CA1071061A - Tuck-in needle - Google Patents

Abstract

Du Pont of Canada Limited (Wuthrich, Jakob) ABSTRACT

An improved tuck-in needle is disclosed, whlch is useful for forming selvedges on woven structures, prepared from flexible tapes, on a loom having the weft supply bobbin or the loom outside the shed of warp tapes. The hook-shaped tuck-in needle is characterized by a beard attached by an arcuate head to a shank having a tapered portion and a straight portion, the narrow part of the tapered portion being attached to the head.
The tip of the beard lies between two lines extending through op-posing edges of the straight portion of shank, the two lines lylng in a plane passing through the centres of the beard, shank, head and beard tip.

Description

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me pre~ent ~nvention relates to a tuck-in need~e u8e~Ul ~or forming ~elvedges on wo~en ~tructure~ prepared from Plexible tapes, and particularly tapes of therm~pla~tic polymer, on a loom having the weft 8upply bobbin of the loom out~lde the ~hed oP warp tapes oP the loom.
In a weaving proces~ in which ~eft tape~ are fed ~rom a weft bobbin, which re~ains out~ide a shed of warp tapes, a wePt tape may be pulled Prom the we~t bobbln and picked in-to the shed by a gripper ~ype shuttle. Upon emerging from the ~h~d the wePt tapa is grasped at both ~ldes of the ~hed by selvedge grippers. The we~t tape i~ released ~rom the shuttle and is cut out~ide thie shed, next to the ~elvedge gripper neare~t thQ ~e~t ~upply bobbin, between the selve~ge gripper a~d thc ~ePt supply bobbin. The shea 18 cau~ed to chango and the wePt tapo i8 boaten against previou~ly woven material b~ a roed, thw trapping the w ~t tape. Tuck-in needle~ are drive~ through tho lower ~arp tapo~ of the shed close to the odge~ o~ the shed and caw ed to engage, out3ide the ~hed~ wlth the end~ o~ the ~e~t tape hold by the ~el~edge gripper6. The ~eft tape i~ then released ~rom the selvedgo grlppers thu# allow-lng the tuck-in needle~ to pt~ll the ends of the ~eft tape into the shed. Th~ ends Or th~ we~t tape are le~t between the upper a~d lo~er warp tapes at the edge~ of the ~hed as the tuck-in needlos are ~ithdraw~ through the lower warp tapos. The shed ~8 caw ed to change and the ~e~ly tucked in weft tape is beate~ again~t the previously wo~en ~abric by a reed; the ~hed i~ cauJed to chango by the movomant o~ heddles and the cycle i8 r-poatod. E~ch throw of the ~huttle i~ referred to a~ a pick~
One such ~a~rlng oper8,tion for ro~ g sel~edges Or cloth in which t~ck-in ~edles are u~ed on ~ gri.pp~r ~shuttle loom i8 deECrib~d i~l U.S. P~tent 3,499,474 whieh i~uod 10th M~rchi:~197Q to 1:~. P~arrNaller.
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1~1061 Mo~t ~nown tuck-in needle6 u3e~ ~n a loom for carry-ing out the above process are hook-shaped and are ch3racter-i~ed by having a shank ~oined to a be~rd by a head, the hook-~hape generally de~crlbing an arc of abo~t 180 when viewed in plan. The shankcomprise~ a straight portion and a tapered portlon. The ~traight portlon has ~ub~tantially parallel ~ides and 1~ ~o$ned at one end to a securing mean~ by which the tuck-in needle i8 attached to a mechani~m ~or m~ving the tuck-in needle through a predetermined path and ~n a 8yn-chronou~ mAnner with the other mechanisms o~ the loom, andi~ Joined at the other end to the ~ider end of the tapered portion. The tapercd portion i~ Joined at lts narrower end to the head, and the odge of the ~traight and taper~d portions opposite the edge raclng the beard i8 ~traight and continuous.
The taper i8 normally about 10. The tip Or the beard i8 blunt and roun~ed and i~ the portion of the beard furthest~
a~ay rrOm th~ head. The head no~m~llg h~8 two saddle ~haped groovs~ e~tending acro~ th~ width o~ the h ad, each groove bsing on oppoclte ~ide~ Or a plane tbrough the c~ntres of the ~hank, the head and th~ beard.
The space ~urrounded ~y the 8hank, head, be~rd and - tl~ i8 re~erred to as the e~e. The di~tance between the ~ur-face~ Or tho beard tip and th~ ~h~nk that are closost together 18 referred to as the eye ntrance gap; the groatest di~tance, acro~s the eye and along a llno parallel to the line dor~n~ng the eye entrance gap, between the ~urfaces Or the beard ~nd the shank that are clo~ect to~e~ner 18 re~erred to a~ the eye width; th~ dista;llco betdeen the extremity o~ the beard tip aad the sur~ace of the head ~ext to the eye i8 referrod to as the eyo longth, tho gre~te~t distance, acros~ the eye and along a line p~ra~el to the line do~ining the e~e entrance

