LOOM AND WOVEN TAPE MADE THEREFROM
United States Patent 3674058
A loom having weft insertion means in the form of three pivotally mounted arcuate members which lay loops of weft in a weft shed, and also having selvedge knitting means reciprocable alongside the warp shed. Two of the arcuate inserting members lay loops of weft in a split shed which is used for producing body tape and the third arcuate inserter is used for laying weft in a shed created for the production of pockets on the body tape. The two wefts laid in the body are brought together at an edge remote from insertion for the knitting therethrough of a catch thread to form a knitting selvedge, while the pocket weft loops are themselves knitting together to form interdigitated loops with or without a catch thread.
US Patent References:
CURTAIN HEADING TAPE
Griffiths et al. - September 1970 - 3529634
Weft yarn tying device for needle looms
Muller - November 1968 - 3411549
Double fabric
Bunger - August 1966 - 3266529
Header-tape
Klahre - September 1959 - 2904080
Loom attachment for weaving ladder webbing
Murdock et al. - May 1949 - 2469202
CURTAIN HEADING TAPE
Griffiths et al. - September 1970 - 3529634
Weft yarn tying device for needle looms
Muller - November 1968 - 3411549
Double fabric
Bunger - August 1966 - 3266529
Header-tape
Klahre - September 1959 - 2904080
Loom attachment for weaving ladder webbing
Murdock et al. - May 1949 - 2469202
Application Number:
05/107401
Publication Date:
07/04/1972
Filing Date:
01/18/1971
Export Citation:
Primary Class:
Other Classes:
139/20, 139/387A
International Classes:
D03D1/06; D03D35/00; D03C13/00; D03D47/00
Field of Search:
139/124A,124R,387A,387R,384R,20,22
View Patent Images:
US Patent References:
| 1697155 | Multiple shed loom | January 1929 | Zulueta |
Other References:
1,910,104 9-1970 German Application (Guth).
Primary Examiner:
Kee Chi, James
Claims:
I claim
1. A loom comprising
2. The loom according to claim 1 wherein said second means includes two needles, one of said needles being adapted to receive a catch thread from a thread guide and the other of said needles being adapted to knit loops thereof, one through the other to bind directly loops of weft laid in the shed of said body tape.
3. The loom according to claim 1 wherein said first means includes a deflector element mounted on said slide means.
4. The loom according to claim 1 wherein one of said two weft inserters is adapted to lay loops of weft in the upper shed and the other of said two weft inserters being adapted to lay loops of weft in the lower shed.
5. The loom according to claim 1 wherein one of said body weft yarns comprises a relatively stiff yarn of synthetic plastic material.
6. The loom according to claim 5 wherein said stiff yarn is in the form of a monofilament.
1. A loom comprising
2. The loom according to claim 1 wherein said second means includes two needles, one of said needles being adapted to receive a catch thread from a thread guide and the other of said needles being adapted to knit loops thereof, one through the other to bind directly loops of weft laid in the shed of said body tape.
3. The loom according to claim 1 wherein said first means includes a deflector element mounted on said slide means.
4. The loom according to claim 1 wherein one of said two weft inserters is adapted to lay loops of weft in the upper shed and the other of said two weft inserters being adapted to lay loops of weft in the lower shed.
5. The loom according to claim 1 wherein one of said body weft yarns comprises a relatively stiff yarn of synthetic plastic material.
6. The loom according to claim 5 wherein said stiff yarn is in the form of a monofilament.
Description:
This invention concerns curtain heading tapes and in particular the production of such tapes in a loom having weft insertion means other than a shuttle or shuttles.
In one form of curtain heading tape it is known to introduce a monofilament weft to give lateral stiffness and pleating control. An example of a curtain heading tape is the subject of our prior British Pat. No. 919 378.
One of the problems with a curtain heading tape including a monofilament weft is the lateral instability of the weave due to the "slippery" nature of the monofilament weft whereby any lateral stress applied to the surface of the tape can easily cause the warp yarns to be parted to expose a grid of the monofilament weft picks. Such problems can be reduced by packing the warp yarns closer together but this has other disadvantages such as stiffening the tape longitudinally and increasing the weight and cost of the tape.
Not only does the packing of the warp yarns increase the longitudinal stiffness and cost of the tape but also it makes the tape more difficult to pleat than is normally acceptable, particularly in the case in which the tape is to be used commercially in the production of custom made or ready to hang curtains.
