Abstract:
A spout-equipped bag feed apparatus allows an increased number of spout-equipped bags to be stored. A plurality of conveyor rails are attached to a conveying device at a predetermined space and carried along an endless track. Each conveyor rail is capable of being loaded with and unloaded of a plurality of spout-equipped bags from one end thereof and capable of supporting the spout portions of the bags in such a manner that the bags are movable in the axial direction. Loading of bags into the conveyor rail is effected with a bag loading tool capable of being loaded with and unloaded of bags from one end thereof and capable of supporting the spout portions of the bags in such a manner that the bags are movable in the axial direction. The one end of the bag loading tool is butted against the one end of the conveyor rail, and the bags are pushed into the conveyor rail. From conveyor rails conveyed to a bag unloading position along the endless track of the conveying device, the bags are unloaded and sent to a receiving device by an unloading device. The bags received by the receiving device are successively supplied to bag holding members of a packaging machine by a bag delivery device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for feeding spout-equipped bags to a filling and packaging machine using them. More particularly, the present invention relates to a spout-equipped bag feed apparatus capable of storing an increased number of spout-equipped bags and hence capable of reducing the number of times at which the bag feed apparatus must be replenished with spout-equipped bags, thus allowing the operating efficiency to be increased. The present invention also relates to a spout-equipped bag feed method making it possible to store an increased number of spout-equipped bags and to reduce the number of times at which the bag replenishing operation must be performed, thereby allowing the operating efficiency to be increased. Further, the present invention relates to a bag loading tool suitable for use in loading bags into a spout-equipped bag feed apparatus. 
     2. Discussion of Related Art 
     Bags fitted with spouts are used as packaging containers for beverages. Spout-equipped bags are fitted with spouts in advance in the bag making process in such a manner that the spouts project from the bags. Thereafter, the spout-equipped bags are supplied to a spout-equipped bag packaging machine to fill the bags with a material to be packed. 
     When spout-equipped bags are supplied to the filling and packaging machine from a bag feed apparatus, the bags may be stored, for example, in a magazine of the bag feed apparatus. In such a case, because the spout-equipped bags are bulky owing to the projecting spout portions, the magazine can store only an extremely small number of spout-equipped bags in comparison to spoutless bags. Accordingly, the operating efficiency is unfavorably low. In addition, there is an extremely large difference in thickness between the top of the bag, which is fitted with a spout, and the bottom of the bag. Therefore, spout-equipped bags lack stability when they are piled on each other. 
     To solve the above-described problems, Japanese Patent No. 2500557, for example, discloses an apparatus arranged as follows. Magazines holding nozzled pouches are carried on a chain conveyor with attachments. A magazine reaching one end of the conveyor is moved to a predetermined position by a relay conveyor. At this position, the pouches are unloaded from the magazine with a pusher and transferred to an accumulator rail, from which the pouches are successively supplied to a filling and sealing packaging machine. Meanwhile, the emptied magazine is moved to an empty magazine accumulating section by a relay conveyor. 
     However, with the achievement of an increased operating speed of filling and packaging machines, an arrangement capable of storing an increased number of spout-equipped bags has been demanded. With the feed apparatus disclosed in Japanese Patent No. 2500557, only the upper side of the chain conveyor is used to hold magazines. Therefore, the number of bags that can be held per unit installation area is limited. In order to increase the number of spout-equipped bags that can be stored, it is necessary to increase the length of the track of the chain conveyor for carrying magazines. This causes the installation area of the apparatus to increase correspondingly. 
     SUMMARY OF THE INVENTION 
     The present invention was made in view of the above-described problems associated with the prior art. 
     Accordingly, an object of the present invention is to provide a spout-equipped bag feed apparatus and method capable of storing an increased number of spout-equipped bags per unit installation area of the apparatus. 
     Another object of the present invention is to provide a bag loading tool suitable for use in loading bags into the above-described apparatus. 
