Holding device

Abstract

To provide a holding device capable of preventing a seal part of a packaging bag from breaking.SOLUTION: A holding device includes a left gripper 11 and a right gripper 12. The left gripper includes a left front side pad 16 and a left depth side pad 17. In a state where the left front side pad and the left depth side pad are driven so as to come closer to each other and an inside region 10a of a seal part of a left side edge of a packaging bag 10 is being held, a left side region 16b of the left front side pad and a left side region 17b of the left depth side pad are separated from each other so as not to hold the seal part of the left side edge of the packaging bag. The right gripper includes a right front side pad 18 and a right depth side pad 19. In a state where the right front side pad and the right depth side pad are driven so as to come closer to each other and the inside region 10a of the seal part of the right side edge of the packaging bag 10 is being held, a right side region 18b of the right front side pad and a right side region 19b of the right depth side pad are separated from each other so as not to hold the seal part of the right side edge of the packaging bag.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a gripping device for gripping a packaging bag having seal portions on both a left edge and a right edge.

Background Art

[0002] Conventionally, for example, packaging bags filled (accommodated) with articles to be packaged inside have been manufactured and sold in various forms.

[0003] When performing the operation of filling a commodity into a packaging bag, it is necessary to hold the packaging bag in a state where the upper part of the packaging bag is open. For example, Patent Document 1 discloses a gripper for holding a packaging bag. The gripper of Patent Document 1 is configured to hold a packaging bag by opposing gripper plates.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the gripper plates of the gripper of Patent Document 1 grip a packaging bag having seal portions on both a left edge and a right edge, they sandwich both the region inside the seal portion and the seal portion. The inventor of the present case has found that at this time, due to the welding or adhesion condition of the seal portion, local stress is applied to a part of the seal portion, and the seal portion may be torn.

[0006] Furthermore, the inventor of the present case has found that when the material of the packaging bag is a material that is relatively difficult to shrink, such as paper or a paper composite material, the frequency of tearing of the seal portion increases.

[0007] This invention is based on the above findings and aims to provide a gripping device that can prevent the sealing portion of a packaging bag from tearing. [Means for solving the problem]

[0008] To achieve the above-mentioned objective, the present invention provides a gripping device for gripping a packaging bag having a seal portion on both the left and right edges, comprising a left gripper for gripping a portion of the left side of the packaging bag and a right gripper for gripping a portion of the right side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other, wherein when the left front pad and the left rear pad are driven to move closer to each other, they grip the area inside the seal portion of the left edge of the packaging bag (the area inside the seal portion of the left edge of the packaging bag that is not a seal portion), and thereafter when they are driven to move further apart from each other, they release the area inside the seal portion of the left edge of the packaging bag (the area inside the seal portion of the left edge of the packaging bag that is not a seal portion), wherein when the left front pad and the left rear pad are driven closer to each other and gripping the area inside the seal portion of the left edge of the packaging bag, the left side of the left front pad and the left The gripping device is characterized in that, when the left region of the rear pad is driven toward each other and grips the area inside the seal portion of the right edge of the packaging bag, the right region of the rear pad and the right region of the rear pad are driven toward each other and separated, and when the rear pad is driven toward each other, it grips the area inside the seal portion of the right edge of the packaging bag (the area inside the seal portion of the right edge of the packaging bag that is not the seal portion), and when it is driven apart, it releases the area inside the seal portion of the right edge of the packaging bag (the area inside the seal portion of the right edge of the packaging bag that is not the seal portion), and when the rear pad is driven toward each other and grips the area inside the seal portion of the right edge of the packaging bag, the right region of the rear pad and the right region of the rear pad are driven toward each other and separated, so as not to grip the seal portion of the right edge of the packaging bag.

[0009] According to the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they are designed to grip the inner area of ​​the seal portion on the left edge of the packaging bag. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and gripping the inner area of ​​the seal portion on the left edge of the packaging bag, the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the seal portion on the left edge of the packaging bag. As a result, localized stress is not applied to the seal portion on the left edge of the packaging bag, and the possibility of the seal portion tearing is significantly reduced.

[0010] Similarly, when the right front pad and the right rear pad are driven to move close to each other, they grip the inner area of ​​the seal on the right edge of the packaging bag. However, when the right front pad and the right rear pad are driven to move close to each other and gripping the inner area of ​​the seal on the right edge of the packaging bag, the right side of the right front pad and the right side of the right rear pad are separated from each other so as not to grip the seal on the right edge of the packaging bag. As a result, localized stress is not applied to the seal on the right edge of the packaging bag, and the possibility of the seal tearing is significantly reduced.

[0011] Preferably, the left front pad and the left rear pad are driven to move closer to each other, gripping the inner area of ​​the seal portion on the left edge of the packaging bag, and the right front pad and the right rear pad are driven to move closer to each other, gripping the inner area of ​​the seal portion on the right edge of the packaging bag, while the left gripper and the right gripper move together to move the packaging bag.

[0012] In conventional grippers (gripper plates), when the left and right grippers move together to move the packaging bag, there is a high possibility of localized stress being applied to the seal area, leading to tearing. However, according to the present invention, since the seal area is not clamped (contacted) by a pad, the possibility of the seal area tearing can be significantly suppressed, even when the left and right grippers move together to move the packaging bag.

[0013] Preferably, the left front pad and the left rear pad are driven to move closer to each other to grip the inner area of ​​the seal portion on the left edge of the packaging bag, and the right front pad and the right rear pad are driven to move closer to each other to grip the inner area of ​​the seal portion on the right edge of the packaging bag, and the left gripper and the right gripper are moved closer to each other to assist in opening and unfolding the packaging bag.

[0014] In conventional grippers (gripper plates), when the left and right grippers are positioned close to each other to assist in opening and closing the packaging bag, there is a high possibility of localized stress being applied to the seal area, leading to tearing. However, according to the present invention, since the seal area is not clamped (contacted) by a pad, the possibility of the seal area tearing can be significantly suppressed, even when the left and right grippers are positioned close to each other to assist in opening and closing the packaging bag.

[0015] In this case, the pads may come into contact with each other in the outer region, outside the sealing portion of the packaging bag. In this case, it may be easier to adjust the opening and closing stroke of the pads.

[0016] One aspect of this invention is a gripping device for gripping a packaging bag having a seal portion on both its left and right edges, comprising a left gripper for gripping a portion of the left side of the packaging bag and a right gripper for gripping a portion of the right side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other, and when the left front pad and the left rear pad are driven to move closer to each other, the left inner region grips the area inside the seal portion of the left edge of the packaging bag (the area inside the seal portion of the left edge of the packaging bag). The left outer region is positioned to grip the area (non-sealed area) and to contact each other outside the seal portion of the left edge of the packaging bag (the area outside the seal portion of the left edge of the packaging bag that is not a seal portion), and when driven to separate from each other, the left inner region opens the area inside the seal portion of the left edge of the packaging bag (the area inside the seal portion of the left edge of the packaging bag that is not a seal portion), and the left outer region is positioned outside the seal portion of the left edge of the packaging bag (the area outside the seal portion of the left edge of the packaging bag that is not a seal portion) The left front pad and the left rear pad are driven to move closer to each other, gripping the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and contacting each other outside the seal portion of the left edge of the packaging bag in the left outer region, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag, and the right gripper is mutual It has a right front pad and a right rear pad that are driven to move closer to and further apart from each other, and when the right front pad and the right rear pad are driven to move closer to each other, they grip the area inside the seal portion of the right edge of the packaging bag (the area inside the seal portion of the right edge of the packaging bag that is not the seal portion) in the right inner region and come into contact with each other on the outside of the seal portion of the right edge of the packaging bag (the area outside the seal portion of the right edge of the packaging bag that is not the seal portion) in the right outer region, and then when they are driven to move further apart from each other,The gripping device is characterized in that, in the right inner region, the area inside the seal portion of the right edge of the packaging bag (the area inside the seal portion of the right edge of the packaging bag but not the seal portion) is left open, and in the right outer region, the area outside the seal portion of the right edge of the packaging bag (the area outside the seal portion of the right edge of the packaging bag but not the seal portion) is separated from each other, the right front pad and the right rear pad are driven to move closer to each other so as to grip the area inside the seal portion of the right edge of the packaging bag in the right inner region and contact each other outside the seal portion of the right edge of the packaging bag in the right outer region, and the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag.

[0017] According to this aspect of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion on the left edge of the packaging bag in their left inner region and abut each other on the outside of the seal portion on the left edge of the packaging bag in their left outer region. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion on the left edge of the packaging bag in their left inner region and abut each other on the outside of the seal portion on the left edge of the packaging bag in their left outer region, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion on the left edge of the packaging bag. As a result, localized stress is not applied to the seal portion on the left edge of the packaging bag, and the possibility of the seal portion tearing can be significantly reduced.

[0018] Similarly, when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion on the right edge of the packaging bag in their right inner region and abut each other on the outside of the seal portion on the right edge of the packaging bag in their right outer region. On the other hand, when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion on the right edge of the packaging bag in their right inner region and abut each other on the outside of the seal portion on the right edge of the packaging bag in their right outer region, the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right outer region of the right rear pad are separated from each other so as not to grip the seal portion on the right edge of the packaging bag. As a result, localized stress is not applied to the seal portion on the right edge of the packaging bag, and the possibility of the seal portion tearing is significantly reduced.

[0019] Here, even in cases where the pads clamp a portion of the sealing area of ​​the packaging bag (for example, about 1 mm in width) in their outer regions due to dimensional errors, this is also within the scope of the present invention, at least as of the time of filing this application.

[0020] This embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on both the left and right edges, comprising a left gripper for gripping a portion of the left side of the packaging bag and a right gripper for gripping a portion of the right side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other, and when the left front pad and the left rear pad are driven to move closer to each other, the left inner region is the region inside the seal portion of the left edge of the packaging bag (the seal portion inside the seal portion of the left edge of the packaging bag) The left outer region is designed to grip the area (not the sealed area) and also grip a portion of the seal portion of the left edge of the packaging bag, and when it is then driven to separate from each other, the left inner region releases the area inside the seal portion of the left edge of the packaging bag (the area inside the seal portion of the left edge of the packaging bag that is not the sealed area), and the left outer region releases a portion of the seal portion of the left edge of the packaging bag, and the left front pad and the left rear pad are driven to move closer to each other, and the left inner region grips the left edge of the packaging bag The right gripper grips the inner region of the sealing portion and the left outer region grips a portion of the sealing portion of the left edge of the packaging bag, and the region between the left inner region and the left outer region of the left front pad and the region between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the sealing portion of the left edge of the packaging bag, and the right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other, and the right front pad and the right rear pad are driven to move closer to each other. The right inner region grips the area inside the seal portion of the right edge of the packaging bag (the area inside the seal portion of the right edge of the packaging bag that is not the seal portion), and the right outer region grips a part of the seal portion of the right edge of the packaging bag. Subsequently, when driven to separate from each other, the right inner region releases the area inside the seal portion of the right edge of the packaging bag (the area inside the seal portion of the right edge of the packaging bag that is not the seal portion), and the right outer region releases a part of the seal portion of the right edge of the packaging bag.The gripping device is characterized in that the right front pad and the right rear pad are driven to move close to each other, gripping the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and gripping a portion of the seal portion of the right edge of the packaging bag in the right outer region, while the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right outer region of the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag.

