to FIGS.
  • the top and bottom reed frames 6 and 6 are made hollow to serve as an air reservoir and4 associated piping and are filled with air under pressure directed through conduit 57.
  • Arranged in the reed frames 6 and 6 are respective bars 46 and 46 which are formed with or to hold auxiliary blast nozzles 8 and 8', respectively.
  • the sliding contact between the bar 46 or 46 and the slide plate 47 or 47 is made close in the regions of the nozzles and -cooperating Iapertures but in the remaining regions they are preferably slightly spaced apart from each other.
  • the bars and slide plates should be made of a material which does not require frequent oiling.
  • Rods 48 and 48 are connected to the adjacent ends of the slide plates 47 and 47 and extend outwardly through the adjacent end walls of the hollow reed frames 6 and 6', respectively, to carry rollers 49 and 49.
  • Cams 50 and 50 are provided to drive respective rollers 49 and v49 right and left, rollers 49 and -49 being held in pressure contact with respective cams under the bias of springs indicated at 61 and 61', respectively, in FIG. 1.
  • a bevel gear 60 is secured to the shaft I54 described hereinbefore to cooperate with another -bevel gear 59, which is secured to a vertical shaft 51 supported by bearings 52, 52 and 52".
  • the shaft 51 rotates with cams 50 and 50 mounted thereon, the raised portions of the cams actuate respective rollers '49 and 49.
  • the timing and duration of the auxiliary blasts can thus be controlled by adjustment of the circumferential position and extent of the raised portions of respective cams 50 and 50'. It is preferable that the auxiliary nozzles are arranged for limited lateral and back and forth movement as is often required with reeds of different densities.
  • auxiliary blast device is not limited t-o the illustrated arrangement but may be constructed and arranged in various manner-s as long as it is arranged in the region of the reed frame for back and forth movement therewith and the blasts are periodically interrupted during such movement.
  • Yet another important feature of the present invention lies in the provision of a shielding device for preventing dissipation of the air stream formed in the warp shed.
  • a shielding device for preventing dissipation of the air stream formed in the warp shed.
  • Use of such shielding device on air jet looms has been linown per se, but any of previous shielding devices cannot be used with success on jet looms employing low pressure air as used in the present invention.
  • Conventional devices have only included screens or shield plates secured to the top and bottom members of the reed frame close to the opposing edges thereof, as indicated at 64 and 64.- in FIGS. 19E and 19].
  • a exible and slightly resilient sheet for example, made of soft plastic, is attached to the warp side of each of the screens or shield plates, which are of the conventional type, for the purpose of substantially completely shielding the warp shed on its top and bottom sides.
  • reference numeral It? designates warp yarns which are shed by heddles 63 and 63' to form a weft passage or shed 68.
  • the screens or shield plates 64 and 6d. are secured to the front sides of the top and bottom members 6 and 6 of the reed frame so as to extend along the warp yarns when the shed is at its maximum, and each has a length about half the reed stroke.
  • the flexible and slightly resilient sheet members 65 and 65' for example, made of vinyl chloride have their rear edges secured to the inside of the respective shield plates 64 and 6ft in a manner so that the sheet members extend forwardly beyond the respective shield plates.
  • the flexible sheet members extend along the warp yarns to the vinicity of the beating line and thus together with the screens 64 and 64 cover the warp yarns substantially completely on the top and bottom sides thereof so that dissipation or scattering of the ejected air is prevented.
  • the upper sheet member b is bent gently along the upper surface of the woven fa'bric without causing any damage thereto.
  • flexible sheet members are secured to the upper and lower screens, as described and shown, the flexible member 65 on the lower screen 6d does not come into contact with the fabric surface even if it be arranged close to the warp yarns at the maximum of shed and may itself be extended to the vicinity of the beating line instead of securing flexible sheet o5' thereto.
  • the screens 64 and 64' are not necessarily made entirely solid but their portions overlapping sheet members 65 and 65 may be made foraminous or latticed if desired.
