Yarn splicing apparatus

Abstract: A yarn splicing apparatus provided with a splicing nozzle 4 wherein two yarn ends YP,YB are introduced and compressed air is applied, and a pair of untwisting nozzles 5,6, each of the untwisting nozzles placed for each of the yarn YP and YB, and positioned with said splicing nozzle in between. The yarn splicing apparatus is further provided with a pair of resistance members 2,3 which give resistance against shrinkage of each of said yarn ends YP,YB that go to said untwisting nozzles 5,6 to prevent splicing errors (Fig. 2).

Description: Field of the Invention The present invention relates to a yarn splicing apparatus wherein compressed air is applied to the ends of two yarns to splice them together. The yarn splicing apparatus is especially effective in splicing spun yarn containing elastic yarn such as polyurethane yarn. Background of the Invention A conventional yarn splicing apparatus is comprised of components such as a pair of untwisting nozzles, a pair of cutters, and a pair of yarn shifting levers, each of the pairs positioned on the upper and the lower sides of a splicing nozzle (US-A-4 505 097). The operation of the yarn splicing apparatus is as follows. First, after the upper yarn and lower yarn are pressed into the splicing nozzle by a pair of yarn shifting levers and clamped, a pair of cutters cut the edge of the upper yarn and the lower yarn. Secondly, each of the cut yarn ends is sucked into the untwisting nozzles and is untwisted. At that time, the yarn shifting levers are drawn back slightly to make sufficient length of the ends of the yarn be sucked into the untwisting nozzle. Thirdly, after the yarn shifting levers are pushed to deeper positions to pull out appropriate length of the yarn ends from the untwisting nozzles, compressed air is jet whereby the ends of the yarn are intertwined for the splicing to be finished. The aforesaid yarn splicing apparatus secures splicing of ordinary yarn. However, when spun yarn wherein elastic yarn is wrapped by surrounding fibers is spliced using the aforesaid yarn splicing apparatus, many splicing errors occur. The efforts to look for the cause of the trouble revealed that the yarn ends brought together by the yarn shifting levers are elongated because of the elasticity of the yarn, so that the moment the cutters cut the yarn, they shrink and cannot be sucked into the untwisting nozzles. Even when the yarn ends are sucked into the untwisting nozzles, the yarn shrinks when the covering fibers are untwisted and blown off, because the elastic yarn core has been elongated while it is wrapped, and as a result, the yarn ends stay outside the splicing nozzles, leading to splicing errors. It is thus an object of the present invention to provide a yarn splicing apparatus that assures successful splicing of elastic spun yarn. Summary of the Invention In order to accomplish this object, according to a first aspect of the present invention, in a yarn splicing apparatus provided with a compressed-air-jetting splicing nozzle into which two yarn ends are introduced, and a pair of untwisting nozzles that correspond to each of the two yarn ends respectively, one of the untwisting nozzles placed on one side of the aforesaid splicing nozzle, and on the other side the aforesaid splicing nozzle, the present invention is a yarn splicing apparatus characterized in that a pair of resistance members are provided, which give resistance to prevent the shrinkage of the yarn ends that are introduced into the untwisting nozzles. With this improvement, the yarn ends that are sucked into the untwisting nozzles are prevented from shrinking due to the elasticity of the yarn core, because said resistance members give resistance to the yarn ends that are introduced into the untwisting nozzles. As a result, a predetermined operation of splicing is secured. According to a second aspect of the present invention, the aforesaid resistance members hook the fibers that constitute the aforesaid yarn ends. This prevents the yarn from shrinking due to the elasticity of the yarn. And at the same time, the yarn end is just temporarily hooked so that they can be released easily from the resistance member after the splicing. The resistance members, which are formed to hook the fibers can be formed as comb-like teeth, brush-like implanted hair, or weak clamps. In a third aspect of the present invention, each of the resistance members and the untwisting nozzles described in a first and second aspects of the present invention corresponds to one of the ends of the two yarns respectively, and placed with the splicing nozzle in center, and each resistance member for each yarn is positioned at the opposite side of each of the untwisting nozzles, and the resistance member is positioned on the side of the yarn main body, and the untwisting nozzle is positioned on the side of the yarn end. With this arrangement, the resistance against shrinking is given on the