Abstract:
A packaging bag line-folding and sealing machine includes a first sealing unit and a second sealing unit for sealing a packaging bag therebetween, a first rocker arm and a second rocker arm mounted at the first sealing unit, a locating block, a first link coupled between the first rocker arm and the locating block, two line-folding units, and two second links coupled between the second rocker arm and the line-folding units for moving the line-folding units to make folding lines on the packaging bag between the first and second sealing units upon movement of the first sealing unit relative to the locating block. The application of the packaging bag line-folding and sealing machine greatly improves the packaging quality of packaging bags, and allows adjustment of the line-folding units to fit different sizes of packaging bags, enhancing user convenience.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to bag sealing technology and more particularly, to a packaging bag line-folding and sealing machine, which enhances the sealing yield and prolongs the machine lifespan. 
     2. Description of the Prior Art 
     Referring to  FIG. 1 , a front view of a conventional packaging bag line-folding and sealing machine is illustrated. As illustrated, the packaging bag line-folding and sealing machine  10  comprises an upper sealing unit  11 , a lower sealing unit  13 , a connection rod  15 , two guide units  17 , and two line-folding units  19 . Moving the upper sealing unit  11  will bias the line-folding unit  19  to fold a packaging bag  12  therebetween the upper sealing unit  11  and the lower sealing unit  13 , and then to seal the packaging bag  12 . 
     The upper sealing unit  11  and the lower sealing unit  13  are set facing each other, and movable relative to each other to clamp and seal the packaging bag  12 . If the upper sealing unit  11  is moved upwards during actual application, the lower sealing unit  13  will be moved downwards to increase the gap  14  between the upper sealing unit  11  and the lower sealing unit  13  for enabling the packaging bag  12  to be moved through the gap  14  between the upper sealing unit  11  and the lower sealing unit  13 . 
     After the packaging bag  12  has been delivered to a predetermined position, the upper sealing unit  11  will be moved downwards and the lower sealing unit  13  will be moved upwards, causing the upper sealing unit  11  and the lower sealing unit  13  to clamp and heat the packaging bag  12 , finishing the packaging bag sealing operation. In order to improve the packaging bag  12  sealing quality, the line-folding units  19  are controlled to make a folding line one side, for example, the opposing side panels of the packaging bag  12  prior to the action of driving the upper sealing unit  11  and the lower sealing unit  13  to seal the packaging bag  12 . 
     The two guide units  17  are coupled to the upper sealing unit  11 , each defining therein a groove  171 . The line-folding units  19  each have one end thereof respectively coupled to the connection rod  15 , and are respectively coupled to the grooves  171  of the guide units  17  by a respective coupling device  191  that is movable along the mating groove  171 . When moving the upper sealing unit  11  relative to the connection rod  15 , the line-folding units  19  are moved along the grooves  171  of the respective guide units  17 , causing the line-folding units  19  to turn about the connection rod  15 . 
     During movement of the upper sealing unit  11  and the lower sealing unit  13  toward the packaging bag  12 , the line-folding units  19  will be moved toward the opposing side panels of the packaging bag  12  to compress the packaging bag  12 , making a folding line on the packaging bag  12 . Thereafter, the upper sealing unit  11  and the lower sealing unit  13  start sealing the packaging bag  12 . 
     The aforesaid prior art packaging bag line-folding and sealing machine  10  can make a folding line on a packaging bag  12  and then seal it, however it is still not satisfactory in function. At first, the line-folding units  19  of the packaging bag line-folding and sealing machine  10  are movable by a swinging action. When driving the line-folding units  19  to make a folding line on the packaging bag  12 , the folding line thus made may be not presented in an accurately symmetric condition, affecting the packaging quality of the packaging bag  12 . Further, if the size (width and/or height) of the packaging bag  12  is changed, the operator must adjust the relative positions of the upper sealing unit  11 , the lower sealing unit  13 , the connection rod  15 , the guide units  17  and/or the line-folding units  19 , enabling the line-folding units  19  to make a folding line on the packaging bag  12 . However, because multiple component parts must be adjusted, these component parts will affect one another during adjustment. Thus, this adjustment needs quite a bit of time to finish. 