While it has been possible in some instances to produce an initially laterally stable tape not using synthetic yarn it has been found that the tape will lose its stiffness if it is subjected to washing or cleaning, and thus such tapes have not been generally acceptable.
Attempts have been made to achieve stiffness by the use of relatively wide tapes in combination with long pronged suspension hooks and while pleasing effects can be obtained the disadvantages of such a system of obtaining stiffness are many. For example, long pronged hooks are expensive to produce and thus use, and also they are difficult to use properly and to obtain pleasing effects they have to be very carefully spaced apart to avoid the possibility of uneven pleating effects occuring.
The overall effect of the disadvantage of using non stiffened tapes are such therefore that curtain manufacturers and users have avoided the use of such tapes and a demand has thus arisen for a laterally stable tape which is easy to use, can be used with short prong hooks and will not be so stiff as to cause jamming of the tape between a suspension rail and a runner or glider.
While it is possible to produce a curtain heading tape which overcomes the problems that have existed using a loom employing shuttles it is now the object of the present invention to produce a curtain heading tape using a loom having weft inserting means other than shuttles since it is thought that production rates can be increased substantially by the use of such a loom.
According to the present invention there is provided a loom having weft insertion means in the form of pivotally mounted arcuate members adapted to enter and leave a weft shed to lay loops of weft therein and selvedge knitting means reciprocable alongside the warp shed characterized in that there are provided three such weft inserters two of which are adapted to lay loops of weft in a split shed used for producing a body tape and the third for laying weft in a shed created for the production of pockets on said body tape, the two wefts laid in the body being brought together at the edge remote from insertion for the knitting therethrough of a catch thread to form a knitted selvedge while the pocket weft loops are themselves knitted together to form interdigitated loops with or without a catch thread.
Conveniently at least one of the weft threads inserted for the body tape is deflected in a vertical plane in the selvedge region of the warp to ensure the laying of the two loops in close proximity whereby a selvedge knitting catch thread may be looped around the warp threads simultaneously thus to bind both sets of weft loops together.
Preferably, in the curtain heading tape being woven one of the body weft yarns is a relatively stiff yarn composed of, or including, synthetic plastic's material.
The invention will now be described further, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 is a cross section through the weft of a fabric showing one repeat of pattern;
FIGS. 2 to 5 show diagrammatically the various steps of shedding these warp yarns which produce a body part of the fabric;
FIG. 6 is a detail view of part of a mechanism used in a loom to insert weft threads into a warp shed;
FIG. 7 is an underneath view of the mechanism of FIG. 6;
FIG. 8 is a perspective front view of a fabric produced by the carrying out of the invention, and
FIG. 9 is a view similar to FIG. 1 of an alternative form of weaving, in this case only part of one pattern repeat is shown.
A curtain heading tape made in accordance with this invention and illustrated in FIG. 8 consists of a body part B on one side of which is superimposed a narrower tape C bound to the body part B by warps of the narrower tape being shed with the body warps, to form, by such periodic binding of the warp of the narrower tape C to the body B, a series of pockets into some of which may be inserted curtain hooks or rings. The tape also has pleating cords P which are symmetrically arranged so that, when drawn, they both induce the same pleating formation in the body B of the tape. The pleat formation shown in FIG. 8 is not of course the only one which can be produced. Variation of such pleat formation is possible by alteration of the position of the pleating cords and pleating hooks.
The tape is woven, as can best be seen from FIGS. 1 to 5, using two spun wefts and a monofilament weft. As can best be seen from FIG. 2 one of the spun wefts 10 is used only in conjunction with the warp yarns 11 and 12 of the narrower tape C and the other spun weft 13 is used with the monofilament weft 14 to weave the body B of the tape. The warp yarns 15, 16, 17 and 18 for the body B and the warp yarns 11 and 12 of the narrower tape C and the pleating cords P are shed using a loom equipped with seven shafts. This loom is of the kind in which weft is inserted by means of a sickle and thus each insertion and retraction of the sickle will form a loop of yarn in the shed hence each pick is shown by two dots on the drawing.
The shafts for the warp yarns and the pleating cords are arranged as follows:
No. 1 shaft for carrying the pleating cords P.
Nos. 2 and 3 shafts for carrying respectively the warp threads 11 and 12 for the narrow tape C used to form the pockets.
Nos. 4, 5, 6, and 7 shafts for carrying respectively the warp threads 15, 16, 17 and 18 for the body tape B.
