FR2510623A1 - IMPROVED DEVICE FOR FORMING AN EDGE OF THE "FULL TURN GAS" TYPE ON THE SIDE EDGES OF A FABRIC IN A WEAVING MATERIAL - Google Patents

Abstract

THE DEVICE ACCORDING TO THE PRESENT INVENTION INCLUDES, COMPARED TO THE CONVENTIONAL DEVICE, A SECOND CONTROL PLATE 34 ARTICULATED TO THE HINGED FRAME 49 NEXT TO THE HINGED FRAME 17 TO WHICH THE MAIN CONTROL PLATE 26 IS CONNECTED, THE MAIN PLATE 26 BEING BRAKED 33. THE ADDITIONAL CONTROL PLATE 34 INCLUDES TWO SLOTS 37, 38 SIMILAR TO THE SLOTS 28, 29 OF THE MAIN PLATE 26 BUT INCLINED INVERSEWHERE FROM THESE SLOTS, THE TWO ADDITIONAL SLOTS ABOVE BEEN INTENDED TO RECEIVE TWO 8 STRANDS, 9 THE DISTANCE BETWEEN THE WINGS 40, 41 OF THE SUPPLEMENTARY PLATE 34 BEING EQUAL TO THE LENGTH OF THE SAID MAIN PLATE 26 INCREASED BY TWICE THE HEIGHT OF EACH OF THE SAID SLOTS 28, 29 OF THE MAIN PLATE 26.

Description

Improved device for forming a selvedge of the "tower gauze" type

  complete "on the side edges of a fabric in

a loom.

  The present invention relates to an improved device

  born to form a selvedge like "full turn gauze" on the

  lateral edges of a fabric, this device being driven posi-

  tively, that is to say independently, of the tension of the tying or linking threads, and making it possible, by presetting at the start of the crossing of the threads, to maintain constant and minimize the crowd depth and the tension binding threads and thus make a weaving operation possible

  effective with obtaining a very good quality fabric.

  As is well known, the operation of looms> in which weft threads are inserted into the opening of the shed by two insertion tweezers, requires that each inserted weft thread be cut at the two lateral edges of the fabric during weaving For this reason, the weft threads are not adequately connected to the warp threads at the location of the side edges of the fabric which, therefore, have a tendency to fray or taper . To overcome this drawback, various types of tying have been adopted on the side edges of the fabric, the most common being full-turn gauze tying which uses four

  additional binder yarns to be suitably intertwined

  with each weft thread inserted For more details, two pairs of tying threads are moved alternately and opposite on a vertical plane, in the same way as what

  is made for the warp threads, in order to surround alterna-

  on the opposite sides the inserted weft threads and, in addition, the tying threads of one or the other of said pairs of threads are also moved in a horizontal plane in order to cross each other and to mutually block the threads tying of the other pair The simultaneous movements of the two pairs of tying threads thus generate a very tight and reliable tying opposing the fraying of the lateral edges of said fabric. The prior art already provides devices,

  called SPLITZ, which are suitable for carrying out such binding.

  One of these conventional devices, which uses the vertical reciprocating movements of two neighboring heddle frames to effect the vertical displacement of the two pairs of tying threads concerned, is essentially composed of a frame mounted vertically on a heddle frame and provided with two identical needles arranged opposite one another and in the eyes or eyelets of which the two tying threads of one or the other pair of threads are threaded after crossing

  two input wire guides and appropriate deflection devices.

  Said frame then acts as a support member for a closure plate which can slide vertically along this frame and which is provided in its median section with two similar slots, inclined symmetrically with respect to the axis

  longitudinal of the closing plate and angularly offset

  rement of 90 relative to each other, and through the corresponding ends of which pass the two tying threads intended to cross said other pair of tying threads, these latter threads being driven in their vertical movement by two struts of the heald frame which is close to the heald frame to which said frame is fixed The slots of the closure plate are further arranged so that their ends are on opposite sides with respect to the thread-carrying needles located opposite one on the other and that comprises the frame, whereby the two tying threads which pass through the corresponding ends of said slots are always placed externally with respect to the two other tying threads, the latter passing, on the other hand, through the eye of said needles, so that these latter threads, once they have crossed, are in a

  position where they block the two other tying threads together.