     SUMMARY OF THE PRESENT INVENTION 
     It is, therefore, the main object of the present invention to provide a packaging bag line-folding and sealing machine, which enables the line-folding units thereof to be moved linearly to make symmetrical folding lines on the packaging bag to be sealed, improving the packaging quality of the packaging bag. 
     It is another object of the present invention to provide a packaging bag line-folding and sealing machine, which allows the operator to adjust the packaging bag line-folding and sealing machine to fit different sizes of packaging bags simply by means of adjusting the position and/or elevation of the line-folding member of each line-folding unit, enhancing application usability and user convenience. 
     It is still another object of the present invention to provide a packaging bag line-folding and sealing machine, which uses protective members to drive line-folding units, providing better protection to the packaging bag line-folding and sealing machine to reduce the chance of damage to the component parts. 
     To achieve the above mentioned and other objectives, the present invention provides a packaging bag line-folding and sealing machine, comprising: a first sealing unit; a second sealing unit facing toward the first sealing unit and movable relative to the first sealing unit to seal a packaging bag therebetween; a locating block; a first link coupled to the locating block; a first rocker arm mounted at the first sealing unit and coupled to the first link, the first rocker arm being movable by the first link to swing upon movement of the first sealing unit relative to the locating block; a second rocker arm connected to the first rocker arm and movable by the first rocker arm to swing; two line-folding units respectively coupled to the two second links and movable relative to each other by the second links to fold a packaging bag therebetween upon a swinging action of the second rocker arm. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein each the second link is a retractable protective member. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein each the line-folding unit comprises at least one connection member, at least one first sliding rail, at least one adjustment member and at least one line-folding member. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein the at least one connection member is located at the at least one first sliding rail and connected with the at least one adjustment member and one the second link, and the at least one line-folding member is connected with the at least one adjustment member in such a manner that the at least one line-folding member is movable to fold a packaging bag between the line-folding units upon movement of the at least one connection member along the at least one first sliding rail. 
     In one embodiment of the packaging bag line-folding and sealing machine, further comprising at least one second sliding rail adapted to support the first sealing unit, the second sealing unit and the locating block. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein each the line-folding unit further comprises a locating member mounted at the second sliding rail to support the at least one first sliding rail. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein the at least one first sliding rail and the second sliding rail are kept in a substantially orthogonal manner. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein the first sealing unit and the second sealing unit are movable in a first direction, and the line-folding units are movable in a second direction substantially perpendicular to the first direction. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein the first rocker arm comprises a fulcrum and a swing portion and the first link is coupled to the swing portion of the first rocker arm. 
     In one embodiment of the packaging bag line-folding and sealing machine, wherein the second rocker arm comprises a fulcrum connected to the fulcrum of the first rocker arm, and two swing portions respectively coupled to the second links. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic front view of a packaging bag line-folding and sealing machine according to the prior art. 
         FIG. 2  is a schematic front view of a packaging bag line-folding and sealing machine in accordance with a first embodiment of the present invention. 
         FIG. 3  is a schematic front view of a packaging bag line-folding and sealing machine in accordance with a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 2 , a front view of a packaging bag line-folding and sealing machine in accordance with a first embodiment of the present invention is illustrated. As illustrated, the packaging bag line-folding and sealing machine  20  comprises a first sealing unit  21 , a second sealing unit  23 , a locating block  25 , a first link  271 , a first rocker arm  273 , a second rocker arm  275 , a plurality of for example, two second links  277 , and two line-folding units  29 . 
     The first sealing unit  21  and the second sealing unit  23  are set facing each other and movable relative to each other between an open position and a close position. In one embodiment, the first sealing unit  21  is disposed at the bottom side, and the second sealing unit  23  is disposed above the first sealing unit  21 . During working of the packaging bag line-folding and sealing machine  20 , the first sealing unit  21  and the second sealing unit  23  are moved in reversed directions, for example, when moving the first sealing unit  21  upwards, the second sealing unit  23  is moved downwards, and therefore, the first sealing unit  21  and the second sealing unit  23  can clamp a packaging bag  2  therebetween and then seal the packaging bag  2 . 