For the sake of convenience the manner in which the body of the tape is woven will be described initially (with reference to FIG. 1 to 5) without reference to the manner in which the narrower, pocket forming warp yarns are woven and initially no reference will be made to the formation of the selvedge. To weave the body of the fabric the spun weft 13 and the relatively stiff weft 14 are used. Each of these wefts 13 and 14 is inserted into a warp shed by means of a weft inserting sickle 19 and 20 (see FIG. 6) which pivots about a vertically disposed pivot 21 to lay a loop of weft. The spun weft 13 is inserted by the sickle 20 and the other weft 14 by the sickle 19. The two sickles 19, 20 used are moved simultaneously and in order to trap the relatively stiff weft 14 (particularly if it is a monofilament weft having a slippery surface) a split shed is used as can be seen from FIGS. 2 to 5. The spun weft 13 is inserted into the upper part of the split shed and the other weft 14 into the lower part. The shed changes are such as to ensure that the warp yarns 15, 16, 17 and 18 of each part of the split shed are interchanged and in order to achieve this in one practical manner shafts 4 to 7 may be shed as follows assuming that a cycle of shedding that commences with shaft 5 in an upper shed position.
That portion of the total number of warp yarns controlled by shaft 5, that is yarns 16, is uppermost whilst the warp yarns 17 and 18 of shafts 6 and 7 are in the lowermost shed position with the warp yarns 15 of the shaft 4 in the mid position. The relatively stiff weft 14 is inserted in the lower shed so formed and the spun yarn 13 is inserted into the upper shed.
The first shed change after insertion of the weft causes the shafts to become positioned such that shafts 6 and 7 remain in the lower shed position and shafts 4 and 5 are reversed so as to be located respectively in the upper and middle shed position. Weft loops of yarns 13 and 14 are now inserted in the two parts of the shed.
The next shed change causes the shafts to become positioned such that shafts 4 and 5 are in the lower shed position shaft 7 is in the middle position and shaft 6 is in the upper shed position. Weft loops 13 and 14 are again inserted in the two parts of the shed.
The next shed change reverses the positions of shafts 6 and 7 and shafts 4 and 5 remain in the lower shed position. Weft is inserted in the two parts of the shed.
The next shed change occurs and the shafts return to their original positions with shaft 5 in the upper shed position and the cycle repeats continuously.
Referring now to the formation of the selvedge for the body fabric it will be appreciated that loops of weft are inserted by each of the two sickles 19, 20. Contrary to normal, practice, and in the interests of producing a non bulky selvedge, these loops are not looped one through the other but are laid close together one above the other by causing the weft 13 of the upper sickle to be deflected downwardly after it has passed through the shed. The wefts 13 and 14, at the instant of time at which the sickles 19 and 20 are fully inserted in their respective sheds are thus located in close proximity and at this time a catch thread 22 (see FIGS. 2 to 5) supplied in the warp-wise direction alongside the fell of the fabric is positioned such that it can be entrained in the hook of a latch needle 23 which reciprocates alongside the edge of the fabric. When the catch thread 22 is caught by the hook of the latch needle 23 the latter is retracted to lay the catch thread 22 across the two wefts 13, 14. As this takes place the sickles 19, 20 retract and thus the catch thread 22 is contained within loops of weft 13, 14 now formed. On the next forward movement of the latch needle 23 the catch thread in the hook passes onto the shank of the needle thus opening the latch which now enables the hook to entrain a further loop of the catch thread 22 which is located in the two weft loops. Upon retraction of the latch needle 23 the loop in the hook is drawn through the loop which slips off the shank (closing the latch to prevent it becoming caught by the hook) and a knitted stitch is produced. This cycle of operations continues in synchronism with the movements of the weft inserting sickles 19, 20 to produce a knitted edge binding the two wefts 13, 14 together. Since only the catch thread 22 is knitted the selvedge is not of bulky appearance.
FIGS. 6 and 7 illustrate the sickle arrangement used to carry out the operating cycle described above. As shown in FIGS. 6 and 7 the sickles 19 and 20 are mounted on a common control arm 24 together with a sickle 25 which is used to insert weft 10 into the shed of warp yarns 11 and 12 of narrow tape C. The control arm 24 is mounted upon a carrier plate 26 formed at its end remote from the arm 24 with a toothed segment 27 through which passes the pivot 21 about which the sickles move in their arcuate path. Also carried by the pivot 21 is a cam element 28 (see FIG. 7) and this is arranged to move in synchronism with the segment 27 for a purpose to be explained below.
