Top forming device for paper containers with folding mechanism

Abstract

In order to obtain a top forming part crease applying mechanism which is for a paper container top forming device and which can apply a crease, for facilitating the folding of a top forming part, to a top forming part of a cylindrical carton blank for molding a paper container having a top that is a flat folded shape and provided with a suction-discharge opening in the center thereof, the present invention comprises: a first crease applying means 4 which valley-folds left and right side surface panels 112, 114 of a carton blank 126 fitted to a mandrel 2 while pushing the panels outward from the center from horizontal folding lines 111, 113; a second crease applying means 5 for applying a crease by mountain-folding a top upper surface panel 108 and a top upper surface auxiliary panel 110 inward from horizontal folding lines 107, 109; and a third crease applying means 6 for applying a crease by valley-folding a seal panel 117 on the tip end of the top upper surface auxiliary panel 110 outward from a horizontal folding line 116.

Description

[Technical Field]

[0001] The present invention relates to a top forming portion crease imparting mechanism in a paper container top forming device that imparts a crease to the top forming portion of a cylindrical carton blank that forms a paper container having a flat, folded top with a suction port in the center. [Background technology]

[0002] The applicant has filed an application for a paper container having a central spout and a flat, folded top that is placed inside a refill container (International Application No. PCT / JP2018 / 012929).

[0003] The top of this paper container is constructed as follows. A front panel 103, a right side panel 104, a back panel 105, and a left side panel 106 are connected via vertical fold lines 100, 101, and 102, a top panel 108 is connected to the top end of the back panel 105 via a horizontal fold line 107, a top auxiliary panel 110 is connected to the top end of the front panel 103 via a horizontal fold line 109, and is folded under and overlapped with the top panel 108, and a top auxiliary panel 110 is connected to the top end of the right side panel 104 via a horizontal fold line 111. The bag has a right side panel 112 that is connected to the upper end of the left side panel 106 of the body via a horizontal fold line 113 and is folded outward as the top panel 108 and the top auxiliary panel 110 are superimposed on each other, and a left side panel 114 that is connected to the upper end of the left side panel 106 of the body via a horizontal fold line 113 and is folded outward as the top panel 108 and the top auxiliary panel 110 are superimposed on each other. The top panel 108 has an outlet 115 located at its center, and the top auxiliary panel 110 has a length that is equal to or longer than the length of the top panel 108. The length of the panel 108 is such that it does not reach the suction port 115 provided on the face panel 108, and the tip of the panel 108 has a seal panel 117 connected via a horizontal fold line 116. Also, the panel 108 has bottom panels 120 and 121 connected via horizontal fold lines 118 and 119 to the lower ends of the front panel 103 and the back panel 105 of the body, and bottom fold panels 124 and 125 connected via horizontal fold lines 122 and 123 to the lower ends of the right side panel 104 and the left side panel 106 of the body, and at least the inner surface is made of a thermoplastic resin. The carton blank 126 (see FIG. 14), on which a thin, flexible resin layer is laminated, is formed into a square tube by joining longitudinal edges 127 (see FIG. 15). The seal panel 117 connected to the top auxiliary panel 110 of the cylindrical carton blank 126 is folded along the horizontal fold line 116 (see FIG. 16). The inner surface of the seal panel 117 is sealed with the inner surface of the top panel 108. The overlapping surfaces of the folded right side panel 112 and left side panel 113 are sealed together to form a flat top panel 12. 8 It is composed of:

[0004] Conventionally, a paper container bottom forming device that forms the flattened bottom of a rectangular tubular paper container is known, which attaches a tubular carton blank to a mandrel and creates creases in the bottom constituent panels of the tubular carton blank attached to the mandrel to make folding easier (see, for example, Patent Documents 1 and 2).

