Apparatus for supplying a large amount of bag

An apparatus for supplying a large amount of bags includes: a bag stocking mechanism that stocks a large amount of raised bags and guides the stocked bags to the front end thereof; and a bag transport mechanism that transports the bags of the bag stocking mechanism to a packaging machine. The apparatus further includes, a bag pickup mechanism and a bag delivery mechanism that pick up the bag from the bag stocking mechanism; a detection unit that detects the orientation of the picked up bag; and a bag turning mechanism that turns the bag in the predetermined transport direction of the bag transport mechanism according to the orientation of the bag detected by the detection unit.

RELATED APPLICATIONS

This application is a National Stage of International Application No. PCT/JP13/82527 filed Dec. 4, 2013, which claims the benefit of Japanese Patent Application No. 2012-266949, filed Dec. 6, 2012, and Japanese Patent Application No. 2013-199693, filed Sep. 26, 2013.

FIELD OF THE INVENTION

The present invention relates to an apparatus for supplying a large amount of bags, the apparatus supplying a large volume of zipper bags vertically stocked in a standing position in alignment, for example, a standing pack and a gusset bag, to a packaging machine.

BACKGROUND OF THE INVENTION

A typical rotary packaging machine includes a clamp on the outer edge of a rotary filling table. A bag sucked by a sucking device is delivered from a bag supplying apparatus to the clamp by a delivery device and then is rotated and transported while being filled with a material to be packaged. After that, the opening of the bag is sealed to package the material. In an existing bag supplying apparatus, about 200 bags can be stocked at the same time. In the case of a packaging machine capable of packaging 50 bags per minute, an operation continues for about four minutes. This requires an operator dedicated to constantly refill bags to the bag supplying apparatus.

In Japanese Patent Laid-Open No. 2007-290768, a vertical bag-stocking mechanism is used to store a large number of bags in a standing position. The bag stocking mechanism can simultaneously stock a large number of bags with space saving and stability, reducing the number of times of refilling of bags by an operator.

FIG. 21is a schematic diagram of a related bag supplying apparatus disclosed in Japanese Patent Laid-Open No. 2007-290768. The bag supplying apparatus includes a bag stocking mechanism1that stores a large number of stacked bags W and transport the bags W forward, a bag positioning mechanism2that transports the bags W one by one and positions the bags W at a predetermined point before the bags W are supplied to a packaging machine (not shown), bag delivery mechanisms3that are disposed between the bag stocking mechanism1and the bag positioning mechanism2, receives the bags W one by one from the bag stocking mechanism1, and delivers the bags W to the bag positioning mechanism2, and a bag supplying mechanism4that supplies the bag W positioned at the predetermined point of the bag positioning mechanism2to the packaging machine.

The bag stocking mechanism1stores the multiple bags W placed in a standing position with the openings directed upward, transports the bags W forward, and positions the front bag W at the predetermined point on the front side of the bag stocking mechanism1in a transport direction. The bag stocking mechanism1includes a frame6mounted on a stand5, a pair of right and left cassette guide members7mounted on the frame6, and first conveyors8mounted in the frame6.

The frame6includes a receiver9gently tilting forward and a pair of right and left side plates11. The front and rear ends of the side plates11longitudinally protrudes from the receiver9. Support shafts15and16are rotatably supported in a horizontal direction by the side plates such that pulleys13and14at the front and rear of the first conveyors8are fixed on the support shafts15and16. A conveyor belt17is longitudinally looped over the pulleys13and14. The upper side of the conveyor belt17is supported over the receiver9. The support shafts15and16inFIG. 21are intermittently rotated counterclockwise by a motor (not shown), allowing the conveyor belt17to intermittently rotate forward (to the left inFIG. 21) while sliding on the receiver9.

The cassette guide member7includes a plate part18disposed in a vertical plane along the transport direction of the first conveyor8(also the transport direction of the bag W) and first stoppers19formed on the front end of the plate part18so as to be perpendicular to the transport direction. The pair of right and left cassette guide members7is disposed with an adjustable spacing on the receiver9. The first stoppers19acting as stoppers are opposed to each other. A front bag Wa of the bags W stored in the bag stocking mechanism1comes into contact with the first stoppers19and thus is positioned thereon. The front bag Wa comes into contact with the first stoppers19with a predetermined width only in the vicinity of both side edges of the bag Wa.

The bag stocking mechanism1includes a bag supply cassette21. The bag supply cassette21is substantially shape like an open box, accommodating the multiple bags W disposed in a vertical plane along the transport direction of the first conveyor8in a standing position with the openings directed upward. The bottom wall of the bag supply cassette21supports the vicinity of both bottom edges of the bags W. Both side edges of the bag W are restricted by the side walls of the bag supply cassette21while the bags W are transported forward by the first conveyor8.

The bag stocking mechanism1further includes a bag retainer29. The bag retainer29is placed on the first conveyor8and is moved forward with the bags w; meanwhile, the retainer29holds the rear ends of the multiple bags W stored in the bag supply cassette21so as to keep the standing position of the bags W.

The operations of the bag supplying apparatus are performed as follows:

(1) First, the bag supply cassette21, in which the multiple bags W are stacked and stored in a standing position with the openings directed upward, is inserted between the cassette guide members7and is placed on the receiver9, and then the bag retainer29is placed at the rear of the bag supply cassette21.

(2) A shutter for fixing the bags W is picked up and then the first conveyor8is driven one time. Thus, the front bag Wa in the cassette comes into contact with the first stoppers19and is positioned at a pickup point. The rear ends of the bags in the cassette are held by the bag retainer29.

(3) The bag delivery mechanisms3of the rotor31are rotated to suck and pick up the front bag Wa positioned at the pickup point. Each time the bag Wa is picked up, the first conveyor8is intermittently driven to transport the remaining bags accordingly in the bag supply cassette21. In each time of pickup, the front bag Wa comes into contact with the first stoppers19and is positioned at the pickup point.