     To attain the above-described objects, the present invention provides a spout-equipped bag feed apparatus wherein a plurality of holding members for conveying bags are attached to a conveying device with an endless track at a predetermined space so as to be movable along the entire circumference of the endless track. Each holding member for conveying bags is of continuous length and has a bag support portion capable of being loaded with and unloaded of a plurality of spout-equipped bags at at least one end in the axial direction thereof. The bag support portion is adapted to hold the spout portions of the spout-equipped bags in such a manner that the spout-equipped bags are movable in the axial direction of the bag support portion. The holding members for conveying bags are attached to the conveying device in such a manner that the axial direction of the holding members for conveying bags extends in a direction perpendicularly intersecting the conveying direction of the conveying device. The apparatus further includes an unloading device for unloading the spout-equipped bags from one end of one of the holding members for conveying bags conveyed to a bag unloading position provided at a predetermined position along the endless track of the conveying device. A bag receiving device receives the spout-equipped bags unloaded from the holding member for conveying bags. A delivery device successively delivers the spout-equipped bags from the bag receiving device to bag holding members of a packaging machine. 
     In one embodiment of the present invention, each holding member for conveying bags is arranged to hold the spout-equipped bags in such a manner that the bag portions of the spout-equipped bags extend from the holding member for conveying bags outward of the endless track. 
     Further, the holding member for conveying bags may be arranged as follows. The holding member for conveying bags has a tubular member, at least one end of which is open. The tubular member is formed with a slit extending from the open end in the axial direction of the tubular member. The slit constitutes the bag support portion. 
     In addition, the present invention provides a bag loading tool suitable for use in loading spout-equipped bags into the holding members for conveying bags of the above-described spout-equipped bag feed apparatus. The bag loading tool is formed as a member of continuous length and has a bag support portion capable of being loaded with and unloaded of a plurality of spout-equipped bags at at least one end in the axial direction thereof. The bag support portion holds the spout portions of the spout-equipped bags in such a manner that the spout-equipped bags are movable in the axial direction of the bag support portion. A guide portion is formed at at least either one of the one end of each holding member for conveying bags and the one end of the bag loading tool to guide and position the other of them. When the one end of the bag loading tool is butted against the one end of the holding member for conveying bags through the guide portion, the spout-equipped bags are movable from the bag support portion of the bag loading tool to the bag support portion of the holding member for conveying bags so as to be loaded thereinto. 
     In addition, the present invention provides a spout-equipped bag feed apparatus including a holding member for conveying bags of continuous length that has a bag support portion capable of being loaded with and unloaded of a plurality of spout-equipped bags at at least one end in the axial direction thereof. The bag support portion holds the spout portions of the spout-equipped bags in such a manner that the spout-equipped bags are movable in the axial direction. The apparatus further includes a conveying device having an endless track. A plurality of the holding members for conveying bags are attached to the conveying device at a predetermined space in such a manner that the axial direction of the holding members for conveying bags extends in a direction perpendicularly intersecting the conveying direction of the conveying device. The holding members for conveying bags are conveyed along the entire circumference of the endless track. An unloading device unloads the spout-equipped bags from one end of one of the holding members for conveying bags conveyed to a bag unloading position provided at a predetermined position along the endless track of the conveying device. A bag receiving device receives the spout-equipped bags unloaded from the holding member for conveying bags. A delivery device successively delivers the spout-equipped bags from the bag receiving device to bag holding members of a packaging machine. Further, the apparatus includes a bag loading tool of continuous length for loading spout-equipped bags into each holding member for conveying bags. The bag loading tool has a bag support portion capable of being loaded with and unloaded of spout-equipped bags at at least one end in the axial direction thereof. The bag support portion holds the spout portions of the spout-equipped bags in such a manner that the spout-equipped bags are movable in the axial direction. When the one end of the bag loading tool is butted against the one end of the holding member for conveying bags, the bag support portion of the bag loading tool connects with the bag support portion of the holding member for conveying bags so that the spout-equipped bags are movable from the bag loading tool to the holding member for conveying bags so as to be loaded thereinto. 