Movement of the segment 27 and thus the sickles and cam element is controlled from the loom main drive via a linkage system (not shown) and a first reciprocable shaft 29 upon which is mounted a gear segment 30 meshing with the segment 27.
The cam element 28 has in abutment therewith a follower 31 mounted on a shaft 32 carried in brackets 33 formed on the underside of a carrier plate 34 mounted on the loom frame (not shown). The shaft 32 is spring loaded (by spring 35) to ensure that the follower 31 remains in contact with the cam 28. Mounted on the free end of the shaft 32 is a catch thread guide 36 which is adapted, by virtue of the movement imparted to it by the shaft 32, to reciprocate in a vertical arc in such manner as to cause, in use, the catch thread 22 to be laid in the hook of latch needle 23.
The latch needle 23 is mounted in a slide element 37 which also carries a second latch needle 23a reciprocable in a horizontal plane in a fore and aft direction relative to the loom healds. To control this movement there is provided a second shaft 38 driven from the loom main drive and this shaft has mounted thereon one link 39 of a parallel link arrangement. The other end of the link 39 is pivotally secured to the slide element 37. A second link 40 of the system is pivotally mounted on a bracket 41 of the carrier plate 34 and on the slide element 37.
Mounted above the slide element 37 is a plate 42 in which are mounted two weft deflectors 43 and 44. The deflector 44 is arranged to deflect the weft 14 of sickle 20 downwardly into close proximity with the weft 13 of sickle 19 when the sickles approach the extent of their travel through the shed so that the catch thread 22 laid in the hook of needle 23 can be looped by the two wefts 13 and 14 as described above. The other deflector 43 serves, as will be explained below, to deflect the weft 10 of the narrow tape C onto the latch needle 23a to enable loops of this weft to be knitted one through the other as is usual in the formation of a selvedge in a needle loom.
During the weaving of the body B the pocket forming narrower tape C is also woven and this is achieved by shedding the shafts 2 and 3 alternately into the top shed position to produce a separate shed (when the pockets are being woven).
The third sickle 25 inserts loops of spun yarn weft 10 into the shed formed by the warps 11 and 12 of shafts 2 and 3 and the loops of weft so formed are passed one through the other to form a knitted selvedge by the latch needle 23a which reciprocates alongside the warp shed. In this case no catch thread is used and the latch needle 23a collects the loops of weft in its hook and loops one through the other in known manner.
In the spaces between the pockets formed by the narrower tape C the warp yarns 11 and 12 forming this tape are shed with body warp threads 15, 16, 17 and 18 to be woven with the spun yarn weft 13 of the body tape B. The shafts 2 and 3 thus become shed with these shafts 4, 5, 6 and 7 which are at any instant in the cycle in the upper and middle shed positions so that the stiff weft 14 is woven throughout the tape always in the bottom part of the split shed of the body B.
Shaft 1 is shed to cause draw cords P to be inserted into the body tape B at the requisite intervals.
The tape so produced is capable of being woven relatively rapidly and it has the property of being relatively stiff in the weftwise direction.
Referring now to FIG. 9, upon which reference numerals identical to those of FIG. 1 have been used it will be seen that it is possible to weave the body fabric B in a manner different to that disclosed above. In this case it is seen that shaft 5 moves from an upper shed position to a middle shed position and then to a lower shed position and back to a middleshed position while shaft 4 moves from a middle shed position to an upper shed position and then back to a middle shed position and from there to a lower shed position. During these four picks shaft 6 moves from a middle shed position to a lower shed position, then back to a middle shed position and then an upper shed position while shaft 7 moves from a lower shed position to a middle shed position, then an upper shed position and back to a middle shed position. This shed change cycle repeats continuously as the fabric B is being woven. In contradistinction to the previously described weaving operation it will be seen that the stiff weft 14 is woven at every double pick into the fabric as opposed to ever alternate double pick.
In one form of curtain heading tape it is known to introduce a monofilament weft to give lateral stiffness and pleating control. An example of a curtain heading tape is the subject of our prior British Pat. No. 919 378.
One of the problems with a curtain heading tape including a monofilament weft is the lateral instability of the weave due to the "slippery" nature of the monofilament weft whereby any lateral stress applied to the surface of the tape can easily cause the warp yarns to be parted to expose a grid of the monofilament weft picks. Such problems can be reduced by packing the warp yarns closer together but this has other disadvantages such as stiffening the tape longitudinally and increasing the weight and cost of the tape.