(4) When all the bags W in the bag supply cassette21are picked up, an operator detaches the bag supply cassette21and then sets another bag supply cassette21accommodating the multiple bags W (changing of cassettes), thereby refilling the bag stocking mechanism1with bags.

The bag stocking mechanism1in Japanese Patent Laid-Open No. 2007-290768 includes the bag retainer29that retains the rear ends of the bags in the bag supply cassette21and presses the bags forward in parallel while keeping the standing positions of the bags W. However, in the case of zipper bags such as a standing pack and a gusset bag that vary in thickness in a vertical direction (between the opening and bottom of the bag), a difference in thickness in the vertical direction among the bags increases with the number of bags. Thus, the bags may be curved so as to rise in an improper position in the bag stocking mechanism, causing suction holding members32to incorrectly suck the bags. Thus, with the related bag stocking mechanism1, even if the bags W are placed in a standing position, this configuration limits the number of bags that can be set at the same time.

The present invention has been devised to solve the problem. An object of the present invention is to provide an apparatus for supplying a large amount of bags, the apparatus being capable of stocking a large amount of bags and allowing a packaging machine to continuously operate for a longer time than the related art.

SUMMARY OF THE INVENTION

An apparatus for supplying a large amount of bags according to the present invention is an apparatus for supplying a large amount of bags, each being stocked to be picked up and supplied to a packaging machine, the apparatus including a bag stocking unit having a mechanism that stocks a large amount of bags and guides the stocked bags to the front end of the unit; and a bag transport unit that transports the bags of the bag stocking unit to the packaging machine, wherein the apparatus includes, between the bag stocking unit and the bag transport unit, a bag pickup unit that picks up the bag from the bag stocking unit; a bag orientation detection unit that detects the orientation of the bag; and a bag turning unit that turns the bag in a predetermined direction of the bag transport unit according to the bag orientation detected by the bag orientation detection unit.

A refill tool for the apparatus for supplying a large amount of bags according to the present invention is a refill tool for refilling the bag stocking passage of the bag stocking unit with the bags, including partition plates that are shaped to be fit into the bag stocking passage and are connected via a connecting plate with a predetermined distance.

With this configuration, the apparatus for supplying a large amount of bags according to the present invention stocks the bags in the bag stocking unit so as to equalize the thicknesses of the bags with the laterally reversed openings, thereby stocking a large amount of bags.

Moreover, with this configuration, the refill tool for the apparatus for supplying a large amount of bags according to the present invention can easily refill the bag stocking unit with the bags.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a perspective view showing an apparatus for supplying a large amount of bags according to the present invention.FIG. 2is a front view of the apparatus.FIG. 3is a plan view of the apparatus. The apparatus for supplying a large amount of bags according to the present embodiment includes a bag stocking unit that has a mechanism for stocking a large amount of raised bags W and guiding the stocked bags to the front end of the apparatus, and a bag transport unit that transports the bags W of the bag stocking unit to the packaging machine. The apparatus further includes a bag pickup unit provided between the bag stocking unit and the bag transport unit so as to pick up a bag W from the bag stocking unit, a bag orientation detection unit that detects the orientation of the bag W picked up by the bag pickup unit, and a bag turning unit that turns the bag W in a predetermined direction of the bag transport unit according to the orientation of the bag W detected by the bag orientation detection unit. These units will be described below.

InFIG. 1, a bag stocking mechanism50acting as the bag stocking unit is disposed at the front of the apparatus for supplying a large amount of bags. The bag stocking mechanism50includes a bag stocking passage52longitudinally provided at the center of a pedestal51composed of rectangular plates. In the bag stocking passage52, a large amount of bags is placed in a standing position with the horizontally oriented openings. The bags are zipper bags such as a standing pack and a gusset bag. A flat bag or the like may be used instead. In the case of the bags W varying in thickness between the opening side and the bottom side, a difference in thickness between the opening side and the bottom side increases with the number of bags W staked in the same direction, leading to a twist of the bags. Thus, the bags W may be risen in an incorrect position in the bag stocking mechanism50and incorrectly picked up by the bag pickup unit. To address this problem, the opening sides and bottom sides of a certain number of the bags W, e.g., ten or twenty of the stocked bags W may be laterally reversed so as to equalize differences in thickness between the opening side and the bottom side. Thus, the bags W are stocked in the bag stocking passage52entirely uniformly in proper alignment without deformation.

Side feed conveyors53are disposed on both sides of the bag stocking passage52. The side feed conveyor53has a strip belt72looped over a driving pulley55, which is provided on a rod-like rotating shaft54raised at the front of the conveyor53, and a driven pulley (not shown) at the rear of the conveyor53. The rotation of the rotating shaft54rotates the strip belt72so as to slowly deliver the bags forward. The side feed conveyors53are mounted on frames56disposed in the longitudinal direction of the pedestal51. The frames56are supported by a plurality of installation rods57extended in the width direction of the pedestal51. The frame56is slidable in the width direction of the pedestal51. A distance between the frames56and a distance between the side feed conveyors53are adjusted according to the dimensions of the bag W by rotating a handle58inFIG. 2.

A bag pressing belt59is longitudinally provided at the center of the bottom of the bag stocking passage52, and a bag pressing member60is set on the bag pressing belt59so as to be vertically detached. When the bag pressing belt59is rotated, the bag pressing member60is slowly moved forward to press the bags stocked in the bag stocking passage52from the rear to the front, delivering the bags to the bag pickup unit.

On the bag stocking passage52, a gate plate61is provided on the end of the frame56having the side feed conveyor53. A stopping plate62is placed across the upper parts of the ends of the plates61(SeeFIGS. 1 and 3). The stopping plate62holds a front bag Wa of the bags pressed forward of the bag stocking passage52by means of the side feed conveyor53and the bag pressing member60so as not to protrude until the bag Wa is delivered to the bag pickup unit, which will be described later.

