Capping device and capping system

Abstract

To make a capping device compact and improve production efficiency by increasing a processing speed of capping, while maintaining good precision of skirt-curl forming of a cap.SOLUTION: The capping device for attaching a topped cylindrical cap on a mouthpiece part of a bottomed cylindrical can with a screw comprises: a turret; a spindle assembly; an upper cam; and a lower cam. The spindle assembly includes a pressure block 2 that presses a top wall of the cap; a plurality of screw-forming rollers 5A for forming a screw part that screws on the mouthpiece part on a peripheral wall of the cap; and at least 3 skirt-curling rollers 5B for skirt-curl forming a bottom edge of the peripheral wall of the cap on the mouthpiece part. A series of actions in which each roller 5 of the screw-forming roller 5A and the skirt-curling roller 5B comes in contact with the peripheral wall of the cap, rolls on the peripheral wall, and separates from the peripheral wall is considered as one action.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a capping device and a capping system.

Background Art

[0002] Conventionally, a capping device for attaching a cap to the mouth part of a screw - top can filled with contents such as beverages is known. In the capping device of Patent Document 1, as the cone cam is guided and descends along the first - stage descending part of the guide bar for the lower cam, the RO roller (thread - forming roller) and the PP roller (skirt - winding roller) are pressed against the peripheral wall of the cap. Thereafter, the cone cam is guided to the upper - stage part of the guide bar and once ascends, whereby the contact state of the RO roller and the PP roller with respect to the cap is once released. Further thereafter, the cone cam is guided to the second - stage descending part of the guide bar and descends again, and the RO roller and the PP roller are pressed against the peripheral wall of the cap again.

[0003] Specifically, in the winding method of the capping device of Patent Document 1, a first winding step is executed in which the RO roller and the PP roller wind the cap once to form a screw part and a temper evidence part (skirt - winding part), and thereafter, a second winding step is executed in which winding is performed in the same manner as the first winding step. That is, in Patent Document 1, capping by double - action is performed, in which the RO roller and the PP roller contact the peripheral wall of the cap, roll on the peripheral wall, and a series of operations until leaving the peripheral wall are repeated twice. Conventionally, in this way, the formability of the temper evidence part is ensured by double - action.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] This type of capping device requires maintaining good accuracy in forming the temper evidence section (hemming), while also being compact and increasing the capping processing speed to improve production efficiency.

[0006] The present invention aims to provide a capping device and capping system that can improve production efficiency by making the device more compact and increasing the capping processing speed, while maintaining good accuracy in the cap hem rolling process. [Means for solving the problem]

[0007] One aspect of the present invention is a capping device for attaching a top-cylindrical cap to the mouth of a bottom-cylindrical screw-top can, comprising: a turret that rotates around a vertically extending turret axis; a spindle assembly positioned on the outer circumference of the turret and extending vertically, with a capping head positioned at its lower end; an upper cam extending around the turret axis and engaging with the upper cam follower of the spindle assembly; and a lower cam extending around the turret axis and engaging with the lower cam follower of the spindle assembly. A fixed gear extending around the turret shaft and meshing with the spindle gear of the spindle assembly, The spindle assembly comprises: a pressure block positioned on the capping head that presses against the top wall of the cap as the upper cam follower moves downward; a plurality of thread forming rollers provided on the capping head that contact the circumferential wall of the cap as the lower cam follower moves downward and form a threaded portion on the circumferential wall that screws into the mouth portion; and at least three hem rollers provided on the capping head that contact the circumferential wall of the cap as the lower cam follower moves downward and form a hem around the lower end of the circumferential wall onto the mouth portion, wherein the series of movements in which each of the thread forming rollers and the hem rollers contacts the circumferential wall of the cap, rolls on the circumferential wall, and then separates from the circumferential wall constitutes one operation.

[0008] According to the capping device of the present invention, the capping head of the spindle assembly is provided with at least three hem-rolling rollers. That is, because a large number of hem-rolling rollers are provided, even if the operation of each hem-rolling roller to form the hem of the cap is limited to one action, the accuracy of the hem-rolling can be maintained well.

[0009] Therefore, it becomes possible to keep the circumference (total length) of the lower cam extending around the turret axis short, and to reduce the diameter of the turret, thereby making the device more compact. Alternatively, compared to conventional double-action type capping devices, the single-action type capping device of the present invention can significantly increase the rotational speed of the turret around the turret axis when the turret diameter is the same.

[0010] Based on the above, the present invention makes it possible to maintain good accuracy in the cap hem molding process, while also making the device more compact and increasing the capping processing speed to improve production efficiency.

[0011] In the capping device described above, the lower cam has a descending portion that extends downward as it moves toward the turret rotation direction around the turret axis, a forming portion connected to the end of the descending portion in the turret rotation direction and extending toward the turret rotation direction, and an ascending portion connected to the end of the forming portion in the turret rotation direction and extending toward the turret rotation direction, wherein the lower cam is provided with only one set of the descending portion, the forming portion and the ascending portion.

[0012] In this case, the lower cam follower moves downward as it is guided by the descending portion of the lower cam, and consequently, the thread forming roller and the hem rolling roller come into contact with the circumferential wall of the cap. Also, while the lower cam follower is guided by the forming portion of the lower cam, the thread forming roller forms the threads on the circumferential wall of the cap, and the hem rolling roller forms the hem of the lower end of the circumferential wall of the cap. Furthermore, the lower cam follower moves upward as it is guided by the ascending portion of the lower cam, and consequently, the thread forming roller and the hem rolling roller move away from the circumferential wall of the cap. Through the action of each roller, the circumferential wall of the cap is formed well.

[0013] In the capping device, it is preferable that at least three screw forming rollers are provided on the capping head.

[0014] In this case, because a large number of thread forming rollers are available, even if the operation of each thread forming roller to form the threads on the cap is limited to one time (single action), good accuracy in thread forming can be maintained.

[0015] In the capping device, it is preferable that three screw forming rollers and three hem rolling rollers are provided.

[0016] As shown in the configuration above, by providing three screw forming rollers and three hem-rolling rollers, the molding accuracy of the cap can be stably improved even if the operation of each roller forming the cap perimeter is limited to one time. Furthermore, since the number of rollers is kept from increasing excessively while ensuring molding accuracy, the device can be made more compact and lighter.