     In addition, the present invention provides a method of feeding spout-equipped bags to a packaging machine. The method uses a plurality of holding members for conveying bags of continuous length each capable of being loaded with and unloaded of a plurality of spout-equipped bags at at least one end in the axial direction thereof. The holding members for conveying bags hold the spout portions of the spout-equipped bags in such a manner that the spout-equipped bags are movable in the axial direction. The holding members for conveying bags are attached to a conveying device having an endless track at a predetermined space in such a manner that the axial direction of the holding members for conveying bags extends in a direction perpendicularly intersecting the conveying direction of the conveying device. The holding members for conveying bags are moved along the entire circumference of the endless track so that spout-equipped bags can be loaded into the holding members for conveying bags in an any desired order at a plurality of positions along the endless track. At a predetermined position along the endless track, the spout-equipped bags are unloaded from one end of one of the holding members for conveying bags conveyed to the position, and the unloaded spout-equipped bags are sent to the outside of the endless track. The spout-equipped bags sent out are successively supplied to the packaging machine. 
     In one embodiment of the present invention, spout-equipped bags are loaded into each holding member for conveying bags by using a bag loading tool. The tool is capable of being loaded with and unloaded of a plurality of spout-equipped bags at at least one end in the axial direction thereof and capable of supporting the spout-equipped bags in such a manner that the spout-equipped bags are movable in the axial direction. The one end of the bag loading tool is butted against the one end of the holding member for conveying bags, whereby the spout-equipped bags held on the bag loading tool are moved to the holding member for conveying bags so as to be loaded thereinto. 
     In another embodiment of the present invention, a guide portion is formed at at least either one of the one end of the holding member for conveying bags and the one end of the bag loading tool to guide and position the other of them, thereby facilitating the bag loading operation. 
    
    
     Other objects and advantages of the present invention will become apparent from the following detailed description of illustrated embodiments of the invention. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic plan view of a spout-equipped bag feed apparatus according to an embodiment of the present invention. 
     FIG. 2 is a schematic front view of the spout-equipped bag feed apparatus. 
     FIG. 3 is a schematic side view of the spout-equipped bag feed apparatus. 
     FIG. 4 is a front view of a spout-equipped bag used in the spout-equipped bag feed apparatus. 
     FIG. 5 is a perspective view showing a conveyor rail and a guide member. 
     FIG. 6 is a perspective view of a bag loading tool. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted, however, that the scope of the present invention is not limited to the embodiments stated below. 
     FIG. 1 is a plan view schematically showing the arrangement of a spout-equipped bag feed apparatus  1  according to an embodiment of the present invention. FIGS. 2 and 3 are schematic front and side views, respectively, of the spout-equipped bag feed apparatus  1 . 
     The spout-equipped bag feed apparatus  1  supplies spout-equipped bags  11  (described later) to a filling and packaging machine  3  shown above the spout-equipped bag feed apparatus  1  in FIG.  1 . The spout-equipped bag feed apparatus  1  includes conveyor rails  61 , a conveying device  31 , an unloading device  71 , a receiving device  79 , and a bag delivery device  81 , which will be described later in detail. 
     FIG. 4 shows a spout-equipped bag  11 . The spout-equipped bag  11  has a bag portion  13  formed from a laminated composite material consisting essentially of aluminum foil and a synthetic resin film. A spout  15  is fitted to the center of the upper side (as viewed in the figure) of the bag portion  13  in such a manner as to project therefrom by a predetermined length. The portion of the spout  15  that projects from the bag portion  13  is formed with three radially extending flanges  17   a,    17   b  and  17   c  at predetermined positions in order from the upper side. The lowermost flange  17   c  abuts on the upper end of the bag portion  13  to position the spout  15  with respect to the bag portion  13 . 