As shown inFIG. 4, alignment rods73are raised inside the gate plates61. The alignment rod73is a hollow pipe that is connected to an air source and has an injection hole (not shown) opened forward. The alignment rods73curve the bags stocked in the bag stocking passage52so as to protrude forward, allowing a bag detection piece74on the end of the bag stocking passage52to detect the bag.

Specifically, the bags W may be curved and thus the bags W simply stocked in the bag stocking passage52may become wavy in the rear (an upper part inFIG. 4) as shown inFIG. 4. If the bags W wavy in the rear are pressed by the bag pressing member60, the bags W curved like waves so as to protrude to the rear may not be detected because the bag W on the end does not come into contact with the bag detection piece74. If the bag W is not detected by the bag detection piece74, it is decided that the bags W are absent. Thus, the bag pressing belt59is rotated to further deliver the bags forward even if the bags W are present. Since both sides of the bags W vertically varying in thickness are tightly placed in the bag stocking passage52, the bags W cannot be delivered forward by the rotation of the bag pressing belt59.

To prevent this problem, the alignment rods73are raised inside the gate plates61so as to restrict a movement of both sides of the bags W while protruding the centers of the bags W. Thus, the bags W curved and protruded forward are delivered. The front bag Wa of the bags W curved thus can be reliably brought into contact with the bag detection piece74. In the absence of the bags W, the bag detection portion74slightly protrudes upward (upward in the plane ofFIG. 4) from the bottom of the bag stocking passage52so as to be turned off. The bag detection portion74in contact with the bag W retracts downward (downward in the plane ofFIG. 4) from the bottom of the bag stocking passage52so as to be turned on. The presence or absence of the bags W is detected according to the protrusion and retraction of the bag detection portion74. The need for the alignment rods73may be eliminated depending upon the type of bag W and thus the alignment rods may be detachable.

As has been discussed, the injection hole for air injection is formed on the end of the alignment rod73. Air from the injection hole is fed to both ends of the bags W, leading to air injection between the bags. Thus, the front bag Wa is easily picked up by suckers76of the bag pickup unit, which will be described later. Moreover, air returns an end of the excessively curved bags W to original shapes. The injection hole is not always necessary and the alignment rod73does not always need to have a hollow structure. The alignment rod73may have any structure as long as a movement of both ends of the bag W is restricted and the center of the bag W is protruded.

The bag pickup unit is a mechanism that picks up the bag W located on the end of the bag stocking mechanism50and delivers the bag W to the bag orientation detection unit. In the present embodiment, the back pickup unit includes a bag pickup mechanism63that picks up the bag W from the bag stocking mechanism50and a bag delivery mechanism64that receives the bag W picked up from the bag pickup mechanism63and then delivers the bag W to the bag orientation detection unit, which will be described later.

The bag pickup mechanism63has parallel rods66that are horizontally supported like cantilevers on one side of a first driving box65. The parallel rods66may be supported on both ends. As shown inFIG. 1, the parallel rods66include a main rod67and a sub rod68. Both ends of the rods67and68are connected via connecting plates69. The main rod67is connected to a drive mechanism (not shown). A screw rod70is pivotally supported between the main rod67and the sub rod68. A handle71is provided on the end of the screw rod70. The handle71is rotated so as to laterally adjust an interval between the suckers76, which will be described later.

On both ends of the parallel rods66, slide plates75, which are shaped like reversed letter L in front view inFIG. 5(A), are slidably provided inside the connecting plates69. The slide plate75has formed internal threads in which the screw rod70is engaged. The screw rod70is rotated by the handle71such that the slide plates75on both ends move toward and away from each other. This can laterally adjust an interval between the suckers76. As shown inFIG. 5(A), an air cylinder77is attached to the lower end of the slide plate75. A mounting plate78is vertically attached to an operation rod77A of the air cylinder77. Slide rods79are attached in parallel with the mounting plate78to a support piece extending from both ends of the mounting plate78. The two suckers76are fixed on each of the slide rods79with screws80so as to slide in the vertical direction. Thus, the four suckers76in total are fixed on the two slide rods79. As has been discussed, the distance between the suckers76,76can be adjusted by rotating the handle71. Moreover, the vertical positions of the suckers76can be adjusted by loosening the screws80so as to slide the suckers76along the slide rods79. In the explanation, the four suckers76in two rows and two columns are attached. The upper two left and right suckers76are not always necessary because the bag W can be placed on a bag table90, which will be later described, only by the lower two left and right suckers76.

The bag delivery mechanism64receives the bags W from the bag pickup mechanism63and places the bag W on the bag table90of the bag orientation detection unit, which will be described later.FIG. 5Bis a front view of the bag delivery mechanism64. The bag delivery mechanism64is adjacent to the bag pickup mechanism63and is horizontally supported like a cantilever from the first driving box65. As a matter of course, the bag delivery mechanism64may be supported on both ends. A rotary cylinder81of the bag delivery mechanism64contains an outer shaft82and an intermediate shaft83. A plate-like sliding guide84is attached to the outer shaft82so as to protrude to the outside. The sliding guide84is rotated forward and backward according to a rotation of the outer shaft82.

A sliding portion85slidably covers the sliding guide84, and a body plate86is fixed on the sliding portion85. An air cylinder87is attached in the longitudinal direction of the body plate86, and a holding portion88is pivotally supported on the end of the body plate86. The holding portion88is opened and closed by the air cylinder87so as to hold the bag W.

One end of an L-shaped link89is connected to the intermediate shaft83of the rotary cylinder81while the other end of the L-shaped link89is connected to the outer portion of the body plate86. A rotation of the intermediate shaft83is transmitted to the link89, and a folding movement of the link89moves forward and backward the sliding portion85along the sliding guide84via the body plate86.