[0017] Furthermore, one embodiment of the capping system of the present invention comprises a filler for filling screw-top cans with contents, and the aforementioned capping device to which the screw-top cans discharged from the filler are supplied, wherein the transport direction of the screw-top cans discharged from the filler toward the capping device extends along the tangent to the outer circumference of the turret when viewed from the axial direction of the turret.

[0018] According to the capping system of the present invention, the threaded cans discharged from the filler are smoothly supplied to the capping device without being abruptly changed in the direction of conveyance, that is, while being less affected by centrifugal force. For this reason, the processing speed of capping can be stably increased, and the production efficiency can be further improved.

Effect of the Invention

[0019] According to the capping device and the capping system of the above aspect of the present invention, it is possible to maintain good accuracy in the hemming forming of the cap while making the device more compact, or to increase the processing speed of capping to improve the production efficiency.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a perspective view showing a capping head included in the capping device of the present embodiment. [Figure 2] FIG. 2 is a perspective view showing the capping head of the present embodiment. [Figure 3] FIG. 3 is a cross-sectional view (vertical cross-sectional view) showing the capping head of the present embodiment. [Figure 4] FIG. 4 is a bottom view showing the capping head, and represents a state in which a jig for assembly is locked to a plurality of lower arms. The forming rollers are represented by a two-dot chain line as a transparent view. [Figure 5] FIG. 5 is an enlarged view showing a portion V in FIG. 4. [Figure 6] FIG. 6 is an enlarged view showing a portion VI in FIG. 4. [Figure 7] FIG. 7 is a perspective view showing the body main body of the capping head of the present embodiment. [Figure 8] FIG. 8 is a perspective view showing the body main body of the capping head of the present embodiment. [Figure 9] FIG. 9 is a perspective view showing the body flange of the capping head of the present embodiment. [Figure 10]Figure 10 is a cross-sectional view (longitudinal cross-sectional view) of the spindle assembly of this embodiment, with the capping head shown in a simplified form. [Figure 11] Figure 11 is a cross-sectional view (vertical cross-sectional view) showing a part of the capping device of this embodiment, with the capping head shown in a simplified form. [Figure 12] Figure 12 is a schematic side view showing the outer periphery of the capping device of this embodiment unfolded on a plane, illustrating the operation of the spindle assembly and the capping head. [Figure 13] Figure 13 is a schematic top view illustrating the capping system of this embodiment. [Figure 14] Figure 14 is a perspective view showing a part of a capping head of a modified example of this embodiment. [Figure 15] Figure 15 is a cross-sectional view (longitudinal section) showing a portion of the capping head in Figure 14. [Figure 16] Figure 16 is a schematic diagram of a screw illustrating a method for measuring screw depth, showing the number of turns of the screw unfolded on a plane. [Figure 17] Figure 17 is a cross-sectional (longitudinal) image showing the vicinity of the lower end of the peripheral wall of the cap after capping, and is a diagram illustrating the evaluation of the hem curl. [Modes for carrying out the invention]

[0021] A capping head 10, spindle assembly 80, capping device 120, and capping system 100 of one embodiment of the present invention will be described with reference to Figures 1 to 13. In this specification, the capping head 10, spindle assembly 80, etc., may be simply referred to as "devices."

[0022] The capping head 10, spindle assembly 80, and capping device 120 of this embodiment are devices for sealing a screw-top can by attaching a top-cylindrical cap to the mouth of a bottom-cylindrical screw-top can. Examples of screw-top cans and caps that can be used include those described in Japanese Patent Application Publication No. 2019-011103. Note that "screw-top can" may be replaced with "bottle can."

[0023] Detailed illustrations are omitted, but the general configuration of the screw-on can and cap is as follows. Screw-cap cans are made of, for example, aluminum alloy. A screw-cap can comprises a can body, which is the peripheral wall of the can, and a can bottom, which is the bottom wall of the can. The opening of the can body is a nozzle section with a smaller diameter than the rest of the can (body and shoulder). The nozzle section is roughly cylindrical with the can axis at its center. The nozzle section has a curled section, a male threaded section, and a bulging section in that order, extending from its opening end toward the can bottom along the can axis.

[0024] The bulge is annular in shape with the can shaft as the center. The bulge is formed to protrude outward from the male thread portion in the can diameter direction perpendicular to the can shaft. As shown in Figure 17(a), the bulge 201 has a convex shape that bulges outward in the can diameter direction in the cross section (longitudinal section) of the nozzle portion 200 along the can shaft.

[0025] The cap 300 has a cap body that is cylindrical with a top and fits over the nozzle portion 200, and a disc-shaped liner (not shown) positioned on the inner surface of the top wall of the cap body. The liner contacts the curled portion of the nozzle portion 200. The cap body is made of, for example, an aluminum alloy, and the liner is made of, for example, a resin. In this specification, when simply referring to the peripheral wall 301 and the top wall of the cap 300, unless otherwise specified, it refers to the peripheral wall 301 and the top wall of the cap body. As shown in Figure 17(c), etc., the lower end of the peripheral wall 301 of the cap 300 is wrapped around the bulge portion 201.

[0026] As shown in Figures 1 to 3, the capping head 10 comprises a body 1 centered on a central axis O, a pressure block 2, a support member 3, a cam follower 4, a molding roller 5, and a biasing member 6. Also, as shown in Figure 12, the central axes (can axes; not shown) of the screw-on can B and cap 300 capped by the capping head 10 are arranged coaxially with the central axis O shown in Figures 1 to 3.

[0027] Here, we will explain the "definition of direction" in this embodiment. In this embodiment, the direction in which the central axis O of the body 1 extends is called the vertical direction. In other words, the central axis O extends in the vertical direction. The vertical direction corresponds to the Z-axis direction in each figure. In the vertical direction, the cam follower 4 and the forming roller 5 are positioned at different locations from each other. Of the vertical directions, the direction from the forming roller 5 toward the cam follower 4 is called the upper side (+Z side), and the direction from the cam follower 4 toward the forming roller 5 is called the lower side (-Z side). The vertical direction can also be referred to as the axial direction. In this case, the upper side corresponds to one side of the axial direction, and the lower side corresponds to the other side of the axial direction.

[0028] The direction perpendicular to the central axis O is called the radial direction. Within the radial direction, the direction approaching the central axis O is called the radially inward direction, and the direction moving away from the central axis O is called the radially outward direction. The direction of rotation around the central axis O is called the circumferential direction. Of the circumferential directions, a predetermined direction of rotation is called the circumferential direction one side C1, and the opposite direction of rotation is called the circumferential direction other side C2. In this embodiment, as shown in Figure 4, in a bottom view of the capping head 10 from below, the clockwise direction around the central axis O is the circumferential direction one side C1, and the counterclockwise direction is the circumferential direction other side C2.