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gap, between the surface~ of the ~hAnk and the beard ~urtheSt awa~ ~rom the eye i~ re~erred to aæ the needle width, and the lea~t di~tance between the oxtremity o~ the beard tip and the ~urrace of the ~hank furtheat away from the eye i8 referred to as tho tip wldth. The width o~ the straight portion o~
the ~hank i~ referred to as the ~hank width.
Whea using the know~tuck-in needle~ hereinbe~ore deacribed, for tucking in weft tapes to rorm a 3elvedge, there i~ a tcndoncy for the needle to ~nag the edge warp tapes a~
the needlo i8 withdra~n through the lower warp t~pe~ of the warp shed. Such ~n~gging of the tape~ either dam~e~ or breaks a warp tape at the edgo of the fabrlc, thoreby gi~ng a fabric with a poor quality selvedge. In the case of a brok~n Narp tape the loom nor~lly i8 stopped automatically until the break i~ ropaired. Each ~toppage 1~ re~erred to a~ a warp ~top. Broken tape~ aro unde~irable a~ both the guallty of the uovon fabric and the productlvlty of the loom are ad~er~oly ,. ar~octod.
One known method used to improve the perfor~ance Or the tuck-in neodle i~ to provide a larger tha~ normal opening in th~ low~r ~arp tape~ at the point where tho tuck-in needle e~ters and exits ~rom the warp ehed. Thi~ 1B accomplished by lifting up 80me o~ the lower ~axp tape~ ln the centor portlon Or the uarp ~hed in relatlon to the lower warp tspe~ at the edg~ o~ the ~hod, b~ ~ean~ o~ ~ lifter plate. Tho improvement a~ordod by such u8e 0~ ~ llrter plate ha8 been ~hown to be m~rginol when ~a~ing t~pcs~
It iB an ob~ect o~ the present inv~ntion ther~oro, to pro~lde a tuck-in noedle ~hich gi~o~ greatlg improved per-

3~ for~nce ~ith r~poct to ~elvo~ qualit~ and ~abric prod~tivlty Or fabrio~ en from ~at tap~ ana ~abricated on looms havlnl5 th ~re ~upp~r bobbin of th loom ou~1d the ~ho~ Or . .

1~7 1~ 61 warp tapeB of the loo~, without th~ need ~or u~e o~ ter plate~. :
Accordingly, the pres~nt inv~ntion pro~ides an im- -proved hook-shapea tuck-~n needle, characterised by a beard att~ched by an arcuate head to a shank ha~ing a tapered portion and a oub~tanti~lly straight portion~ the narro~ part of the tapered portion belng attached to the head and the wide part of the tapered portion being attached to th~ ~traight portlon, and the beard having a rounded tip furthest awa~ ~rom the head, ~he improvement ~heroin the tip lles between l~nc~ ~xtendlng along two oppo8in4 ed~es o~ the stralght portioa, the edges being in a plane pa~ing through the center~ o~ the ~hank, head, beard and tip.
In a pre~erred e~bodlment the ~dge o~ the tapercd and stralght portlon~ Or the ~hank opposito the edge ~aclng the : bear~ lo straight and continuow .
In another preferred embod~m~nt tho ratio of thn tlp ~idth to the ~h~nk ~idth i~ bet~een about 0.8 and about 0.95 and m~re pre~erably bet~eon about 0.8 and about 0.9.
In another embodiment the tuck-in noedle al~e ba8 an o~e~ntrance gap o~ bet~een about 0.75 mm and about 1.2 mm ~nd an eye length Or bet~eon about 3.5 ~m and about 5 m~.
~; The pro~ent inventlon al~o pro~ldes an improved process ror tuck~ng the end~ of weft tapo~ into the ed~e Or a ~-~hed o~ ~arp tapes on a loo~ ha~ing a *ert ~upply bobbin out-, , side the shed, characteri3ed by the rollo~ing 8tep~
a) picking a wert tape into and through tho shed b) gripping and ~overing the picko~ ueft tape out- :
~ide the 8hed ~uch that ~aid ~Ort tap~ ha8 grlpped end portions 30 c) trapping the ~e~t tape in the shed by chang~ng the ohed snd bcating the we~t tape ,' ' .