[0005] However, even though they have the same flat folded shape, the shapes of the top upper panel 108, top upper auxiliary panel 110, right side panel 112, and left side panel 114, which form the top forming portion 129 that forms the top 128 of the above-mentioned paper container, are different from the shapes of the bottom panels that form the bottom of the paper containers described in Patent Documents 1 and 2, and the folding method is complex, so it is difficult to fold the top forming portion 129 that forms the top 128 of the paper container using the paper container bottom forming devices described in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-210185 [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-23320 Summary of the Invention [Problem to be solved by the invention]

[0007] In order to efficiently form the flattened top 128 of the above-mentioned rectangular tubular paper container, it is desirable to attach a tubular carton blank 126 to a mandrel, fold the top forming portion 129 that forms the top 128 of the carton blank 126, and seal it to form the top 128. The inventors have completed the present invention after repeated tests to create folds in the top upper panel 108, top upper auxiliary panel 110, right side panel 112, and left side panel 114, which form the top forming portion 129 that forms the top 128 of the paper container when folded flat, so that the top forming portion 129 can be easily folded and the top of the paper container can be formed.

[0008] The object of the present invention is to provide a top forming portion crease imparting mechanism in a top forming device for paper containers, which is capable of imparting a crease to the top forming portion of a cylindrical carton blank that forms a paper container having a flat, folded top with a suction port in the center, to make it easier to fold the top forming portion. [Means for solving the problem]

[0009] In order to achieve the above object, the invention described in claim 1 comprises a body front panel, left and right body side panels, a body back panel, a top panel connected to the upper end of the body back panel via a horizontal fold line, a top auxiliary panel that is folded under and overlapped with the top panel that is connected to the upper end of the body front panel via the horizontal fold line, and left and right side panels that are connected to the upper ends of the left and right body side panels via the horizontal fold line and are folded outward as the top panel and the top auxiliary panel are overlapped, wherein the top panel has a suction opening located at its center, and the top auxiliary panel has a vertical length that does not reach the suction opening provided on the top panel, and has a seal panel connected to its tip via the horizontal fold line, and at least an inner surface a top forming section crease imparting mechanism in a top forming device for paper containers, which forms a top by joining vertical edges of a carton blank having a thermoplastic resin layer laminated thereon to form a rectangular tubular shape, attaching the tubular carton blank to a mandrel, protruding a top forming section consisting of the top upper panel, the top upper auxiliary panel, and the left and right side panels of the carton blank from the tip of the mandrel, valley-folding the seal panel connected to the protruding top upper auxiliary panel from a horizontal fold line, sealing its inner surface with the inner surface of the top upper panel, and sealing the overlapping surfaces of the folded left and right side panels together; ,before a second folding means for folding the top upper surface panel and the top upper surface auxiliary panel inward from the horizontal folding line to form a mountain fold; ,before and a third folding means for folding the seal panel at the tip of the top upper surface auxiliary panel outward from the horizontal folding line to form a valley crease.

[0010] According to the invention described in claim 1, the first fold-creasing means pushes the left and right side panels, which form the top forming portion of the carton blank attached to the mandrel, outward from the center and creates a valley fold from the horizontal fold line to create a fold; the second fold-creasing means folds the top top panel and the top top auxiliary panel inward from the horizontal fold line to create a mountain fold; and the third fold-creasing means folds the seal panel at the tip of the top top auxiliary panel inward from the horizontal fold line to create a valley fold, thereby creating a fold, so that the top forming portion of the carton blank can be created with a fold that makes it easier to fold.

[0011] The invention described in claim 2 is characterized in that the first fold imparting means described in claim 1 is supported so as to be able to move forward and backward toward the top forming portion, and comprises an expander body that advances and enters the top forming portion, and pushes the left and right side panels outward from the center, thereby creating a valley fold from the horizontal fold line.

[0012] According to the invention described in claim 2, the left and right side panels can be folded by a simple operation of advancing the spreader toward the top forming portion of the carton blank, inserting it into the top forming portion, pushing the left and right side panels outward from the center, and making a valley fold from the horizontal fold line.

[0013] The invention described in claim 3 is characterized in that the second crease imparting means described in claim 1 comprises a first pressing body supported so as to be able to move back and forth toward the top upper surface panel, and which advances to press the top upper surface panel and cause a mountain fold from the horizontal fold line, and a second pressing body supported so as to be able to move back and forth toward the top upper surface auxiliary panel, and which advances to press the top upper surface auxiliary panel and cause a mountain fold from the horizontal fold line.