[0029] Furthermore, the shaft central axis A, which is the central axis of the support shaft 31 of the support member 3 (described later), is positioned radially outward from the central axis O and extends parallel to the central axis O in the vertical direction (Z-axis direction). In this embodiment, the definition of the direction based on the shaft central axis A is distinguished from the definition of the direction based on the central axis O of the body 1 described above, and is as follows.

[0030] The direction perpendicular to the shaft's central axis A is called the shaft's radial direction. Within the shaft's radial direction, the direction approaching the shaft's central axis A is called the inner shaft radial direction, and the direction moving away from the shaft's central axis A is called the outer shaft radial direction. The direction in which the shaft rotates around its central axis A is called the circumferential direction of the shaft.

[0031] As shown in Figure 10, the capping head 10 is mounted on a spindle assembly 80 that extends vertically and constitutes part of the spindle assembly 80. Specifically, the spindle assembly 80 is positioned above the capping head 10, and the lower end of the spindle assembly 80 is inserted into the capping head 10 from above. More specifically, the lower end of the spindle 85, which will be described later, is attached to the body 1. Also, the lifting shaft 81, which will be described later, is attached to the pressure block 2. The central axis (spindle axis) of the spindle assembly 80 is positioned coaxially with the central axis O of the body 1. The capping head 10 is supported by the spindle assembly 80 and moves vertically together with the spindle assembly 80. The body 1 is rotated about the central axis O by the spindle 85.

[0032] Furthermore, the spindle 85 is fixed to the body 1 while being inserted into the cylindrical cone cam 7 of the lifting cylinder 90, which will be described later, as part of the spindle assembly 80. As shown in Figures 1 to 3, the cone cam 7 is located on the upper side of the body 1 and extends vertically around the spindle axis (central axis O).

[0033] As will be explained in more detail later, in Figures 10 and 11, the lifting shaft 81, spindle 85, capping head 10, and lifting cylinder 90 including the cone cam 7 are connected to separate cam mechanisms 126 and 127, which will be described later, and move in the vertical direction by each of the cam mechanisms 126 and 127. In addition, the spindle 85 and body 1 rotate around the central axis O relative to the cone cam 7. The cone cam 7 may also be one of the components of the capping head 10. In this case, the capping head 10 further includes the cone cam 7.

[0034] As shown in Figures 1 to 3, the body 1 is substantially cylindrical. In this embodiment, the body 1 is made of an aluminum alloy, specifically, for example, duralumin. The body 1 has a body body 11 and a body flange 12. The body body 11 may also be referred to as a body base or body base.

[0035] As shown in Figures 7 and 8, the body 11 is cylindrical with a central axis O, and specifically, it is substantially cylindrical. Therefore, the body 1 has a cylindrical outer surface 1c. As shown in Figure 9, the body flange 12 is a roughly annular plate shape with a central axis O at its center. The body flange 12 is fixed to the upper end of the body body 11 by bolts or the like.

[0036] Furthermore, as shown in Figures 1 to 3 and Figures 7 to 9, the body 1 has a peripheral wall portion 11c, a bottom wall portion 11d, a cone cam housing recess 13, a cylindrical portion 14, a spindle mounting portion 15, a housing cylinder 16, a support projection 17, a skirt portion 11h, a biasing member housing hole 23, an operating portion 21, and a drain hole 22.

[0037] The peripheral wall portion 11c is substantially cylindrical with respect to the central axis O. The peripheral wall portion 11c constitutes the cylindrical portion of the outer circumferential wall of the body 1, located above the bottom wall portion 11d. The bottom wall portion 11d is roughly annular in shape with the central axis O at its center. The outer periphery of the bottom wall portion 11d is connected to the lower end of the peripheral wall portion 11c.

[0038] As shown in Figure 3, the cone cam housing recess 13 is a concave shape that is recessed downward from the upper surface 1a of the body 1. The cone cam housing recess 13 is a substantially circular hole centered on the central axis O. The cone cam housing recess 13 opens onto the upper surface 1a and extends in the vertical direction. The cone cam housing recess 13 is a recess defined by the inner circumferential surface of the body flange 12, the inner circumferential surface of the peripheral wall portion 11c, and the upper surface of the bottom wall portion 11d.

[0039] In this embodiment, the cone cam housing recess 13 is positioned vertically, extending from the body flange 12 to the upper portion of the body body 11. Specifically, the upper part of the cone cam housing recess 13 is located inside (through hole) the body flange 12, and the lower part of the cone cam housing recess 13 is located in a recess 11b that is recessed downward from the upper end surface 11a of the body body 11. That is, the cone cam housing recess 13 penetrates the body flange 12 vertically and is positioned across the recess 11b of the body body 11.

[0040] The vertical dimension between the upper surface 1a of body 1 and the bottom wall 13a of the cone cam housing recess 13 is greater than the vertical dimension between the lower surface 1b of body 1 and the bottom wall 13a. In other words, the vertical dimension between the upper surface 1a of body 1 and the upper surface of the bottom wall portion 11d (i.e., the depth dimension of the cone cam housing recess 13) is greater than the vertical dimension between the upper and lower surfaces of the bottom wall portion 11d (i.e., the thickness dimension of the bottom wall portion 11d).

[0041] Although not specifically shown in the figures, when the cone cam 7 moves downward relative to the spindle 85 and the body 1 fixed to the spindle 85, the cone cam housing recess 13 accommodates at least the lower end of the cone cam 7. Specifically, the cone cam housing recess 13 accommodates at least the large-diameter rolling surface 72 and the tapered rolling surface 73, which will be described later and are located at the lower end of the cone cam 7. Furthermore, a portion of the small-diameter rolling surface 71 of the cone cam 7, which will be described later, may also be located in the cone cam housing recess 13.

[0042] The cylindrical portion 14 protrudes upward from the bottom wall 13a of the cone cam housing recess 13. The cylindrical portion 14 protrudes upward from the inner circumference of the bottom wall portion 11d. The cylindrical portion 14 is cylindrical in shape with a central axis O. The upper end surface of the cylindrical portion 14 is located below the upper surface 1a of the body 1, and in this embodiment, it is located below the upper end surface 11a of the body body 11.