[0021] According to this embodiment of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. As a result, even when a portion of the seal portion of the left edge of the packaging bag is gripped in the left outer region, local stress on the seal portion of the left edge of the packaging bag is suppressed, and the possibility of the seal portion tearing is suppressed.

[0022] Similarly, when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and a portion of the seal portion of the right edge of the packaging bag in the right outer region. On the other hand, when the right front pad and the right rear pad are driven to move closer to each other, and both grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and a portion of the seal portion of the right edge of the packaging bag in the right outer region, the areas between the right inner and right outer regions of the right front pad and the areas between the right inner and right outer regions of the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag. As a result, even when a portion of the seal portion of the right edge of the packaging bag is gripped in the right outer region, localized stress on the seal portion of the right edge of the packaging bag is suppressed, and the possibility of the seal portion tearing is reduced.

[0023] Conversely, due to dimensional errors or other reasons, a configuration in which the pads sandwich a relatively small area (for example, about 1 mm in width) of the sealing portion of the packaging bag within their inner regions is also within the scope of the present invention, at least as of the time of filing this application.

[0024] Such an aspect of the invention is a gripping device for gripping a packaging bag having seal portions on both the left and right edges, comprising a left gripper for gripping a part of the left side of the packaging bag and a right gripper for gripping a part of the right side of the packaging bag. The left gripper has a left front pad and a left rear pad that are driven to approach and separate from each other. The left gripper has a left front pad and a left rear pad that are driven to approach and separate from each other. When the left front pad and the left rear pad are driven to approach each other, they sandwich a region inside the seal portion of the left edge of the packaging bag (a region that is not a seal portion inside the seal portion of the left edge of the packaging bag) over a relatively large area and sandwich a part of the seal portion of the left edge of the packaging bag over a relatively small area. Then, when they are driven to separate from each other, they open the region inside the seal portion of the left edge of the packaging bag (a region that is not a seal portion inside the seal portion of the left edge of the packaging bag) and the seal portion of the left edge of the packaging bag (a part of the seal portion). The right gripper has a right front pad and a right rear pad that are driven to approach and separate from each other. When the right front pad and the right rear pad are driven to approach each other, they sandwich a region inside the seal portion of the right edge of the packaging bag (a region that is not a seal portion inside the seal portion of the right edge of the packaging bag) over a relatively large area and sandwich a part of the seal portion of the right edge of the packaging bag over a relatively small area. Then, when they are driven to separate from each other, they open the region inside the seal portion of the right edge of the packaging bag (a region that is not a seal portion inside the seal portion of the right edge of the packaging bag) and the seal portion of the right edge of the packaging bag (a part of the seal portion). The gripping device is characterized in that it is configured as described above.

[0025] According to such an aspect of the present invention, when the left front pad and the left rear pad are driven to approach each other, they sandwich a region inside the seal portion of the left edge of the packaging bag over a relatively large area and sandwich a part of the seal portion of the left edge of the packaging bag over a relatively small area. As a result, local stress is prevented from being applied to the seal portion of the left edge of the packaging bag, and the possibility of the seal portion being broken can be suppressed.

[0026] Similarly, when the right front pad and the right rear pad are driven to be close to each other, they sandwich a relatively large area of the region inside the seal portion of the right side edge of the packaging bag and sandwich the seal portion of the right side edge of the packaging bag with a relatively small area. Thereby, it is possible to suppress the application of local stress to the seal portion of the right side edge of the packaging bag, and it is possible to suppress the possibility that the seal portion is broken.

[0027] In the above aspect, the ratio of the relatively large area to the relatively small area is preferably 2 or more times.

[0028] In this case, it is possible to more effectively suppress the application of local stress to the seal portions of the left and right side edges of the packaging bag, and it is possible to more effectively suppress the possibility that the seal portions are broken.

[0029] Furthermore, due to dimensional errors or the like, an aspect in which the pads sandwich a part (for example, about 1 mm in width) of the seal portion of the packaging bag in the right outer region (not sandwiching in the left outer region) is also within the scope of the present invention at least at the time of filing of the present application.

[0030] This embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on both the left and right edges, comprising a left gripper for gripping a portion of the left side of the packaging bag and a right gripper for gripping a portion of the right side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other, and when the left front pad and the left rear pad are driven to move closer to each other, they grip the area inside the seal portion of the left edge of the packaging bag, and thereafter When driven to move apart from each other, the left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the seal on the left edge of the packaging bag, while the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the seal on the left edge of the packaging bag, and the right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. The gripping device is characterized in that, when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and grip a part of the seal portion of the right edge of the packaging bag in the right outer region, and then when they are driven to move further apart from each other, they release the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and release a part of the seal portion of the right edge of the packaging bag in the right outer region, and when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and grip a part of the seal portion of the right edge of the packaging bag in the right outer region, and the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right outer region of the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag.

[0031] According to this embodiment of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they are configured to grip the inner area of ​​the seal portion on the left edge of the packaging bag. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and gripping the inner area of ​​the seal portion on the left edge of the packaging bag, the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the seal portion on the left edge of the packaging bag. As a result, localized stress is not applied to the seal portion on the left edge of the packaging bag, and the possibility of the seal portion tearing is significantly reduced.

[0032] Furthermore, when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion on the right edge of the packaging bag in the right inner region and a portion of the seal portion on the right edge of the packaging bag in the right outer region. On the other hand, when the right front pad and the right rear pad are driven to move closer to each other, and both grip the inner area of ​​the seal portion on the right edge of the packaging bag in the right inner region and a portion of the seal portion on the right edge of the packaging bag in the right outer region, the areas between the right inner and right outer regions of the right front pad and the areas between the right inner and right outer regions of the right rear pad are separated from each other so as not to grip the seal portion on the right edge of the packaging bag. As a result, even when a portion of the seal portion on the right edge of the packaging bag is gripped in the right outer region, localized stress on the seal portion on the right edge of the packaging bag is suppressed, and the possibility of the seal portion tearing is reduced.

[0033] Furthermore, if you view the front and back sides in reverse, the left-right relationship will be reversed. In other words, in the above embodiment, the left-right relationship may also be reversed.

[0034] Furthermore, due to dimensional errors, etc., an arrangement in which the pads clamp a relatively small area (for example, about 1 mm in width) of the sealing portion of the packaging bag in the right inner region (without clamping in the left inner region) is also within the scope of the present invention, at least as of the time of filing this application.

[0035] This embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on both the left and right edges, comprising a left gripper for gripping a portion of the left side of the packaging bag and a right gripper for gripping a portion of the right side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other, wherein when the left front pad and the left rear pad are driven closer to each other, they grip the area inside the seal portion of the left edge of the packaging bag, and when they are driven further apart from each other, they release the area inside the seal portion of the left edge of the packaging bag, wherein when the left front pad and the left rear pad are driven closer to each other, they grip the area inside the seal portion of the left edge of the packaging bag The gripping device is characterized in that, while gripping the inner area of ​​the left front pad, the left area of ​​the left rear pad and the left area of ​​the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag, the right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other, and when the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag with a relatively large area and grip the seal portion of the right edge of the packaging bag with a relatively small area, and then when they are driven to move further apart from each other, they release the inner area of ​​the seal portion of the right edge of the packaging bag and the seal portion of the right edge of the packaging bag.

[0036] According to this embodiment of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they are configured to grip the inner area of ​​the seal portion on the left edge of the packaging bag. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and gripping the inner area of ​​the seal portion on the left edge of the packaging bag, the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the seal portion on the left edge of the packaging bag. As a result, localized stress is not applied to the seal portion on the left edge of the packaging bag, and the possibility of the seal portion tearing is significantly reduced.

[0037] Furthermore, when the right front pad and the right rear pad are driven to move close to each other, they grip the area inside the seal on the right edge of the packaging bag with a relatively large area, while gripping the seal on the right edge of the packaging bag with a relatively small area. This suppresses localized stress on the seal on the right edge of the packaging bag, thereby reducing the possibility of the seal tearing.

[0038] Furthermore, if you view the front and back sides in reverse, the left-right relationship will be reversed. In other words, in the above embodiment, the left-right relationship may also be reversed.

[0039] Furthermore, in the above embodiment, it is preferable that the ratio of a relatively large area to a relatively small area is 2 or more.

[0040] In this case, localized stress on the sealed areas of the left and right edges of the packaging bag can be more effectively suppressed, thereby more effectively reducing the possibility of the sealed areas tearing.

[0041] Furthermore, even in cases where the pads clamp a portion of the sealing area of ​​the packaging bag (for example, about 1 mm in width each) in the left outer region and the right inner region due to dimensional errors, this is also within the scope of the present invention, at least as of the time of filing this application.

[0042] This embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on both the left and right edges, comprising a left gripper for gripping a portion of the left side of the packaging bag and a right gripper for gripping a portion of the right side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer together and further apart from each other, wherein when the left front pad and the left rear pad are driven to move closer together, they grip the inner area of ​​the seal portion on the left edge of the packaging bag in the left inner region and grip a portion of the seal portion on the left edge of the packaging bag in the left outer region, and thereafter when they are driven to move further apart from each other, they release the inner area of ​​the seal portion on the left edge of the packaging bag in the left inner region and move further apart from each other from the release of a portion of the seal portion on the left edge of the packaging bag in the left outer region, wherein when the left front pad and the left rear pad are driven to move closer together, the left inner The gripping device is characterized in that, in the region, it grips the area inside the seal portion of the left edge of the packaging bag, and in the left outer region, it grips a part of the seal portion of the left edge of the packaging bag, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag, the right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other, and when the right front pad and the right rear pad are driven to move closer to each other, they grip the area inside the seal portion of the right edge of the packaging bag with a relatively large area and grip the seal portion of the right edge of the packaging bag with a relatively small area, and then when they are driven to move further apart from each other, they release the area inside the seal portion of the right edge of the packaging bag and the seal portion of the right edge of the packaging bag.

[0043] According to this embodiment of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. As a result, even when a portion of the seal portion of the left edge of the packaging bag is gripped in the left outer region, local stress on the seal portion of the left edge of the packaging bag is suppressed, and the possibility of the seal portion tearing is suppressed.

[0044] Furthermore, when the right front pad and the right rear pad are driven to move close to each other, they grip the area inside the seal portion on the right edge of the packaging bag with a relatively large area, while gripping the seal portion on the right edge of the packaging bag with a relatively small area. This suppresses localized stress on the seal portion on the right edge of the packaging bag, thereby reducing the possibility of the seal portion tearing.

