Abstract:
An elongated-strip-article processor comprises: a processing section for applying printing to a plurality of continuous elongated strip articles along conveying passages of the elongated strip articles by an ink jet printer; a conveying section disposed in a vicinity of the processing section for intermittently conveying the elongated strip articles by a predetermined length; tension adjusting sections respectively disposed upstream and downstream out of a range of the conveying passages including the processing section and the conveying section for adjusting tension of each of the elongated strip articles at a constant value; sensors respectively provided at the tension adjusting sections for detecting a length of slack of each of the elongated strip articles; and feed sections disposed respectively upstream of the upstream-side tension adjusting section and downstream of the downstream-side tension adjusting section so as to correspond to the individual elongated strip articles. Each of the feed sections is adapted to switch between a state of positively feeding each elongated strip article and a state of suppressing feed of each elongated strip article based on detection signals from the respective sensors. By the elongated-strip-article processor, a plurality of elongated strip articles on an ink jet printer or the like can be accurately conveyed with optimum tension for the respective articles.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an elongated-strip-article processor mounted to an ink jet printer or the like for moving the elongated strip article, such as a fastener or the like, to be printed. 
     2. Description of the Related Art 
     Japanese Patent Laid-open Publication No. 3-69658 and Japanese Patent Laid-open Publication No. 5-330085 respectively discloses an ink jet printer for applying printing to the elongated strip article such as a fastener or a surface fastener. The ink jet printer comprises a processor for conveying the elongated strip article to be printed. This type of elongated-strip-article processor has conveying passages for a plurality of elongated strip articles, the passages being arranged in a substantially horizontal posture below print heads having ink jet nozzles. A driving roller abuts on one faces of the elongated strip articles and follower rollers abut on the driving roller via the elongated strip articles, thereby advancing the elongated strip articles at a predetermined speed intermittently by predetermined lengths for printing. The driving roller is mounted on only one side of the print head relative to a conveying direction of the elongated strip articles as disclosed in Japanese Patent Application Laid-open No. 3-69658, or mounted on both sides of the print head as disclosed in Japanese Patent Application Laid-open No. 5-330085. 
     In the above prior art, the ink jet printer can clearly print fine patterns, but there has been a problem that the printed patterns are disarranged on a product if the elongated strip article is slackened or stretched. Particularly when a plurality of elongated strip articles are mounted to the ink jet printer, because the respective elongated strip articles are slackened or excessively stretched in different states, each of the elongated strip articles needs to be brought into an optimum state by individual adjustment when conveyed. However, it has been difficult to easily adjust a tension per each elongated strip article. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished with above prior art in view. So, it is an object of the invention to provide an elongated-strip-article processor which can accurately convey a plurality of elongated strip articles on an ink jet printer respectively with optimum tensions. 
     To achieve the above object, according to the invention, there is provided an elongated-strip-article processor including a processing section for applying printing to a plurality of continuous elongated strip articles along conveying passages of the elongated strip articles by an ink jet printer and a conveying section which is disposed in a vicinity of the processing section for intermittently conveying the elongated strip articles by a predetermined length. The processing section may include a print head and a drier unit of the ink jet printer, and the conveying section may be a print roller for conveying the elongated strip articles. 
     The elongated-strip-article processor further includes tension adjusting sections, such as dancer rollers, disposed upstream and downstream out of a range of the conveying passages including the processing section and the conveying section for adjusting tension of each of the elongated strip articles at a constant value, and sensors respectively provided at the tension adjusting sections as the dancer rollers. Each of the dancer rollers moves up or down according to a length of slack of the elongated strip article in contact with the dancer roller. The sensors detect the length of slack of each elongated strip article by detecting positions of the dancer rollers. Further, the processor includes feed sections disposed respectively upstream of the upstream-side tension adjusting section and downstream of the downstream-side tension adjusting section so as to correspond to the individual elongated strip articles. Each of the feed sections switches between a state of positively feeding each elongated strip article and a state of suppressing feed of each elongated strip article based on detection signals from the respective sensors. 