The bag detection unit is a mechanism that causes a detection unit91to detect the orientation of the bag W bridged over on the bag table90from the bag delivery mechanism64. The bag orientation unit includes a bag table90where the bag W picked up from the bag stocking mechanism50is bridged over and the detection unit91that detects the thickness of the opening or the bottom of the bag W on the bag table90and decides the orientation of the bag W.

FIG. 6is a side view of the bag table90.FIG. 7is a perspective view of the bag table90. The bag table90includes counter parts92that are two steel parts extended in parallel with each other. As shown inFIG. 6, the counter part92is a steel part shaped like a reversed letter L in cross section. An upper horizontal part belongs to the counter part92while a lower horizontal part belongs to a side plate102. As shown inFIG. 7, the side plate102slightly extends like eaves in the horizontal direction. A distance between the counter parts92,92is set shorter than the longitudinal dimension of the bag W and longer than the width dimension of the bag W. The width of the bag table90can be adjusted with a handle93and screws depending upon the bag W. Thus, on the bag table90shown inFIG. 6, the opening and bottom of the bag W bridged over in the longitudinal direction of the bag W are placed on the counter parts92,92, whereas both ends of the bag W rotated in the width direction of the bag W are transferred onto the side plates102without being placed on the counter parts92,92; meanwhile, the bag W is transferred onto a strip belt conveyor101of a bag transport mechanism100, which will be described later.

On the outer sides of the counter parts92,92of the bag table90, U-shaped retainer plates94are disposed so as to hold and retain the opening and bottom of the bag W bridged over in the longitudinal direction. The upper part of the retainer plate94approaches the counter parts92and holds the opening and the bottom of the bag W bridged over on the counter part92. Thus, when a bag turning sucker107of the bag turning unit, which will be described later, moves up from below and comes into contact with the bag W, the bag W is not removed from the bag table90. The lower end of the retainer plate94is connected to an air cylinder95that expands and contracts so as to vertically move the retainer plate94. This can hold and release the bag W on the counter part92.

The detection unit91for measuring the thickness of the bag W is disposed next to the retainer plate94. As shown inFIG. 6, the detection unit91includes a detected plate96that is U-shaped like the retainer plate94, and a measuring sensor97that measures the position of the detected plate96to measure the thickness of the bag W. Moreover, an air cylinder98is connected to the lower end of the detected plate96. The air cylinder98expands and contracts so as to vertically move the detected plate96, pressing the bag W on the counter part92. As shown inFIG. 6, when one end of the bag W is held between the detected plate96and the counter part92, the measuring sensor97measures a distance from the detected plate96. Thus, it can be decided whether the detected plate96holds the zippered opening of the bag or the bottom of the bag without the zipper. Specifically, the detected plate96is slightly lifted on the zippered opening of the bag, resulting in a longer distance than at the bottom of the bag. The opening of the bag is detected thus. Alternatively, the retainer plate94and the detected plate96may be integrated into a single plate to be detected by the measuring sensor97or the retainer plate94may also act as the detected plate96to be detected by the measuring sensor97.

The bag transport unit is a bag transport mechanism100that is disposed from the lower part of the bag table90to a packaging machine and includes a strip belt conveyor101that transport the bag W from the lower part of the bag table90to a bag opening lift mechanism106, which will be described. The bag transport mechanism100is disposed under the bag table90. The side plates102are disposed in parallel on both sides of the strip belt conveyor101. The strip belt conveyor101is disposed between the side plates102. As shown inFIG. 6, a distance between the side plates102is smaller than the width of the bag W. The bag W turned in the plane direction is transported between the counter parts92,92of the bag table90by a bag turning mechanism105, which will be described later, is moved down, and is placed on the side plates102,102on both sides and the strip belt conveyor101. The bag W is supported with both ends placed on the side plates102,102and a central part placed on the strip belt conveyor101. Thus, the bag W is transported to the opening lift mechanism106by driving the strip belt conveyor101.

As shown inFIG. 3, optical sensors103are provided at three points on the end of the bag transport mechanism100. The optical sensor103in the rear detects the bag W approaching the front end and reduces the speed of the strip belt conveyor101to prevent an overrun of the bag W. The two front sensors are provided to detect whether both ends of the end of the bag W are accurately stopped at a predetermined position without being inclined on the end of the bag transport mechanism100.

FIG. 8is a perspective view of the bag turning mechanism105which is a kind of a bag turning unit. The bag turning mechanism105is a mechanism that rotates forward and backward the bag W bridged over on the bag table90by the bag delivery mechanism64. The bag turning mechanism105is provided to turn the bag W in a predetermined direction and deliver the bag W to the bag transport mechanism100. Specifically, the bags W are stocked with the openings and bottoms laterally reversed. If the bags W in this state are transported to the packaging machine by the bag transport mechanism100, some of the bags W are delivered to the packaging machine with the bottoms placed face up, leading to inconvenience. Thus, the bag orientation detection unit detects the orientation of the bag W on the bag table90, and then the bag turning mechanism105rotates the opening of the bag W downstream such that the opening of the bag W transported by the bag transport mechanism100is always sucked by the opening lift mechanism106.

The bag turning mechanism105includes the bag turning sucker107on the upper end of a suction pipe108. The center of the bag W held by the retainer plate94is sucked from below by the bag turning sucker107. A suction hose (not shown) is joined to an elbow on the lower end of the suction pipe108. The suction pipe108is joined to a rotary shaft111of a rotary actuator110via a bracket109and is rotated forward and backward by the air-driven rotary actuator110. The rotary actuator110is slidably set on a rectangular substrate112and is connected to one end of a screw thread113acting as a positioning mechanism. A handle114attached to the other end of the screw thread113is rotated to slide the rotary actuator110on the substrate112, adjusting the position of the bag turning sucker107.

Specifically, as has been discussed, the bag turning sucker107is set at the center position of the bag W bridged over on the bag table90. The bags W vary in dimension among the kinds of bags W, displacing the center position during a change of the bags W. In this case, the handle114is rotated to slide the rotary actuator110, setting the bag turning sucker107at the center position of the bag W.