  • the shielding device of the present invention is formed so as to cover the Warp shed at all times substantially completely thereby to prevent dissipation of ejected air and thus has an advantage that consumption of air pressure is substantially reduced. This is important particularly on looms in which low pressure air is used to form jets each continuing for a relatively long period of time.
  • An additional advantage of this shielding device is that, since air is not allowed to flow vertically through the spaces between the adjacent warp yarns, the weft yarn is effectively kept from being flexed in flight and its end can never present itself through or between the adjacent warp-s; thus ensuring smooth insertion of the weft through the shed of warp yarns.
  • the present invention has solved all of the problems pointed out hereinbefore and relating to the use of low pressure air for weft insertion, including provision of an optimum lll arrangement for auxiliary air blasts, extension of the air ejecting time, prevention of the ejected weft from contacting warp yarns, and elimination of shock and resistance to the weft in iiight.
  • the range of yarns weavable into fabric is extremely widened including tine ones which have been unweavable on conventional jet looms; weaving operation can be per-formed eiciently and with comfort causing no unpleasant explosive sounds which occur with use of high air pressure.
  • the loom according to the present invention is also highly advantageous from the standpoint of energy cost since it employs air at a pressure of about one-third to one-fifth the pressure of air previously used in the art.
  • a yarn measuring device for a shuttleless loom comprising a measuring drum, a feed roller cooperable therewith to pull out weft yarn and a yarn catching pin arranged to wind the said weft yarn about the said measuring drum and to be retracted within the measuring drum at a pin-retracting point during weft ejection movement to allow the weft to be introduced into a shed, a yarn payed-out point forme-d by the contact ⁇ of the said yarn measuring drum and the roller, said yarn payedout point being radially further distant from the axis of the measuring drum than is the pin-retracting-point at the surface of the measuring drum whereby the speed of the yarn fed by said feed roller and drum is faster than the speed of the portion of the yarn caught by said catching pin so that slack is introduced in the portion of the yarn between said yarn payed-out point and said catching pin.
  • a jet loom of the type including a reed movable between forward and rearward positions, a Huid nozzle for inserting a weft along a path into a shed formed of warp yarns, said jet loom further comprising means for moving said fluid nozzle along the warp in a rectilineal path in association with the beat-up movement of the reed while maintaining the direction of the axis of said nozzle in a manner so that the distance between the axis of said nozzle and the plane of the reed is varied during each cycle of operation.
  • a jet loom as set forth in claim 5, wherein said means for biasing comprises spring means.
  • An air jet loom as claimed in claim 2 having a shielding device for continuously shielding most portions of the shed formed of warp yarns to prevent dissipation of air ejected therein, said shielding device including planar screens arranged on the top and bottom sides of the shed and a flexible slightly resilient sheet member secured to at least one of said planar screens.
  • a yarn measuring device for a loom and of the type including a measuring drum arranged to be driven inrsequence with the loom, roller means arranged to make pressure contact with said measuring drum for drawing a weft yarn in a manner so that it is wound albout said measuring drum, said device being characterized in that said measuring drum includes cylindrical sections of different diameters and said roller means includes a plurality of feed rollers arranged to make pressure contact with said respective drum sections so as to draw the weft yarn at different speeds and means for alternately moving said feed rollers out of pressure contact with said respective drum sections but always leaving at least one roller in pressure contact with its respective section so that the length of yarn measured for each weft insertion and the yarn tension can be selectively controlled.
  • a jet loom of the type including a reed adapted to move in a beating-up motion, a fluid nozzle positioned ⁇ forward of said reed, means for moving said uid nozzle in a rectilineal path toward and away from said reed in relation to the beating-up movement of said reed, said fluid nozzle having a yarn inlet aperture formed on its rearward side facing said reed, and a yarn guide means located rearwardly of the axis of said nozzle, a yarn measuring device for feeding weft yarns to said nozzle in a predetermined amount, said yarn guide means guiding said weft yarns fed from said yarn measuring device to said yarn inlet aperture.