[0043] The outer circumferential surface of the cylindrical portion 14 is positioned radially inward from the inner circumferential surface of the cone cam housing recess 13 (i.e., the inner circumferential surface of the peripheral wall portion 11c) (see Figure 7). Therefore, a circular ring-shaped groove centered on the central axis O is provided between the outer circumferential surface of the cylindrical portion 14 and the inner circumferential surface of the cone cam housing recess 13. This groove opens upward and extends in the circumferential direction. When the cone cam 7 moves downward relative to the spindle 85 and the body 1 fixed to the spindle 85, the lower end of the peripheral wall of the cone cam 7 may be positioned in the groove.

[0044] The spindle mounting portion 15 opens onto the upper end surface of the cylindrical portion 14 and extends vertically. The spindle mounting portion 15 is a substantially circular hole centered on the central axis O. The lower end of the spindle 85 is inserted into the spindle mounting portion 15. The spindle mounting portion 15 and the spindle 85 are fastened to each other, for example, by screwing them together. In other words, the spindle mounting portion 15 is attached to the spindle 85.

[0045] The upper part of the spindle mounting portion 15 is located inside the cylindrical portion 14. Therefore, when viewed radially, the spindle mounting portion 15 (at least its upper part) is positioned to overlap with the cone cam housing recess 13. In this embodiment, the lower part of the spindle mounting portion 15 is located below the bottom wall 13a. In other words, the upper part of the spindle mounting portion 15 is located on the inner circumference of the cylindrical portion 14, and the lower part of the spindle mounting portion 15 is located on the inner circumference of the bottom wall portion 11d.

[0046] The housing cylinder 16 protrudes downward from the lower surface 1b of the body 1. The housing cylinder 16 extends downward from the lower surface of the bottom wall portion 11d. The housing cylinder 16 is substantially cylindrical with a central axis O.

[0047] The support projections 17 protrude downward from the lower surface 1b of the body 1. The support projections 17 extend downward from the outer circumference of the lower surface of the bottom wall portion 11d. The support projections 17 are positioned radially outward of the housing cylinder 16. Multiple support projections 17 are provided in a circumferential direction so as to surround the housing cylinder 16 from the radially outward direction (see Figure 8). The number of support projections 17 is the same as the number of molding rollers 5, and in this embodiment, six are provided. The multiple support projections 17 are arranged with spacing between them in the circumferential direction.

[0048] Each support projection 17 is positioned radially outward from the housing cylinder 16, and adjacent support projections 17 in the circumferential direction are positioned far apart from each other. Therefore, the body 1 has weight-reducing sections between the support projections 17 and the housing cylinder 16, and between adjacent support projections 17 in the circumferential direction. The weight-reducing sections are concave spaces formed by hollowing out a part of the body 1.

[0049] The weight-reducing portions between adjacent support projections 17 in the circumferential direction may be referred to as roller shaft housing pockets 19. The roller shaft housing pockets 19 extend vertically inside the body 1 and open to the lower side of the body 1. Multiple roller shaft housing pockets 19 are provided arranged in the circumferential direction. The number of roller shaft housing pockets 19 is the same as the number of molding rollers 5.

[0050] The skirt portion 11h is cylindrical with respect to the central axis O. The skirt portion 11h is located below the peripheral wall portion 11c. The skirt portion 11h constitutes a cylindrical portion of the outer peripheral wall of the body 1, located below the bottom wall portion 11d. The upper end of the skirt portion 11h is connected to the lower end of the peripheral wall portion 11c and the outer peripheral portion of the bottom wall portion 11d. The outer peripheral surface of the skirt portion 11h and the outer peripheral surface of the peripheral wall portion 11c are continuous in the vertical direction, and each outer peripheral surface is formed integrally without any steps. The outer peripheral surface of the skirt portion 11h and the outer peripheral surface of the peripheral wall portion 11c each constitute a part of the outer peripheral surface 1c of the body 1.

[0051] Support projections 17 are positioned radially inward of the skirt portion 11h. The outer circumference of the lower part of the support projections 17 is connected to the inner circumference of the skirt portion 11h. The skirt portion 11h and the multiple support projections 17 are formed integrally. The skirt portion 11h surrounds the multiple support projections 17, the multiple roller shaft housing pockets 19, the housing cylinder 16, and a part of the pressure block 2 from the radial outside.

[0052] The biasing member housing holes 23 extend vertically through the interior of the body 1. The biasing member housing holes 23 penetrate the body 1 in the vertical direction. There are as many biasing member housing holes 23 as there are biasing members 6, and multiple holes are provided arranged in the circumferential direction. Each biasing member 6 is housed in each biasing member housing hole 23. In addition, the support shafts 31 of each support member 3, which will be described later, are inserted through each biasing member housing hole 23 and protrude upward and downward.

[0053] As shown in Figures 3 and 7 to 9, the biasing member housing hole 23 has a body hole portion 23a located in the body body 11 and a flange hole portion 23b located in the body flange 12. The body hole portion 23a and the flange hole portion 23b overlap each other when viewed from the top and bottom.

[0054] The main body hole 23a extends vertically through the interior of the main body 11 and penetrates the main body 11 in the vertical direction. Specifically, the main body hole 23a penetrates the peripheral wall 11c, the bottom wall 11d, and the support projection 17 in the vertical direction. The flange hole 23b penetrates the body flange 12 in the vertical direction.

[0055] As shown in Figures 1, 2, and 9, the operating section 21 is a notched recess that extends radially inward from the outer circumferential surface of the body 1. In this embodiment, the operating section 21 is located on the body flange 12 and opens onto the outer circumferential surface of the body flange 12. Multiple operating sections 21 are provided, spaced apart from each other in the circumferential direction.

[0056] When attaching or detaching the body 1 to the spindle 85, a hook-shaped work tool, such as a hook wrench (not shown), is locked to the operating part 21. With the work tool locked to the operating part 21, the body 1 can be attached to or detached from the spindle 85 by operating the work tool and rotating the body 1 circumferentially relative to the spindle 85.

[0057] As shown in Figure 3, the drain holes 22 penetrate the support projections 17 in the vertical direction. Multiple drain holes 22 are provided, with each of the support projections 17 having its own drain hole. The upper end of the drain hole 22 opens onto the upper surface of the support projection 17 and is located radially inward from the skirt portion 11h. The lower end of the drain hole 22 opens onto the lower surface of the support projection 17. In other words, the drain holes 22 connect the inside of the biasing member housing hole 23 to the outside of the body 1. Any liquid, such as water, that accumulates in the biasing member housing hole 23 is discharged to the outside of the capping head 10 through the drain holes 22.