[0045] Furthermore, if you view the front and back sides in reverse, the left-right relationship will be reversed. In other words, in the above embodiment, the left-right relationship may also be reversed.

[0046] Furthermore, in the above embodiment, it is preferable that the ratio of a relatively large area to a relatively small area is 2 or more.

[0047] In this case, localized stress on the sealed areas of the left and right edges of the packaging bag can be more effectively suppressed, thereby more effectively reducing the possibility of the sealed areas tearing.

[0048] Each of the above inventions relates to a gripping device for gripping a packaging bag having a seal portion on both the left and right edges. However, at least as of the time of filing this application, a gripping device for gripping a packaging bag having a seal portion on the left edge (only) is also within the scope of the present invention.

[0049] In other words, one such invention is a gripping device for gripping a packaging bag having a seal portion on its left edge, comprising a left gripper for gripping a part of the left side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other, wherein when the left front pad and the left rear pad are driven to move closer to each other, they grip the area inside the seal portion on the left edge of the packaging bag, and thereafter, when they are driven to move further apart from each other, they release the area inside the seal portion on the left edge of the packaging bag, wherein when the left front pad and the left rear pad are driven closer to each other and gripping the area inside the seal portion on the left edge of the packaging bag, the left side of the left front pad and the left side of the left rear pad are separated from each other so as not to grip the seal portion on the left edge of the packaging bag.

[0050] According to this embodiment of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they are configured to grip the inner area of ​​the seal portion on the left edge of the packaging bag. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and gripping the inner area of ​​the seal portion on the left edge of the packaging bag, the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the seal portion on the left edge of the packaging bag. As a result, localized stress is not applied to the seal portion on the left edge of the packaging bag, and the possibility of the seal portion tearing is significantly reduced.

[0051] Furthermore, if the front and back are viewed in reverse, the left-right relationship will be reversed. In other words, in the embodiment of this invention, the left-right relationship may be reversed.

[0052] Alternatively, one such embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on its left edge, comprising a left gripper for gripping a portion of the left side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer together and further apart from each other, wherein when the left front pad and the left rear pad are driven to move closer together, they grip the inner area of ​​the seal portion on the left edge of the packaging bag in the left inner region and come into contact with each other outside the seal portion on the left edge of the packaging bag in the left outer region, and thereafter when they are driven to move further apart from each other, they grip the seal portion on the left edge of the packaging bag in the left inner region The gripping device is characterized in that the inner region of the loop is open, and the left outer region is spaced apart from each other outside the seal portion of the left edge of the packaging bag, the left front pad and the left rear pad are driven to move closer to each other so as to grip the inner region of the seal portion of the left edge of the packaging bag in the left inner region, and are in contact with each other outside the seal portion of the left edge of the packaging bag in the left outer region, and the region between the left inner region and the left outer region of the left front pad and the region between the left inner region and the left rear pad are spaced apart from each other so as not to grip the seal portion of the left edge of the packaging bag.

[0053] According to this aspect of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in their left inner region and abut each other on the outside of the seal portion of the left edge of the packaging bag in their left outer region. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in their left inner region and abut each other on the outside of the seal portion of the left edge of the packaging bag in their left outer region, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. As a result, localized stress is not applied to the seal portion of the left edge of the packaging bag, and the possibility of the seal portion tearing can be significantly reduced.

[0054] Furthermore, if the front and back are viewed in reverse, the left-right relationship will be reversed. In other words, in the embodiment of this invention, the left-right relationship may be reversed.

[0055] Alternatively, one such embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on its left edge, comprising a left gripper for gripping a portion of the left side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer together and further apart from each other, and when the left front pad and the left rear pad are driven to move closer together, they grip the inner area of ​​the seal portion on the left edge of the packaging bag in the left inner region and grip a portion of the seal portion on the left edge of the packaging bag in the left outer region, and thereafter, when they are driven to move further apart from each other, they release the inner area of ​​the seal portion on the left edge of the packaging bag in the left inner region and release a portion of the seal portion on the left edge of the packaging bag in the left outer region.

[0056] According to this embodiment of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region. On the other hand, when the left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region, the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. As a result, even when a portion of the seal portion of the left edge of the packaging bag is gripped in the left outer region, local stress on the seal portion of the left edge of the packaging bag is suppressed, and the possibility of the seal portion tearing is suppressed.

[0057] Furthermore, if the front and back are viewed in reverse, the left-right relationship will be reversed. In other words, in the embodiment of this invention, the left-right relationship may be reversed.

[0058] Alternatively, one such embodiment of the invention is a gripping device for gripping a packaging bag having a seal portion on its left edge, comprising a left gripper for gripping a portion of the left side of the packaging bag, wherein the left gripper has a left front pad and a left rear pad that are driven to move closer together and further apart from each other, and when the left front pad and the left rear pad are driven to move closer together, they grip the area inside the seal portion on the left edge of the packaging bag with a relatively large area and grip the seal portion on the left edge of the packaging bag with a relatively small area, and then when they are driven to move further apart from each other, they release the area inside the seal portion on the left edge of the packaging bag and the seal portion on the left edge of the packaging bag.

[0059] According to this aspect of the present invention, when the left front pad and the left rear pad are driven to move closer to each other, they grip the area inside the seal portion on the left edge of the packaging bag with a relatively large area, while gripping the seal portion on the left edge of the packaging bag with a relatively small area. This suppresses localized stress on the seal portion on the left edge of the packaging bag, thereby reducing the possibility of the seal portion tearing.

[0060] Furthermore, if the front and back are viewed in reverse, the left-right relationship will be reversed. In other words, in the embodiment of this invention, the left-right relationship may be reversed.

[0061] Furthermore, in the above embodiment, it is preferable that the ratio of a relatively large area to a relatively small area is 2 or more.

[0062] In this case, localized stress on the sealed areas of the left and right edges of the packaging bag can be more effectively suppressed, thereby more effectively reducing the possibility of the sealed areas tearing. [Effects of the Invention]

[0063] According to the present invention, localized stress is not applied to the sealed portion on the left edge and / or the sealed portion on the right edge of the packaging bag, and the possibility of the sealed portion tearing can be significantly suppressed.

[0064] Alternatively, localized stress on the sealed portion of the left edge and / or right edge of the packaging bag can be suppressed, thereby reducing the possibility of the sealed portion tearing. [Brief explanation of the drawing]

[0065] [Figure 1] This is a schematic plan view of a packaging apparatus including a gripping device according to the first embodiment of the present invention. [Figure 2] This is a schematic plan view illustrating the gripping operation of the gripping device according to this embodiment. [Figure 3] This is a schematic perspective view showing the open state of the left gripper and the right gripper of the gripping device according to the first embodiment of the present invention. [Figure 4] This is a schematic perspective view showing the closed state of the left gripper and the right gripper of the gripping device according to the first embodiment of the present invention. [Figure 5] This is a schematic plan view of the left front pad of the left gripper and the right front pad of the right gripper of the gripping device according to the first embodiment of the present invention. [Figure 6] Figure 5 shows schematic rear views of the left front pad and the right front pad. [Figure 7] Figure 5 shows schematic side views of the left front pad and the right front pad. [Figure 8] This is a schematic plan view illustrating the bag opening operation by the gripping device according to this embodiment. [Figure 9] Figure 1 is a schematic front view illustrating the first static elimination air supply device of the packaging apparatus. [Figure 10] Figure 1 is a schematic plan view illustrating the filling operation of the packaging device. [Figure 11] Figure 1 is a schematic front view illustrating the second static elimination air supply device of the packaging apparatus. [Figure 12] This is a schematic plan view illustrating the state in which the right gripper and left gripper of the gripping device according to the second embodiment of the present invention are in a closed state. [Figure 13] This is a schematic plan view illustrating the state in which the right gripper and left gripper of the gripping device according to the third embodiment of the present invention are in the closed position. [Figure 14] This is a schematic plan view illustrating the state in which the right gripper and left gripper of the gripping device according to the fourth embodiment of the present invention are in a closed state. [Modes for carrying out the invention]

[0066] Embodiments of the present invention will be described below with reference to the drawings.

[0067] (composition) Figure 1 is a schematic plan view of a packaging apparatus 2 including a gripping device 1 according to a first embodiment of the present invention. The packaging apparatus 2 in Figure 1 is configured as a rotary packaging apparatus, and 10 stations S1 to S10 are arranged in a circumferential direction.

[0068] At the first station S1, a pair of opposing left grippers 11 and right grippers 12 are configured to hold the upper edges of both sides of a single flat, rectangular packaging bag 10 (see Figures 2 and 8).

[0069] The packaging bag 10 of this embodiment is made of a paper composite material and is formed as a so-called standing pouch with a width of 159 mm, a height of 220 mm, and a thickness of 120 μm. The packaging bag 10 contains powder such as wheat flour. The intended filling weight of the packaging bag 10 is 400 g. The packaging bag 10 also has a seal portion 10a with a width of 5.5 mm on both the right edge and the left edge. The seal portion 10a is heat-sealed.

[0070] Figure 2 is a schematic plan view illustrating the gripping operation of the gripping device 1 according to this embodiment. More specifically, Figure 2(a) is a schematic plan view illustrating the right gripper and left gripper of the gripping device according to this embodiment in an open state, and Figure 2(b) is a schematic plan view illustrating the right gripper and left gripper of the gripping device according to this embodiment in a closed state.

[0071] Furthermore, Figure 3 is a schematic perspective view showing the open state of the left gripper and right gripper of the gripping device according to the first embodiment of the present invention. More specifically, Figure 3(a) is a schematic perspective view showing the open state of the left gripper of the gripping device according to the first embodiment of the present invention, and Figure 3(b) is a schematic perspective view showing the open state of the right gripper of the gripping device according to the first embodiment of the present invention.

[0072] Furthermore, Figure 4 is a schematic perspective view showing the closed state of the left gripper and right gripper of the gripping device according to the first embodiment of the present invention. More specifically, Figure 4(a) is a schematic perspective view showing the closed state of the left gripper of the gripping device according to the first embodiment of the present invention, and Figure 4(b) is a schematic perspective view showing the closed state of the right gripper of the gripping device according to the first embodiment of the present invention.

[0073] Furthermore, Figure 5 is a schematic plan view of the left front pad of the left gripper and the right front pad of the right gripper of the gripping device according to the first embodiment of the present invention. More specifically, Figure 5(a) is a schematic plan view of the left front pad of the left gripper of the gripping device according to the first embodiment of the present invention, and Figure 5(b) is a schematic plan view of the right front pad of the right gripper of the gripping device according to the first embodiment of the present invention. Furthermore, Figure 6 is a schematic rear view of the left front pad and the right front pad of Figure 5. More specifically, Figure 6(a) is a schematic rear view of the left front pad of Figure 5(a), and Figure 6(b) is a schematic rear view of the right front pad of Figure 5(b). Furthermore, Figure 7 is a schematic side view of the left front pad and the right front pad of Figure 5. More specifically, Figure 7(a) is a schematic side view of the left front pad of Figure 5(a), and Figure 7(b) is a schematic side view of the right front pad of Figure 5(b).