Not only does the packing of the warp yarns increase the longitudinal stiffness and cost of the tape but also it makes the tape more difficult to pleat than is normally acceptable, particularly in the case in which the tape is to be used commercially in the production of custom made or ready to hang curtains.
While it has been possible in some instances to produce an initially laterally stable tape not using synthetic yarn it has been found that the tape will lose its stiffness if it is subjected to washing or cleaning, and thus such tapes have not been generally acceptable.
Attempts have been made to achieve stiffness by the use of relatively wide tapes in combination with long pronged suspension hooks and while pleasing effects can be obtained the disadvantages of such a system of obtaining stiffness are many. For example, long pronged hooks are expensive to produce and thus use, and also they are difficult to use properly and to obtain pleasing effects they have to be very carefully spaced apart to avoid the possibility of uneven pleating effects occuring.
The overall effect of the disadvantage of using non stiffened tapes are such therefore that curtain manufacturers and users have avoided the use of such tapes and a demand has thus arisen for a laterally stable tape which is easy to use, can be used with short prong hooks and will not be so stiff as to cause jamming of the tape between a suspension rail and a runner or glider.
While it is possible to produce a curtain heading tape which overcomes the problems that have existed using a loom employing shuttles it is now the object of the present invention to produce a curtain heading tape using a loom having weft inserting means other than shuttles since it is thought that production rates can be increased substantially by the use of such a loom.
According to the present invention there is provided a loom having weft insertion means in the form of pivotally mounted arcuate members adapted to enter and leave a weft shed to lay loops of weft therein and selvedge knitting means reciprocable alongside the warp shed characterized in that there are provided three such weft inserters two of which are adapted to lay loops of weft in a split shed used for producing a body tape and the third for laying weft in a shed created for the production of pockets on said body tape, the two wefts laid in the body being brought together at the edge remote from insertion for the knitting therethrough of a catch thread to form a knitted selvedge while the pocket weft loops are themselves knitted together to form interdigitated loops with or without a catch thread.
Conveniently at least one of the weft threads inserted for the body tape is deflected in a vertical plane in the selvedge region of the warp to ensure the laying of the two loops in close proximity whereby a selvedge knitting catch thread may be looped around the warp threads simultaneously thus to bind both sets of weft loops together.
Preferably, in the curtain heading tape being woven one of the body weft yarns is a relatively stiff yarn composed of, or including, synthetic plastic's material.
The invention will now be described further, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 is a cross section through the weft of a fabric showing one repeat of pattern;
FIGS. 2 to 5 show diagrammatically the various steps of shedding these warp yarns which produce a body part of the fabric;
FIG. 6 is a detail view of part of a mechanism used in a loom to insert weft threads into a warp shed;
FIG. 7 is an underneath view of the mechanism of FIG. 6;
FIG. 8 is a perspective front view of a fabric produced by the carrying out of the invention, and
FIG. 9 is a view similar to FIG. 1 of an alternative form of weaving, in this case only part of one pattern repeat is shown.
A curtain heading tape made in accordance with this invention and illustrated in FIG. 8 consists of a body part B on one side of which is superimposed a narrower tape C bound to the body part B by warps of the narrower tape being shed with the body warps, to form, by such periodic binding of the warp of the narrower tape C to the body B, a series of pockets into some of which may be inserted curtain hooks or rings. The tape also has pleating cords P which are symmetrically arranged so that, when drawn, they both induce the same pleating formation in the body B of the tape. The pleat formation shown in FIG. 8 is not of course the only one which can be produced. Variation of such pleat formation is possible by alteration of the position of the pleating cords and pleating hooks.
The tape is woven, as can best be seen from FIGS. 1 to 5, using two spun wefts and a monofilament weft. As can best be seen from FIG. 2 one of the spun wefts 10 is used only in conjunction with the warp yarns 11 and 12 of the narrower tape C and the other spun weft 13 is used with the monofilament weft 14 to weave the body B of the tape. The warp yarns 15, 16, 17 and 18 for the body B and the warp yarns 11 and 12 of the narrower tape C and the pleating cords P are shed using a loom equipped with seven shafts. This loom is of the kind in which weft is inserted by means of a sickle and thus each insertion and retraction of the sickle will form a loop of yarn in the shed hence each pick is shown by two dots on the drawing.