     Each of the feed sections further includes a driving roller disposed under the elongated strip articles and having a rotation axis perpendicular to a feed direction of the elongated strip articles, at least one retainer disposed under the elongated strip articles and in parallel to the driving roller for retaining the elongated strip articles, a plurality of follower rollers disposed above the elongated strip articles and in parallel to the driving roller, and a plurality of retaining members above the elongated strip articles so as to face the retainer via the elongated strip articles, the follower rollers or the retaining members being adapted to be alternatively pressed against the driving roller or the retainer so as to clamp the elongated strip articles between the follower rollers and the driving roller or between the retaining members and the retainer. For example, each pair of the follower roller and the retaining member are respectively and rotatably attached to opposite ends of a single actuator having a rotation shaft substantially at a center of the actuator. The actuator has at one end portion thereof a moving means, such as an air cylinder, for pivotally moving or swinging the actuator about the rotation shaft and for pressing the follower roller or the retaining member against the driving roller or the retainer via each of the elongated strip article. 
     The retainer of the feed section may be a driving roller disposed in parallel to the first-mentioned driving roller and rotating at a lower speed than the first-mentioned driving roller. In this case, the follower roller is also pressed against the second-mentioned driving roller. 
     Each of the driving rollers may be a single roller with respect to a plurality of elongated strip articles. The numbers of the follower rollers and the moving means thereof disposed above the driving rollers may correspond to the number of the plurality of elongated strip articles conveyed in parallel to each other. 
     In the elongated-strip-article processor of the invention, the elongated strip articles are conveyed by predetermined intermittent conveyance. If a feed amount of each elongated strip article becomes larger than that intermittent conveying amount so that a length of each elongated strip article becomes excessive, the corresponding dancer roller moves down. Then, the corresponding sensors detect that the dancer roller has reached its lower limit position, and a signal is transmitted to the corresponding moving means such as a cylinder. Then, the cylinder moves the corresponding retaining member or the corresponding follower roller to move down to be pressed against the corresponding retainer, or to be pressed against one of the corresponding driving rollers rotating at a lower rotation speed through the elongated strip article. Thus, the elongated strip article is retained by the retaining member or conveyed slowly by the slow driving roller and the follower roller. As a result, the feed amount of the elongated strip article decreases, so that the dancer roller does not further move down. As a result, the length of the elongated strip article gradually decreases, and the corresponding dancer roller moves up. 
     If the corresponding dancer roller moves up to reach its upper limit position, the corresponding sensors detect that the dancer roller has moved up and a signal is transmitted to the moving means such as a cylinder. Then, the cylinder moves, such that the corresponding follower roller moves down to be pressed against the other one of the corresponding driving rollers rotating at a higher rotation speed through the elongated strip article. Thus, the elongated strip article is conveyed by that driving roller and the follower roller. As a result, the feed amount of each elongated strip article from a feed bobbin increases, and the dancer roller does not move up, so that the length of each elongated strip article gradually increases, and the corresponding dancer roller moves down. Thus, tension of the elongated strip article can be maintained at a constant value at the processing section. 
     As mentioned above, the dancer rollers move between the lower limit position and the upper limit position which is sufficient to give each elongated strip article a length of slack, for preventing the elongated strip article from begin excessively tight or loose between the intermittent conveying section and the feed section. Further, the tensions of the elongated strip articles are adjusted by predetermined weights of the dancer rollers so that abnormal fluctuations of the tensions can not occur. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view showing an embodiment of an elongated-strip-article processor according to the present invention. 
     FIG. 2 is a perspective view of the elongated-strip-article processor of this embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the present invention will be described below with reference to the drawings. A processor of the embodiment is an ink jet printer comprising conveying passages arranged in a substantially horizontal posture for conveying elongated strip articles to be printed, below a print head having ink jet nozzles as a processing section. A plurality of elongated strip articles are retained in parallel to each other on the conveying passages by a feed unit  1  and are respectively carried at predetermined speeds. 