opposite side of each of the untwisting nozzles across the splicing nozzle. This configuration reduces the distance between the untwisting nozzles and the splicing nozzle. According to a forth aspect of the present invention, the aforesaid resistance members are formed in a way that gives greater resistance in the direction away from the untwisting nozzles than the resistance given in the direction toward the aforesaid untwisting nozzles. As a result, it is easier to bring the yarn ends to the untwisting nozzles, and at the same time the resistance applied in the direction away from the untwisting nozzles is greater so that the introduction of the yarn ends into the untwisting nozzles is enhanced. According to a fifth aspect of the present invention, the yarn that constitutes the aforesaid yarn ends in a first, second, third, and fourth aspect of the present invention is spun yarn containing elastic yarn. According to this, because spun yarn containing elastic yarn is elastic and difficult to splice, the resistance members that are placed on both sides of the splicing nozzle prevent shrinkage of the yarn ends to result in successful splicing. Brief Description of the Drawings Figure 1 is a perspective view of a preferred embodiment of a yarn splicing apparatus employing the present invention. Figure 2 is a front view of an important part of the preferred embodiment of the present invention. Figure 3 shows one example of the resistance members. Figure 3A is a top view seen in the direction A shown in Figure 2. Figure 3B is a cross-sectional view of the comb-like teeth. Figure 4 is a cross-sectional view to show the first process of the operation of the yarn splicing apparatus. Figure 5 is a cross-sectional view to show the second process of the operation of the yarn splicing apparatus. Figure 6 is a cross-sectional view to show the third process of the operation of the yarn splicing apparatus. Detailed Description of the Preferred Embodiments The preferred embodiments of the present invention will now be explained in detail with reference to the accompanying drawings. As shown in Figure 1, a yarn splicing apparatus 1 is installed in an automatic winder to wind up the spun yarn fed from a supply bobbin B into a package P. The yarn splicing apparatus 1 is designed to splice together the ends of two yarns made after a breakage or after a yarn defect is fixed, one of which is called an upper yarn (on the side near the package P) and the other a lower yarn YB (on the side of the supply bobbin B). As is shown in Figure 1 and Figure 2, the yarn splicing apparatus 1 is provided with a splicing nozzle 4 in the middle of the configuration and on each side of the splicing nozzle 4 are placed one of a pair of untwisting nozzles 5,6, a pair of resistance members 2,3, a pair of yarn holding levers 7,8, a pair of yarn shifting levers, 9,10, a pair of yarn-end cutters 11,12, and a pair of yarn clamping plates 13,14. As is shown in Figure 1, the yarn clamping plate 13, the resistance member 2, the splicing nozzle 4, the untwisting nozzle 6, the yarn-end cutter 12 are placed in the descending order for the upper yam YP. Seen from the lower yarn YB, the yarn clamping plate 14, the resistance member 3, the splicing nozzle 4, the untwisting nozzle 5, and the yarn-end cutter 11 are placed in the ascending order. The pair of the yarn holding levers 7,8 are placed between the splicing nozzle 4 and the untwisting nozzles 5,6, and operated simultaneously on the upper yarn YP and the lower yarn YB. The splicing nozzle 4 comprises a circular splicing hole 16 and a slit 17 for inserting the lower yarn YB and the upper yarn YP into the splicing hole 16, and is mounted on the bracket 15 using a plurality of bolts. An air blowing hole 18 is formed so that it opens tangentially to the splicing hole 16, which is connected to a compressed air source (not shown in the drawings). The splicing nozzle 4 works as follows; the compressed air ejected from the air blowing hole 18 to the splicing hole 16 intertwines the two ends of the two yarns YB and YP and gives twist to splice them together. There are also regulator plates 19,20 on each side of openings of the splicing hole 16. The regulator plates 19,20 are positioned so that they traverse partially the openings of the splicing hole 16, to regulate the positions of the lower yarn YB and the upper yarn YP that are inserted into the splicing hole 16. They also regulate the air currents that flow out of the splicing hole16. As a result, the intertwining of fibers at both ends of the yarns YB and YP are improved, and the appearance and the strength of the splicing become improved. Each of the pair of the untwisting nozzles 5,6 are placed on the upper and lower sides of the splicing nozzle 4, and positioned so that one of the untwisting nozzles 5,6 is placed on the right and the other is on the left of the center of the splicing hole 16. As is shown in Figure 5, air paths 21,21 blow out