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d) at each edge of th¢ ~h~d, dr~ving a hook-shaped tuck-in needle through the lower warp tape~, engaging the end portion of the we~t t~pe with the hook of a tuck-in needle, releaslng the grlp on th~ end portion, pull~ng each enga~ed end portlon into the shed with the tuck-in needle, wlthdraw-ing the tuck-in needle ~rom the ~hod, ~nd e) trapping the end portions in ~he shed by chang-ing th~ shed and beating ~aid ond portion~,in which the improve-ment comprise~ carrying out steP d) with a tuck-in needle 1~ having a beard attached to a shank by an arcuate head, the shank having a tapered portion and a ~ub~tantially ~traight portion, thc narDO~ part Or the tapered portion b~lng attached to the head ana the wide part o~ the tapered portipn being att~ched to the straight portion, ths beard having a rounded tip furth~st aw4y from the hoad, 8nd tho tlp lying botween lines extending along two oppo~lng odge~ of tho straight portlon, tho edges being in a plane pa88ing through the centres Or the 8hanX, hoad, beard and tip.
Tho in~ontion m4~ be illw trat~d by reference to th accompanying drawing~, wherein Figure 1 i8 a sch~matic representation o~ a par~ o~
ono ombodi~ent Or a tuck-in needle o~ the presont invention FiguFe 2 i8 a schom~tic repre~entation Or a part Or a further embodim~nt of a tuck-in needl~ of the present lnven-tion and Figure 3 i~ un end elevatio~ sf a tuck-in needle Or the pre~ent lnv-nt~on vi~od ~rom po~tion ~-3 in Figuro 2.
Rererring to Figuro 1, the tuck-in n~edle compri~s a ~hank 10, havi~g a straight portlon 11 and a tap~red portion ; 30 12, Joined at the narro~ ~nd o~ the tapor~d portion to a hook 20.
Th ~ook 20 cD~prl~ n ~rcu te head 13, ~hich 1- ~olned ~t on~

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end to the ~hank 10 and at the other to a beard 14, having a blw~t, rounded tip 15 at it~ e~tremity. mere iB a gap, the eye entrance gap 16, between the beard tip 15 and the shank 10.
The ~traieht portlon 11 o~ shank 10 i8 Jo~ned to a mechanism (not shown) for moving the tuck-in needle through a circuitous and predetermined path. In the embodi~ent ~hown ln Figure 1, tho eye width, ~hown by the double ended arrow marked W, is sub-stantially the Bame wldth as the eye entrance gap, ~hown by the double ended arrow marked E.
As can be ~een in the embodiment of the preeent in- -vention illustrated by Figure 2, the eye width W i~ greater than th~ eye ~ntrance gap E. The tlp width i~ shown by double-ended arrow A.
As ~hown in Flguro 3 the head 13 has two ~addle shaped grooveo. The arcu~te grooved head 13 Join~ Bhflnk 10 to beard 14.
In needle~ of tho prlor art descrlbed hereln the beard i8 substantially straight and parhllel to the surface o~ the tapered portion of the shank ne~t to the eye, and the tip width i8 greater than the ~hank ~idth. The tip of the beard al~o lio8 out d a~ the area bo~nd~d by tNo li~es e~t~nding.along th~ t~o oppoeing edge~ of the straight portion Or the ~s~k, the edge~ b~ng in a plane pa~sing through the center~ of the ~hank~ h~ad, beard and tip. ~`
The ~ollowing de~criptlon s~rves to illw trat~ a method in which the tuck-in n edle of the present invention may be u~ed on a loom having a w~ft ~upply bobbin of the loom out~id~ the ~h~d of ~arp tapes o~ the loom, tQ form a ~olvedge~
Thn we~t tape 1~ pulled from the weft ~uppl~ bobbin ~ 30 and picked i~to ~nd through the shed by a gripper ~huttl~
Upon ~merging ~rom the shod the weft tape is gra~ed by a sel-vedge gripper and i8 rolea~ed from the ~huttle. The ~hod i8 . : .