[0058] The pressure block 2 is positioned on the underside of the body 1. The pressure block 2 is a roughly bottomed cylindrical shape with a central axis O, extending in the vertical direction. The pressure block 2 is fastened to the lower end of the lifting shaft 81, for example by screwing, and is fixed to the lifting shaft 81. During capping, the bottom wall of the pressure block 2 contacts the top wall of the cap 300 from above, pressing against the top wall (see Figure 12).

[0059] As shown in Figure 3, a portion of the pressure block 2 is housed in the housing cylinder 16 of the body 1. Specifically, the upper portion of the pressure block 2 is inserted into the housing cylinder 16. The vertical position of the upper end surface of the pressure block 2 is approximately the same as the vertical position of the lower surface 1b of the body 1. In other words, because the upper portion of the pressure block 2 is housed in the housing cylinder 16 that protrudes downward from the lower surface 1b, it does not penetrate the portion of the body 1 located above the lower surface 1b (i.e., the portion of the body 1 above the bottom wall portion 11d).

[0060] The pressure block 2 does not necessarily have to be one of the components of the capping head 10. In this case, the pressure block 2 is one of the components of the spindle assembly 80. That is, in this case, the spindle assembly 80 further includes the pressure block 2.

[0061] As shown in Figures 1 to 4, the support members 3 are attached to the body 1 and support the cam followers 4 and the forming rollers 5. Multiple support members 3 are provided arranged in the circumferential direction. The number of support members 3 is the same as the number of cam followers 4 and the same as the number of forming rollers 5.

[0062] The support member 3 includes a support shaft 31, an upper arm 32, and a lower arm 33. As shown in Figure 3, the support shaft 31 is substantially cylindrical with respect to the shaft central axis A and extends in the vertical direction. The upper end of the support shaft 31 protrudes above the upper surface 1a of the body 1. The lower end of the support shaft 31 protrudes below the lower surface 1b of the body 1 and also below the support projection 17.

[0063] The support shaft 31 is supported by the body 1 via a bearing member, such as a sliding bearing. Multiple bearing members (a pair in this embodiment) supporting each support shaft 31 are provided, spaced apart from each other in the vertical direction. Specifically, the upper portion of the support shaft 31 is supported by the body flange 12 via an upper bearing member. The lower portion of the support shaft 31 is supported by a support projection 17 via a lower bearing member. The intermediate portion of the support shaft 31, located between the upper and lower ends, is positioned in the biasing member housing hole 23. The support shaft 31 is rotatable within a predetermined range around the shaft central axis A.

[0064] As shown in Figure 2, the upper arm 32 is positioned on the upper side of the body 1 and connects the support shaft 31 and the cam follower 4. The upper arm 32 is fixed to the upper end of the support shaft 31 and extends outward from the support shaft 31 in the radial direction of the shaft. Specifically, the upper arm 32 extends from the support shaft 31 toward one side C1 in the circumferential direction.

[0065] The upper arm 32 surrounds the support shaft 31 around its axis (in the circumferential direction of the shaft) and has an upper clamp portion 32a that is deformable to press against the outer surface of the support shaft 31. The upper clamp portion 32a is a curved wall portion that extends in the circumferential direction of the shaft when viewed from above or below. By screwing the fastening screw 34 into the upper arm 32, the upper clamp portion 32a is deformed to narrow its diameter in the radial direction of the shaft. As a result, the inner surface of the upper clamp portion 32a and the outer surface of the support shaft 31 come into close contact, and the upper arm 32 is fixed to the support shaft 31.

[0066] As shown in Figure 1, the lower arm 33 is positioned on the underside of the body 1 and connects the support shaft 31 and the molding roller 5. The lower arm 33 is fixed to the lower end of the support shaft 31 and extends outward from the support shaft 31 in the radial direction of the shaft. Specifically, the lower arm 33 extends from the support shaft 31 toward one side C1 in the circumferential direction.

[0067] The lower arm 33 has a lower clamp portion 33a that surrounds the support shaft 31 around its axis (in the circumferential direction of the shaft) and is deformable to press against the outer surface of the support shaft 31. The lower clamp portion 33a is a curved wall portion that extends in the circumferential direction of the shaft when viewed from above or below. By screwing the fastening screw 35 into the lower arm 33, the lower clamp portion 33a is deformed to narrow its diameter in the radial direction of the shaft. As a result, the inner surface of the lower clamp portion 33a and the outer surface of the support shaft 31 come into close contact, and the lower arm 33 is fixed to the support shaft 31.

[0068] At least one of the upper clamp portion 32a and the lower clamp portion 33a has a deformation assist groove 36 that is arranged on the circumferential surface of the clamp portion and extends in the vertical direction. As shown in Figures 5 and 6, in this embodiment, at least the lower clamp portion 33a has the deformation assist groove 36. The deformation assist groove 36 is groove-shaped, recessed inward in the shaft diameter direction from the outer circumferential surface (clamp portion circumferential surface) of the lower clamp portion 33a and extending in the vertical direction.

[0069] Multiple deformation assist grooves 36 may be provided on the outer circumferential surface of the lower clamp portion 33a (or upper clamp portion 32a) in the direction of the shaft circumference, or only one may be provided. In this embodiment, one deformation assist groove 36 is provided on the lower clamp portion 33a of the lower arm 33 that supports the screw forming roller 5A, which will be described later. In addition, multiple deformation assist grooves 36 are provided on the lower clamp portion 33a of the lower arm 33 that supports the hem rolling roller 5B, which will be described later, at intervals from each other in the shaft circumferential direction. However, the number of deformation assist grooves 36 provided on each lower clamp portion 33a is not limited to this example in this embodiment.

[0070] The deformation assist groove 36 is, for example, an R groove (round groove), and the cross-sectional shape of the groove is a concave arc. The groove width of the deformation assist groove 36 is, for example, 1.5 mm. The number of deformation assist grooves 36 provided in the lower clamp portion 33a (or upper clamp portion 32a) is, for example, three.

[0071] Furthermore, the lower arm 33 has a stepped portion 37 positioned on the radially inward-facing surface of the lower arm 33. Specifically, the stepped portion 37 is positioned at the end of one side C1 in the circumferential direction of the radially inward-facing surface of the lower arm 33. The depth to which the stepped portion 37 recesses radially outward from the radially inward-facing surface of the lower arm 33 increases as it approaches the other side C2 in the circumferential direction. The stepped portion 37 has a wall surface 37a facing one side C1 in the circumferential direction, and an inclined surface 37b that faces radially inward and extends radially outward as it approaches the other side C2 in the circumferential direction.