     The first rocker arm  273  and the second rocker arm  275  are coupled together and arranged on the first sealing unit  21 . In one embodiment, the first rocker arm  273  comprises a fulcrum  2731  and a swing portion  2733 , and the second rocker arm  275  comprises a fulcrum  2751  and two swing portions  2753 . The fulcrum  2731  of the first rocker arm  273  is connected to the fulcrum  2751  of the second rocker arm  275 . Thus, forcing the first rocker arm  273  to swing will drive the second rocker arm  275  to swing. In one embodiment, the fulcrum  2731  of the first rocker arm  273  and the fulcrum  2751  of the second rocker arm  275  are coincided with each other and coupled to the first sealing unit  21 , allowing the first rocker arm  273  and the second rocker arm  275  to be oscillated back and forth relative to the first sealing unit  21 . 
     The locating block  25  is disposed adjacent to the first sealing unit  21 , and coupled to the first rocker arm  273  at the first sealing unit  21  by the first link  271 , for example, coupled to the swing portion  2733  of the first rocker arm  273  by the first link  271 . When operating the packaging bag line-folding and sealing machine  20  to seal a packaging bag  22 , the locating block  25  is kept immovable, and the first sealing unit  21  is movable relative to the locating block  25 . During movement of the first sealing unit  21  relative to the locating block  25 , the first link  271  at the locating block  25  will carry the first rocker arm  273  to swing, causing the second rocker arm  275  to swing. 
     The two swing portions  2753  of the second rocker arm  275  are respectively coupled to respective one ends of the second links  277 . The respective other ends of the second links  277  are respectively coupled to the line-folding units  29 . During swinging of the second rocker arm  275  about the axis extending through its fulcrum  2751 , the two second links  277  will move the line-folding units  29  in reversed directions to compress the packaging bag  22 . 
     In one embodiment, the first sealing unit  21  and the second sealing unit  23  are movable in a first direction Y, the two line-folding units  29  are movable in a second direction X substantially perpendicular to the first direction Y. Further, when moving the first sealing unit  21  and the second sealing unit  23  toward the packaging bag  22 , the two line-folding units  29  will also be moved toward the packaging bag  22 . 
     In actual application, the two line-folding units  29  are disposed at opposing left and right sides relative to the packaging bag  22  to be sealed, and moved toward the opposing side panels of the packaging bag  22 . After the line-folding units  29  touched the packaging bag  22 , the two opposing side panels of the packaging bag  22  are folded inwards. The first sealing unit  21  and the second sealing unit  23  are respectively disposed at opposing top and bottom sides relative to the packaging bag  22  to be sealed, and moved toward the packaging bag  22  to clamp and seal the laterally inwardly folded packaging bag  22 . 
     The packaging bag line-folding and sealing machine  20  is characterized by the relative motion between the first sealing unit  21  and the locating block  25  to move the first link  271 , the first rocker arm  273 , the second rocker arm  275  and the second links  277 , driving the line-folding unit  29  to make folding lines on the packaging bag  22 . By means of adjusting the relative positions or lengths among the locating block  25 , the first sealing unit  21 , the first link  271 , the first rocker arm  273 , the second rocker arm  275 , the second links  277  and/or the line-folding units  29 , the line-folding units  29  can make folding lines on the packaging bag  22  at a selected location. Further, the first sealing unit  21  and the second sealing unit  23  will seal the packaging bag  22  only after the line-folding units  29  have make folding lines on the packaging bag  22  at the selected location. 
     In one embodiment, each line-folding unit  29  comprises a connection member  291 , at least one first sliding rail  293 , at least one adjustment member  295  and at least one line-folding member  297 . The connection member  291  is located at the first sliding rail  293 , and connected to one respective second link  277 . The adjustment member  295  is located at the connection member  291 , and connected to the line-folding member  297 . During the operation to make folding lines on the packaging bag  22 , the respective second link  277  will move the connection member  291  along the first sliding rail  293 , causing the line-folding member  297  to fold the respective side panel of the packaging bag  22  to be sealed. During an adjustment operation, the line-folding member  297  can be moved along the adjustment member  295  to the desired position, enabling the line-folding member  297  to make a folding line on the packaging bag  22  at a predetermined location. 