  • An auxiliary air blast device for an air jet loom of the type having a reed frame and a main air nozzle for inserting a weft into a shed formed of warp yarns, said auxiliary air blast device comprising auxiliary nozzle means positioned on the reed frame for directing auxiliary jets of fluid along the path of insertion to aid the ight of the weft yarn as ejected through the main air nozzle, air conduit means for feeding air to said auxiliary nozzle means, and means provided on said reed frame adjacent to the points where said air conduit means cornmunicates with said auxiliary nozzle means for intermittently interrupting the air ow between said air conduit means and said auxiliary nozzle means.

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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3370618A (en) * 1964-11-21 1968-02-27 Elitex Zavody Textilniho Thread dispensing apparatus
US3399701A (en) * 1964-11-03 1968-09-03 Strake Maschf Nv Reed for a loom
US3517704A (en) * 1963-09-12 1970-06-30 Saurer Ag Adolph Weft inserting device
US3604472A (en) * 1969-12-22 1971-09-14 North American Rockwell Filling storage device for looms
FR2086212A1 (es) * 1970-04-21 1971-12-31 Te Strake Maschf
US3693668A (en) * 1969-10-08 1972-09-26 Elitex Zavody Textilniho Pneumatic weft delivery means for shuttleless looms
US3705608A (en) * 1969-10-22 1972-12-12 Geert Jan Vermeulen Method for transporting a weft thread through a weaving shed and a loom for performing said method
US3821972A (en) * 1970-09-18 1974-07-02 Elitex Zavody Textilniho Method of picking weft yarns in shuttleless looms
US3982568A (en) * 1974-04-12 1976-09-28 Zbrojovka Vsetin, Narodni Podnik Device for gripping and forming a supply of weft thread before weft insertion
US4081000A (en) * 1976-01-26 1978-03-28 Ruti Machinery Works Ltd. Weft insertion nozzle arrangement for a weaving machine
US4118919A (en) * 1976-10-16 1978-10-10 Palitex Project Company Gmbh Yarn take-up and supply mechanism for use with textile machines
DE2836622A1 (de) * 1977-08-25 1979-03-15 Rueti Te Strake Bv Rietbalkeneinheit
US4212330A (en) * 1978-09-05 1980-07-15 Ruti-Te Strake B.V. Reed baulk unit
US4245677A (en) * 1978-02-10 1981-01-20 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Method and apparatus for supplying transport fluid to auxiliary jet nozzles in a jet loom
US4262707A (en) * 1978-02-10 1981-04-21 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Method for injecting transport fluid into a shed from auxiliary jet nozzles
US4448223A (en) * 1980-12-30 1984-05-15 Saurer Diederichs (Societe Anonyme) Device comprising a movable nozzle for the pneumatic insertion of the weft in a shuttle-less loom
US4458729A (en) * 1979-08-06 1984-07-10 Leesona Corporation Strand delivery and storage system
US4494888A (en) * 1981-07-27 1985-01-22 Seisakusho Kabushiki Kaisha Toyoda Jidoshokki Weft inserting method and apparatus for an air jet loom
EP0022112B1 (en) * 1979-06-22 1985-09-18 Tsudakoma Kogyo Kabushiki Kaisha Weft reservoir for an alternate two-pick change type fluid jet shuttleless loom
US4576208A (en) * 1983-12-01 1986-03-18 Sulzer Brothers Limited Weft severing device for a weaving machine
US4703779A (en) * 1985-08-30 1987-11-03 N.V. Weefautomaten Picanol Control valve for auxiliary nozzle of air jet looms
USRE32916E (en) * 1969-10-22 1989-05-02 Method for transporting a weft thread through a weaving shed and a loom for performing said method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1721940A (en) * 1928-06-28 1929-07-23 Lorraine Mfg Company Pneumatic weft-introducing mechanism for looms
FR1040379A (fr) * 1951-08-08 1953-10-14 Amiens France Métier à tisser à circuit d'air