     Meanwhile, the filling and packaging machine  3  has an intermittently rotary table  7  provided on a base  5 , as shown in FIG.  1 . Bag holding members  8  (see FIG. 3) are provided on the intermittently rotary table  7  at predetermined spaces in the circumferential direction. The filling and packaging machine  3  fills each bag  11  with a material to be packed and then seals the bag  11  to produce a packaged article. The filling and packaging machine  3  is publicly known. Therefore, a further detailed description thereof is omitted. It should be noted that the filling and packaging machine  3  processes two bags  11  simultaneously at each step, and the bag feed apparatus  1  (described below) also supplies two bags  11  at a time to the filling and packaging machine  3 . The upper two flanges  17   a  and  17   b  of the bag  11  are used to hold the bag  11  when handled at the bag feed apparatus  1  or the filling and packaging machine  3 . 
     In FIGS. 2 and 3, a base frame  19  has side frames  21   a  and  21   b  attached thereto. The side frames  21   a  and  21   b  extend in vertical planes, respectively, in parallel to each other. Stays  23   a,    23   b  and  23   c  are disposed parallel to each other between the side frames  21   a  and  21   b  and each secured to the side frames  21   a  and  21   b  at both ends thereof. 
     The bag feed apparatus  1  has a conveying device  31  for moving conveyor rails  61  (described later). The conveying device  31  has a driving shaft  33 . The driving shaft  33  has both ends rotatably supported by respective bearings  35   a  and  35   b  secured to portions of the side frames  21   a  and  21   b  near the right-hand ends thereof as viewed in FIG.  1 . The driving shaft  33  has sprocket wheels  37   a  and  37   b  secured thereto at axially spaced positions slightly away from both ends of the driving shaft  33 . The sprocket wheels  37   a  and  37   b  have the same configuration. Further, a gear  39  is secured to the driving shaft  33  at the inner side of the upper side frame  21   a  as viewed in FIG.  1 . 
     A driven shaft  41  is rotatably supported by bearings  43   a  and  43   b  secured to portions of the side frames  21   a  and  21   b  near the left-hand ends thereof as viewed in FIG.  1 . The bearings  43   a  and  43   b  are installed at approximately the same height as the bearings  35   a  and  35   b  for the driving shaft  33 . Further, the driven shaft  41  has sprocket wheels  45   a  and  45   b  secured thereto at axially spaced positions corresponding to the positions of the sprocket wheels  37   a  and  37   b  on the driving shaft  33 . The sprocket wheels  45   a  and  45   b  have the same configuration as that of the sprocket wheels  37   a  and  37   b.    
     A chain  51   a  passes over the sprocket wheels  37   a  and  45   a  so as to rotate around the stays  23   a,    23   b  and  23   c.  Another chain  51   b  passes over the sprocket wheels  37   b  and  45   b  so as to rotate around the stays  23   a,    23   b  and  23   c.  The chains  51   a  and  51   b  have the same length and the same pitch. It should be noted that only the left and right end portions of the chains  51   a  and  51   b  are shown in FIG.  1 . 
     Guide rails  53 ,  54 ,  55  and  56  are secured to the side frames  21   a  and  21   b  by appropriate devices to guide the associated chains  51   a  and  51   b  along the direction of movement thereof. A motor  57  has a gear  59  secured to the output shaft thereof at the inner side of the side frame  21   a.  The gear  59  is in mesh with the gear  39  secured to the driving shaft  33  to drive the driving shaft  33 . When the driving shaft  33  is driven to rotate, the chains  51   a  and  51   b  rotate, causing the driven shaft  41  to rotate. The direction of rotation of the chains  51   a  and  51   b  is indicated by the arrow R shown in FIG.  2 . 