[0074] As shown in Figures 2 to 7, the gripping device 1 according to this embodiment includes a left gripper 11 that grips a portion of the left side of the packaging bag 10, and a right gripper 12 that grips a portion of the right side of the packaging bag 10. The left-right relationship is reversed when viewed from the opposite side, so the left-right relationship may also be reversed.

[0075] The left gripper 11 has a left front pad 16 and a left rear pad 17 that are driven to move closer to and further apart from each other. When the left front pad 16 and the left rear pad 17 are driven to move closer to each other (driven by a drive unit not shown), they grip the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10, and when they are then driven to move further apart from each other (driven by the same drive unit), they release the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10.

[0076] The left front pad 16 and the left rear pad 17 are driven to move closer to each other and are gripping the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10, while the left area 16b of the left front pad 16 and the left area 17b of the left rear pad are separated from each other so as not to grip the sealing portion 10a on the left edge of the packaging bag 10.

[0077] Symmetrically, the right gripper 12 has a right front pad 18 and a right rear pad 19 that are driven to move closer to and further apart from each other. When the right front pad 18 and the right rear pad 19 are driven to move closer to each other, they grip the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10. When they are then driven to move further apart from each other, they release the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10. When the right front pad 18 and the right rear pad 19 are driven closer to each other and gripping the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10, the right side area 18b of the right front pad 18 and the right side area 19b of the right rear pad 19 are separated from each other so as not to grip the sealing portion 10a on the right edge of the packaging bag 10.

[0078] To further describe the configuration of this embodiment in detail, referring to Figures 3(a) and 4(a), the left front pad 16 is supported by a metal holding member 40 so as to be rotatable around the shaft portion 13 relative to the left rear pad 17, and is driven by a drive unit (not shown) to move closer to and further away from the left rear pad 17.

[0079] The left front pad 16 is formed in a rod shape with a rectangular cross-section (see Figure 7(a)). The left front pad 16 comprises an inner (right) inner region 16a (for example, 3 mm wide in the left-right direction and 14 mm high in the up-down direction) and a left region 16b which is formed adjacent to the left side of the inner region 16a and is recessed from the inner region 16a (recessed from the surface that contacts the left rear pad 17) and forms a concave surface (for example, 6 mm wide in the left-right direction, 14 mm high in the up-down direction and 3 mm deep). The inner region 16a forms a flat surface that contacts the left rear pad 17 over a predetermined length from the inner end of the left front pad 16. The left front pad 16 is made of rubber.

[0080] The left rear pad 17 is formed in a rod shape with a rectangular cross-section. The left rear pad 17 comprises an inner (right) inner region 17a and a left region 17b which is formed adjacent to the left of the inner region 17a and forms a flat surface at the same height as the inner region 17a (height from the rear to the front (height in the front-to-back direction)). The left rear pad 17 is made of metal.

[0081] The left front pad 16 and the left rear pad 17 are driven to move closer to each other, and the inner regions 16a and 17a sandwich the inner region 10b of the seal portion 10a on the left edge of the packaging bag 10. At the same time, the left region 16b of the left front pad 16 and the left region 17b of the left rear pad 17 are separated from each other so as not to sandwich the seal portion 10a on the left edge of the packaging bag 10. The left region 16b and the left region 17b form a space in which the seal portion 10a can move slightly. When the inner regions 16a and 17a are close together, a gap space A thicker than the thickness of the seal portion 10a is formed between the left region 16b and the left region 17b.

[0082] Although symmetrical, the right front pad 18 is supported by a metal holding member 42 so as to be rotatable around the shaft portion 13 relative to the right rear pad 19, and is driven by a drive unit (not shown) to move closer to and further away from the left rear pad 17.

[0083] The right front pad 18 is formed in a rod shape with a rectangular cross-section. The right front pad 18 comprises an inner (left) inner region 18a and a right region 18b which is formed adjacent to the right of the inner region 18a and is recessed from the inner region 18a (recessed from the surface that contacts the right rear pad 19) and forms a concave surface. The inner region 18a forms a flat surface that contacts the right rear pad 19 over a predetermined length from the inner end of the right front pad 18. The right front pad 18 is made of rubber.

[0084] The right rear pad 19 is formed in a rod shape with a rectangular cross-section. The right rear pad 19 comprises an inner (left) inner region 19a and a right region 19b which is formed adjacent to the right of the inner region 19a and forms a flat surface at the same height (height in the front-to-back direction) as the inner region 19a. The right rear pad 19 is made of metal.

[0085] When the right front pad 18 and the right rear pad 19 are driven to move closer to each other, the inner area 18a of the right front pad 18 and the inner area 19a of the right rear pad 19 clamp the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10. Subsequently, when they are driven to move further apart from each other, the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10 is released.

[0086] The right front pad 18 and the right rear pad 19 are driven to move closer to each other, and the inner regions 18a and 19a sandwich the inner region 10b of the sealing portion 10a on the right edge of the packaging bag 10. However, the right region 18b of the right front pad 18 and the right region 19b of the right rear pad 19 are separated from each other so as not to sandwich the sealing portion 10a on the right edge of the packaging bag 10. The right region 18b and the right region 19b form a space in which the sealing portion 10a can move slightly.

[0087] With the left front pad 16 and the left rear pad 17 driven to move closer to each other, gripping the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10, and the right front pad 18 and the right rear pad 19 driven to move closer to each other, gripping the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10, the left gripper 11 and the right gripper 12 move together to move the packaging bag 10.

[0088] Returning to the description of the packaging device 2, in this embodiment, at the first station S1, the left gripper 11 and the right gripper 12, which are symmetrically facing each other, hold the upper edges of both sides of the rectangular packaging bag 10, respectively (see Figures 2 and 8). In this state (held by the left gripper 11 and the right gripper 12), the conveying device 15 (circumstantially shown in Figure 8) sequentially and intermittently conveys the packaging bag 10 to the next adjacent station. Ten pairs of left grippers 11 and right grippers 12 are aligned circumferentially, corresponding to the ten stations S1 to S10. (In this specification, the front side of the packaging bag 10 as shown in Figure 9 is referred to as the front, the back side when viewed from the front is referred to as the rear, the right side when viewed from the front of the packaging bag 10 is referred to as the right side, and the left side when viewed from the front is referred to as the left side.)

[0089] Next, at the second station S2, as shown in Figure 8, a pair of suction cup devices 21 and 22, which serve as bag opening devices, are configured to open and widen the opening (bag mouth) of the packaging bag 10 (details will be described later). Also at the second station S2, the first static elimination air supply device 25 (see Figure 9) is configured to supply static elimination air (for example, air containing positive ions) to the inside of the packaging bag 10 through the opened opening of the packaging bag 10.

[0090] Next, at the third station S3, a funnel-shaped cylindrical part 31 (circumstantially shown in Figure 10), which serves as a filling device, fills the contents of the packaging bag 10 into the packaging bag 10 through the opening of the opened packaging bag 10. In this embodiment, the contents of the packaging are powder.

[0091] Next, at the fourth station S4, the tapping device 51 (schematically shown in Figure 11) taps the bottom surface of the packaging bag 10 vertically so that the packaged items filled inside the packaging bag 10 vibrate.

[0092] Next, at the fifth station S5, the second static elimination air supply device 55 (see Figure 11) supplies static elimination air locally to the inside of the opening of the opened packaging bag 10 through the opening of the packaging bag 10. Also at the fifth station S5, similar to the fourth station S4, the tapping device 51 (see Figure 11) taps the bottom surface of the packaging bag 10 vertically so that the packaged items filled inside the packaging bag 10 vibrate.

[0093] Next, at the sixth station S6, a sealing device 61, which serves as a bag closing device, seals the opening of the packaging bag 10.

[0094] Then, at the seventh station S7, the packaging bag 10, which is filled with the packaged goods and has its opening sealed, is removed to the outside of the gripping device.

[0095] Stations S8 through S10 are backup stations.

[0096] (action) Next, with reference to Figure 2, the gripping operation of the gripping device of this embodiment will be described in detail.

[0097] When the packaging bag 10 is transported to the first station S1, as shown in Figure 2(a), a pair of opposing left grippers 11 and right grippers 12 are moved in an open state to gripping positions on the upper edges of both sides of the packaging bag 10. Next, as shown in Figure 2(b), the left front pad 16 and the left rear pad 17 are driven to move closer to each other, and the inner regions 16a and 17a grip the inner region 10b of the seal portion 10a on the left edge of the packaging bag 10. At this time, the seal portion 10a on the left edge of the packaging bag 10 is located to the left of the inner regions 16a and 17a and does not come into contact with them. Also, the left region 16b of the left front pad 16 and the left region 17b of the left rear pad 17 are separated from each other so as not to grip the seal portion 10a on the left edge of the packaging bag 10.

[0098] At approximately the same time, the right front pad 18 and the right rear pad 19 are driven to move closer to each other, and the inner regions 18a and 19a clamp the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10. At this time, the sealing portion 10a on the left edge of the packaging bag 10 is located to the right of the inner regions 18a and 19a and does not come into contact with them. Also, the right region 18b of the right front pad 18 and the right region 19b of the right rear pad 19 are separated from each other so as not to clamp the sealing portion 10a on the right edge of the packaging bag 10.

[0099] The packaging bag 10 is held upright by gripping both sides with the left gripper 11 and the right gripper 12. In this state, the left gripper 11 and the right gripper 12 move together with the packaging bag 10 to the next station S2. Meanwhile, as the bag is transported, the next packaging bag 10' is supplied to the first station S1 and gripped by the pair of left grippers 11' and right grippers 12'.

[0100] Next, with reference to Figures 8 to 11, the bag opening operation and subsequent operations of the packaging device including the gripping device of this embodiment will be described in detail. When the packaging bag 10, whose upper edges on both sides are held by a pair of left grippers 11 and right grippers 12, is transported to the second station S2, the pair of suction cup devices 21 and 22 are brought closer to the front and rear surfaces of the upper part of the center in the left-right direction of the packaging bag 10 (state shown in Figure 8(a)). Then, the pair of suction cup devices 21 and 22 adhere to the front and rear surfaces of the upper part of the center in the left-right direction of the packaging bag 10 (state shown in Figure 8(b)). The suction position of the suction cup device 22 on the front of the packaging bag 10 is shown by a dashed circle in Figure 9.

[0101] Next, the pair of suction cup devices 21 and 22 are pulled apart from each other while still adhering to the front and rear surfaces of the packaging bag 10, respectively. At this time, the pair of left grippers 11 and right grippers 12 are brought closer to each other so that excessive tension is not applied to the packaging bag 10. As a result, the opening of the packaging bag 10 is opened wide, as shown in Figure 8(c). In this way, the left front pad 16 and the left rear pad 17 are driven to be close to each other, gripping the inner area 10b of the seal portion 10a on the left edge of the packaging bag 10, and the right front pad 18 and the right rear pad 19 are driven to be close to each other, gripping the inner area 10b of the seal portion 10a on the right edge of the packaging bag 10, and the left gripper 11 and the right gripper 12 are moved closer to each other to assist in opening and widening the packaging bag 10.