The bag turning mechanism105is vertically moved by an elevating unit115that supports the substrate112from below (SeeFIG. 2). As shown inFIG. 6, the elevating unit115causes the bag turning sucker107to suck, from below, the bag W bridged over on the bag table90, rotate the bag W 90° forward or backward, and move the bag W downward to a lower end position. Thus, the bag W is placed on the side plates102and the strip belt conveyor101. The elevating unit115is vertically moved by a crank mechanism (not shown) in a box116.

The opening lift mechanism106inFIG. 2sucks and lifts the opening of the bag W transported to the end of the bag transport mechanism100and delivers the bag W to the subsequent bag delivery mechanism (not shown). The bag delivery mechanism delivers the bag W received from the opening lift mechanism106, to a rotary packaging machine.

The opening lift mechanism106is attached to a second driving box117adjacent to the first driving box65. As shown inFIGS. 2 and 3, one end of a link118is pivotally supported on a side of the second driving box117, and a triangular plate122is pivotally supported near the other end of the link118so as to attach parallel bars121for placing blocks120of suckers119. As has been discussed, one ends of the parallel bars121are fixed like cantilevers to the triangular plate122. The block120having the two suckers119is held by the parallel bars121.

The opening lift mechanism106pivots one end of the link118clockwise by means of a drive mechanism in the second driving box117. When the other end of the link118reaches the lower end position, the suckers119face downward so as to suck the bag W stopped on the end of the bag transport mechanism100. When one end of the link118is rotated counterclockwise, the action of two rods123connected to the triangular plate122and the parallel bars121moves the suckers119higher than the link118. Subsequently, the bag W on the suckers119is received by the bag delivery mechanism in the subsequent process and then is delivered to the rotary packaging machine.

The opening lift mechanism106and the bag delivery mechanism are basically identical to mechanisms set for related bags and boxes or strip conveyor bag feeders.

For example, about 3000 bags can be simultaneously set in such an apparatus for supplying a large amount of bags. If 50 bags can be handled per minute, an operation can be continued for 60 minutes. Thus, it can be expected that an operator who refills the apparatus with bags would also deal with a different operation. Moreover, the bags W can be set upright in landscape orientation and the openings can be automatically identified. According to this method, even in the case of a large amount of zippered bags that may be curved to one side, the bags W are alternately set in opposite directions, allowing the apparatus to have a relatively short length.

A usage condition of the apparatus for supplying a large amount of bags will be described below.

FIGS. 9 to 11show the usage condition of the apparatus for supplying a large amount of bags according to the present invention. In the bag stocking mechanism50on the left side inFIG. 9(1), a large amount of bags W is standing with the openings and bottoms laterally placed on opposite sides, equalizing differences in thickness between both sides of the bags. Thus, the large amount of bags that are entirely arranged in parallel in proper alignment are stocked in the bag stocking passage52.

First, inFIG. 9(1), the parallel rods66of the bag pickup mechanism63are rotated clockwise about the main rod67such that the suction faces of the suckers76face the surface of the bag Wa on the end of the bag stocking mechanism50. In this state, the operation rod77A of the air cylinder77is extended so as to pick up the bag Wa on the end of the bag stocking mechanism50by means of the suckers76attached to the slide rod79. When the suckers76suck the front bag Wa, the operation rod77A of the air cylinder77contracts. The bag delivery mechanism64still stands by in a stop state.

InFIG. 9(2), the bag pickup mechanism63sucks the front bag Wa of the bag stocking mechanism50and rotates the parallel rods66by 45° counterclockwise about the main rod67; meanwhile, the bag delivery mechanism64slides the sliding portion85downward to a lowest position with the link89in order to receive the bag Wa of the bag pickup mechanism63, and the outer shaft82is rotated 45° clockwise with the opened holding portion88. At a position where the holding portion88holds the bag W held by the suckers76of the bag pickup mechanism63, the air cylinder87is operated to hold the bag W with the holding portion88(SeeFIG. 5(B)).

FIG. 10(3) shows a front view and a side view of the bag stocking mechanism50and the bag transport mechanism100. InFIG. 10(3), the bag delivery mechanism64having received the bag W from the bag pickup mechanism63is directly rotated downward to place the bag W on the bag table90. The bag W bridged over between the counter parts92,92of the bag table90is placed on the bag table90as shown in the right side ofFIG. 10(3). At this point, the opening and bottom of the bag W are not pressed onto the bag table90by the retainer plate94.

InFIG. 10(4), the bag pickup mechanism63rotates 45° clockwise to pick up the subsequent bag W from the bag stocking mechanism50. The bag delivery mechanism64operates the air cylinder95with the bag W placed on the bag table90, allowing the retainer plates94to hold the opening and bottom of the bag W on the bag table90. At the same time, as shown inFIG. 6, the air cylinder98of the detection unit91is operated to press the bag W with the detected plate96. As has been discussed, the bags W are stocked with the openings and bottoms laterally reversed in the bag stocking mechanism50. Thus, inFIG. 6, whether the opening of the bag is located on the right or the left is decided depending upon a stocked state. In this case, the detected plate96presses one side of the bag W while the measuring sensor97vertically measures a distance of the detected plate96. Since the opening has a zipper, the detected plate96is lifted higher than the bottom according to the zipper. Thus, whether the opening or the bottom is pressed is decided depending upon the value of the measuring sensor97.

InFIG. 10(4), the elevating unit115of the bag turning mechanism105lifts the bag turning mechanism105; meanwhile, the bag turning sucker107moves up to suck the center of the back side of the bag W held by the retainer plate94of the bag table90.