     Because each second link  277  has its one end coupled to the second rocker arm  275  and its other end coupled to the connection member  291 , swinging the second rocker arm  275  can drive the second links  277  to move the connection members  291  of the line-folding units  29  along the respective first sliding rails  293 , causing the respective line-folding members  297  to move in the second direction X and to make folding lines on the packaging bag  22 . 
     Unlike the swinging action of the line-folding units  19  of the prior art packaging bag line-folding and sealing machine  10 , the line-folding units  29  of the packaging bag line-folding and sealing machine  20  of the present invention are linearly movable in the second direction (for example, horizontal direction) X to make symmetrical (top and bottom) folding lines on the packaging bag  22 , improving the packaging quality of the packaging bag  22 . 
     When using the packaging bag line-folding and sealing machine  20  to seal packaging bags  22  of a different size, the operator can fix the relative positions of the first sealing unit  21 , the locating block  25 , the first link  271 , the first rocker arm  273 , the second rocker arm  275  and the second links  277 , and then adjust the elevation of the second sealing unit  23  and the position of the line-folding units  29 , for example, the elevations and lengths of the line-folding members  297  of the line-folding units  29 . Thus, the packaging bag line-folding and sealing machine  20  is applicable to seal packaging bags  22  with different sizes. When compared to the prior art packaging bag line-folding and sealing machine  10 , the adjustment of the packaging bag line-folding and sealing machine  20  of the present invention is much easy, shortening the time the operator required to calibrate the packaging bag line-folding and sealing machine  20 . 
     In one embodiment, the line-folding and sealing machine  20  further comprises at least one second sliding rail  28  adapted to support the first sealing unit  21 , the second sealing unit  23  and/or the locating block  25 , facilitating adjustment of relative positions among the first sealing unit  21 , the second sealing unit  23  and/or the locating block  25  for enabling the packaging bag line-folding and sealing machine  20  to fold and seal different sizes of packaging bags  22 . 
     In one embodiment, each line-folding unit  29  further comprises a locating member  292  mounted on one respective second sliding rail  28  to support the associate first sliding rail  293  in a substantially orthogonal manner. 
     When adjusting the packaging bag line-folding and sealing machine  20 , the position of the first sealing unit  21  and/or the position of the locating block  25  are normally remained unchanged, the operator simply needs to lift or lower the second sealing unit  23 , allowing the packaging bag  22  to be delivered through the gap between the first sealing unit  21  and the second sealing unit  23  and the first sealing unit  21  and the second sealing unit  23  to clamp and seal the packaging bag  22 . Thereafter, adjust the line-folding units  29  to move the line-folding members  297  to the position about one half of the height of the packaging bag  22  where the line-folding members  297  can fold the packaging bag  22  to make symmetrical folding lines on the packaging bag  22 . 
     The second links  277  of the packaging bag line-folding and sealing machine  20  in accordance with the first embodiment of the present invention as illustrated in  FIG. 2  can be substituted by respective protective members. In a second embodiment of the present invention, as illustrated in  FIG. 3 , protective members  377  are used in the packaging bag line-folding and sealing machine  30  and coupled between the second rocker arm  275  and the line-folding units  29 . The second rocker arm  275  can move the line-folding units  29  by means of the respective protective members  377 . 
     In this second embodiment, the protective members  377  are protective air cylinders. If the external pressure applied to the opposite ends of the protective members  377  surpasses the protective pressure of the protective air cylinders, the protective members  377  will be forced to retract or expand. If the external pressure applied to the opposite ends of the protective members  377  is within the range of the protective pressure of the protective air cylinders, the protective members  377  will not be forced to retract or expand, and will work like the second links  277 , allowing the second rocker arm  275  to move the line-folding units  29  through the protective members  377 . 
     The arrangement of the protective members  377  can protect the component parts of the packaging bag line-folding and sealing machine  30  against damage. For example, if an internal component part of the packaging bag line-folding and sealing machine  30  is stuck, the protective members  377  can be forced by the applied external force to expand or retract, avoiding transmission of the applied external force to other component parts, lowering the risk of component damage. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.