The shafts for the warp yarns and the pleating cords are arranged as follows:
No. 1 shaft for carrying the pleating cords P.
Nos. 2 and 3 shafts for carrying respectively the warp threads 11 and 12 for the narrow tape C used to form the pockets.
Nos. 4, 5, 6, and 7 shafts for carrying respectively the warp threads 15, 16, 17 and 18 for the body tape B.
For the sake of convenience the manner in which the body of the tape is woven will be described initially (with reference to FIG. 1 to 5) without reference to the manner in which the narrower, pocket forming warp yarns are woven and initially no reference will be made to the formation of the selvedge. To weave the body of the fabric the spun weft 13 and the relatively stiff weft 14 are used. Each of these wefts 13 and 14 is inserted into a warp shed by means of a weft inserting sickle 19 and 20 (see FIG. 6) which pivots about a vertically disposed pivot 21 to lay a loop of weft. The spun weft 13 is inserted by the sickle 20 and the other weft 14 by the sickle 19. The two sickles 19, 20 used are moved simultaneously and in order to trap the relatively stiff weft 14 (particularly if it is a monofilament weft having a slippery surface) a split shed is used as can be seen from FIGS. 2 to 5. The spun weft 13 is inserted into the upper part of the split shed and the other weft 14 into the lower part. The shed changes are such as to ensure that the warp yarns 15, 16, 17 and 18 of each part of the split shed are interchanged and in order to achieve this in one practical manner shafts 4 to 7 may be shed as follows assuming that a cycle of shedding that commences with shaft 5 in an upper shed position.
That portion of the total number of warp yarns controlled by shaft 5, that is yarns 16, is uppermost whilst the warp yarns 17 and 18 of shafts 6 and 7 are in the lowermost shed position with the warp yarns 15 of the shaft 4 in the mid position. The relatively stiff weft 14 is inserted in the lower shed so formed and the spun yarn 13 is inserted into the upper shed.
The first shed change after insertion of the weft causes the shafts to become positioned such that shafts 6 and 7 remain in the lower shed position and shafts 4 and 5 are reversed so as to be located respectively in the upper and middle shed position. Weft loops of yarns 13 and 14 are now inserted in the two parts of the shed.
The next shed change causes the shafts to become positioned such that shafts 4 and 5 are in the lower shed position shaft 7 is in the middle position and shaft 6 is in the upper shed position. Weft loops 13 and 14 are again inserted in the two parts of the shed.
The next shed change reverses the positions of shafts 6 and 7 and shafts 4 and 5 remain in the lower shed position. Weft is inserted in the two parts of the shed.
The next shed change occurs and the shafts return to their original positions with shaft 5 in the upper shed position and the cycle repeats continuously.
Referring now to the formation of the selvedge for the body fabric it will be appreciated that loops of weft are inserted by each of the two sickles 19, 20. Contrary to normal, practice, and in the interests of producing a non bulky selvedge, these loops are not looped one through the other but are laid close together one above the other by causing the weft 13 of the upper sickle to be deflected downwardly after it has passed through the shed. The wefts 13 and 14, at the instant of time at which the sickles 19 and 20 are fully inserted in their respective sheds are thus located in close proximity and at this time a catch thread 22 (see FIGS. 2 to 5) supplied in the warp-wise direction alongside the fell of the fabric is positioned such that it can be entrained in the hook of a latch needle 23 which reciprocates alongside the edge of the fabric. When the catch thread 22 is caught by the hook of the latch needle 23 the latter is retracted to lay the catch thread 22 across the two wefts 13, 14. As this takes place the sickles 19, 20 retract and thus the catch thread 22 is contained within loops of weft 13, 14 now formed. On the next forward movement of the latch needle 23 the catch thread in the hook passes onto the shank of the needle thus opening the latch which now enables the hook to entrain a further loop of the catch thread 22 which is located in the two weft loops. Upon retraction of the latch needle 23 the loop in the hook is drawn through the loop which slips off the shank (closing the latch to prevent it becoming caught by the hook) and a knitted stitch is produced. This cycle of operations continues in synchronism with the movements of the weft inserting sickles 19, 20 to produce a knitted edge binding the two wefts 13, 14 together. Since only the catch thread 22 is knitted the selvedge is not of bulky appearance.