[0072] As shown in Figures 2 and 3, the cam follower 4 is positioned on the upper side of the body 1. The cam follower 4 contacts the outer surface of the cone cam 7 and rolls on the outer surface of the cone cam 7. Specifically, the cam follower 4 rolls on the large-diameter rolling surface 72, the tapered rolling surface 73, and the small-diameter rolling surface 71 of the outer surface of the cone cam 7, which will be described later.

[0073] Multiple cam followers 4 are provided in a row in the circumferential direction. In this embodiment, six cam followers 4 are provided in the circumferential direction, spaced apart from each other.

[0074] The cam follower 4 has a shaft portion 41 that extends in the vertical direction, and a rolling element 42 that is rotatably supported at the lower end of the shaft portion 41 and pressed against the outer surface of the cone cam 7 by the biasing force of a biasing member 6, which will be described later.

[0075] The shaft portion 41 extends parallel to the central axis A of the shaft and is supported at the end of the upper arm 32 on one side C1 in the circumferential direction. The lower end of the shaft portion 41 faces the upper surface 1a of the body 1 from above, with a gap between them.

[0076] The rolling element 42 is annular in shape with a larger outer diameter than the shaft portion 41 and is arranged coaxially with the central axis of the shaft portion 41. The rolling element 42 is attached to the lower end of the shaft portion 41 via a bearing member, such as a rolling bearing. The rolling element 42 is rotatable around the central axis of the shaft portion 41. The lower surface of the rolling element 42 faces the upper surface 1a of the body 1 with a gap between them.

[0077] As shown in Figures 1, 3, and 4, the molding roller 5 is positioned below the body 1 and radially outward from the pressure block 2. The molding roller 5 is connected to the cam follower 4 via a support member 3 and moves radially as the cam follower 4 moves radially.

[0078] The molding rollers 5 are provided in the same number as the cam followers 4, arranged in a row in the circumferential direction. In this embodiment, six molding rollers 5 are provided, spaced apart from each other in the circumferential direction. The six (or more) molding rollers 5 are arranged at equal pitches around the central axis O. The roll diameter of the molding rollers 5 (specifically, the roller body 52 described later) is, for example, φ26 mm.

[0079] As shown in Figure 1, the molding roller 5 includes a roller shaft 51 extending in the vertical direction, a roller body 52 connected to the roller shaft 51 and pressing against the peripheral wall 301 of the cap 300, and a roller biasing part 53.

[0080] The roller shaft 51 is attached to one end C1 in the circumferential direction of the lower arm 33 via a bearing member such as a sliding bearing (not shown). The roller shaft 51 is rotatable about its central axis relative to the lower arm 33 and is movable within a predetermined range in the vertical direction.

[0081] The roller body 52 is disc-shaped with a larger outer diameter than the roller shaft 51 and is positioned coaxially with the central axis of the roller shaft 51. The roller body 52 is connected to the lower end of the roller shaft 51. The roller body 52 is integrally formed with the roller shaft 51 from a single component. The roller body 52 is positioned below the bottom wall of the pressure block 2.

[0082] The roller biasing section 53 is an elastic member such as a compression coil spring. The roller biasing section 53 biases the roller shaft 51 and the roller body 52 upward relative to the lower arm 33. The roller shaft 51 and the roller body 52 are movable downward against the biasing force of the roller biasing section 53. The upper part of the roller shaft 51 and the roller biasing part 53 are housed in the roller shaft housing pocket 19 of the body 1.

[0083] As shown in Figure 12, the multiple forming rollers 5 include multiple screw forming rollers (RO rollers) 5A that form a screw thread on the peripheral wall 301 of the cap 300 to screw into the mouth portion 200 of the screw-on can B, and at least three hem-rolling rollers (PP rollers) 5B that form a hem around the lower end of the peripheral wall 301 of the cap 300 onto the mouth portion 200. In this embodiment, at least three screw forming rollers 5A are also provided on the capping head 10. More specifically, as shown in Figures 1 to 4, in this embodiment, three screw forming rollers 5A and three hem-rolling rollers 5B are provided. That is, the number of screw forming rollers 5A and the number of hem-rolling rollers 5B are the same.

[0084] The screw forming roller 5A, although not specifically shown, presses the peripheral wall 301 of the cap 300 radially inward to form a screw portion (female screw portion) that conforms to the shape of the male screw portion of the mouth portion 200. The vertical positions of the roller bodies 52 of the multiple screw forming rollers 5A are offset from each other. That is, the vertical positions of the multiple screw forming rollers 5A are offset from each other.

[0085] The hem-rolling roller 5B presses the lower end of the peripheral wall 301 of the cap 300 radially inward, thereby forming the lower end of this peripheral wall 301 into a shape that conforms to the lower part of the bulge 201 of the mouthpiece portion 200 (see Figure 17(c), etc.). The vertical positions of each roller body 52 of the multiple hem-rolling rollers 5B are the same. That is, the vertical positions of the multiple hem-rolling rollers 5B are identical to each other.

[0086] As shown in Figure 4, the multiple screw-forming rollers 5A are positioned so as to be rotationally symmetric with respect to the central axis O, that is, they are arranged at equal pitches in the circumferential direction. In this embodiment, three screw-forming rollers 5A are positioned so as to be 120° rotationally symmetric with respect to the central axis O. Furthermore, the multiple hem rollers 5B are positioned so as to be rotationally symmetrical with respect to the central axis O, that is, they are arranged at equal pitches in the circumferential direction. In this embodiment, three hem rollers 5B are positioned so as to be 120° rotationally symmetrical with respect to the central axis O.

[0087] As shown in Figure 3, the biasing member 6 is an elastic member such as a torsion coil spring. The support shaft 31 is inserted inside the biasing member 6. By biasing the support shaft 31 in the circumferential direction, the biasing member 6 biases the cam follower 4 and the molding roller 5 supported by the support member 3 toward the radially inward direction.

[0088] Multiple biasing members 6 are provided in a row in the circumferential direction. The number of biasing members 6 is the same as the number of support members 3, the same as the number of cam followers 4, and the same as the number of molding rollers 5. In this embodiment, six biasing members 6 are provided in the circumferential direction, spaced apart from each other. Each biasing member 6 is placed in each biasing member housing hole 23.