[0102] On the other hand, as shown in Figure 9, the first static elimination air supply device 25 is provided at a position corresponding to the upper part of the central region of the opening of the opened packaging bag 10. The vertical projection position of the first static elimination air supply device 25 is illustrated by a dashed circle in Figure 8(c). The first static elimination air supply device 25 has a cylindrical tubular opening with an inner diameter of 1 to 2 mm and supplies static elimination air produced by the static elimination air generator 26 based on compressed air supplied from the compressed air supply source 27 into the inside of the packaging bag 10. A smaller inner diameter of the opening increases the release speed of the compressed air, allowing the packaging bag 10 to be opened effectively with a smaller amount of compressed air.

[0103] Furthermore, to prevent the opening of the packaging bag 10, which has been opened by the pair of suction cup devices 21 and 22, from closing, the pair of retaining claws 23 and 24 are inserted, and then, as shown in Figure 8(d), the pair of suction cup devices 21 and 22 release the packaging bag 10.

[0104] Subsequently, the packaging bag 10 is held by a pair of left grippers 11 and right grippers 12, and with its opening held open by a pair of retaining claws 23 and 24, it is intermittently transported by the transport device 15 to the next third station S3 (the pair of retaining claws 23 and 24 accompany it to the third station S3). The left grippers 11 and right grippers 12 move together with the packaging bag 10 to the next station.

[0105] Next, as shown in Figure 10, the funnel-shaped cylindrical part 31, which serves as the filling device, is inserted from above into the central area of ​​the opening of the opened packaging bag 10. At the same time, the pair of retaining claws 23 and 24 retract to the upper side of the opening of the packaging bag 10. The pair of retaining claws 23 and 24 return to the second station S2 for operation on the next packaging bag 10'. Then, the contents to be packaged are filled into the packaging bag 10 from the funnel-shaped cylindrical part 31. After that, the funnel-shaped cylindrical part 31 retracts to the upper side of the opening of the packaging bag 10.

[0106] Subsequently, the packaging bag 10 is intermittently transported to the next fourth station S4 by the conveying device 15. The left gripper 11 and the right gripper 12 move with the packaging bag 10 to the next station. At the fourth station S4, the bottom surface of the packaging bag 10 is tapped vertically by the tapping device 51 (see Figure 10), causing the packaged items filled inside the packaging bag 10 to vibrate and balance the contents of the packaged items.

[0107] Subsequently, the packaging bag 10 is intermittently transported to the next fifth station S5 by the conveying device 15. At the fifth station S5, the bottom surface of the packaging bag 10 is tapped vertically by the tapping device 51 (see Figure 11), causing the packaged items filled inside the packaging bag 10 to vibrate and balance the contents of the packaged items. Meanwhile, at the fifth station S5, the second static elimination air supply device 55 (see Figure 11) supplies static elimination air locally to the inside of the opening of the packaging bag 10 through the opened opening of the packaging bag 10.

[0108] Subsequently, the packaging bag 10 is intermittently transported by the conveying device 15 to the next sixth station S6. At the sixth station S6, a sealing device 61, which acts as a bag closing device, seals the opening of the packaging bag 10.

[0109] Subsequently, the packaging bag 10 is intermittently transported by the conveying device 15 to the next station 7 S7. At station 7 S7, the packaging bag 10, which is filled with the packaged goods and has its opening sealed, is removed from the gripping device.

[0110] (test) In this embodiment, a packaging bag 10 was gripped by the left gripper 11 and right gripper 12 of the gripping device 1, filled with 400g of flour, and tested for tearing at the seal portion 10a of the packaging bag 10. The same test was performed on 1000 packaging bags 10, and the number of bags that tore, i.e., the defective product rate, was measured. With the left gripper 11 and right gripper 12 of the gripping device according to this embodiment, the defective product rate due to tearing was 0.1%. In contrast, the same tests were conducted using the left and right grippers of conventional gripping devices. The conventional left and right grippers have front and rear pads that form a flat contact surface from the inner end to the outer end, respectively, and are designed to grip the entire sealed portion of the left and right edges of the packaging bag. With these conventional left and right grippers, the defect rate due to tearing was 52.8%.

[0111] (effect) In the first embodiment of the present invention configured as described above, when the left front pad 16 and the left rear pad 17 are driven to move closer to each other, they are configured to clamp the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10. On the other hand, when the left front pad 16 and the left rear pad 17 are driven to move closer to each other and clamp the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10, the left region 16b of the left front pad 16 and the left region 17b of the left rear pad 17 are separated from each other so as not to clamp the sealing portion 10a on the left edge of the packaging bag 10. As a result, localized stress is not applied to the sealing portion 10a on the left edge of the packaging bag 10, and the possibility of the sealing portion 10a tearing can be significantly reduced.

[0112] Similarly, when the right front pad 18 and the right rear pad 19 are driven to move closer to each other, they are designed to clamp the inner region 10b of the seal portion 10a on the right edge of the packaging bag 10. On the other hand, when the right front pad 18 and the right rear pad 19 are driven to move closer to each other and clamp the inner region 10b of the seal portion 10a on the right edge of the packaging bag 10, the right region 18b of the right front pad 18 and the right region 19b of the right rear pad 19 are separated from each other so as not to clamp the seal portion 10a on the right edge of the packaging bag 10. As a result, localized stress is not applied to the seal portion 10a on the right edge of the packaging bag 10, and the possibility of the seal portion 10a tearing is significantly reduced.

[0113] Furthermore, with the gripping device of this embodiment, since the sealing portion 10a is not gripped (contacted) by the pad, even if the left gripper 11 and the right gripper 12 move together to move the packaging bag 10, the possibility of the sealing portion 10a tearing can be significantly suppressed.

[0114] Furthermore, with the gripping device of this embodiment, since the sealing portion 10a is not gripped (contacted) by the pad, even if the left gripper 11 and the right gripper 12 are positioned close to each other to assist in opening and unfolding the packaging bag, the possibility of the sealing portion 10a tearing can be significantly suppressed.

[0115] Next, a gripping device according to a second embodiment of the present invention will be described with reference to Figure 12. The second embodiment is an example in which a packaging bag to be gripped by the gripping device according to the present invention is gripped at different positions. Figure 12 is a schematic plan view illustrating the state in which the right gripper and left gripper of the gripping device according to the second embodiment of the present invention are in a closed state. Since the gripping device 101 according to the second embodiment has substantially the same structure as the gripping device 1 according to the first embodiment described above, only the differences between the second embodiment of the present invention and the first embodiment will be explained, and similar parts will be denoted by the same reference numerals in the drawings and their explanation will be omitted.

[0116] As shown in Figure 12, the gripping device 101 according to this embodiment includes a left gripper 111 that grips a portion of the left side of the packaging bag 10 and a right gripper 112 that grips a portion of the right side of the packaging bag 10. The gripping device 101 is installed on the packaging device 2 and grips the packaging bag 10 which has sealing portions on both the left and right edges.

[0117] The left gripper 111 has a left front pad 116 and a left rear pad 117 that are driven to move closer to and further apart from each other. When the left front pad 116 and the left rear pad 117 are driven to move closer to each other (driven by a drive unit not shown), they grip the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and come into contact with each other outside the sealing portion 10a on the left edge of the packaging bag 10 in the left outer area B2. Subsequently, when they are driven to move further apart from each other (driven by the drive unit), they release the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and move further apart from each other outside the sealing portion 10a on the left edge of the packaging bag 10 in the left outer area B2. The left outer area B2 is the area outside the left inner area B1 where the left front pad 116 and the left rear pad 117 come into contact with each other. The left front pad 116 and the left rear pad 117 are driven to move closer to each other, and the inner regions 16a and 17a sandwich the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10. At the same time, the outer region 116c of the left front pad 116 and the outer region 117c of the left rear pad 117 are in contact with each other in the left outer region B2 without sandwiching the sealing portion 10a. The outer region 116c forms a flat surface that is slightly higher than the inner region 16a. The outer region 116c is the region outside region 16b. The outer region 117c is the region outside region 17b.

[0118] The left front pad 116 and the left rear pad 117 are driven to move closer to each other, so that in the left inner region B1 they clamp the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10, and in the left outer region B2 they are in contact with each other outside the sealing portion 10a on the left edge of the packaging bag 10. The region 16b between the left inner region B1 and the left outer region B2 of the left front pad 116 and the region 17b between the left inner region B1 and the left outer region B2 of the left rear pad are separated from each other so as not to clamp the sealing portion 10a on the left edge of the packaging bag 10.

[0119] Symmetrically, the right gripper 112 has a right front pad 118 and a right rear pad 119 that are driven to move closer to and further apart from each other. When the right front pad 118 and the right rear pad 119 are driven to move closer to each other, they grip the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and come into contact with each other on the outside of the sealing portion 10a on the right edge of the packaging bag 10 in the right outer area B4. Subsequently, when they are driven to move further apart from each other, they release the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and in the right outer area B4 The right front pad 118 and the right rear pad 119 are positioned apart from each other outside the seal portion 10a on the right edge of the packaging bag 10, and are driven to move closer to each other so as to clamp the inner region 10b of the seal portion 10a on the right edge of the packaging bag 10 in the right inner region B3, and are in contact with each other outside the seal portion 10a on the right edge of the packaging bag 10 in the right outer region B4. The region 18b between the right inner region B3 and the right outer region B4 of the right front pad 118 and the region 19b between the right inner region B3 and the right outer region B4 of the right rear pad 119 are positioned apart from each other so as not to clamp the seal portion 10a on the right edge of the packaging bag 10. The right outer region B4 is the region outside the right inner region B3 where the right front pad 118 and the right rear pad 119 are in contact with each other. The right front pad 118 and the right rear pad 119 are driven to move closer to each other, and the inner regions 18a and 19a sandwich the inner region 10b of the sealing portion 10a on the right edge of the packaging bag 10. At the same time, the outer region 118c of the right front pad 118 and the outer region 119c of the right rear pad 119 are in contact with each other in the right outer region B4 without sandwiching the sealing portion 10a. The outer region 118c is the region outside region 18b. The outer region 118c forms a flat surface that is slightly higher than the inner region 18a. The outer region 119c is the region outside region 19b.