InFIG. 11(5), the bag delivery mechanism64is going to receive the subsequent bag W from the bag pickup mechanism63. According to a measurement result of the measuring sensor97, the rotation direction of the bag turning sucker107is determined depending upon whether the opening or the bottom of the bag is located near the detection unit91. Subsequently, the air cylinder95is operated to lift the retainer plates94and the detected plate96, releasing the bag W. The rotary actuator110inFIG. 8is then operated to rotate the suction pipe108by 90° via a bracket109. The rotation direction of the bag W is determined such that the opening of the bag W transported by the bag transport mechanism100in the subsequent step is sucked by the suckers119of the opening lift mechanism106with the opening directed downstream (to the front end of the bag transport mechanism100). In this way, the bag turning mechanism105rotates the bag W clockwise or counterclockwise such that the opening can be sucked by the opening lift mechanism106.

A change of the dimensions of the bag W may vary the center of the bag W in the width direction. Thus, if the bag W is turned by the bag turning mechanism105, the bag may be rotated out of balance, leading to inconvenience. To address this problem, the screw thread113of the positioning mechanism inFIG. 8is rotated by the handle114to adjust the position of the bag turning mechanism105, allowing the bag turning sucker107to suck the center of the bag W in the vertical and horizontal directions from the bottom.

InFIG. 11(6), the bag W rotated 90° in a proper direction in the foregoing step is sucked by the bag turning sucker107. In this state, the elevating unit115moves down the bag turning mechanism105and places the bag W on the side plates102and the strip belt conveyor101of the transport mechanism100as shown inFIG. 6. When the bag W sucked by the bag turning sucker107is rotated 90°, the upper bag W inFIG. 6is rotated in the width direction of the bag W. Thus, the bag W bridged over on the bag table90can be passed between the counter parts92,92and can be placed on the side plates102and the strip belt conveyor101.

The bag W placed on the side plates102and the strip belt conveyor101is transported downstream by the bag transport mechanism100and is stopped at a predetermined position by the optical sensor103on the end of the bag transport mechanism100. After that, the link118of the opening lift mechanism106is pivoted downward, the stopped bag W is sucked by the suckers119, and then the bag W of the opening lift mechanism106is received by the bag delivery mechanism (not shown) and is delivered to the rotary packaging machine. In the rotary packaging machine, a material to be packaged is filled and the opening of the bag W is sealed.

Another First Embodiment

In the foregoing embodiment, the openings of the bags W are laterally reversed to stock a large amount of bags in the bag stocking mechanism50. In the case of a small amount of bags W, the thickness of the opening and the bottom of the bag does not need to be taken into consideration. Thus, the bags may be stocked in the bag stocking mechanism50with the openings aligned as in the related art. Hence, the structure of the bag stocking mechanism50does not always need to arrange the laterally reversed openings of the bags. Moreover, in the foregoing embodiment, the apparatus for supplying a large amount of bags stocks a large amount of zippered bags and supplies the bags to the packaging machine. In the case of a flat bag, multiple flat bags do not vertically vary in thickness and thus are not curved. In this case, controllers may be switched to prevent rotations of the bags W.

In the foregoing embodiment, the bag stocking passage52of the bag stocking mechanism50is horizontally fixed with the bags stocked in a standing position. The bag stocking passage52may be inclined as in the related bag supplying device ofFIG. 21.

Another Second Embodiment

The bag pickup unit includes the two mechanisms: the bag pickup mechanism63and the bag delivery mechanism64. The present invention is not limited to these two configurations. For example, only the bag pickup mechanism63inFIG. 5(A)may be provided. The bag W sucked by the suckers76of the bag pickup mechanism63may be placed on the bag table90to detect the orientation of the bag W by means of the detection unit91while being held by the retainer plates94. The absence of the bag delivery mechanism64simplifies the structure.

Another Third Embodiment

The bag orientation detection unit includes the bag table90and the detection unit91. The bag W on the bag table90is held by the retainer plates94to detect the thickness of the bag W, thereby detecting the orientation of the bag. However, the bag orientation detection unit may be a noncontact detection unit. For example, the orientation of the bag W may be decided by imaging of a CCD camera or detection of surface irregularities or a thickness with a laser beam.

The second embodiment and the noncontact detection unit may be combined such that the bag pickup mechanism63shown inFIG. 5(A)includes a turning unit (a drive unit, e.g., a motor) for turning the slide rod79so as to turn the bag W sucked by the suckers76. This configuration eliminates the need for the bag table90and the retainer plate94. Specifically, the bag is picked up from the bag stocking mechanism50by the bag pickup mechanism63and then is placed in the bag transport mechanism100; meanwhile, the orientation of the bag W may be detected by the noncontact detection unit and corrected by the bag turning unit before being directly transported by the bag transport mechanism100.

As shown inFIG. 1, the bag pickup mechanism63of the embodiment includes the parallel rods66horizontally supported like cantilevers on the side of the first driving box65. As shown inFIG. 5(A), the slide plates75shaped like reversed letter L are slidably provided on both ends of the parallel rods66. The air cylinder77is attached to the lower end of the slide plate75.

FIG. 12shows the first modification of the bag pickup mechanism63. The modification features a simpler configuration with a smaller number of components than the bag pickup mechanism63of the embodiment. A bag pickup mechanism163according to the first modification will be described below in accordance with the accompanying drawings.

InFIG. 12, reference numeral167denotes a main rod that rotates in connection with a drive mechanism (not shown). One end of the main rod167is supported by the first driving box65and the other end of the main rod167is supported by a support member67A from above. The upper ends of two plate-like parallel pivot arms200are fixed on both ends of the main rod167. A support rod201is pivotally disposed between the lower ends of the two pivot arms200. Two blocks76A having the suckers76are fixed near both ends of the support rod201. One end of a crank rod202is connected to one end of the support rod201while a rotating wheel203is provided on the other end of the crank rod202. The rotating wheel203is fit into a guide groove204A of a guide plate204.