     As shown in FIG. 1, the feed unit  1  has a roller  16  in contact with lower sides of a large number of elongated strip articles  14  fed in parallel to each other from a feed bobbin  12 . The roller  16  rotatably follows the feed of the elongated strip articles  14  and maintains feeding positions of the elongated strip articles at predetermined positions. A first driving roller  18  and a second driving roller  20  which constitute a feed section  10  of the elongated strip articles  14  are disposed downstream in the feeding direction of the roller  16  and under the elongated strip articles  14 , the first and second driving rollers  18  and  20  being spaced by a predetermined distance. The second driving roller  20  is driven at a lower speed than the first driving roller  18 . The single first driving roller  18  and the single second driving roller  20  are arranged respectively in a direction perpendicularly to the feed direction of the large number of elongated strip articles  14 . 
     At positions which face the first driving roller  18  through the elongated strip articles  14 , first follower rollers  22  which respectively correspond to the elongated strip articles  14  and are short in axial directions are rotatably disposed. At positions which face the second driving roller  20  through the elongated strip articles  14 , second follower rollers  24  which respectively correspond to the elongated strip articles  14  and are short in axial directions are rotatably disposed. Each pair of the first follower rollers  22  and the second follower roller  24  are attached to a long and narrow plate-like retaining plate  26 . The axial directions of the first follower rollers  22  and the second follower rollers  24  are in parallel to each other. The first and second follower rollers  22  and  24  are arranged in an axial direction substantially perpendicularly to the feed direction of the elongated strip articles  14 . The respective pair of the first and second follower rollers  22 ,  24  are attached substantially perpendicularly to side faces of the retaining plate  26 , and are respectively positioned at opposite end portions of the retaining plate  26  in a longitudinal direction of the retaining plate  26 . A pivotal shaft  28  is provided penetrating a center of the retaining plate  26  in a direction perpendicular to the feed direction of the elongated strip articles  14 . The retaining plate  26  is retained for a pivotal or swinging movement by the pivotal shaft  28 . Between the pivotal shaft  28  of each retaining plate  26  and each second follower roller  24 , a cylinder  30  as a moving means for individually swinging each the retaining plate  26  is mounted. 
     Rotatable rollers  32 ,  34 , and  36  are disposed downstream of the second driving roller  20 , at the same level as the roller  16 , and spaced at predetermined intervals, while being in contact with the lower sides of the elongated strip articles  14 . Between the rollers  34  and  36 , dancer rollers  38  which constitute tension adjusting sections are respectively mounted to be in contact with the upper sides of the elongated strip articles  14 . The dancer rollers  38  are at arbitrary positions lower than the rollers  34  and  36  move up or down according to lengths of slack of the elongated strip articles  14 . In spaces above and below the respective dancer rollers  38 , there are respectively arranged first sensors  40  which are sensors for detecting the dancer rollers  38  when the dancer rollers  38  are at lower limit positions and second sensors  42  for detecting the dancer rollers  38  when the dancer rollers  38  are at the upper limit positions are respectively mounted. Further, there is mounted a controller (not shown) for transmitting signals for actuating the cylinders  30  when the dancer rollers  38  are detected by the first sensors  40  or the second sensors  42 . 
     An intermittent driving roller  44  which constitutes a conveying section is disposed at the same level height as the roller  36  is mounted downstream of the roller  36  to be in contact with the lower sides of the elongated strip articles  14 . At a position facing the intermittent driving roller  44  through the elongated strip articles  14 , an intermittent follower roller  46  is mounted for intermittently conveying the elongated strip articles  14  by a set length. Above the elongated strip articles  14  with a predetermined distance from the articles  14 , a print head  48  having ink jet nozzles (not shown) is mounted downstream of the intermittent driving roller  44 . Further, a drier unit  50  for drying and hardening printed ink is mounted downstream of the print head  48 . 