[0120] (effect) In the second embodiment of the present invention configured as described above, when the left front pad 116 and the left rear pad 117 are driven to move closer to each other, they grip the inner area of ​​the sealing portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and abut each other on the outside of the sealing portion 10a on the left edge of the packaging bag 10 in the left outer area B2. On the other hand, when the left front pad 116 and the left rear pad 117 are driven to move closer to each other, they grip the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and abut each other on the outside of the sealing portion 10a on the left edge of the packaging bag 10 in the left outer area B2, the area between the left inner area B1 and the left outer area B2 of the left front pad 116 and the area between the left inner area B1 and the left outer area B2 of the left rear pad 117 are separated from each other so as not to grip the sealing portion 10a on the left edge of the packaging bag 10. As a result, localized stress is not applied to the seal portion 10a on the left edge of the packaging bag 10, and the possibility of the seal portion 10a tearing is significantly reduced. Furthermore, since the pads come into contact with each other in the left outer region B2, it becomes easier to adjust the opening and closing stroke of the pads.

[0121] Similarly, when the right front pad 118 and the right rear pad 119 are driven to move closer to each other, they grip the inner area 10b of the seal portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and abut each other on the outside of the seal portion 10a on the right edge of the packaging bag 10 in the right outer area B4. On the other hand, when the right front pad 118 and the right rear pad 119 are driven to move closer to each other, they grip the inner area of ​​the seal portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and abut each other on the outside of the seal portion 10a on the right edge of the packaging bag 10 in the right outer area B4, the area between the right inner area B3 and the right outer area B4 of the right front pad 118 and the area between the right inner area B3 and the right outer area B4 of the right rear pad 119 are separated from each other so as not to grip the seal portion 10a on the right edge of the packaging bag 10. As a result, localized stress is not applied to the seal portion 10a on the right edge of the packaging bag 10, and the possibility of the seal portion 10a tearing is significantly reduced. Furthermore, since the pads come into contact with each other in the right outer region B4, it becomes easier to adjust the opening and closing stroke of the pads.

[0122] Next, a gripping device according to a third embodiment of the present invention will be described with reference to Figure 13. The third embodiment is an example in which a packaging bag to be gripped by the gripping device according to the present invention is gripped at different positions. Figure 13 is a schematic plan view illustrating the state in which the right gripper and left gripper of the gripping device according to the third embodiment of the present invention are in a closed state. Since the gripping device 201 according to the third embodiment has substantially the same structure as the gripping device 1 according to the first embodiment described above, only the differences between the third embodiment of the present invention and the first embodiment will be described, and similar parts will be denoted by the same reference numerals in the drawings and their description will be omitted.

[0123] As shown in Figure 13, the gripping device 201 according to this embodiment includes a left gripper 211 that grips a portion of the left side of the packaging bag 10 and a right gripper 212 that grips a portion of the right side of the packaging bag 10. The gripping device 201 is provided on the packaging device 2 and grips the packaging bag 10 which has sealing portions on both the left and right edges.

[0124] The left gripper 211 has a left front pad 216 and a left rear pad 217 that are driven to move closer to and further apart from each other. When the left front pad 216 and the left rear pad 217 are driven to move closer to each other (driven by a drive unit not shown), they grip the inner area 10b of the seal portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and grip a part of the seal portion 10a on the left edge of the packaging bag 10 in the left outer area B2. Subsequently, when they are driven to move further apart from each other (driven by the drive unit), they release the inner area 10b of the seal portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and release a part of the seal portion 10a on the left edge of the packaging bag 10 in the left outer area B2. The seal portion 10a on the left edge of the packaging bag 10 is gripped in the left outer area B2 over a width of 1 mm in the left-right direction. The left inner region B1 is the region where the packaging bag 10 is held between the left front pad 216 and the left rear pad 217. The left front pad 216 and the left rear pad 217 hold the inner region 10b of the sealing portion 10a within the left inner region B1. The left outer region B2 is the region where the packaging bag 10 is held between the left front pad 216 and the left rear pad 217, located outside the left inner region B1. The left front pad 216 and the left rear pad 217 hold a portion of the sealing portion 10a within the left outer region B2. The left front pad 216 and the left rear pad 217 are driven to move closer to each other, and the inner regions 16a and 17a clamp the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10, while the outer region 216c of the left front pad 216 and the outer region 217c of the left rear pad 217 clamp a part of the outer side of the sealing portion 10a. The outer region 216c forms a flat surface at approximately the same height as the inner region 16a. The outer region 216c is outside region 16b. The outer region 217c is outside region 17b. The outer region 217c forms a flat surface at approximately the same height as the inner region 17a.

[0125] The left front pad 216 and the left rear pad 217 are driven to move closer to each other, so that in the left inner region B1 they grip the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10, and in the left outer region B2 they grip a part of the sealing portion 10a on the left edge of the packaging bag 10. At the same time, the region 16b between the left inner region B1 and the left outer region B2 of the left front pad 216 and the region 17b between the left inner region B1 and the left outer region B2 of the left rear pad 217 are separated from each other so as not to grip the sealing portion 10a on the left edge of the packaging bag 10.

[0126] Symmetrically, the right gripper 212 has a right front pad 218 and a right rear pad 219 that are driven to move closer to and further apart from each other. When the right front pad 218 and the right rear pad 219 are driven to move closer to each other, they grip the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and grip a part of the sealing portion 10a on the right edge of the packaging bag 10 in the right outer area B4. Subsequently, when they are driven to move further apart from each other, they release the inner area 10b of the sealing portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and further apart in the right outer area B4. The packaging bag 10 is designed to open a portion of the seal portion 10a on the right edge, and the right front pad 218 and the right rear pad 219 are driven to move closer to each other, so that the inner region 10b of the seal portion 10a on the right edge of the packaging bag 10 is clamped in the right inner region B3, and a portion of the seal portion 10a on the right edge of the packaging bag 10 is clamped in the right outer region B4. The region 18b between the right inner region B3 and the right outer region B4 of the right front pad 218 and the region 19b between the right inner region B3 and the right outer region B4 of the right rear pad 219 are separated from each other so as not to clamp the seal portion 10a on the right edge of the packaging bag 10. The seal portion 10a on the right edge of the packaging bag 10 is clamped in the right outer region B4 over a width of 1 mm in the left-right direction, for example. The right inner region B3 is the region where the packaging bag 10 is clamped by the right front pad 218 and the right rear pad 219. The right front pad 218 and the right rear pad 219 clamp a portion of the sealing portion 10a together with the inner region 10b of the sealing portion 10a in the right inner region B3. The right outer region B4 is the region that clamps the packaging bag 10 outside the right inner region B3. When the right front pad 218 and the right rear pad 219 are driven to move closer to each other, and the inner regions 18a and 19a clamp the inner region 10b of the sealing portion 10a on the right edge of the packaging bag 10, the outer region 218c of the right front pad 218 and the outer region 219c of the right rear pad 219 clamp a portion of the sealing portion 10a in the right outer region B4. The outer region 218c is the region outside region 18b. The outer region 218c forms a flat surface at approximately the same height as the inner region 18a.The outer region 219c is the region outside of region 19b.

[0127] (test) In this embodiment, a packaging bag 10 was gripped by the left gripper 211 and the right gripper 212 of the gripping device 201, and 400g of flour was filled into it. A test was then conducted to see if the seal portion 10a of the packaging bag 10 would tear. The same test was performed on 1000 packaging bags 10, and the number of bags that tore, i.e., the defective product rate, was measured.

[0128] Specifically, the seal portion 10a on the left edge of the packaging bag 10 was held in the left outer region B2 over a width of 1 mm in the left-right direction. Similarly, the seal portion 10a on the right edge of the packaging bag 10 was held in the right outer region B4 over a width of 1 mm in the left-right direction. In tests using these dimensional relationships, the defect rate due to tearing was 5.3%.

[0129] In another example, the seal portion 10a on the left edge of the packaging bag 10 was held in the left outer region B2 over a width of 1.4 mm in the left-right direction (<3.0 mm ÷ 2 = 1.5 mm). Similarly, the seal portion 10a on the right edge of the packaging bag 10 was held in the right outer region B4 over a width of 1.4 mm in the left-right direction (<3.0 mm ÷ 2 = 1.5 mm). Even in tests using these dimensional relationships, the defect rate due to tearing was less than 6% (an acceptable level).

[0130] In yet another example, the seal portion 10a on the left edge of the packaging bag 10 was held in the left outer region B2 over a width of 1.6 mm in the left-right direction (>3.0 mm ÷ 2 = 1.5 mm). Similarly, the seal portion 10a on the right edge of the packaging bag 10 was held in the right outer region B4 over a width of 1.6 mm in the left-right direction (>3.0 mm ÷ 2 = 1.5 mm). In tests using these dimensional relationships, the defect rate due to tearing was over 10% (an unacceptable level).

[0131] (effect) In the third embodiment of the present invention configured as described above, when the left front pad 216 and the left rear pad 217 are driven to move closer to each other, they grip the inner area of ​​the sealing portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and a part of the sealing portion 10a on the left edge of the packaging bag 10 in the left outer area B2. On the other hand, when the left front pad 216 and the left rear pad 217 are driven to move closer to each other, and they grip the inner area of ​​the sealing portion 10a on the left edge of the packaging bag 10 in the left inner area B1 and a part of the sealing portion 10a on the left edge of the packaging bag 10 in the left outer area B2, the area between the left inner area B1 and the left outer area B2 of the left front pad 216 and the area between the left inner area B1 and the left outer area B2 of the left rear pad 217 are separated from each other so as not to grip the sealing portion 10a on the left edge of the packaging bag 10. As a result, even when a portion of the seal portion 10a on the left edge of the packaging bag 10 is being held in the left outer region B2, localized stress on the seal portion 10a on the left edge of the packaging bag 10 is suppressed, thereby reducing the possibility of the seal portion 10a tearing.

[0132] Similarly, when the right front pad 218 and the right rear pad 219 are driven to move closer to each other, they grip the inner area of ​​the seal portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and a part of the seal portion 10a on the right edge of the packaging bag 10 in the right outer area B4. On the other hand, when the right front pad 218 and the right rear pad 219 are driven to move closer to each other, they grip the inner area of ​​the seal portion 10a on the right edge of the packaging bag 10 in the right inner area B3 and a part of the seal portion 10a on the right edge of the packaging bag 10 in the right outer area B4, the area between the right inner area B3 and the right outer area B4 of the right front pad 218 and the area between the right inner area B3 and the right outer area B4 of the right rear pad 219 are separated from each other so as not to grip the seal portion 10a on the right edge of the packaging bag 10. As a result, even when a portion of the seal portion 10a on the right edge of the packaging bag 10 is being held in the right outer region B4, localized stress on the seal portion 10a on the right edge of the packaging bag 10 is suppressed, thereby reducing the possibility of the seal portion 10a tearing.

[0133] Next, a gripping device according to a fourth embodiment of the present invention will be described with reference to Figure 14. The fourth embodiment is an example in which a packaging bag to be gripped by the gripping device according to the present invention is gripped at different positions. Figure 14 is a schematic plan view illustrating the state in which the right gripper and left gripper of the gripping device according to the fourth embodiment of the present invention are in a closed state. Since the gripping device 301 according to the fourth embodiment has substantially the same structure as the gripping device 1 according to the first embodiment described above, only the differences between the fourth embodiment of the present invention and the first embodiment will be described, and similar parts will be denoted by the same reference numerals in the drawings and their description will be omitted.