     The conveyor rails  61  serve as holding members for conveying bags for conveying a plurality of bags  11  held thereon. As shown in FIG. 5, each conveyor rail  61  is formed in the shape of a tube with a quadrangular cross-sectional configuration having a through-hole. The conveyor rail  61  has a slit or opening  62  in the center of one side wall thereof, more specifically, in the center of the lower wall  64 . The slit  62  extends axially from one end  65  to the other end  66 . The width of the slit  62  is larger than the diameter of the spout  15  of each bag  11  but smaller than the diameter of the flange portion  17 . Therefore, each bag  11  can be loaded into the conveyor rail  61  from the one end  65  thereof in such a manner that the upper two flanges  17   a  and  17   b  of the spout  15  sandwich the lower wall  64  therebetween from the upper and lower sides. The loaded bag  11  is movable along the slit  62 . 
     A guide member  67  is fitted to the one end  65  of the conveyor rail  61 . As shown in FIG. 5, the guide member  67  has a quadrangular cross-sectional configuration similar to that of the conveyor rail  61 . However, the cross-sectional area of the guide member  67  gradually increases from one end thereof fitted to the conveyor rail  61  toward the other end thereof. The lower wall  68  of the guide member  67  is formed with a slit  69  wider than the slit  62  of the conveyor rail  61 . The slit  69  extends over the entire axial length of the guide member  67 . The guide member  67  will be described later again. 
     Each conveyor rail  61  is attached to the chains  51   a  and  51   b  through a conveyor rail attachment member  63 . As shown in FIGS. 2 and 3, the attachment member  63  is an elongated member having a U-shaped sectional configuration, the upper end of which is open. The attachment member  63  is secured at both ends thereof to the outer peripheral sides of the chains  51   a  and  51   b.  More specifically, the attachment members  63  are each secured to the chains  51   a  and  51   b  at the bottom portions near both ends thereof. The attachment members  63  are disposed at predetermined spaces in the direction of travel of the chains  51   a  and  51   b  in a state where the opening portion of each attachment member  63  faces upward. It should be noted that, in FIG. 2, illustration of a link where no attachment member  63  is provided is omitted. The conveyor rail  61  is attached to each individual attachment member  63  secured to the chains  51   a  and  51   b  in a state where the wall  64  formed with the slit  62  faces outward. 
     In FIG. 3, a fall-preventing stopper  25  is disposed in close proximity to the ends  66  of the conveyor rails  61  to prevent the bags  11  loaded in the conveyor rails  61  from the ends  65  from falling off from the ends  66 . As shown in FIG. 3, the fall-preventing stopper  25  is secured to the side frame  21   a  to extend along the direction of movement of the chain  51   a  except a position at which bags  11  are transferred from conveyor rails  61  to a transfer rail  83  (described later). 
     In FIGS. 2 and 3, an unloading device  71  is disposed at a predetermined position below the conveying device  31  to transfer bags  11  from conveyor rails  61  stopped at the unloading device  71 , that is, at a bag unloading position, to the transfer rail  83  (described later). The unloading device  71  has a rectilinear slide type air cylinder  75  fixed to a bracket  77  secured to the base frame  19 . A push member  73  is attached to the air cylinder  75  to move horizontally as viewed in FIG.  3 . 
     The push member  73  moves from the solid-line position to the two-dot chain line position shown in FIG. 3 to push out the bags  11  from the ends  66  of the conveyor rails  61  to the transfer rail  83  (described later). As shown in FIG. 2, the push member  73  has an approximately Y-shaped configuration as viewed from the front, i.e. from this side of the plane of the figure, so as to operate for two conveyor rails  61  simultaneously. It should be noted that the fall-preventing stopper  25  is not present at the position of the push member  73 , as has been stated above. 