  In addition, braking means are mounted on the frame, in cor-

  correspondence with the free region between the two eyes or eyelets of said thread-holding needles in order to delay the travel of the closure plate, thereby making it possible to cross the two tying threads which pass through the corresponding ends of the slots in the plate , when the

  plate is braked, the two aforementioned binding wires, which

  keep being pulled up or down by the

  correspondingly of the healds of the frame, are obliged to slip

  ser along the slots of the plate and they must therefore be brought to the other opposite ends of said slots so that the plate can continue its corresponding movement

  and this is precisely what leads the sons to cross each other-

  lement. However, this classic necessity presents a great

  number of disadvantages, the most important of which is essential

  due to the fact that the plate is negatively driven,

  that is, the movement of the plate along the frame is pro-

  voiced by the tension of the two tying threads which pass through the slots of the plate In reality, since the aforementioned tension must ensure correct operation of the device, it is very often greater than the tension of the warp threads themselves and can even reaching a high value to the point of causing serious difficulties in weaving, either as a result of breaks in the two tying threads stretched too severely, or due to the fact that too strong tying threads must be used, which therefore have a different quality from that of warp threads, which causes serious problems when dyeing or finishing

of a fabric thus produced.

  Another disadvantage of the conventional device is that notable differences appear in the opening of the crowd formed by the tying threads so that this opening cannot be kept constant with, as a consequence, difficulties in adjustment and a great risk. breakage of the wires by the insertion tweezers intended to penetrate said shed opening, this latter defect being able to be overcome only by having recourse to a large shed opening, but this then results in an elongation of the path of the threads tying so that their tension is increased and, consequently, the weaving difficulties mentioned above increase more and more. Indeed, the difference in tension between the two tying threads passing through the slots of the p Nque acts on the plate together with the frictional force opposing the sliding movement and braking of the plate itself and, because this latter force varies

  over time as a result of dust and other impurities

  always found in weaving workshops, it is necessary to stop the plate at different points of its vertical stroke, which gives rise to different widths of openings

crowd.

  Yet another drawback is due to the fact that the crossing of the two binding threads which cross the corresponding ends of the plate takes place in correspondence with the free region comprised between the two eyes of the needles of the frame.

  and, therefore, said free zone, that is to say the interval

  the between the needles, must be wide enough to allow efficient crossing and this imposes a shed opening for the tying thread which is larger than that for the warp threads with the unfortunate consequences already mentioned.

  The object of the present invention is to alleviate the inconveniences

  vénients mentioned above and thereby provide a device for bonding, by a full turn gauze, the side edges

  of a fabric, i.e. a SPLITZ device, capable of

  positively tra iner the plate whatever the tension of the tying threads, to maintain constant the width of the crowd opening formed by the tying threads, and to reduce to a minimum the distance between the eye of the needles of the frame (interval between the needles), and therefore also to reduce the crowd opening width as much as possible, by presetting

  at the very entrance of the heald frame switch the cross

  ment of the two tying wires which pass through the slots of the plate. Essentially, this is achieved by making the vertical displacement of the plate along the frame

  results from the action of a second control plate having sensi-

  the outline of a U-shaped (or C-shaped) profile which, articulated to the heald frame adjacent to the heald frame, carries the frame by means of a link and consequently driven vertically by this neighboring heald frame while being supported vertically in a sliding manner by said frame, drives with itself said second plate by the action of the wings of its U-shaped profile (or C) on the end edges of this plate In this way, we actually obtain double result (a) of making the movement of the plate independent of the tension of the tying threads so that one can then reduce this tension to the value which is best suited to avoid weaving troubles and (b) to keep constant the opening of the crowd formed by the tying threads since the opening of the crowd is now defined mechanically by the constant back and forth movement of the heddle frames and not

  not by the tension of the tying threads.

  On the other hand, to preset the crossing of the two tying threads which pass through the center of the plate, said second control plate in the form of a U-shaped profile (or a "C" profile) is provided in its middle part with two slots which are the exact counterparts of those of the closure plate mentioned first but are inversely inclined with respect to these, and the same two tying threads which pass through the slots of the first plate also pass through said slots of the second plate, said second plate being dimensioned such that the distance between its wings is equal to the distance from the first plate increased by twice the height of each of the two aforementioned inclined slots, while that the first plate is provided with a braking spring which, by pushing said frame, prevents by friction said first

  plate to slide freely along this frame.