One end of the guide plate204has a small width while the other end of the guide plate204increases in width with a curved upper side. The guide plate204is a thick plate that has a rectangular figure on the other end, is flat on the base, and is substantially trapezoidal in overall view. One end of the guide plate204is supported from above by a support205near the bag stocking mechanism50while the other end of the guide plate204is supported from above by a support206near the bag delivery mechanism64. The guide groove204A formed on the guide plate204is curved upward from the left end to the right end. One end of the guide groove204A is formed such that the suction faces of the suckers76come into contact with the bag Wa in parallel on the front end of the bag stocking mechanism50.

In the bag pickup mechanism163, when the main rod167rotates to the left and right, the pivot arm200pivots about 45° according to the rotation of the main rod167. The pivot arm200pivots such that the suckers76pivotally stop at a leftmost point. In this state, the rotating wheel203is located on one end of the guide groove204A, keeping the blocks76A in a horizontal position via the crank rod202and the support rod201. With this configuration, the suction faces of the suckers76attached to the blocks76A come into contact with the bag Wa in parallel on the front end of the bag stocking mechanism50, allowing the suckers76to reliably suck and pick up the bag W.

When the main rod167rotates counterclockwise, the pivot arm200also pivots 45° counterclockwise and then stops with the bag W sucked by the suckers76. The rotating wheel203of the crank rod202is guided by the guide groove204A to revolve to the right direction while moving upward. Thus, the crank rod202rotates according to the movement of the rotating wheel203. Moreover, the support rod201connected to the crank rod202also pivots and thus the suckers76of the blocks76A fixed to the support rod201rotate downward, allowing the holding portion88of the bag delivery mechanism64to hold the bag W sucked by the suckers76.

In the foregoing embodiment, the gate plate61is provided on the end of the frame56having the side feed conveyor53. The stopping plate62is placed between the upper parts of the ends of the gate plates61. The stopping plate62holds the front bag Wa of the bags pressed forward of the bag stocking passage52by means of the side feed conveyor53and the bag pressing member so as not to protrude.

In the second modification shownFIGS. 13 and 14, the vertical and horizontal four sides of the bags Wa stocked in the bag stocking mechanism50are retained so as not to protrude the front bag Wa out of the bag stocking mechanism50. A plate placed across the upper parts of the front ends of the pair of gate plates61is a stopping plate220of the second modification. The stopping plate220can evenly press the upper side of the bag W. The stopping plate220is a rectangular elongated plate having an adjustable height. The stopping plate220is placed on function plates221that are vertically attached to the front ends of the gate plates61and are L-shaped in plan view. The function plate221has two functions as a placement portion221A for placing the stopping plate220and a holding portion221B that laterally restrains the bags Wa so as not to protrude the front bag Wa out of the bag stocking mechanism50as will be described later. The single function plate having the two functions may be replaced with two separated members having the functions of the placing portion221A and the holding portion221B.

As has been discussed, the function plate221is an L-shaped plate in plan view. The front side of the function plate221has a vertical slit223. One end of the stopping plate220is fixed to a fixing handle224through the slit223. When the fixing handle224is loosened, the stopping plate220vertically slides with an adjustable height along the slit223. Although not illustrated, the surface of the function plate221with the slit223formed has a scale for fixing the stopping plate220. This can easily set the height of the stopping plate220according to the size of the bag W.

The other function plate221also has a vertically extended slit (not shown). As shown inFIG. 14, the horizontal dimension of the stopping plate220is larger than a distance between one and the other of the function plates221while the stopping plate220projects through the slit of the other function plate221with one end unfixed to the function plate221. With this configuration, the handle58is rotated according to the size of the bag W so as to adjust a distance between the frames56by means of the screw thread. Also in this case, the stopping plate220passes through the slit of the other function plate221without interfering an adjustment to a distance between the frames56. Moreover, the stopping plate220can be vertically slid along the slits of the function plates221only by loosening the fixing handle224, achieving a height adjustment.

As has been discussed, the rear side of the function plate221has the holding portion221B that laterally restrains the bags W so as not to protrude the front bag W out of the end of the bag stocking passage52. As shown inFIG. 14, the holding portion221B has irregularities at predetermined intervals. Since projecting portions221bhold the side edges of the bag W, pickup of more than one bag W is expected to be prevented. Kinds of function plates221may be prepared such that the holding portions221B vary in the number of irregularities at different intervals according to the size of the bag W.

Furthermore, a lower-part retainer plate230is provided under the end of the bag stocking mechanism50. As shown inFIG. 14, the lower-part retainer plate230is disposed on the downstream side of the bag pressing belt59so as to restrain the lower parts of the bags W.

As has been discussed, in the second modification, the upper end of the bag W is held by the stopping plate220, both sides of the bag W are held by the holding portions221B, and the lower part of the bag W is retained by the lower-part retainer plate230. Thus, even if the bags W stocked in a standing position in the bag stocking mechanism50are strongly pressed forward, the front bag Wa can be stably kept in a position sucked by the suckers76.

In the second modification, a central retainer plate225is further provided to retain an upper central portion of the bag W. The central retainer plate225is located in the upper central portion of the bag W. When the front bag Wa is sucked and picked up by the suckers76, the central retainer plate225presses backward the second bag W and thus the rear second bag W is not collected with the front bag Wa. The central retainer plate225substantially eliminates mistakes of simultaneously collecting two of the bags W, thereby picking up the bags with higher stability. The central retainer plate225is a rectangular plate that is made of stainless steel (SUS304) as a spring material and protrudes to the bag W. The upper end of the central retainer plate225is supported by a laterally extending support plate226. The rear end of the support plate226is fixed to a rectangular clamping plate228with a fixed handle227. The clamping plate228also has a slit229formed. The support plate226can be vertically slid along the slit229by releasing the fixing handle227and thus the contact position of the central retainer plate225with the bag W can be adjusted according to the size of the bag W.