[0089] The cone cam 7 has a small diameter rolling surface 71, a large diameter rolling surface 72, a tapered rolling surface 73, and a relief tapered surface 74.

[0090] The small-diameter rolling surface 71 is the smallest diameter portion of the outer surface of the cone cam 7. The outer diameter dimension (diameter dimension) of the small-diameter rolling surface 71 is constant along the vertical direction. The large-diameter rolling surface 72 is positioned at the lower end of the outer circumferential surface of the cone cam 7. The outer diameter of the large-diameter rolling surface 72 is larger than the outer diameter of the small-diameter rolling surface 71.

[0091] The tapered rolling surface 73 is positioned on the outer circumferential surface of the cone cam 7 between the small-diameter rolling surface 71 and the large-diameter rolling surface 72 in the vertical direction. The tapered rolling surface 73 has a tapered shape that extends radially outward as it is directed downward. That is, the diameter of the tapered rolling surface 73 increases as it is directed downward. The upper end of the tapered rolling surface 73 is smoothly connected to the lower end of the small-diameter rolling surface 71. The lower end of the tapered rolling surface 73 is smoothly connected to the upper end of the large-diameter rolling surface 72.

[0092] The relief tapered surface 74 is located on the outer circumferential surface of the cone cam 7, above the small-diameter rolling surface 71. The relief tapered surface 74 is tapered in a way that extends radially outward as it is directed upward. The lower end of the relief tapered surface 74 is connected to the upper end of the small-diameter rolling surface 71.

[0093] In this embodiment, the amount of radial displacement per unit length along the vertical direction (i.e., the inclination with respect to the central axis O) in at least the lower portion of the relief tapered surface 74 is smaller than the amount of radial displacement per unit length along the vertical direction of the tapered rolling surface 73. In other words, the inclination of the relief tapered surface 74 with respect to the central axis O is smaller (gentler) than the inclination of the tapered rolling surface 73 with respect to the central axis O. As a result, a large vertical length of the relief tapered surface 74 is secured, and even when the cone cam 7 is positioned at its lower end relative to the body 1 (although not specifically shown in the figures), interference between the shaft portion 41 and upper arm 32 of the cam follower 4 and the relief tapered surface 74 is suppressed.

[0094] Next, we will explain how to attach the capping head 10 to the cone cam 7 (assembly method). As shown in Figure 4, in this embodiment, an assembly jig (setting block) 60 is used when attaching the capping head 10 to the cone cam 7. The assembly jig 60 is used by inserting it radially inward into the multiple lower arms 33 with the lower pressure block 2 of the body 1 removed from the lifting shaft 81.

[0095] The assembly jig 60 is columnar in shape with a central axis O at its center. When viewed from above, the assembly jig 60 has a roughly star shape. The assembly jig 60 has a plurality of locking arms 61 that are spaced apart from each other in the circumferential direction. The number of locking arms 61 is the same as the number of forming rollers 5, and in this embodiment there are six.

[0096] When attaching the assembly jig 60 to the capping head 10, first, the assembly jig 60 is placed on the underside of the capping head 10, and each locking arm 61 (not shown in the figure) is positioned between adjacent roller bodies 52 in the circumferential direction. From this position, the assembly jig 60 is moved upward toward the body 1, so that the assembly jig 60 is inserted onto the upper side of the roller body 52.

[0097] Next, using a working tool such as a hex wrench (not shown), the assembly jig 60 is rotated to the other side C2 in the circumferential direction. As a result, the radially outer end of the locking arm 61 slides on the radially inward-facing surface of the lower arm 33 and locks into the stepped portion 37, as shown in Figures 5 and 6. At this time, the lower arm 33 is pushed radially outward by the locking arm 61, causing the support member 3 to rotate in the circumferential direction of the shaft against the biasing force of the biasing member 6, and the cam follower 4 and the molding roller 5 move radially outward. Furthermore, the locking arm 61 contacts the wall surface 37a of the stepped portion 37 from one side C1 in the circumferential direction, thereby restricting further rotation of the assembly jig 60 toward the other side C2 in the circumferential direction.

[0098] In this state, where multiple cam followers 4 are moved radially outward (open state), the lower end of the cone cam 7 can be inserted radially inward of these cam followers 4.

[0099] As shown in Figure 3, once the cone cam 7 is inserted radially inward of the multiple cam followers 4, the assembly jig 60 is removed from the capping head 10 in the reverse order of the procedure described above. As a result, the support member 3 rotates in the circumferential direction of the shaft due to the biasing force of the biasing member 6, causing the cam followers 4 and forming rollers 5 to move radially inward, so that each rolling element 42 of the multiple cam followers 4 comes into contact with the outer circumferential surface of the cone cam 7. After attaching the capping head 10 to the cone cam 7, the pressure block 2 is inserted into the housing cylinder 16 of the body 1, and the pressure block 2 is then attached to the lifting shaft 81.

[0100] Next, the spindle assembly 80 of this embodiment will be described in detail. As shown in Figure 10, the spindle assembly 80 extends in the vertical direction. A capping head 10 is positioned at the lower end of the spindle assembly 80. The spindle assembly 80 of this embodiment comprises the capping head 10, a lifting shaft 81, a spindle 85, and a lifting cylinder 90.

[0101] The lifting shaft 81 extends in the vertical direction. The pressure block 2 is attached to the lower end of the lifting shaft 81 by screws or the like and fixed in place (see Figure 11). The lifting shaft 81 includes a shaft portion 82 extending vertically around a central axis O, an upper cam follower 83 that moves the lifting shaft 81 vertically, and a connecting arm 84 that connects the shaft portion 82 and the upper cam follower 83.

[0102] The spindle 85 is cylindrical in shape, extending vertically around a central axis O. The shaft portion 82 of the lifting shaft 81 is inserted into the spindle 85. The spindle 85 is rotatable around the central axis O relative to the shaft portion 82. The body 1 is attached and fixed to the lower end of the spindle 85 by screws or the like. Therefore, body 1 is made rotatable around the central axis O relative to the pressure block 2.

[0103] The spindle 85 has a spindle gear 86 that rotates the spindle 85 around a central axis O. The spindle gear 86 is an external gear centered on the central axis O. In this embodiment, the spindle gear 86 is positioned at the upper end of the spindle 85.