  Consequently, as will be explained in more detail below, when the heddle frames move

  so as to swap their position, the second plate of com

  mande with C profile starts to drive the other plate, braked by a spring, only when one or the other

  wings of the latter came to push the corresponding edge

  laying of the other plate, that is to say after the other plate has been moved vertically for a distance equal to twice the height of the slot During this first movement, the slots of the second control plate at C profile are found,

  however, coincident with the zones, continuously varying-

  homologous slots which are inversely inclined and which has the associated plate, which is braked and then stops, and, at the end of said movement, said corres-

  coincidence pondering is just transferred from one of the

  slot mites at the other slot end of said braked plate As a result, the two tying threads passing through the slots of the two plates are therefore forced to pass from one of the ends to the other of the other plate, that is to say that they cross, but the crossing is prevented by the presence of one or the other of the needles of the frame Both

  son of Ulage mentioned above are therefore prepared for the cross

  but the crossing actually takes place immediately and within a very narrow space as soon as the deflection action of said needles is completed, the needle concerned being that along which the threads prepared for the crossing must circulate, that is to say towards the end of the needle concerned This fact, of course, makes it possible to reduce to a minimum the interval between the two eyes facing the two opposite needles that the frame comprises, so that 'a

  crowd opening with a narrow width is thus obtained -

  In summary, the device for bonding with a gauze full turn of the lateral edges of a fabric in a loom comprises a frame which, mounted vertically on a heald frame of said loom and comprising two similar needles arranged opposite one from the other and through the eyes of which pass two tying threads, supports on its front face a plate which can slide vertically along this frame and which is provided, in its median section, with two similar inclined slots symmetrically with respect to the horizontal axis of the plate and offset by 900 angularly with respect to each other, two other tying threads passing through the corresponding ends of these slots situated on either side of said needles arranged facing each other and that includes the frame, the aforementioned device being characterized in that said frame supports on its rear face and in a position located opposite said plate and at a distance from this a second control plate being substantially in the form of a

  profiled, this second plate can also slide vertically

  securely along this frame, said control plate, articulated

  abutment by a rod to the heald frame adjacent to the heald frame supporting said frame, acts with the wings of its C-profile alternately on the upper and lower end edges of said first plate which, enclosed between said wings of said second plate control, is provided with a braking spring pushing said frame, said second control plate being provided in its median part with two quite similar slots which are inclined inversely with respect to the slots of the plate mentioned in

  first, the two aforementioned additional binding threads

  pouring said slots of the control plate, the latter having dimensions such that the distance between its two wings is equal to the length of the first plate plus twice

  the height of each of said inclined slots.

  Finally, in a preferred embodiment of the present invention, said second control plate is formed by a rectangular block of rigid plastic material in the middle region of which said slots are formed and at the upper and lower ends of which two metal bars L-shaped profile forming said plate wings are fixed, said block comprising on its lateral edges two vertical grooves in which are inserted two guide shoulders

  vertical serving to guide the rear face of said frame.

  The present invention will now be explained in more detail with reference to the accompanying drawings, in which: FIG. 1 is a front view of the binding device according to the present invention, this view schematically shows the full-turn gauze binding carried out on the edges of a fabric by means of the four threads of Jiage which are represented by different lines; Figure 2 is a side view, partially in section, of the tying device shown in Figure 1;

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  Figure 3 is a front view of the second control plate of the device shown in Figure 1; Figure 4 is a side view of the control plate of Figure 3; Figure 5 is an enlarged front view of the detail of Figure 1 between the lines A-A; Figure 6 shows the same detail as in Figure 5 at a later stage of operation; and Figure 7 is a front view similar to that of Figure 1 but with the heddle frames in an offset position

  relative to their position in Figure 1.

  Referring now to the drawings, it can be seen that the references 1 and 2 indicate, respectively, the two sets of warp threads which, entrained vertically in a conventional manner by the heald frames (not shown in the drawings) intertwine with the weft threads 3 to form a fabric 4 whose fraying of the lateral edge is prevented by a

  connection 5 by full-turn gauze, made using a

  positive binding, or SPLITZ, with four additional binding wires

  referenced 6,7,8 and 9 on the drawings, with different

  annuity tracing lines for purposes of distinction.