[0014] According to the invention described in claim 3, a fold can be formed in the top top panel and the top top auxiliary panel by a simple operation of advancing the first pressure body toward the top top panel, pressing the top top panel to cause a mountain fold from the horizontal fold line, and advancing the second pressure body toward the top top auxiliary panel, pressing the top top auxiliary panel to cause a mountain fold from the horizontal fold line.

[0015] The invention described in claim 4 is characterized in that the third fold imparting means described in claim 1 is composed of a receiving plate member that receives the tip of the seal panel from the inner side with its plate surface, and a folding plate member that presses the connecting portion of the top upper surface auxiliary panel and the seal panel toward the receiving plate member from the outer side, thereby valley-folding the seal panel from the horizontal fold line.

[0016] According to the invention described in claim 4, the tip of the seal panel is supported from the inner side by the plate surface of the receiving plate member, and from this state, the connecting portion between the top upper surface auxiliary panel and the seal panel is pressed from the outer side toward the receiving plate member using a bending plate member, and the seal panel is valley-folded from the horizontal fold line, thereby creating a fold in the seal panel.

[0017] The invention described in claim 5 is characterized in that, as described in claim 4, the support plate member and the folding plate member are arranged facing each other with a gap between them and their rear ends are connected to form one unit, the length of the tip end of the support plate member is longer than that of the folding plate member, and a groove into which the seal panel can be inserted from the upper end side is formed between the support plate member and the folding plate member, and the support plate member is supported so as to be able to move forward and backward toward the seal panel, and when it moves forward, the tip of the seal panel abuts against the plate surface of the support plate member and guides the tip of the seal panel into the groove, and the tip of the folding plate member presses the connection portion between the top upper surface auxiliary panel and the seal panel from the outer surface side toward the support plate member, causing the seal panel to be valley-folded from the horizontal fold line.

[0018] According to the invention described in claim 5, the seal panel can be folded by a simple operation of advancing the integrally formed receiving plate member and the bending plate member toward the seal panel, abutting the tip of the seal panel against the plate surface of the receiving plate member to guide the tip of the seal panel into the groove, and pressing the outer surface of the seal panel guided into the groove with the tip of the bending plate member to fold the seal panel into a valley from the horizontal fold line.

[0019] The invention described in claim 6 is characterized in that, as described in claim 4, the support plate member is supported so that it can move forward and backward toward the inner side of the tip of the seal panel, and the bending plate member is supported so that it can move forward and backward toward the connecting portion between the top upper surface auxiliary panel and the seal panel, the support plate member moves forward to allow the tip of the seal panel to abut against the plate surface of the support plate member, and the bending plate member moves forward to press the connecting portion between the top upper surface auxiliary panel and the seal panel from the outer side toward the support plate member, and by abutting and pressing the tip of the seal panel against the plate surface of the advancing support plate member, the seal panel is valley-folded from the horizontal fold line.

[0020] According to the invention described in claim 6, the support plate member is advanced toward the inner surface of the tip of the seal panel to a position where the tip of the seal panel can abut against the plate surface of the support plate member, and from this state, the folding plate member is advanced, the connecting portion between the top upper surface auxiliary panel and the seal panel is pressed from the outer surface side toward the support plate member, and the tip of the seal panel is abutted and pressed against the plate surface of the support plate member, thereby creating a valley fold in the seal panel from the horizontal fold line.This simple operation allows the seal panel to be folded. [Effects of the Invention]