     Rotatable rollers  52 ,  54 , and  56  are disposed downstream of the drier unit  50 , at the same level as the roller  16 , and spaced at predetermined intervals, while being in contact with the lower sides of the elongated strip articles  14 . Between the rollers  52  and  54 , dancer rollers  58  are mounted to be in contact with the upper sides of the respective elongated strip articles  14 . Each of the dancer rollers  58  has the same weight as each of the upstream dancer rollers  38 . The dancer rollers  58  are at arbitrary positions lower than the rollers  52  and  54  and move up or down according to lengths of slack of the elongated strip articles  14 . In spaces above and below the respective dancer rollers  58 , there are respectively arranged third sensors  60  for detecting the dancer rollers  58  when the dancer rollers  58  are at lower limit positions and fourth sensors  62  for detecting the dancer rollers  58  when the dancer rollers  58  are at the upper limit positions are respectively mounted. Further, there is mounted a device for transmitting signals for actuating cylinders  76  which will be described later when the dancer rollers  58  are detected by the third sensors  60  or the fourth sensors  62 . 
     Each of the dancer rollers  38 ,  58  move between the lower limit position and the upper limit position which is sufficient to give each elongated strip article  14  a length of slack, for preventing the elongated strip article  14  from being excessively tight or loose between the intermittent conveying section  44 ,  46  and the feed section  10 . Further, the tensions of the elongated strip articles  14  are adjusted by predetermined weights of the dancer rollers  38 ,  58  so that abnormal fluctuations of the tensions can not occur. 
     A third driving roller  64  and a fourth driving roller  66  similar to the first driving roller  18  and the second driving roller  20  are mounted downstream of the roller  56 . The rollers  64 ,  66  are arranged under the elongated strip articles  14 , at positions slightly lower than the roller  16  and spaced at a predetermined distance from each other. The fourth driving roller  66  is driven at a lower speed than the third driving roller  64 . At positions which face the third driving roller  64  through the elongated strip articles  14 , third follower rollers  68  which respectively correspond to the elongated strip articles  14  and are short in axial directions are rotatably disposed. At positions which face the fourth driving roller  66  through the elongated strip articles  14 , fourth follower rollers  70  which are short in axial directions are rotatably disposed. Similarly to the first follower rollers  22  and the second follower rollers  24 , each pair of the third follower rollers  68  and the fourth follower roller  70  are attached to a long and narrow plate-like retaining plate  72 . The axial directions of the third follower roller  68  and the fourth follower roller  70  are substantially perpendicular to side faces of the retaining plate  72 , and the third and fourth follower rollers  68  and  70  are respectively positioned at opposite end portions of the retaining plate  72  in a longitudinal direction of the retaining plate  72 . A pivotal shaft  74  is provided to penetrate a center of the retaining plate  72 . The retaining plate  72  is retained by the pivotal shaft  74  for a pivotal or swinging movement. Between the pivotal shaft  74  of each retaining plate  72  and each fourth follower roller  70 , a cylinder  76  for swinging the retaining plate  72  is mounted. A rotatable roller  78  is mounted downstream of the fourth driving roller  66  at the same level as the roller  16 . The elongated strip articles  14  are folded by the roller  78  and taken up by a take-up roller (not shown). 
     In the above-mentioned feed unit  1 , a plurality of elongated strip articles  14 ,  14 ′, . . . are laid in parallel to each other in axial directions of the rollers as shown in FIG.  2 . The first follower rollers  22 , the second follower rollers  24 , the retaining plates  26 , the cylinders  30 , the third follower rollers  68 , the fourth follower rollers  70 , the retaining plates  72 , and the cylinders  76  are respectively positioned on or above the elongated strip articles  14 ,  14 ′, . . . . Each of the retaining plates  26  is retained by the single pivotal shaft  28  while each of the retaining plates  72  is retained by the single pivotal shaft  74 . 