air so that the untwisting nozzles 5,6 work not only to suck the ends of the yarns YB and YP but also to untwist the fibers of the ends of the yarns YB and YP. One of the resistance members 2,3 is placed on the upper side and the other is placed on the lower side of the splicing nozzle 4 respectively and at the same time on left side and the right side of the splicing hole 16 respectively, and positioned so that each of the resistance members is on the opposite side of the untwisting nozzles 5,6 across the center of the splicing nozzle 4. On both of the upper side and the lower side of the splicing nozzle 4 are separators 22 and 23, which are mounted on the bracket 15 to separate the upper yarn YP and the lower yarn YB along the center axis of the splicing hole 16. The resistor 2 is mounted on a front plate 221 placed to the right side of the upper separator 22, and the resistor 3 is mounted on a front plate 231 placed to the left side of the lower separator 23. In other words, for the upper yarn YP, the resistance member 2, the splicing nozzle 4, and the untwisting nozzle 5 are placed from top to bottom, in other words from the package P side to the end of the upper yarn YP, and for the lower yarn YB, the resistance member 3 , the splicing nozzle 4 and the untwisting nozzle 6 are placed in the ascending order, in other words from the supply bobbin B side to the end of the lower yarn YB. Each of the yarn holding levers 7,8 is placed between the splicing nozzle 4 and one of the untwisting nozzles 5,6. The clamping levers 7,8 press the ends of the yarns YP and YB that are introduced into the splicing nozzle 4. Each of the pair of the yarn shifting levers 9,10 is placed on the upper side and the lower side of the bracket 15 respectively to insert the yarns YP and YB into the splicing nozzle 4 and the yarn end cutters 11,12 to regulate the length of the yarn ends that are sucked into the unwinding nozzles 5,6, and to regulate the length of the yarn ends that are introduced into the splicing nozzle 4. One 11 of the pair of the yarn end cutters 11,12 is positioned above the upper untwisting nozzle 5 and the other yarn end cutter 12 is positioned lower than the lower untwisting nozzle 6 to cut the tip of the yarn ends of the yarns YP and YB. One 13 of the pair of the yarn clamping plate 13,14 is placed above the bracket 15 and the other yarn clamping plate 14 is placed under the bracket to clamp the yarns YP and YB. The details of the resistance member 2 are shown in Figure 3. Figure 3A depicts the resistance member 2 seen in A direction of the Figure 2. Figure 3B is a cross section of the comb-like teeth. The resistance member 2 is an array of many comb-like teeth mounted on the side of the base 201. The comb-like teeth 202 are formed in zigzag. The teeth 202 have slant surfaces 203 that are at the angle 1 from the horizontal plane, and further have a plurality of cuts 204 that are administered at an angle 2, which is larger than the angle 1. The pitch of the comb-like teeth 202 is small enough to prevent the end of the yarn from going into it. The comb-like teeth 202 are mounted on the front plate 221 with bolts (not shown in the drawing) so that the comb-like teeth 202 are projected from the front plate 221. When the spun yarn Y with the fibers wrapping around the elastic yarn is pressed against the comb-like teeth 202, the fibers of the spun yarn Y are hooked on the comb-like teeth 202 so that resistance against shrinking is given to the spun yarn Y, which is elastic. The comb-like teeth 202 are formed slant, so that the resistance given by the teeth 202 toward (a1) of the Figure 3B (away from the untwisting nozzle 6 and the splicing nozzle 4) is larger than the resistance given in a direction toward (a2) (toward the untwisting nozzle 6 and the splicing nozzle 4). In other words, when the lower yam YB fed from the supply bobbin B is moved toward the untwisting nozzle 6 and the splicing nozzle 4, the resistance given by the comb-like teeth 202 is minimum, while when the lower yarn YB is moved away from the untwisting nozzle 6 and the splicing nozzle 4, the resistance is bigger. The structure of the resistance member 3 is similar except that the direction of the comb-like teeth 202 is in reversed direction. Next, processes of splicing are explained in accordance with Figure 4 and Figure 6. The first process is as follows. After yarn breakage, a pair of sucking members SB and SP guide the upper yarn YP derived from the Package P and the lower yarn YB fed from the supply bobbin B to the yarn splicing apparatus 1, as shown in Figure 2. Next, as is shown in Figure 4, the clamping plate 14 clamps the lower yarn YB from the bobbin B and the clamping plate 13 clamps the upper yarn YP derived from the Package P. Then the yarn shifting levers 9,10 move toward the splicing nozzle 4 to touch a stopper 49 and insert each of the yarns YB and YP into a splicing hole 16 and the yarn-end cutters 11,12. The yarn