[0021] According to the top forming portion crease imparting mechanism in the paper container top forming device of the present invention, a crease that makes it easier to fold the top forming portion of a cylindrical carton blank that forms a paper container having a flat, folded top with a suction port in the center can be imparted to the top forming portion. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is an explanatory diagram showing an example of an embodiment of a crease imparting mechanism for a top forming section in a top forming device for a paper container according to the present invention. FIG. [Figure 2] 2 is an explanatory diagram showing the operation of the first crease imparting means shown in FIG. 1; FIG. [Figure 3] 2 is an explanatory diagram showing the operation of the first crease imparting means shown in FIG. 1; FIG. [Figure 4] 1. FIG. 4 is an explanatory diagram showing the operation of the second crease imparting means shown in FIG. [Figure 5] 1. FIG. 4 is an explanatory view showing the operation of the third folding means shown in FIG. [Figure 6] 1. FIG. 4 is an explanatory view showing the operation of the third folding means shown in FIG. [Figure 7] 1. FIG. 4 is an explanatory view showing the operation of the third folding means shown in FIG. [Figure 8] 1. FIG. 4 is an explanatory view showing the operation of the third folding means shown in FIG. [Figure 9] 1. FIG. 4 is an explanatory view showing another example of the third crease imparting means shown in FIG. [Figure 10] 10 is an explanatory diagram showing the operation of the third crease imparting means shown in FIG. 9; FIG. [Figure 11] 10 is an explanatory diagram showing the operation of the third crease imparting means shown in FIG. 9; FIG. [Figure 12] 10 is an explanatory diagram showing the operation of the third crease imparting means shown in FIG. 9; FIG. [Figure 13] 10 is an explanatory diagram showing the operation of the third crease imparting means shown in FIG. 9; FIG. [Figure 14]1 is a plan view showing a carton blank for a paper container having a top formed thereon by a paper container top forming device according to the present invention. [Figure 15] FIG. 15 is a perspective view of the carton blank of FIG. 14 formed into a cylindrical shape. [Figure 16] FIG. 16 is an explanatory diagram showing the carton blank of FIG. 15 in the middle of being folded. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a crease imparting mechanism for a top forming unit in a top forming device for a paper container according to the present invention will be described in detail below with reference to the drawings. Figure 1 is an explanatory diagram showing an example of an embodiment of a top forming section creasing mechanism in a top forming device for paper containers according to the present invention, Figures 2 and 3 are explanatory diagrams showing the creasing operation of the first creasing means shown in Figure 1, Figure 4 is an explanatory diagram showing the creasing operation of the second creasing means shown in Figure 1, Figures 5, 6, 7 and 8 are explanatory diagrams showing the creasing operation of the third creasing means shown in Figure 1, Figure 9 is an explanatory diagram showing another example of the third creasing means shown in Figure 1, and Figures 10, 11, 12 and 13 are explanatory diagrams showing the creasing operation of the third creasing means shown in Figure 9.

[0024] The top forming portion crease imparting mechanism 1 in the top forming device for paper containers of this example is a mechanism for imparting creases to the top forming portion of a cylindrical carton blank in a paper container formed from the carton blanks shown in Figures 14 to 16. The cylindrically formed carton blank 126 is attached to the mandrel 2, and the top forming portion 129 consisting of the top upper panel 108, the top upper auxiliary panel 110, the right side panel 112, and the left side panel 114 of this carton blank 126 is caused to protrude from the tip of the mandrel 2, and the seal panel 117 connected to the protruding top upper auxiliary panel 110 is valley-folded from the horizontal fold line 116 to seal the inner surface of the seal panel 117 with the inner surface of the top upper panel 108. The carton is configured to seal the overlapping surfaces of the folded right side panel 112 and left side panel 114 to form a top 128, and is equipped with a first fold-crease imparting means 4 that pushes the right side panel 112 and left side panel 114 of the carton blank 126 attached to the mandrel 2 outward from the center, thereby making a valley fold from the horizontal fold lines 111, 113, a second fold-crease imparting means 5 that mountain-folds the top upper panel 108 and the top upper auxiliary panel 110 inward from the horizontal fold lines 107, 109 to make a fold, and a third fold-crease imparting means 6 that valley-folds the seal panel 117 at the tip of the top upper auxiliary panel 110 outward from the horizontal fold line 116 to make a fold.