[0134] As shown in Figure 14, the gripping device 301 according to this embodiment includes a left gripper 311 that grips a portion of the left side of the packaging bag 10 and a right gripper 312 that grips a portion of the right side of the packaging bag 10. The gripping device 301 is provided on the packaging device 2 and grips the packaging bag 10 which has sealing portions on both the left and right edges.

[0135] The left gripper 311 has a left front pad 316 and a left rear pad 317 that are driven to move closer to and further apart from each other. When the left front pad 316 and the left rear pad 317 are driven to move closer to each other (driven by a drive unit not shown), they grip the inner area 10b of the seal portion 10a on the left edge of the packaging bag 10 with a relatively large area and grip the seal portion 10a on the left edge of the packaging bag 10 with a relatively small area. Subsequently, when they are driven to move further apart from each other (driven by the drive unit), they release the inner area 10b of the seal portion 10a on the left edge of the packaging bag 10 and the seal portion 10a on the left edge of the packaging bag 10. In the left gripper 311, the ratio of the relatively large area to the relatively small area is 2 times or more. The seal portion 10a on the left edge of the packaging bag 10 is gripped between the inner area 16a and the inner area 17a over a width of 1 mm in the left-right direction. The inner region 10b of the sealing portion 10a is sandwiched between the inner region 16a and the inner region 17a over a width of 2 mm in the left-right direction.

[0136] The shape of the area where the inner region 10b of the sealing portion 10a is sandwiched between the inner region 16a and the inner region 17a is not limited to a rectangular plane, but may be changed by protrusions or grooves formed on the inner region 16a or the inner region 17a. Similarly, the shape of the area where the sealing portion 10a is sandwiched between the inner region 16a and the inner region 17a (the area where the pads come into contact) is not limited to a rectangular plane, but may be changed by protrusions or grooves formed on the inner region 16a or the inner region 17a.

[0137] The left front pad 316 and the left rear pad 317 are driven to move closer to each other, and the inner regions 16a and 17a are clamping the inner region 10b of the sealing portion 10a on the left edge of the packaging bag 10. At the same time, the right region 18b of the right front pad 318 and the right region 19b of the right rear pad 319 are separated from each other so as not to clamp the sealing portion 10a on the right edge of the packaging bag 10.

[0138] Symmetrically, the right gripper 312 has a right front pad 318 and a right rear pad 319 that are driven to move closer to and further apart from each other. When the right front pad 318 and the right rear pad 319 are driven closer to each other, they grip the inner area 10b of the seal portion 10a on the right edge of the packaging bag 10 with a relatively large area and grip the seal portion 10a on the right edge of the packaging bag 10 with a relatively small area. Subsequently, when they are driven to move further apart from each other, they release the inner area 10b of the seal portion 10a on the right edge of the packaging bag 10 and the seal portion 10a on the right edge of the packaging bag 10. In the right gripper 312, the ratio of the relatively large area to the relatively small area is 2 times or more. The seal portion 10a on the right edge of the packaging bag 10 is gripped, for example, between the inner area 18a and the inner area 19a over a width of 1 mm in the left-right direction. The inner region 10b of the sealing portion 10a is, for example, sandwiched between the inner region 18a and the inner region 19a over a width of 2 mm in the left-right direction.

[0139] The shape of the area in which the inner region 10b of the sealing portion 10a is sandwiched between the inner region 18a and the inner region 19a is not limited to a rectangular plane, but may be changed by protrusions or grooves formed on the inner region 18a or the inner region 19a. Similarly, the shape of the area in which the sealing portion 10a is sandwiched between the inner region 18a and the inner region 19a (the area in which the pads come into contact) is not limited to a rectangular plane, but may be changed by protrusions or grooves formed on the inner region 18a or the inner region 19a.

[0140] (test) In this embodiment, a packaging bag 10 was gripped by the left gripper 311 and the right gripper 312 of the gripping device 301, and 400g of flour was filled into it. A test was then conducted to see if the seal portion 10a of the packaging bag 10 would tear. The same test was performed on 1000 packaging bags 10, and the number of bags that tore, i.e., the defective product rate, was measured.

[0141] Specifically, the seal portion 10a on the left edge of the packaging bag 10 was sandwiched between inner regions 16a and 17a over a width of 1 mm in the left-right direction. The inner region 10b of the seal portion 10a was sandwiched between inner regions 16a and 17a over a width of 2 mm in the left-right direction. Similarly, the seal portion 10a on the right edge of the packaging bag 10 was sandwiched between inner regions 18a and 19a over a width of 1 mm in the left-right direction. The inner region 10b of the seal portion 10a was also sandwiched between inner regions 18a and 19a over a width of 2 mm in the left-right direction. In tests using these dimensional relationships, the defect rate due to tearing was 3.8%.

[0142] In another example, the seal portion 10a on the left edge of the packaging bag 10 was sandwiched between inner regions 16a and 17a over a width of 1.4 mm (<3.0 mm ÷ 2 = 1.5 mm) in the left-right direction. The inner region 10b of the seal portion 10a was also sandwiched between inner regions 16a and 17a over a width of 1.6 mm in the left-right direction. Similarly, the seal portion 10a on the right edge of the packaging bag 10 was also sandwiched between inner regions 18a and 19a over a width of 1.4 mm (<3.0 mm ÷ 2 = 1.5 mm) in the left-right direction. The inner region 10b of the seal portion 10a was also sandwiched between inner regions 18a and 19a over a width of 1.6 mm in the left-right direction. Even in tests using these dimensional relationships, the defect rate due to tearing was less than 6% (an acceptable level).

[0143] In yet another example, the seal portion 10a on the left edge of the packaging bag 10 was sandwiched between inner regions 16a and 17a over a width of 1.6 mm (>3.0 mm ÷ 2 = 1.5 mm) in the left-right direction. The inner region 10b of the seal portion 10a was also sandwiched between inner regions 16a and 17a over a width of 1.4 mm in the left-right direction. Similarly, the seal portion 10a on the right edge of the packaging bag 10 was also sandwiched between inner regions 18a and 19a over a width of 1.6 mm (>3.0 mm ÷ 2 = 1.5 mm) in the left-right direction. The inner region 10b of the seal portion 10a was also sandwiched between inner regions 18a and 19a over a width of 1.4 mm in the left-right direction. In tests using these dimensional relationships, the defect rate due to tearing was over 10% (an unacceptable level).

[0144] (effect) In this third embodiment of the present invention, when the left front pad 316 and the left rear pad 317 are driven to move closer to each other, they grip the inner area 10b of the sealing portion 10a on the left edge of the packaging bag 10 with a relatively large area, while gripping the sealing portion 10a on the left edge of the packaging bag 10 with a relatively small area. This suppresses localized stress on the sealing portion 10a on the left edge of the packaging bag 10, thereby reducing the possibility of the sealing portion 10a tearing.

[0145] Similarly, when the right front pad 318 and the right rear pad 319 are driven to move closer to each other, they grip the inner area of ​​the seal portion 10a on the right edge of the packaging bag 10 with a relatively large area, while gripping the seal portion 10a on the right edge of the packaging bag 10 with a relatively small area. This suppresses localized stress on the seal portion 10a on the right edge of the packaging bag 10, thereby reducing the possibility of the seal portion 10a tearing.

[0146] Furthermore, preferably, the ratio of a relatively large area to a relatively small area is 2 times or more, which suppresses localized stress on the seal portions 10a on the left and right edges of the packaging bag 10, and further reduces the possibility of the seal portions 10a tearing.

[0147] The embodiments for carrying out the present invention are not limited to those described above, and further variations can be applied. As a variation, a concave surface may be formed in the left region 17b that is recessed more than that of the inner region 17a. Alternatively, as a further variation, a concave surface may be formed in the left region 17b, and the left region 16b may not have a concave surface, but instead have a plane of the same height adjacent to the left side of the inner region 16a. Alternatively, as yet another variation, the concave surface formed in the left region 16b or the left region 17b is not limited to a concave surface, but may be formed in other shapes that form a gap space A that does not clamp the seal portion 10a, such as a curved shape or a sloping shape.

[0148] Furthermore, the gripping device 1 of this embodiment is also applicable to packaging bags 10 made of materials other than paper. For example, the packaging bag may be made of polyethylene, which is mainly composed of plastic, and may be formed as a so-called standing pouch with a width of 190 mm, a height of 290 mm, and a thickness of 68 μm. The packaging bag 10 contains powder such as wheat flour, and the intended weight of the contents filled into the packaging bag 10 is 1 kg. The packaging bag 10 may have a seal portion 10a with a width of 5 mm on both the right edge and the right edge.

[0149] Furthermore, as a modified example, the left gripper and the right gripper in the above-described embodiment can be freely combined to construct a gripping device.

[0150] For example, a gripping device combining the left gripper 11 according to the first embodiment and the right gripper 212 according to the third embodiment is also within the scope of the present invention, at least as of the time of filing this application. As with the other embodiments, the left-right relationship is reversed when viewed from the opposite side, so the left-right relationship may also be reversed.

[0151] As another variation, a gripping device combining the left gripper 11 according to the first embodiment and the right gripper 312 according to the fourth embodiment is also within the scope of the present invention, at least as of the time of filing this application. As with the other embodiments, the left-right relationship is reversed when viewed from the opposite side, so the left-right relationship may also be reversed.

[0152] As another variation, a gripping device combining the left gripper 211 according to the third embodiment and the right gripper 312 according to the fourth embodiment is also within the scope of the present invention, at least as of the time of filing this application. As with the other embodiments, the left-right relationship is reversed when viewed from the opposite side, so the left-right relationship may also be reversed.

[0153] Furthermore, as a modification, a gripping device equipped with only one of the left gripper and the right gripper in the above-described embodiment is also within the scope of the present invention, at least as of the time of filing this application. Such a gripping device grips a packaging bag having a seal portion on only one side, for example, on the left edge. The packaging bag is, for example, a side-seal type packaging bag in which a seal is provided at only one place on the side of the bag. For example, a gripping device equipped with only the left gripper 11 according to the first embodiment may be configured, that is, the right gripper may be omitted, and the packaging bag may be gripped by the left gripper 11 alone. As with the other embodiments, if the front and back are viewed from the opposite side, the left and right relationship will be reversed, so the left and right relationship may also be reversed. With this configuration, localized stress is not applied to the seal portion 10a on the left edge of the packaging bag 10, and the possibility of the seal portion 10a tearing can be significantly suppressed.