end cutters 11,12 are activated and cut each of the yarns YB and YP at certain length from the position where the clamping plates 14,13 clamp each of the yarns YB and YP whereby the yarn ends are made. At this point, each of the yarns YB and YP between the yarn clamping plates 14,13 and the sucking members SB and SP is tense because the elastic yarn used as the yarn core is pulled, so that when the yarn-end cutters 11,12 are activated, each of the yarns YB and YP begins to shrink. However the comb-like teeth 202 of the resistance member 2 work against the upper yarn YP, so that the contraction is limited to the portion below the resistance member 2. Likewise, the lower yarn YB begins to shrink toward the yarn clamping plate 14, but the comb-like teeth 202 of the resistance member 3 work, and the contraction of the lower yarn YB is limited to the portion above the resistance member 3. As a result, a certain length of the yarn ends required for the suction into the untwisting nozzle 5,6 is secured, and the sucking of the yarn ends into the untwisting nozzles 5,6 is secured. The second process is as follows. As in Figure 5, the untwisting nozzles 5,6 activated at the same time or at a certain interval before or after the cutter activation suck the end-side portion of the yarns YB and YP into the untwisting nozzles 5,6 and untwist the fibers that cover the elastic yarn. At the same time, the yarn shifting levers 10,9 are returned to the position away from the yarns YB and YP. As a result, the sufficient length of the yarns YB and YP are sucked into the untwisting nozzles 5,6. The resistance given by the resistance members 2,3 decreases toward the untwisting nozzles 5,6, so that the resistance members 2,3 do not prevent the sucking of the yarn ends into the untwisting nozzles 5,6. The fibers at the end of each of the yarns YB and YP untwisted by the untwisting nozzles 5,6 are almost parallel. At that time, because the elastic yarn is elongated when it is covered by fibers, it begins to shrink after the untwisting operation. However, the resistance members 2,3 work to prevent the shrinkage, and prevent the yarn ends from flowing out of the untwisting nozzles 5,6 and the splicing nozzle 4. The third process is as follows. As shown in Figure 6, after the ends of the yarns YB and YP are untwisted, each of the untwisting nozzles 5,6 is stopped, and the yarn shifting levers 9,10 are reactivated, the ends of the yarns YB and YP are guided and drawn out of the untwisting nozzles 5,6. The activation of the yarn holding levers 7,8 help determine the position of the yarns YB and YP inside the splicing hole 16 in cooperation with the regulator plates 19,20. Now, both ends of the yarns YB and YP are set with one placed on the other inside the splicing hole 16. After the ends of the yarns YB and YP are set inside the splicing nozzle 4, compressed air is blown out from the air blowing hole 18 into the splicing hole 16. The rotating currents of the compressed air intertwine the fibers at the end of the yarns YB and YP, so that the two elastic yarn cores are placed one upon another wrapped up by surrounding fibers that are twisted, thus the splicing is done. After the air blow into the splicing hole 16 is stopped, the yarn holding levers 7,8 are released, and the yarn clamping plates 13,14 are released, then the splicing is finished. The spliced yarn is guided back to the ordinary yarn path leading to the winding released from the yarn path for the splicing nozzle 4. The resistance members 2,3 are simply hooking the fibers and the vibration generated by the rotating flow of the compressed air weakens the hooking, so that after the yarn holding levers 7,8 are released, the fibers are released easily from the resistance members 2,3. As a result the resistance members 2,3 do not hamper the running of the yarn after the splicing. The resistance member 2 and the untwisting nozzle 6 are placed on each side of the splicing nozzle 4 for the upper yarn YP. The resistance member 3 and the untwisting nozzle 5 are placed on each side of the splicing nozzle 4 for the lower yarn YB. As shown in Figure 2, on both sides of the separator 22 are placed the untwisting nozzle 5 and the resistance member 2. Likewise, on both sides of the separator 23 are placed the resistance member 3 and the untwisting nozzle 6. As a result, the addition of the resistance members 2,3 does not affect the size of the yarn splicing apparatus 1. The resistance given by the resistance members 2,3 is increasingly stronger in the direction away from the splicing nozzle 4 than in the direction nearing the splicing nozzle 4. The difference of resistance between each of the two directions can help control the length of the yarn ends that go into the untwisting nozzles 5,6 through the splicing nozzle 4 when the untwisting nozzles 5,6 are operating. Now another example of preferred embodiments is as follows. (1) A resistance member with brush-like hair can be used