  The binding device, or SPLITZ, in question is composed of a frame or support 10 which essentially consists of two U or C sections, 11 and 12, respectively; these sections arranged vertically and facing each other, are assembled, their base being in contact with each other, by means of two metal blocks, 13 and 14 which are fixed respectively by screws 15 to the ends of the C-sections. In addition, the two metal blocks 13 and 14 are fixed by screws 16 to a heald frame 17 of the loom so that the frame 10 is mounted vertically on said heald frame Through the shoulders 12 'and 12 "from the profile 12, in correspondence with the median section of the latter, two entry holes 18 and 19 have been formed through which the additional bonding wires 6 and 7 pass. These wires, arriving from coils of appropriate feeds, then wrap around deflection grooves, 20 and 21, formed in the metal blocks 13 and 14, then pass, respectively, through the eyes, 22 and 33, facing each other, of two identical needles, 24 and 25, the latter being supported, opposite

  one from the other, by the metal blocks 13 and 14, respectively

  tively. The edges of the two front and facing vertical shoulders, 11 'and 12', respectively, of the two sections 11 and 12, act as vertical guides with respect to a plate 26 comprising, for this purpose, on its sides lateral, two vertical grooves 27 (only one of which is shown in FIG. 2, the other being in an opposite position) in which said edges are inserted The plate 26 comprises,

  in correspondence with its middle section, two identical slots

  ticks, 28 and 29, these slots, as can best be seen in FIG. 5, being inclined symmetrically with respect to the longitudinal axis 30 of the plate concerned and being spaced angularly from each other by approximately 90 being positioned so that their corresponding ends 28 ', 29' and 28 ", 29", respectively, are on opposite sides with respect to the needles 24 and 25 of the frame 10 The two additional binding threads 8 and 9, which also arrive from suitable supply coils, are led to pass through the slots 28 and 29 In addition, to the front face of the plate 26, is fixed, by means of rivets 31, a metal spring leaf 32 which constitutes a flat braking spring 33 pushing the front shoulder 11 ′ of section 11 of the frame 10 so that, as a result of friction, the plate 26 cannot slide freely along the above-mentioned frame 10 The edges of the two rear shoulders 11 "and 12" arranged opposite one another and that comprise the sections 11 and 12, respectively, (in FIG. 2, we can only see the shoulder 12 "because the other is in an opposite position and does not appear in the figure due to the representation in cut), act on the other hand, like a vertical guide with respect to a second

  plate 34 which is a control plate.

  The control plate 34 is in the form of a rectangular block 35 (which can best be seen in FIGS. 3 and 4) made of rigid plastic, in the lateral edges of which two vertical slots 36 have been formed (one of which only one appears on figures 2 and 4, the other being on the

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  opposite side) into which the edges of the vertical shoulders 11 "and 12" are inserted. In correspondence with the middle section of the block 35, two slots 37 and 38 are then formed; these slots are quite similar to each other, but their slope is directed in an opposite direction with respect to that of the corresponding slots 28 and 29 of the plate 26 (see on this subject Figures 5 and 6); the two tying threads

  additional 8 and 9 therefore also pass through the

  third slots 37 and 38 At the upper and lower ends of the block 35 are also fixed respectively, using screws 39, two metal bars 40 and 41 with an L-shaped profile, the projecting wings 40 'and 41' of which are brought to cooperate, respectively, both with the upper edge 42 and the lower edge 43 of the plate 26 (see FIG. 2) which is enclosed between said wings Finally, the block 35, the length of which

  is chosen so that the distance between the wings

  lantes 40 'and 41' is equal to the length of the plate 26 increased by twice the height of each of the two inclined slots 28,29, 37 and 38, that is to say increased in fact by the length referenced h in Figure 5, is articulated, by the axis 44, at the end of a link 45 whose other end is articulated, by an axis 46, to a lug 47; this tab is fixed by screws 48 to the heald frame 49 which is adjacent to the heald frame 17 supporting the frame 10 Thanks to such a constructive arrangement, the second control plate 34 is driven vertically along the frame 10 directly by the movement vertical alternative of the frame to

smooth 49.

  The operation of such a device can now

be understood immediately.

  When the two heald frames, 17 and 49, reach the open position shown in FIGS. 1 and 2, this position corresponding to the top dead center of the heald frame 49 and to the bottom dead center of the heald frame 17, the plate 26 has been moved upwards along the frame 10 by the action of the second control plate 34; this plate, because it is driven by the heald frame 49, acts on the

  lower edge 43 of the plate 26 by means of its lower wing

41 'lower.