     The transfer rail  83  functions as a bag receiving device  79  for holding bags  11  pushed out from the conveyor rails  61  by the unloading device  71 . In this embodiment, the transfer rail  83  is formed from three plates disposed parallel to each other at predetermined spaces to receive bags  11  simultaneously sent out in two rows from two rails  83 . The bags  11  are movable along the transfer rail  83  in such a manner that the respective spout portions  15  of bags  11  are fitted in two gaps defined between the three plates and the spout flanges  17  of the bags  11  slide on the plates. The transfer rail  83  is suspended by a gate-shaped frame  82  stood on the machine base  5 . The transfer rail  83  is vibrated by a vibrator (not shown) provided for the transfer rail  83 , thereby allowing the bags  11  to move rightward as viewed in FIG. 3 along the transfer rail  83 . Alternatively, pressurized air may be blown on the bags  11  to send them forward instead of using the vibrator. In this embodiment, the transfer rail  83  is shorter in length than the conveyor rails  61 . The distance between the gaps for retaining the bags  11  is the same as the distance between the slits of a pair of adjacent conveyor rails  61  attached to the chains  51   a  and  51   b.  Further, the transfer rail  83  is installed on the gate-shaped frame  82  in such a manner that the right-hand end  87  (as viewed in FIG. 3) of the transfer rail  83  is slightly lower than the left-hand end  85  thereof. First and second stoppers (not shown) are provided in the vicinity of the right-hand end  87  of the transfer rail  83 . The first and second stoppers are capable of advancing and retracting. When advanced, the first and second stoppers abut on the top and second bags  11  to temporarily stop the advance of the bags  11 . 
     A rectilinear slide type air cylinder  89  constitutes a bag delivery device  81  for delivering bags  11  to the packaging machine  3 . The air cylinder  89  is installed on the top of the gate-shaped frame  82 , as shown in FIG. 3 (illustration of the air cylinder  89  is omitted in FIGS.  1  and  2 ). The air cylinder  89  actuates an advancing and retracting frame  91  attached thereto to reciprocate horizontally as viewed in FIG. 3 by a predetermined distance. As shown in FIG. 3, the advancing and retracting frame  91  is formed in an L shape from a horizontal portion  93  secured to the top of the air cylinder  89  and a vertical portion  95  extending downward from the right-hand end of the horizontal portion  93 . A chuck opening and closing air cylinder  97  is fixed to the lower end of the vertical portion  95 . A gripping chuck  99  is secured to the lower end of the air cylinder  97 . The gripping chuck  99  is opened and closed by the air cylinder  97 . The gripping chuck  99  grips the top bags  11  on the transfer rail  83 . In this state, the advancing and retracting frame  91  advances to deliver the bags  11  to a bag holding member  8  of the packaging machine  3 . 
     The following is a description of a method of supplying bags  11  to the filling and packaging machine  3  by using the bag feed apparatus  1  arranged as stated above. 
     First, a plurality of bags  11  are loaded into each conveyor rail  61  by using a bag loading tool  101  capable of holding a plurality of bags  11 . The bag loading tool  101  has a configuration similar to that of the conveyor rail  61 . As shown in FIG. 6, the bag loading tool  101  is a tubular member with a quadrangular cross-sectional configuration having a through-hole. One wall of the bag loading tool  101 , i.e. the lower wall  107  as viewed in FIG. 6, is formed with an axially extending slit  103 . The width of the slit  103  is larger than the diameter of the spout  15  but smaller than the diameter of the flanges  17 . Therefore, a large number of bags  11  can be loaded into the bag loading tool  101  from an opening  106  in such a manner that the flanges  17  lie on the lower wall  107 . The loading of bags  11  is performed during the process of producing bags  11 . The openings at both ends of the bag loading tool  101  are covered with caps to prevent the bags  11  from falling off during transport. The bag loading tool  101  loaded with bags  11  and supplied in this way is inserted into a guide member  67  attached to a conveyor rail  61  (see FIG. 5) after the cap has been removed from one opening of the bag loading tool  101 . The guide member  67  guides the bag loading tool  101  to a position where it butts against the conveyor rail  61  such that the axis of the bag loading tool  101  is approximately coincident with the axis of the conveyor rail  61 . At this time, the slit  103  of the bag loading tool  101  and the slit  62  of the conveyor rail  61  coincide with each other. Thereafter, the spout-equipped bags  11  held on the bag loading tool  101  are pushed toward the conveyor rail  61  by hand, thereby loading the bags  11  into the conveyor rail  61 . The loading operation can be performed independently of the order in which the conveyor rails  61  are arranged side by side. It is also possible to carry out the bag loading operation irrespective of whether the relevant conveyor rail  61  is located above or below the chains  51 . The conveying device  31  is driven intermittently in such a way that it stops temporarily after moving through a distance corresponding to two conveyor rails  61 . 