instead of the resistance members 2,3 with comb-like teeth 202. The direction in which the resistance is given can be changed with the changing of the implantation angle of the hair. Further, a clamper that clamps the yarn with weak force can be used instead of the resistance member 2,3. Slanting the clamper against the yarn will give a certain direction of the resistance and hence change the strength of the resistance. (2) Or else, the resistance can be the same for both directions toward and away from the splicing nozzle 4 without orientating the resistance of the resistance member 2,3. (3) Still further, the resistance member 2,3 of the Figure 2 can be changed to positions between the untwisting nozzles 6,7 and the splicing nozzle 4. In this case, because the shrinkage of the elastic yarn is prevented shortly before the untwisting nozzles 5,6, so that troubles derived from the yarn shrinkage can be further alleviated. (4) This invention is effective for not only spun yarn wherein covering fibers wrap around elastic yarn, but also any elastic spun yarn. (5) Further, the above-mentioned example is an application to an automatic winder wherein the yarn of a supply package is unwound and then wound up in a package. However, the invention can be applied to a yarn splicing apparatus of a revolutionary spinning machine and other types of machines. According to a first aspect of the present invention, a pair of resistance members are provided to give resistance to each of the yarns going to each of the untwisting nozzles respectively to prevent each end of the yarns being sucked into each of the untwisting nozzles from shrinking due to the elasticity of the yarn. This ensures the splicing of elastic yarn. According to a second aspect of the present invention, the resistance member is designed so that the fibers that make up the yarn ends are hooked. The fact that the yarn end is hooked prevents the yarn from returning to normal position because of the elasticity, and at the same time, removal of the yarn end from the resistance member is easy. According to a third aspect of the present invention, for each yarn, one of the resistance members is positioned on the side of the yarn main body with one of the untwisting nozzles on the side of the yarn end, the splicing nozzle in between. This configuration results in a compact size of a yarn splicing apparatus. According to a fourth aspect of the present invention, the resistance member is designed so that it gives a greater resistance in the direction away from the untwisting nozzle than the resistance in the direction toward the untwisting nozzle. As a result, it is easier to bring each of the yarn ends to the untwisting nozzle and at the same time the resistance is stronger when each of the yarn ends goes away from the untwisting nozzles. Consequently, the adjustment of each of the length of the yarn ends that are introduced into the untwisting nozzles becomes easy, and the form and appearance of the spliced yarn is improved. According to a fifth aspect of the present invention, since the yarn that constitutes the yarn end is a spun yarn containing elastic yarn, thus is naturally elastic, but the contraction of the two yarn ends on both sides of the splicing nozzle is prevented by the resistance member, and the success rate for the splicing is improved.

Claims: A yarn splicing apparatus comprising a splicing nozzle (4) for blowing compressed air in which ends of two yarns are introduced, and a pair of untwisting nozzles (5, 6), each placed on both sides of said splicing nozzle respectively for each of the yarn ends that are introduced into the said splicing nozzle, the yarn splicing apparatus further being characterized in that it comprises two resistance members (2, 3) to give resistance to the said each yarn end so as to prevent the shrinkage of the said each yarn end that goes into said each untwisting nozzle (5, 6). A yarn splicing apparatus as in claim 1, wherein fibers that constitute the yarn end are hooked on the resistance member. A yarn splicing apparatus as in claim 1 or claim 2, wherein the resistance member for the yarn is positioned on the side of the yarn main body, and the untwisting nozzle is positioned on the side of the yarn end, and the splicing nozzle is positioned between the resistance member and the untwisting nozzle. A yarn splicing apparatus as in claim 3, in which each of said resistance member is formed so that the resistance given in the direction away from the untwisting nozzle is greater than the resistance given in the direction towards the untwisting nozzle. A yarn splicing apparatus as in any one of claims 1-4, in which the yarn that constitutes said yarn end is a spun yarn containing a elastic yarn.

Inventors: SATO MOTOHIKO, YOSHIDA YASUNORI, SATO, MOTOHIKO, YOSHIDA, YASUNORI
Applicants: MURATA MACHINERY LTD, MURATA KIKAI KABUSHIKI KAISHA
Application year: 2000
Main classification: B65H69
IPC codes: B65H69, D01H15