     Now, an operation of the feed unit  1  will be described. First, the intermittent driving roller  44  and the intermittent follower roller  46  intermittently convey the elongated strip articles  14  at a predetermined timing, and the print head  48  reciprocates above the plurality of elongated strip articles  14 ,  14 ′, . . . , thereby printing on the articles simultaneously. Then, the elongated strip articles  14  are conveyed to the drier unit  50  where ink on the articles  14  are dried and hardened. At this step, each of the elongated strip articles  14  is pulled in upstream and downstream directions with proper tension by sets of dancer rollers  38  and  58 . 
     Each upstream-side dancer roller  38  moves down when the corresponding elongated strip article  14  is fed from the feed bobbin  12  at a high speed and the lengths of slack of the article  14  increases excessively. Before the dancer roller  38  moves down abnormally, the first sensors  40  detect that the dancer roller  38  has reached the lower limit position and the signal is transmitted to the cylinder  30 . Then, a piston of the cylinder  30  is pushed down, so that the retaining plate  26  swings about the pivotal shaft  28  counterclockwise in FIG. 2, and then the second follower roller  24  moves down and is pushed against the second driving roller  20  through each elongated strip article  14 . Then, the elongated strip article  14  is conveyed at a rotation speed of the second driving roller  20 . Because the second driving roller  20  rotates at a lower speed than the first driving roller  18 , a feeding speed of the article  14  from the feed bobbin  12  decreases. Furthermore, the second driving roller  20  rotates at a lower speed than the intermittent driving roller  44  of the conveying section, and a feeding amount of the elongated strip article  14  by the second driving roller  20  is smaller than a feeding amount of the elongated strip article  14  by the intermittent driving roller  44 . Therefore, the dancer roller  38  does not move down lower than the first sensors  40 , and then the length slack of the elongated strip article  14  gradually decreases so that the dancer roller  38  moves up. 
     Before the dancer roller  38  moves up abnormally, the second sensors  42  detect that the dancer roller  38  has reached the upper limit position and the signal is transmitted to the cylinder  30 . Then, a piston of the cylinder  30  is pulled up so that the retaining plate  26  swings about the pivotal shaft  28  clockwise in FIG. 2, then the first follower roller  22  moves down and is pushed against the first driving roller  18  through each elongated strip article  14 . Then, the elongated strip article  14  is conveyed at a rotation speed of the first driving roller  18 . Because the first driving roller  18  rotates at a higher speed than the second driving roller  20 , a feeding speed of the article  14  from the feed bobbin  12  increases. Furthermore, the first driving roller  18  rotates at a higher speed than the intermittent driving roller  44 , and a feeding amount of the elongated strip article  14  by the first driving roller  18  is larger than a feeding amount of the elongated strip article  14  by the intermittent driving roller  44 . Therefore, the dancer roller  38  does not move higher than the second sensors  42 , and the length slack of the elongated strip article  14  gradually increases and the dancer roller  38  moves down. 
     At this time, because the first driving roller  18  and the second driving roller  20  are arranged at the levels slightly lower than the rollers  16  and  32  and are lower than conveying faces of the elongated strip articles  14 , the elongated strip articles  14  do not come into contact with the second driving roller  20  when the elongated strip articles  14  are carried by the first driving roller  18 , while the elongated strip articles  14  do not come into contact with the first driving roller  18  when the elongated strip articles  14  are carried by the second driving roller  20 . 
     Similarly, each downstream-side dancer roller  58  moves down when the corresponding elongated strip articles  14  are slowly fed toward the take-up roller and the lengths of slack of the articles  14  increase excessively. When the dancer roller  58  reaches the lower limit position, the corresponding third sensors  60  detect that the dancer roller  58  has reached the lower limit position and the signal is transmitted to the cylinder  76 . Then, a piston of the cylinder  76  is pulled up, so that the retaining plate  72  swings about the pivotal shaft  74  in a clockwise direction, and the third follower roller  68  moves down and is pushed against the third driving roller  64  through each elongated strip article  14 . Then, the elongated strip article  14  is conveyed at a rotation speed of the third driving roller  64 . Because the third driving roller  64  rotates at a higher speed than the fourth driving roller  66  and the intermittent driving roller  44 , a feeding speed of the article  14  to the take-up roller increases. Therefore, the dancer roller  58  does not move down lower than the third sensors  60 , and the lengths of slack of the elongated strip articles  14  gradually decrease so that the dancer roller  58  moves up. 