[0154] Furthermore, as another variation, a gripping device equipped with only one of the left gripper and the right gripper in the second embodiment described above is also within the scope of the present invention, at least as of the time of filing this application. Such a gripping device grips a packaging bag having a seal portion on only one side, for example, the left edge. For example, depending on the position of the packaging bag 10, a gripping device equipped with only the left gripper 111 according to the second embodiment may be configured, that is, the right gripper may be omitted and the packaging bag may be gripped by the left gripper 111 alone. As with the other embodiments, if the front and back are viewed from the opposite side, the left-right relationship will be reversed, so the left-right relationship may also be reversed. With such a configuration, local stress is not applied to the seal portion 10a on the left edge of the packaging bag 10, and the possibility of the seal portion 10a tearing can be significantly suppressed.

[0155] Furthermore, as another variation, a gripping device equipped with only one of the left gripper and the right gripper in the third embodiment described above is also within the scope of the present invention, at least as of the time of filing this application. Such a gripping device grips a packaging bag having a seal portion on only one side, for example, on the left edge. For example, depending on the position of the packaging bag 10, a gripping device equipped with only the left gripper 211 according to the third embodiment may be configured, that is, the right gripper may be omitted and the packaging bag may be gripped by the left gripper 211 alone. As with the other embodiments, if the front and back are viewed from the opposite side, the left-right relationship will be reversed, so the left-right relationship may also be reversed. With such a configuration, even if a part of the seal portion 10a on the left edge of the packaging bag 10 is gripped in the left outer region B2, local stress on the seal portion 10a on the left edge of the packaging bag 10 is suppressed, and the possibility of the seal portion 10a tearing can be suppressed.

[0156] Furthermore, as another variation, a gripping device equipped with only one of the left gripper and the right gripper in the fourth embodiment described above is also within the scope of the present invention, at least as of the time of filing this application. Such a gripping device grips a packaging bag having a seal portion on only one side, for example, the left edge. For example, depending on the position of the packaging bag 10, a gripping device equipped with only the left gripper 311 according to the fourth embodiment may be configured, that is, the right gripper may be omitted and the packaging bag may be gripped by the left gripper 311 alone. As with the other embodiments, the left-right relationship is reversed when viewed from the opposite side, so the left-right relationship may also be reversed. With such a configuration, local stress on the seal portion 10a on the left edge of the packaging bag 10 can be suppressed, and the possibility of the seal portion 10a tearing can be suppressed. [Explanation of symbols]

[0157] 1 Gripping device 2 Packaging equipment 10 packaging bags 10a Seal part 10b Inner region 11 Left Gripper 12 Right Gripper 16. Left front pad 16b Left area 17 Left rear pad 17b Left side area 18 Right front pad 18b Right-hand area 19 Right rear pad 19b Right-hand area 40 Metal retaining member 42 Metal retaining member

Claims

1. A gripping device for gripping a packaging bag having sealing portions on both the left and right edges, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, A right gripper that grasps a portion of the right side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. The left front pad and the left rear pad are designed to grip the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move closer together, and to release the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move further apart. The left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the sealing portion on the left edge of the packaging bag, while the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the sealing portion on the left edge of the packaging bag. The right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. The right front pad and the right rear pad are designed to clamp the inner area of ​​the sealing portion on the right edge of the packaging bag when driven to move closer together, and then release the inner area of ​​the sealing portion on the right edge of the packaging bag when driven to move further apart from each other. The right front pad and the right rear pad are driven to move closer to each other and grip the inner area of ​​the sealing portion on the right edge of the packaging bag, while the right area of ​​the right front pad and the right area of ​​the right rear pad are separated from each other so as not to grip the sealing portion on the right edge of the packaging bag. A gripping device characterized by the following features.

2. The left front pad and the left rear pad are driven to move closer to each other, and they clamp the inner area of ​​the sealing portion on the left edge of the packaging bag, and, With the right front pad and the right rear pad driven to move closer to each other, and gripping the inner area of ​​the sealing portion on the right edge of the packaging bag, The left gripper and the right gripper are designed to move together in order to move the packaging bag. The gripping device according to feature 1.

3. The left front pad and the left rear pad are driven to move closer to each other, and they clamp the inner area of ​​the sealing portion on the left edge of the packaging bag, and, With the right front pad and the right rear pad driven to move closer to each other, and gripping the inner area of ​​the sealing portion on the right edge of the packaging bag, The left gripper and the right gripper are positioned to be brought close to each other in order to assist in opening and unfolding the packaging bag. The gripping device according to claim 1 or 2.

4. A gripping device for gripping a packaging bag having sealing portions on both the left and right edges, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, A right gripper that grasps a portion of the right side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. When the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and come into contact with each other outside the seal portion of the left edge of the packaging bag in the left outer region; and when they are then driven to move apart from each other, they release the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and move apart from each other outside the seal portion of the left edge of the packaging bag in the left outer region. The left front pad and the left rear pad are driven to move closer to each other so that they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and are in contact with each other outside the seal portion of the left edge of the packaging bag in the left outer region, while the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. The right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. When the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and come into contact with each other outside the seal portion of the right edge of the packaging bag in the right outer region; and when they are then driven to move apart from each other, they release the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and move apart from each other outside the seal portion of the right edge of the packaging bag in the right outer region. The right front pad and the right rear pad are driven to move close to each other so that they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and are in contact with each other outside the seal portion of the right edge of the packaging bag in the right outer region, while the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right outer region of the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag. A gripping device characterized by the following features.

5. A gripping device for gripping a packaging bag having sealing portions on both the left and right edges, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, A right gripper that grasps a portion of the right side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. When the left front pad and the left rear pad are driven to move closer together, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region. Subsequently, when they are driven to move further apart, they release the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and release a portion of the seal portion of the left edge of the packaging bag in the left outer region. The left front pad and the left rear pad are driven to move closer to each other, so that the left inner region grips the inner region of the seal portion of the left edge of the packaging bag, and the left outer region grips a portion of the seal portion of the left edge of the packaging bag, while the region between the left inner region and the left outer region of the left front pad and the region between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. The right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. When the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and grip a portion of the seal portion of the right edge of the packaging bag in the right outer region. Subsequently, when they are driven to move further apart from each other, they release the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and release a portion of the seal portion of the right edge of the packaging bag in the right outer region. The right front pad and the right rear pad are driven to move close to each other, so that the right inner region grips the inner area of ​​the seal portion of the right edge of the packaging bag, and the right outer region grips a portion of the seal portion of the right edge of the packaging bag, while the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right outer region of the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag. A gripping device characterized by the following features.

6. A gripping device for gripping a packaging bag having sealing portions on both the left and right edges, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, A right gripper that grasps a portion of the right side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. The left front pad and the left rear pad are designed to grip the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move closer together, and to release the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move further apart. The left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the sealing portion on the left edge of the packaging bag, while the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the sealing portion on the left edge of the packaging bag. The right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. When the right front pad and the right rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and grip a portion of the seal portion of the right edge of the packaging bag in the right outer region. Subsequently, when they are driven to move further apart from each other, they release the inner area of ​​the seal portion of the right edge of the packaging bag in the right inner region and release a portion of the seal portion of the right edge of the packaging bag in the right outer region. The right front pad and the right rear pad are driven to move close to each other, so that the right inner region grips the inner area of ​​the seal portion of the right edge of the packaging bag, and the right outer region grips a portion of the seal portion of the right edge of the packaging bag, while the area between the right inner region and the right outer region of the right front pad and the area between the right inner region and the right outer region of the right rear pad are separated from each other so as not to grip the seal portion of the right edge of the packaging bag. A gripping device characterized by the following features.

7. A gripping device for gripping a packaging bag having sealing portions on both the left and right edges, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, A right gripper that grasps a portion of the right side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. The left front pad and the left rear pad are designed to grip the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move closer together, and to release the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move further apart. The left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the sealing portion on the left edge of the packaging bag, while the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the sealing portion on the left edge of the packaging bag. The right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. When the right front pad and the right rear pad are driven to move closer together, they grip the inner area of ​​the seal portion on the right edge of the packaging bag with a relatively large area and grip the seal portion on the right edge of the packaging bag with a relatively small area. Subsequently, when they are driven to move further apart, they release the inner area of ​​the seal portion on the right edge of the packaging bag and the seal portion on the right edge of the packaging bag. A gripping device characterized by the following features.

8. The ratio of the aforementioned relatively large area to the aforementioned relatively small area is 2 times or more. The gripping device according to feature 7.

9. A gripping device for gripping a packaging bag having sealing portions on both the left and right edges, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, A right gripper that grasps a portion of the right side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. When the left front pad and the left rear pad are driven to move closer together, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and grip a portion of the seal portion of the left edge of the packaging bag in the left outer region. Subsequently, when they are driven to move further apart, they release the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and release a portion of the seal portion of the left edge of the packaging bag in the left outer region. The left front pad and the left rear pad are driven to move closer to each other, so that the left inner region grips the inner region of the seal portion of the left edge of the packaging bag, and the left outer region grips a portion of the seal portion of the left edge of the packaging bag, while the region between the left inner region and the left outer region of the left front pad and the region between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. The right gripper has a right front pad and a right rear pad that are driven to move closer to and further apart from each other. When the right front pad and the right rear pad are driven to move closer together, they grip the inner area of ​​the seal portion on the right edge of the packaging bag with a relatively large area and grip the seal portion on the right edge of the packaging bag with a relatively small area. Subsequently, when they are driven to move further apart, they release the inner area of ​​the seal portion on the right edge of the packaging bag and the seal portion on the right edge of the packaging bag. A gripping device characterized by the following features.

10. The ratio of the aforementioned relatively large area to the aforementioned relatively small area is 2 times or more. The gripping device according to feature 9.

11. A gripping device for gripping a packaging bag having a sealing portion on its left edge, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. The left front pad and the left rear pad are designed to grip the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move closer together, and to release the inner area of ​​the sealing portion on the left edge of the packaging bag when driven to move further apart. The left front pad and the left rear pad are driven to move closer to each other and grip the inner area of ​​the sealing portion on the left edge of the packaging bag, while the left area of ​​the left front pad and the left area of ​​the left rear pad are separated from each other so as not to grip the sealing portion on the left edge of the packaging bag. A gripping device characterized by the following features.

12. A gripping device for gripping a packaging bag having a sealing portion on its left edge, A left gripper that grasps a portion of the left side of the aforementioned packaging bag, Equipped with, The left gripper has a left front pad and a left rear pad that are driven to move closer to and further apart from each other. When the left front pad and the left rear pad are driven to move closer to each other, they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and come into contact with each other outside the seal portion of the left edge of the packaging bag in the left outer region; and when they are then driven to move apart from each other, they release the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and move apart from each other outside the seal portion of the left edge of the packaging bag in the left outer region. The left front pad and the left rear pad are driven to move close to each other so that they grip the inner area of ​​the seal portion of the left edge of the packaging bag in the left inner region and are in contact with each other outside the seal portion of the left edge of the packaging bag in the left outer region, while the area between the left inner region and the left outer region of the left front pad and the area between the left inner region and the left outer region of the left rear pad are separated from each other so as not to grip the seal portion of the left edge of the packaging bag. A gripping device characterized by the following features.

Images