     While the conveying device  31  is at rest, the bags  11  are sent out to the transfer rail  83  from two conveyor rails  61  having stopped at the bag unloading position by the unloading device  71 . More specifically, the air cylinder  75  is activated to move the push member  73  from the left-hand solid-line position toward the right-hand two-dot chain line position shown in FIG.  3 . Thus, the bags  11  held on the conveyor rails  61  are forced to move from the left side toward the right side. In this case, first, the bags  11  are sent forward until the top bags  11  in the two rows reach the distal end  87  of the transfer rail  83 , that is, the position where the bags  11  are taken out by the gripping chuck  99 . At this time, some bags  11  still remain in the conveyor rails  61 . The top and second bags  11  are positioned by the above-described first and second stoppers, respectively. 
     It should be noted that a sensor (not shown) is provided in association with the unloading device  71  to judge whether or not bags  11  are held on two conveyor rails  61  having stopped at the bag unloading position. If it is sensed that either or both of the conveyor rails  61  are empty, the conveying device  31  is further fed through a distance corresponding to one pitch (corresponding to two conveyor rails  61 ). The pitch-by-pitch feed of the conveying device  31  is repeated until it is sensed that both of the conveyor rails  61  are loaded with bags  11 . When a pair of conveyor rails  61  loaded with bags  11  are detected, the bag unloading operation is performed by the unloading device  71 . 
     Then, the push member  73  is intermittently advanced by one pitch (corresponding to one bag  11 ) at a time in synchronism with the timing at which bags  11  are successively taken out and delivered to the packaging machine  3  by the bag delivery device  81 , as described later. When the push member  73  reaches the foremost end, the supply of all the bags  11  from the two conveyor rails  61  to the transfer rail  83  is completed. Then, the push member  73  returns to the previous position. Thereupon, the conveying device  31  is driven to move through a distance corresponding to one pitch (corresponding to two conveyor rails  61 ). The conveying device  31  stops when two subsequent conveyor rails  61  loaded with bags  11  reach the bag unloading position. Meanwhile, the bags  11  on the transfer rail  83  should preferably be advanced by the action of a vibrator, for example. Then, the push member  73  is activated again to send new groups of bags  11  until the top bags  11  in the new groups abut on the last bags  11  in the groups of bags  11  sent previously. After all the new groups of bags  11  have been sent to the transfer rail  83 , the subsequent conveyor rails  61  are driven. 
     Although in the foregoing embodiment the push member  73  is advanced by one pitch at a time synchronously with the timing at which bags  11  are successively taken out and delivered to the packaging machine  3 , the arrangement may be such that the push member  73  is advanced by a predetermined distance when it is sensed with a sensor that the last bags  11  on the transfer rail  83  have reached a predetermined position. In such a case, the vibrator should preferably be activated at all times to advance the bags  11  on the transfer rail  83 . 