     When the dancer roller  58  reaches the upper limit, the corresponding fourth sensors  62  detect that the dancer roller  58  has reached the upper limit position and the signal is transmitted to the cylinder  76 . Then, a piston of the cylinder  76  is pushed down, the retaining plate  72  swings about the pivotal shaft  74  in a counterclockwise direction, so that the fourth follower roller  70  moves down and is pushed against the fourth driving roller  66  through each elongated strip article  14 , and then the elongated strip article  14  is conveyed at a rotation speed of the fourth driving roller  66 . Because the fourth driving roller  66  rotates at a lower speed than the third driving roller  64  and the intermittent driving roller  44 , a feeding speed of the article  14  to the take-up roller decreases. Therefore, the dancer roller  58  does not move higher than the fourth sensors  62 , and the lengths of slack of the elongated strip articles  14  gradually increase so that the dancer roller  58  moves down. 
     Because the third driving roller  64  and the fourth driving roller  66  are arranged at the positions slightly lower than the rollers  56  and  78  and are lower than conveying faces of the elongated strip articles  14 , the elongated strip articles  14  do not come into contact with the fourth driving roller  66  when the elongated strip articles  14  are carried by the third driving roller  64 , while the elongated strip articles  14  do not come into contact with the third driving roller  64  when the elongated strip articles  14  are carried by the fourth driving roller  66 . 
     According to the feed unit  1  of the embodiment, a plurality of elongated strip articles  14  can be accurately fed while preventing generation of slack or excessive tension of the articles  14 , thereby accurately printing fine patterns on the elongated strip articles  14  by the ink jet printer. Because the slack and the excessive tension which are different depending on the respective elongated strip article  14  are individually adjusted to keep the tension of each the article  14  constant, tensions of the long articles  14  can be separately adjusted even if a width, a thickness, material, or the like is different depending on the article  14 , so that printing can be applied to the articles  14  efficiently. Because a balanced tension is applied to the intermittent driving roller  44  disposed in the vicinity of the print head  48  by the upstream and downstream dancer rollers  38  and  58 , there is less resistance to driving, so that the resistance does not affect the print driving. The dancer rollers  38  and  58  can be maintained at the proper positions by detecting the upper and lower limit positions of the dancer rollers  38  and  58  by the first sensors  40 , the second sensors  42 , the third sensors  60 , and the fourth sensors  62 , by means of automatically selecting the first driving roller  18  or the second driving roller  20  and the third driving roller  64  or the fourth driving roller  66  respectively rotating at different speeds, and adjusting the conveying speed of the elongated strip articles  14 . 
     The processor of the invention is not limited to the configuration of the above embodiment, but the number of rollers of the feed unit can be varied properly. Also, the shape of each retaining plate  26 ,  72  each mounted with the two follower rollers may be such a shape as a triangle and an angular U, as far as the two follower rollers can be reliably switched from and to each other. Further, the speeds of the driving rollers can be varied properly, in which case the roller rotating at the lower speed may be a retainer such as a retaining table which completely stops the elongated strip articles. 
     According to the elongated-strip-article processor of the invention, the plurality of elongated strip articles which are laid in the ink jet printer or the like can be respectively conveyed accurately, and can be treated accurately. Therefore, treatment such as printing can be individually and simultaneously applied to the elongated strip articles with different thicknesses, widths, materials, or the like. Furthermore, the processor can be operated continuously so that efficiency of the operation can be increased.