FIGS. 6 and 7 illustrate the sickle arrangement used to carry out the operating cycle described above. As shown in FIGS. 6 and 7 the sickles 19 and 20 are mounted on a common control arm 24 together with a sickle 25 which is used to insert weft 10 into the shed of warp yarns 11 and 12 of narrow tape C. The control arm 24 is mounted upon a carrier plate 26 formed at its end remote from the arm 24 with a toothed segment 27 through which passes the pivot 21 about which the sickles move in their arcuate path. Also carried by the pivot 21 is a cam element 28 (see FIG. 7) and this is arranged to move in synchronism with the segment 27 for a purpose to be explained below.
Movement of the segment 27 and thus the sickles and cam element is controlled from the loom main drive via a linkage system (not shown) and a first reciprocable shaft 29 upon which is mounted a gear segment 30 meshing with the segment 27.
The cam element 28 has in abutment therewith a follower 31 mounted on a shaft 32 carried in brackets 33 formed on the underside of a carrier plate 34 mounted on the loom frame (not shown). The shaft 32 is spring loaded (by spring 35) to ensure that the follower 31 remains in contact with the cam 28. Mounted on the free end of the shaft 32 is a catch thread guide 36 which is adapted, by virtue of the movement imparted to it by the shaft 32, to reciprocate in a vertical arc in such manner as to cause, in use, the catch thread 22 to be laid in the hook of latch needle 23.
The latch needle 23 is mounted in a slide element 37 which also carries a second latch needle 23a reciprocable in a horizontal plane in a fore and aft direction relative to the loom healds. To control this movement there is provided a second shaft 38 driven from the loom main drive and this shaft has mounted thereon one link 39 of a parallel link arrangement. The other end of the link 39 is pivotally secured to the slide element 37. A second link 40 of the system is pivotally mounted on a bracket 41 of the carrier plate 34 and on the slide element 37.
Mounted above the slide element 37 is a plate 42 in which are mounted two weft deflectors 43 and 44. The deflector 44 is arranged to deflect the weft 14 of sickle 20 downwardly into close proximity with the weft 13 of sickle 19 when the sickles approach the extent of their travel through the shed so that the catch thread 22 laid in the hook of needle 23 can be looped by the two wefts 13 and 14 as described above. The other deflector 43 serves, as will be explained below, to deflect the weft 10 of the narrow tape C onto the latch needle 23a to enable loops of this weft to be knitted one through the other as is usual in the formation of a selvedge in a needle loom.
During the weaving of the body B the pocket forming narrower tape C is also woven and this is achieved by shedding the shafts 2 and 3 alternately into the top shed position to produce a separate shed (when the pockets are being woven).
The third sickle 25 inserts loops of spun yarn weft 10 into the shed formed by the warps 11 and 12 of shafts 2 and 3 and the loops of weft so formed are passed one through the other to form a knitted selvedge by the latch needle 23a which reciprocates alongside the warp shed. In this case no catch thread is used and the latch needle 23a collects the loops of weft in its hook and loops one through the other in known manner.
In the spaces between the pockets formed by the narrower tape C the warp yarns 11 and 12 forming this tape are shed with body warp threads 15, 16, 17 and 18 to be woven with the spun yarn weft 13 of the body tape B. The shafts 2 and 3 thus become shed with these shafts 4, 5, 6 and 7 which are at any instant in the cycle in the upper and middle shed positions so that the stiff weft 14 is woven throughout the tape always in the bottom part of the split shed of the body B.
Shaft 1 is shed to cause draw cords P to be inserted into the body tape B at the requisite intervals.
The tape so produced is capable of being woven relatively rapidly and it has the property of being relatively stiff in the weftwise direction.
Referring now to FIG. 9, upon which reference numerals identical to those of FIG. 1 have been used it will be seen that it is possible to weave the body fabric B in a manner different to that disclosed above. In this case it is seen that shaft 5 moves from an upper shed position to a middle shed position and then to a lower shed position and back to a middleshed position while shaft 4 moves from a middle shed position to an upper shed position and then back to a middle shed position and from there to a lower shed position. During these four picks shaft 6 moves from a middle shed position to a lower shed position, then back to a middle shed position and then an upper shed position while shaft 7 moves from a lower shed position to a middle shed position, then an upper shed position and back to a middle shed position. This shed change cycle repeats continuously as the fabric B is being woven. In contradistinction to the previously described weaving operation it will be seen that the stiff weft 14 is woven at every double pick into the fabric as opposed to ever alternate double pick.