[0025] The mandrel 2 has a head 11 at its tip that slides against the inner surface of the attached carton blank 126 to support it, and a support portion (not shown) at its base that abuts against the tip of the bottom panels 120, 121 of the attached carton blank 126 to position the top forming portion 129 of the carton blank 126 attached to the mandrel 2 at a position where it protrudes from the upper end surface of the head 11.

[0026] As shown in FIG. 1, the first fold imparting means 4 comprises an expander 13 that is supported so as to be able to move toward and away from the top forming portion 129, moves forward into the top forming portion 129, and pushes the right side panel 112 and the left side panel 114 outward from the center, thereby creating valley folds from the horizontal fold lines 111 and 113.

[0027] In this example, as shown in FIG. 2, the expander 13 has a bottom side 13a that is shorter than the inner dimension L of the apex forming portion 129, and an upper side 13b that is longer than the inner dimension L of the apex forming portion 129. and Hypotenuse of the same angle 13c and It is a plate body, and as shown in Figure 3, by inserting the expander body 13 into the top forming portion 129, the oblique side 13c pushes the right side panel 112 and the left side panel 114 outward from the center, causing valley folds from the horizontal fold lines 111, 113, and creating folds from the horizontal fold lines 111, 113.

[0028] The expander 13 is not limited to this example as long as it can expand the right side panel 112 and the left side panel 114 from the center outward.

[0029] As shown in FIG. 1, the second crease imparting means 5 is composed of a first pressing body 14 that is supported so as to be able to move back and forth toward the top upper surface panel 108 and that moves forward to press the top upper surface panel 108 and create a mountain fold from the horizontal fold line 107, and a second pressing body 15 that is supported so as to be able to move back and forth toward the top upper surface auxiliary panel 110 and that moves forward to press the top upper surface auxiliary panel 110 and create a mountain fold from the horizontal fold line 109.

[0030] In this example, the base ends of the first pressing body 14 and the second pressing body 15 are fixed to the rotation shafts 16 and 17, and the first pressing body 14 and the second pressing body 15 rotate by the rotation of the rotation shafts 16 and 17, so that the tips of the first pressing body 14 and the second pressing body 15 can advance and retreat toward the top upper panel 108 and the top upper auxiliary panel 110, respectively. Then, as shown in FIG. 4, by rotating the first pressing body 14 and the second pressing body 15 toward the top upper panel 108 and the top upper auxiliary panel 110, the tips of the first pressing body 14 and the second pressing body 15 advance toward the top upper panel 108 and the top upper auxiliary panel 110, respectively, and press the top upper panel 108 and the top upper auxiliary panel 110 with their tips. 0 is pressed from the outer surface side to fold the sheet in a mountain shape from the horizontal fold lines 107, 109, and creases are formed from the horizontal fold lines 107, 109.

[0031] The first pressing body 14 and the second pressing body 15 need only be capable of pressing the top upper surface panel 108 and the top upper surface auxiliary panel 11 from the outer surface side at their tips to cause mountain folds from the horizontal fold lines 107, 109, and are not limited to this example.

[0032] As shown in FIG. 1, the third folding means 6 is composed of a receiving plate member 20 that receives the tip of the seal panel 117 from the inner surface of the plate, and a folding plate member 21 that presses the connecting portion between the top upper surface auxiliary panel 110 and the seal panel 117 toward the receiving plate member 20 from the outer surface, thereby valley-folding the seal panel 117 from the horizontal fold line 116.

[0033] 1, the receiving plate member 20 and the bending plate member 21 are arranged facing each other with a gap between them, and are integrally formed with their rear ends connected, and the length of the leading end of the receiving plate member 20 is longer than that of the bending plate member 21, and a groove 22 into which the seal panel 117 can be inserted from the upper end side is formed between the receiving plate member 20 and the bending plate member 21. The receiving plate member 20 and the bending plate member 21 are supported so that they can advance and retreat toward the seal panel 117. and, 3rd bend imparting means 6 As the plate member 20 advances, the tip of the seal panel 117 first abuts against the inner surface of the support plate member 20 (see Figures 5 and 6), and as it advances further, the tip of the seal panel 117 slides along the inner surface of the support plate member 20 and enters the groove portion 22, and the outer surface of the seal panel 117 abuts against the tip of the folding plate member 21 (see Figure 7), and as it advances further, the tip of the folding plate member 21 presses against the connection portion between the top upper surface auxiliary panel 110 and the seal panel 117, causing the seal panel 117 to be valley-folded from the horizontal fold line 116 (see Figure 8), and creating a fold from the horizontal fold line 116.