  In said position, the two plates 26 and 34 take

  nent therefore the arrangement that appears best in Figure 5 and the two additional binding son, 8 and 9, which must

  be crossed one above the other, are advanced, respec-

  tively, through the corresponding lower ends of the slots 37 and 38 of the plate 34 as well as through the corresponding upper ends, 28 'and 29', of the slots 28 and 29 of the plate 26, so that these wires 8 and 9 se

  found on either side of the needle 24 of the frame 10.

  When the above-mentioned heald frames 17 and 49 begin to reverse their position, the control plate 34 begins to descend along the frame 10 under the driving force of the associated heald frame 49, but the Dlaaue 26, braked by the spring 33, remains fixed until its upper edge 42 comes into contact with the upper wing 40 'of the control plate 34, that is to say until the time when the plate 34 has moved towards the bottom over a distance h However, while this movement h of the plate 34 takes place, the slots 37 and 38 (which can be better seen in FIG. 5) of this

  plate move downward relative to the cor-

  28 and 29 of the fixed plate 26 and coincide with the latter slots at points which are offset from the upper ends, 28 'and 29', to the lower ends, 28 "and 29", from the slots, 28 and 29, of the plate 26 and, finally, at the end of the stroke h, the slots of the two plates 26 and 34 are in a face to face position just in correspondence with the lower ends

  28 "and 29" of the slots 29 of the fixed plate 26.

  It therefore follows, that the two son of binding 8 and 9

  are forced to pass, respectively, from the upper ends

  laughing, 28 'and 29', at the lower ends, 28 "and 29", of the slots 28 and 29 of the plate 26 and are therefore forced to cross, but the crossing is actually prevented by the presence of the needle 24 , as can best be seen in FIG. 6 which shows how the thread 8 arriving from above, is forced to pass around the needle 24, this also being valid for the thread 9 arriving from below In summary, when the plate command 34 starts to lead towards the

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  bottom plate 26, the situation is that shown in FIG. 6, the binding wires 8 and 9 already being ready to cross; the crossing takes place immediately and in a minimal space when the deflection action of the needle 24 is finished, the tying threads being forced to slide along the needle, that is to say that the crossing has place when the plate 26, in its downward stroke, reaches the eye 22 of the needle 24 and therefore crosses the region which extends between the eyes 22 and 23 of the two needles 24 and 25 of the frame 10, after what the two plates 26 and 34 continue to move down until they reach

  the final position shown in Figure 7.

  At this stage, as soon as the heald frames, 17 and 49, begin to reverse their mutual position to resume the initial opening position, the control plate 34

  begins to move upward and prepares another condi-

  crossover for tying threads 8 and 9, the cycle

  described in the foregoing description thus repeating itself again.

Claims (2)

  1 Device for forming a selvedge of the "full turn gauze" type on the lateral edges of a fabric in a loom comprising a support which, mounted vertically on a heald frame of said loom and comprising two identical needles placed face face and through the eyes or eyelets of which pass two tying threads, supports on its front face, a plate which can slide vertically   along this face, this plate comprising, in corres-   pondance with its midpoint, two similar symmetrical slits   three times inclined with respect to the horizontal axis of the plate and offset angularly by 900 with respect to each other, two other tying threads passing through the corresponding ends of these slots situated on the opposite sides with respect to said facing needles one of the other that comprises the frame, characterized in that said frame supports on its rear face and in a position located opposite and at a distance from said plate, a second control plate having substantially the shape of a profiled and also capable of sliding vertically along said frame, said control plate articulated by a rod to the heald frame adjacent to the heald frame supporting said frame, acts with the wings of its C profile alternately on the upper end edges and lower of said first plate which, enclosed between said wings of said second control plate, is provided with a braking spring pushing said frame, said second control plate of being provided in its middle part with two exactly similar slots which are inclined in reverse with respect to the slots of the plate mentioned first, the two aforementioned additional tying threads passing through said slots of the control plate, the latter being proportional to such that the distance between its two wings is equal to the length of the first plate increased by twice the height of each said inclined slots.   2 Device according to claim 1, characterized in that said second profile control plate   in C is formed by a rectangular block of a plas-   rigid tick, in the middle region of which the   said slots and at the upper and lower ends of which are fixed two metal bars with an L-profile forming said wings, said block comprising on its lateral edges two vertical grooves in which are inserted two vertical guide shoulders intended to guide the face rear of said frame.