In the foregoing embodiment, as shown inFIG. 4, the bag detection portion74that detects the front bag Wa is disposed only at a point on the end of the bag stocking passage52. In a third modification, as shown inFIG. 15, bag detection portions240are provided at two points inside the gate plates61. Since the bag detection portions240are provided at the two points inside the gate plates61, if the front bag Wa is not detected by the bag detection portions240simultaneously at the two points, the bag pressing belt59is operated to press the bags forward and keeps pressing the bags W on the bag pressing belt59until the bag W is simultaneously detected by the bag detection portions240at the two points. With this configuration, the bag detection portion240detects whether or not the bag W is located on the end of the bag stocking mechanism50. Furthermore, even laterally twisted bags can be corrected into an upright standing position, thereby preventing erroneous suction of the suckers76.

The bag detection portions240inFIG. 15are pivotally supported inside the gate plates61. A protrusion240B is formed at an upper central portion of an L-shaped rocking portion240A. When the bag W comes into contact with the protrusion240B, the rocking portion240A is rotated to separate a lower end portion240C from a proximity switch241. Whether the bag W is in contact with the bag detection portion240or not can be detected thus.

In the foregoing embodiment, as shown inFIG. 4, the injection hole for air injection is formed on the end of the alignment rod73. Air from the injection hole is fed to both ends of the bags W, leading to air injection between the bags. Thus, the front bag Wa is easily picked up by the suckers76of the bag pickup unit, which will be described later.

FIGS. 16 and 17show a fourth modification of the embodiment. In the fourth modification, three air nozzles are disposed on the upper part of the end of the bag stocking mechanism50. A large first air nozzle251disposed on the upper part of the end is fixed to a clamping plate228via a pipe250such that a slit-like injection hole is in parallel with the bag W. Second and third air nozzles252and253provided inside the upper parts of the gate plates61are adjacent to the bags W such that slit-like injection holes cross the bag W.

Generally, when the tightly stacked front bag Wa is collected by the suckers76, the second bag W may be also similarly collected because the first and second bags are in intimate contact with each other under a vacuum. As has been discussed, air is injected from the first, second, and third air nozzles251,252, and253so as to forcibly inject air between the first and second bags W. This reduces the degree of vacuum, suppressing the occurrence of mistakes of simultaneously picking up two bags.

In the foregoing embodiment, the bag pressing member60is set vertically detachably on the bag pressing belt59. When the bag pressing belt59is rotated, the bag pressing member60slowly moves forward to press the bags stocked in the bag stocking passage52from the rear to the front and then delivers the bags to the bag pickup unit. Moreover, the side feed conveyors53are disposed on both sides of the bag stocking passage52and the strip belt72is rotated to slowly feed the bags forward from both sides.

FIG. 18is a perspective view showing a fifth modification of the embodiment. In the fifth modification, as will be described later, the bag pressing member60is replaced with refill tools300for the apparatus for supplying a large amount of bags. In the fifth modification, the side feed conveyors53are not provided and long stopping plates310that are L-shaped in cross section are attached along the frames56so as to hold the refill tools300onto the frames56.

FIG. 19is a perspective view of the refill tool300. In a packaging operation, the bag stocking passage52needs to be refilled with the bags W with a decrease in the number of bags W stocked in the bag stocking passage52. The bag stocking passage52is hard to refill because the thin bags W are likely to be fell sideways or be curved. The refill tools300are necessary for continuously and easily refilling the bag stocking passage52without stopping the apparatus for supplying a large amount of bags. The refill tools300are usable for the bag stocking mechanism50described in the foregoing embodiment.

The refill tool300has two plate-like partition plates301spaced at predetermined intervals. A rectangular connecting plate303connects the corners of the partition plates301. The partition plate301is cut stepwise with a step portion304formed so as to be fit into the bag stocking passage52. The partition plate301is narrower and higher than the bag stocking passage52, thereby stably placing the bags W in an upright position in the bag stocking passage52. The partition plates301are spaced such that the bag stocking passage52is refilled with a sufficient number of bags W and the bulk of the bags W can easily stand.

As shown inFIG. 19, locking slits305and306are formed on both sides of the step portion304of the partition plate301and are used for refilling the bags W. The outer locking slit305is used for the large bag W while the inner slit306is used for the small bag W. The slits are used depending on the size of the bag W.FIG. 20is a perspective view for refilling the bags W. As shown in the perspective view, the locking slits305are locked onto the stopping plate310to fix the refill tools300in the bag stocking passage52during refilling of the bags W.

As has been discussed, similar to the foregoing embodiment, the opening sides and bottom sides of a certain number of the bags W, e.g., ten or twenty of the bags W being laterally reversed are stocked in the refill tools300located in the bag stocking passage52so as to equalize differences in thickness between the opening side and the bottom side. Thus, the bags W are stocked in proper alignment without deformation.

As shown inFIG. 18, the bags W are placed between the partition plates301and then the refill tools300are laid down from the locking state. InFIG. 18, the two refill tools300are used to refill the bag stocking passage52with the bags W and thus the front refill tool300is removed. Since the refill tools300are placed on the bag pressing belt59, a continuous operation of the apparatus for supplying a large amount of bags transfers the refill tool300to the front gate plates61via the bag pressing belt59. The refill tool300supports the rear of the bags so that the bulk of the bags does not collapse, and then the bags are entirely delivered to the bag pickup mechanism63according to a movement of the bag pressing belt59.

In the foregoing embodiment, as shown inFIG. 1, the bag pressing member60vertically set on the bag pressing belt59may be removed so as not to interfere with the bags W after refilling with the refill tools300.

The shape of the partition plate301is not limited to that ofFIG. 19as long as the two partition plates301are fit into the bag stocking passage52and are connected to each other at a predetermined interval via the connecting plate303.

INDUSTRIAL APPLICABILITY

The present invention is useful for an apparatus for supplying a large amount of bags vertically varying in thickness, e.g., a standing pack and a gusset bag.

REFERENCE SIGNS LIST