[0034] FIG. 9 shows another example of the third folding means 6. In this example, the receiving plate member 20 is supported so as to be able to advance and retreat toward the inner side of the tip of the seal panel 117, and the folding plate member 21 is supported so as to be able to bend toward the top upper surface auxiliary panel 1. 1 0 and the seal panel 117. Then, the receiving plate member 20 advances to allow the tip of the seal panel 117 to abut against the plate surface of the receiving plate member 20 (see Figures 10 and 11), and the bending plate member 21 advances to press the connecting portion between the top upper surface auxiliary panel 110 and the seal panel 117 from the outer surface side toward the receiving plate member 20 (see Figure 12), and by abutting and pressing the tip of the seal panel 117 against the plate surface of the advancing receiving plate member 20, the seal panel 117 is folded laterally. line 1 It is designed to be folded at point 16 (see Figure 13).

[0035] The third folding means 6 may be any means capable of folding the seal panel 117 in a valley shape from the horizontal folding line 116, and is not limited to this example.

[0036] As described above, the first crease imparting means 4, the second crease imparting means 5, and the third crease imparting means 6 provided in the top forming section crease imparting mechanism 1 are configured to operate in the order of the first crease imparting means 4, the second crease imparting means 5, and the third crease imparting means 6, and are arranged in positions where they do not interfere with each other's operations.

[0037] With this configuration, the carton blank 126 mounted on the mandrel 2 of the mandrel rotating body 3 is first folded outward from the center by the spreading body 13 constituting the first folding creasing means 4, and the right side panel 112 and the left side panel 114 are folded in a valley shape from the horizontal fold lines 111, 113 to the right side panel 112 and the left side panel 114. Next, the first pressing body 14 and the second pressing body 15 constituting the second folding creasing means 5 fold the right side panel 112 and the left side panel 114 in a valley shape from the horizontal fold lines 111, 113 to the top. The top panel 108 and the top auxiliary panel 110 are pressed from the outer surface side and are mountain-folded from the horizontal fold lines 107, 109, and a mountain fold is imparted to the top panel 108 and the top auxiliary panel 110 from the horizontal fold lines 107, 109.Next, the receiving plate member 20 and the bending plate member 21 that constitute the third fold imparting means 6 make a valley fold on the seal panel 117 from the horizontal fold line 116, and a valley fold is imparted to the seal panel 117 from the horizontal fold line 116.

[0038] According to the head forming portion creasing mechanism 1 configured in this manner, the head forming portion 129 of the carton blank 126 attached to the mandrel 2 can be easily creasing. [Explanation of symbols]

[0039] 1 Top forming part crease imparting mechanism 2 mandrels 4 1st bending means 5 Second folding means 6 Third folding means 11 Head 13 Expansion Field 13a Bottom 13b Top 13c hypotenuse 14 First pressing body 15 Second pressing body 16, 17 Rotation axis 20 Support plate member 21 Bent plate member 22 Groove 100, 101, 102 Body vertical fold lines 103 Front body panel 104 Right side panel of fuselage 105 Back panel of the body 106 Left side panel of fuselage 107 Horizontal fold line 108 Top panel 109 Horizontal fold line 110 Top surface auxiliary panel 111 horizontal fold line 112 Right side panel 113 Horizontal fold line 114 Left side panel 115 Suction port 116 Horizontal fold line 117 Seal Panel 118, 119 Horizontal fold lines 120, 121 bottom panel 122, 123 horizontal fold lines 124, 125 Bottom fold panel 126 Carton Blanks 127 longitudinal edge 128 Top 129 top forming part