     Next, the operation of delivering bags  11  to the packaging machine  3  by the bag delivery device  81  will be described. After the presence of the top bags  11  positioned by the first stopper has been conformed with a sensor, the gripping chuck  99  of the bag delivery device  81  is closed to grip the spout portion  15 , for example, of each of the top bags  11 . At this time, the first stopper retracts to allow the top bags  11  to move. That is, the top bags  11  are allowed to be taken out. The advancing and retracting frame  91  advances to move the gripping chuck  99  to the packaging machine  3 . After the bags  11  have been delivered to a bag holding member  8  of the packaging machine  3 , the advancing and retracting frame  91  retracts. Meanwhile, the second stopper is retracted to allow the second bags  11  to advance, and the first stopper is advanced to position these bags  11 . When the third bags  11  advance to a predetermined position, these bags  11  are positioned at a stop position by the second stopper that has already advanced. 
     In the foregoing first embodiment, the length of the transfer rail  83  is shorter than the length of each conveyor rail  61 . However, the length of the transfer rail  83  may be longer than the length of each conveyor rail  61 . A second embodiment in which the transfer rail  83  is longer than the conveyor rails  61  will be described below. 
     In the second embodiment, the way in which bags  11  are loaded from the bag loading tool  101  into each conveyor rail  61  and the way of intermittently driving the conveying device  31  are the same as in the first embodiment. The way in which bags  11  are delivered from the transfer rail  83  to the packaging machine  3  by the bag delivery device  81  is also the same as in the first embodiment. 
     In the second embodiment, the unloading device  71  transfers the bags  11  from the conveyor rails  61  to the transfer rail  83  as follows. First, the push member  73  is advanced to send all the bags  11  in the conveyor rails  61  to the transfer rail  83 . When the senior senses that the top bags  11  reaching a predetermined position have been stopped and positioned by the first stopper, the bag delivery device  81  begins operating to deliver the bags  11  to the packaging machine  3  one after another. Meanwhile, the push member  73  retracts to the previous position, and the conveying device  31  is driven by one pitch. Thus, the subsequent conveyor rails  61  advance to a predetermined position and stop there. It should be noted that the transfer rail  83  is vibrated by a vibrator constantly or intermittently in synchronism with the delivery of the bags  11 , thereby conveying the bags  11  on the transfer rail  83  forwardly. As the bags  11  are successively delivered from the transfer rail  83  to the packaging machine  3  by the bag delivery device  81 , the number of bags  11  on the transfer rail  83  decreases. When the sensor senses that the number of remaining bags  11  has become less than a predetermined value, the push member  73  is activated again, whereby all the bags  11  in the conveyor rails  61  are forced into the transfer rail  83 . This is repeated thereafter. 
     The first and second embodiments may be arranged such that the delivery of bags  11  is not performed when the top bags  11  are not present at a predetermined position, that is, when the top bags  11  have not yet been stopped and positioned at a predetermined position by the first stopper, at the time when the bag delivery device  81  should deliver bags  11  from the transfer rail  83  to the packaging machine  3 . The fact that no bags are held on the corresponding bag holding member  8  of the packaging machine  3  is sensed with a sensor provided at the packaging machine  3 , and operations such as filling of a material to be packed are not carried out for this bag holding member  8 . Alternatively, the operations performed on the packaging machine  3  may be temporarily stopped. 
     As will be clear from the foregoing description, the spout-equipped bag feed apparatus  1  according to the present invention can hold spout-equipped bags  11  not only on the upper side of the conveying device  31  but also on the entire circumference thereof. Therefore, it is possible to store more than twice as many spout-equipped bags  11  as in the conventional apparatus per unit installation area of the apparatus. Accordingly, it is possible to reduce the number of times at which the bag feed apparatus  1  must be replenished with spout-equipped bags  11 . The operation of replenishing the bag feed apparatus  1  with spout-equipped bags  11  need not be performed in the order in which the conveyor rails  61  are arranged side by side. Further, the replenishing operation can be carried out for any emptied conveyor rail  61  irrespective of whether the conveyor rail  61  is located above or below the chains  51 . Therefore, the operator can perform the replenishing operation efficiently without restriction on his/her moving direction or the loading position. 
     It should be noted that the present invention is not limited to the foregoing embodiments but can be modified in a variety of ways.