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caused to change and the we~t tape i~ beaten again~t prevleusly woven material by a reed. me tuck-in needle 18 driven, by a m~chaninm- which i~ attached to ~hank lQ, through ~he lower warp tapes of the shed, the hook 20 being the first part of the tuck-ln needle to penetrate into the shed. During and a~ter penetration into the ~hed, the tuck-in needle and the weft grlpper are synchronou~ly and cooperatively moved such that the end portion of the we~t tape outside the shed 1~
caused to engage ~ith the eye of the hook and sub~equently to draw the end portion o~ the weft tape into the æhed. A~ the tuck-in needle ifi then withdrawn through the lower ~arp tapes of the shed, the end portion ofthe weft tape i8 released from tho hook 20 thereby trapping the end portion in the ~hed.
While the tuck-in proce~ iB occurlng a further weft tape i~ plcked and a~ter this ~urther weft tape i~ held by the wert grippor, the shed i8 cau~ed to change again and the ~ur-ther we~t tape and the end portion of the ~irst-de~cribed we~t tape are beaten, together, by the reed. The sequence 1# re-peated ~or each cycle o~ the loom. It uill be under~tood by tho~e skilled in the art that the weft tape must have a free end in order to be tucked in to form a selvedge. A~ the side of the shod neare~t to the weft BUpply bobbin and at points along the wldth of the shed ~here a ~elvedge ls required it is noce~sary to cut the weft tape on thc side o~ the eelvedge gripper ~urthest away from the aesired ~elvedgo.
The examples shown ln the ~ollowing ~able serve to illustrate the lmprovement in woa~lng perrormance occa~ioned~.
by the use o~ the tuck-in needles of the pre~ent ~nvention.
In th Table, the weaving per~ormance of conventlo~al tuck-in noedle~ and conventlonal tuck-in needles w ed in combination w~th ll~ter plate~ are compared with t~o tuck-in ncedle~, de-c$gnated ~dles I and II, o~ the present lnventlon. Dim~n-~o~

sions of the tuck-in needles are also given. Weavlng p~r~or-mance i~ mRaæured in warp stops per million pick~ ~hen we~ing pol~propylene w~rp and ~eft tapes ha~ing a width of 2.2 mm on a we~aving machine available from ~ulzer Bro~.
Conventlonal Conventional Needle & Needle ~eedle Needle Ll~ter Plate I II :
~hank width mm3.60 3.60 3.60 3.60 tip width mm 4.00 4.00 ~.38 3.38 nee~le width mm4~50 4.50 4.50 4.50 ~ye ~ldth mm 2.10 2.10 2.~0 1.20 eye- ontrance gap mm 2.10 ?.lo 1.20 1.20 warp BtopB/106 plck~ 68.4 47.0 8.0 8.0 Preferred tuck-in n~edles accordlng to the present invention, for tucking in w~rt tape~ into a warp shed comprl~ing tape~ bet~een abou~ 2.2 mm and about 5.0 mm have an eye entrance gap o~ betwoen about 0.75 ~nd about 1.2 mm~ a tip width o~ between about 3.2 to about 3.4 mm and an eye length of between about 3.5 mm and about 5.0 mm.
Tuck-in ncodles of the pre~ent ln~ention m~y be u~ed i~ proce~es ~or tucking in sel~edges o~ woven fabric6 m~de ~ith wert tapes of any fle~ible yarn or tApe. They are par-ticularly w-ful for tucking in fl~xible tapes made from thermo-plastic polymerlc materlal. Pre~orred therDoplastic polymer~
are homopolymRrs and copolymers of l-olerin~; polyethylene and polypropyl~ne being especially pr~ferred. The linear dcn~lty of ~uch floxlble tape~ made from the thermopla~tic polymer i8 UBUally ~ro~about 500 dtex to about 5000 dtex, and pref~rably ~rom about 550 dte~ to about 1500 dtex~