Claims

1. a top panel connected to the upper end of the back panel via a horizontal fold line; a top auxiliary panel connected to the upper end of the front panel via a horizontal fold line and folded under the top panel; and left and right side panels connected to the upper ends of the left and right side panels via horizontal fold lines and folded outward as the top panel and the top auxiliary panel are overlapped, wherein the top panel has a suction port located at its center, and the top auxiliary panel has a vertical length that does not reach the suction port provided in the top panel and has a seal panel connected to its tip via the horizontal fold line; and a carton blank having a thermoplastic resin layer laminated on at least its inner surface is formed into a rectangular tubular shape by joining vertical edges thereof, and the tubular carton blank is fitted to a mandrel. a top forming section crease imparting mechanism in a top forming device for paper containers, which forms a top by protruding a top forming section consisting of the top upper panel, the top upper auxiliary panel, and the left and right side panels of the carton blank from the tip of the mandrel, valley-folding the seal panel connected to the protruding top upper auxiliary panel along a horizontal fold line, sealing the inner surface of the seal panel with the inner surface of the top upper panel, and sealing the overlapping surfaces of the folded left and right side panels together; A top forming section crease imparting mechanism in a top forming device for paper containers, characterized in that it is composed of: a first crease imparting means that pushes the left and right side panels of the carton blank attached to the mandrel outward from the center to make a valley fold from the horizontal fold line; a second crease imparting means that folds the top upper panel and the top upper auxiliary panel inward from the horizontal fold line to make a mountain fold; and a third crease imparting means that folds the seal panel at the tip of the top upper auxiliary panel outward from the horizontal fold line to make a valley fold.

2. The crease imparting mechanism of the top forming section in the paper container top forming device described in claim 1, characterized in that the first crease imparting means is supported so as to be able to move back and forth toward the top forming section, and comprises an expander body that advances and enters the top forming section, pushing the left and right side panels outward from the center to form valley folds from the horizontal fold lines.

3. 2. The paper container top forming device according to claim 1, wherein the second crease imparting means comprises a first pressing body supported so as to be able to move back and forth toward the top upper panel and which advances to press the top upper panel and cause a mountain fold from the horizontal fold line, and a second pressing body supported so as to be able to move back and forth toward the top upper auxiliary panel and which advances to press the top upper auxiliary panel and cause a mountain fold from the horizontal fold line.

4. The third crease imparting means is composed of a receiving plate member that receives the tip of the seal panel from the inner side with its plate surface, and a folding plate member that presses the connecting portion of the top upper surface auxiliary panel and the seal panel toward the receiving plate member from the outer side, thereby valley-folding the seal panel from the horizontal fold line.

5. 5. The paper container top forming device according to claim 4, wherein the receiving plate member and the folding plate member are arranged opposite each other with a gap between them, and the length of the leading end of the receiving plate member is longer than that of the folding plate member. A groove into which the seal panel can be inserted from the upper end side is formed between the receiving plate member and the folding plate member. The receiving plate member is supported so as to be able to move forward and backward toward the seal panel, and advances to abut the leading end of the seal panel against the plate surface of the receiving plate member, guiding the leading end of the seal panel into the groove. The leading end of the folding plate member presses the connecting portion between the top upper auxiliary panel and the seal panel from the outer surface side toward the receiving plate member, thereby valley-folding the seal panel from the horizontal fold line.

6. 5. The crease imparting mechanism for a top forming device for paper containers according to claim 4, wherein the receiving plate member is supported so as to be able to advance and retreat toward the inner surface of the tip of the seal panel, and the folding plate member is supported so as to be able to advance and retreat toward the connecting portion between the top upper surface auxiliary panel and the seal panel, the receiving plate member advances so that the tip of the seal panel can abut against the plate surface of the receiving plate member, and the folding plate member advances so that the connecting portion between the top upper surface auxiliary panel and the seal panel can abut against the plate surface of the receiving plate member from the outer surface side, and the tip of the seal panel is abutted and pressed against the plate surface of the advancing receiving plate member, thereby valley-folding the seal panel from the horizontal fold line.

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