US2668560A (en) * 1949-04-02 1954-02-09 Ceskoslovenske Textilni Zd Y Device for weaving of fabrics
FR1261463A (fr) * 1959-05-25 1961-05-19 Métier à tisser à insertion pneumatique de la trame
CA655672A (en) * 1963-01-08 Te Strake Lambertus Weaving-loom

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA655672A (en) * 1963-01-08 Te Strake Lambertus Weaving-loom
US1721940A (en) * 1928-06-28 1929-07-23 Lorraine Mfg Company Pneumatic weft-introducing mechanism for looms
US2668560A (en) * 1949-04-02 1954-02-09 Ceskoslovenske Textilni Zd Y Device for weaving of fabrics
FR1040379A (fr) * 1951-08-08 1953-10-14 Amiens France Métier à tisser à circuit d'air
FR1261463A (fr) * 1959-05-25 1961-05-19 Métier à tisser à insertion pneumatique de la trame

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3517704A (en) * 1963-09-12 1970-06-30 Saurer Ag Adolph Weft inserting device
US3399701A (en) * 1964-11-03 1968-09-03 Strake Maschf Nv Reed for a loom
US3370618A (en) * 1964-11-21 1968-02-27 Elitex Zavody Textilniho Thread dispensing apparatus
US3693668A (en) * 1969-10-08 1972-09-26 Elitex Zavody Textilniho Pneumatic weft delivery means for shuttleless looms
USRE32916E (en) * 1969-10-22 1989-05-02 Method for transporting a weft thread through a weaving shed and a loom for performing said method
US3705608A (en) * 1969-10-22 1972-12-12 Geert Jan Vermeulen Method for transporting a weft thread through a weaving shed and a loom for performing said method
US3604472A (en) * 1969-12-22 1971-09-14 North American Rockwell Filling storage device for looms
FR2086212A1 (es) * 1970-04-21 1971-12-31 Te Strake Maschf
US3821972A (en) * 1970-09-18 1974-07-02 Elitex Zavody Textilniho Method of picking weft yarns in shuttleless looms
US3982568A (en) * 1974-04-12 1976-09-28 Zbrojovka Vsetin, Narodni Podnik Device for gripping and forming a supply of weft thread before weft insertion
US4081000A (en) * 1976-01-26 1978-03-28 Ruti Machinery Works Ltd. Weft insertion nozzle arrangement for a weaving machine
US4118919A (en) * 1976-10-16 1978-10-10 Palitex Project Company Gmbh Yarn take-up and supply mechanism for use with textile machines
FR2401248A1 (fr) * 1977-08-25 1979-03-23 Rueti Te Strake Bv Ensemble a poutre de support de peigne, pour machine pneumatique a tisser
DE2836622A1 (de) * 1977-08-25 1979-03-15 Rueti Te Strake Bv Rietbalkeneinheit
US4245677A (en) * 1978-02-10 1981-01-20 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Method and apparatus for supplying transport fluid to auxiliary jet nozzles in a jet loom
US4262707A (en) * 1978-02-10 1981-04-21 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Method for injecting transport fluid into a shed from auxiliary jet nozzles
US4212330A (en) * 1978-09-05 1980-07-15 Ruti-Te Strake B.V. Reed baulk unit
EP0022112B1 (en) * 1979-06-22 1985-09-18 Tsudakoma Kogyo Kabushiki Kaisha Weft reservoir for an alternate two-pick change type fluid jet shuttleless loom
US4458729A (en) * 1979-08-06 1984-07-10 Leesona Corporation Strand delivery and storage system
US4448223A (en) * 1980-12-30 1984-05-15 Saurer Diederichs (Societe Anonyme) Device comprising a movable nozzle for the pneumatic insertion of the weft in a shuttle-less loom
US4494888A (en) * 1981-07-27 1985-01-22 Seisakusho Kabushiki Kaisha Toyoda Jidoshokki Weft inserting method and apparatus for an air jet loom
US4576208A (en) * 1983-12-01 1986-03-18 Sulzer Brothers Limited Weft severing device for a weaving machine
US4703779A (en) * 1985-08-30 1987-11-03 N.V. Weefautomaten Picanol Control valve for auxiliary nozzle of air jet looms

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