Claims (14)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An improved hook-shaped tuck-in needle, charact-erised by a beard attached by an arcuate head to a shank having a tapered portion and a substantially straight portion, the narrow part of the tapered portion being attached to the head and the wide part of the tapered portion being attached to the straight portion, and the beard having a rounded tip furthest away from the head, the improvement wherein the tip lies between lines extending along two opposing edges of the straight portion, the edges being in a plane passing through the centers of the shank, head, beard and the tip.

2. A tuck-in needle according to Claim 1 wherein the edge of the tapered and straight portions of the shank opposite the edge facing the beard is straight and continuous.

3. A tuck-in needle according to Claim 2 wherein the ratio of the tip width to the shank width is between about 0.8 and about 0.95.

4. A tuck-in needle according to Claim 3 wherein the ratio of the tip width to the shank width is between about 0.8 and about 0.9.

5. A tuck-in needle according to Claims 1, 2 or 3 wherein the tuck-in needle has a tip width of between about 3.2 mm and about 3.4 mm, and eye entrance gap of between about 0.75 mm and about 1.2 mm and an eye length of between about 3.5 mm and about 5 mm.

6. An improved process for tucking the ends of weft tapes into the edge of a shed of warp tapes on a loom having a weft supply bobbin outside the shed, characterised by the following steps:

a) picking the weft tape into and through the shed;
b) gripping and severing the picked weft tape outside the shed such that said weft tape has gripped end portions;
c) trapping the weft tape in the shed by changing the shed and beating the weft tape;
d) at each end of the shed, driving a hook-shaped tuck in needle through the lower warp tapes, engaging the end portion of the weft tape with the hook of the tuck-in needle, pulling each engaged end portion into the shed with the tuck-in needle, withdrawing the tuck-in needle from the shed, and e) trapping the end portions in the shed by changing the shed and beating said end portions in which the improvement comprises carrying out step d) with a tuck-in needle having a beard attached to a shank by an arcuate head, the shank having a tapered portion and a substantially straight portion, the narrow part of the tapered portion being attached to the head and the wide part of the tapered portion being attached to the straight portion, the beard having a rounded tip furthest away from the head, and the tip lying between lines extending along two opposing edges of the straight portion the edges being in a plane passing through the centers of the shank, head, beard and tip.

7. A process according to Claim 6 in which step d) is carried out using a tuck-in needle in which the edge of the tapered and straight portions of the shank opposite the edge facing the beard is straight and continuous.

8. A process according to Claim 7 wherein the tuck-in needle has a ratio of the tip width to the shank width between about 0.8 and about 0.95.

9. A process according to Claim 8 wherein the warp and weft tapes are of thermoplastic polymeric material.

10. A process according to Claim 9 wherein the thermo-plastic polymeric material in a homopolymer or copolymer of a l-olefin.

11. A process according to Claim 10 wherein the thermoplastic polymeric material is polyethylene or polypro-pylene.

12. A process according to Claim 8 wherein the tuck-in needle has a tip width of between about 3.2 mm and about 3.4 mm, an eye entrance gap of between about 0.75 mm and about 1.2 mm and an eye length of between about 3.5 mm and 5 mm.

13. A process according to Claims 8, 11 or 12 wherein the warp and weft tapes are greater than 2.2 mmin width and have a linear density of between 500 dtex and 5000 dtex.

14. A process according to Claims 8, 11 or 12 wherein the warp and weft tapes are between 2.2 mm and 5.0 mm in width and have a linear density of between 550 dtex and 1500 dtex.