[0104] The lifting cylinder 90 is cylindrical in shape, extending vertically around a central axis O. The shaft portion 82 of the lifting shaft 81 and the spindle 85 are inserted into the lifting cylinder 90. In this embodiment, the lifting cylinder 90 is positioned below the spindle gear 86. The lifting cylinder 90 is movable vertically relative to the lifting shaft 81 and the spindle 85.

[0105] The lifting cylinder 90 includes a cylindrical cone cam 7 and a lower cam follower 91 that moves the lifting cylinder 90 in the vertical direction. The cone cam 7 is positioned at the lower end of the lifting cylinder 90. The lower cam follower 91 is positioned at the upper end of the lifting cylinder 90.

[0106] Next, the capping device 120 of this embodiment will be described. As shown in Figure 11, the capping device 120 comprises a device base 125 centered on the turret axis T, a turret 121 that rotates around the turret axis T, a spindle assembly 80 positioned on the outer circumference of the turret 121, a fixed gear 122 that meshes with a spindle gear 86 and extends around the turret axis T, an upper cam 123 that extends around the turret axis T and engages with an upper cam follower 83, and a lower cam 124 that extends around the turret axis T and engages with a lower cam follower 91.

[0107] The turret shaft T is parallel to the central axis O and extends in the vertical direction. The turret 121 is roughly cylindrical with the turret shaft T as its center. In Figure 11, only the upper end of the turret 121 is shown, and the other parts are not shown. The turret 121 is connected to the device base 125 via a bearing member 128 that extends around the turret shaft T. The turret 121 is rotationally driven around the turret shaft T relative to the device base 125 by a drive motor or the like (not shown).

[0108] In this embodiment, the direction in which the turret axis T extends is called the turret axis direction. The turret axis direction corresponds to the vertical direction (Z axis direction). The direction perpendicular to the turret axis T is called the turret radial direction. Within the turret radial direction, the direction approaching the turret axis T is called the inner turret radial direction, and the direction moving away from the turret axis T is called the outer turret radial direction. The direction of rotation around the turret axis T is called the turret circumferential direction. As shown in Figures 12 and 13, in this embodiment, the direction in which the turret 121 rotates within the turret circumferential direction is called the turret rotation direction R, and the rotation direction opposite to this is called the opposite direction to the turret rotation direction R or the anti-turret rotation direction.

[0109] Figure 12 is a schematic side view showing the outer periphery of the capping device 120 unfolded on a plane, illustrating the operation of the spindle assembly 80 and the capping head 10 when attaching (capping) the cap 300 to the mouthpiece 200 of the screw-on can B.

[0110] As shown in Figure 11, the spindle assembly 80 is held on the outer circumference of the turret 121 so as to be movable in the vertical direction. Specifically, a part of the lifting cylinder 90 and a part of the connecting arm 84 of the spindle assembly 80 are engaged with a groove (not shown) located on the outer circumference of the turret 121. The groove of the turret 121 extends in the vertical direction, and the spindle assembly 80, while held in the groove of the turret 121, is slidable in the vertical direction relative to the turret 121.

[0111] Multiple spindle assemblies 80 are provided on the outer circumference of the turret 121, arranged around the turret axis T. The multiple spindle assemblies 80 are arranged at equal pitches around the turret axis T on the outer circumference of the turret 121. The number of spindle assemblies 80 is, for example, 10 or more.

[0112] The fixed gear 122 is an annular plate-shaped external gear centered on the turret axis T. The fixed gear 122 is fixed to the device base 125 and extends in the circumferential direction of the turret. The vertical dimension of the spindle gear 86 is greater than the vertical dimension of the fixed gear 122. Therefore, even when the spindle assembly 80 moves in the vertical direction, the meshing state between the fixed gear 122 and the spindle gear 86 is maintained in good condition.

[0113] The upper cam 123 is an annular groove that extends around the entire circumference of the turret axis T. The upper cam 123 is provided on the outer circumferential surface of the device base 125. In this embodiment, the upper cam 123 is positioned above the fixed gear 122. The upper cam 123 changes its vertical position as it approaches the turret axis T.

[0114] As shown in Figure 12, the upper cam 123 has a head lowering portion 123a, a horizontal portion 123b, and a head raising portion 123c. The head lowering portion 123a, the horizontal portion 123b, and the head raising portion 123c are arranged in this order along the turret rotation direction R. The upper cam 123 has only one set of the head lowering portion 123a, the horizontal portion 123b, and the head raising portion 123c.

[0115] The head lowering section 123a extends downward as it moves in the turret rotation direction R.

[0116] The horizontal section 123b is connected to the end of the head lowering section 123a in the turret rotation direction R and extends in the turret rotation direction R. The vertical position of the horizontal section 123b is constant along the turret rotation direction R.

[0117] The head lifting section 123c is connected to the end of the horizontal section 123b in the turret rotation direction R, and extends upward as it moves toward the turret rotation direction R.

[0118] The upper cam mechanism 126 is comprised of an upper cam 123 and an upper cam follower 83 that engages with the upper cam 123. In other words, the capping device 120 includes the upper cam mechanism 126.

[0119] The lower cam 124 is an annular groove that extends around the entire circumference of the turret axis T. The lower cam 124 is provided on the outer circumferential surface of the device base 125. In this embodiment, the lower cam 124 is positioned below the fixed gear 122. The position of the lower cam 124 changes in the vertical direction as it approaches the turret axis T.

[0120] The lower cam 124 has a front lowering section 124a, a first horizontal section 124b, a lowering section 124c, a molding section 124d, an upward section 124e, a second horizontal section 124f, and a rear upward section 124g. The front lowering section 124a, the first horizontal section 124b, the lowering section 124c, the molding section 124d, the upward section 124e, the second horizontal section 124f, and the rear upward section 124g are arranged in this order along the turret rotation direction R. The lower cam 124 has only one set of the front lowering section 124a, the first horizontal section 124b, the lowering section 124c, the molding section 124d, the upward section 124e, the second horizontal section 124f, and the rear upward section 124g. In other words, the lower cam 124 is provided with only one set of components: a lowering section 124c, a molding section 124d, and an upward section 124e.

[0121] The front lowering section 124a extends downward as it moves in the turret rotation direction R. The position of the front lowering section 124a in the turret circumferential direction is the same as the position of the head lowering section 123a in the turret circumferential direction.

[0122] The first horizontal section 124b connects to the end of the front downward section 124a in the turret rotation direction R and extends in the turret rotation direction R. The vertical position of the first horizontal section 124b is constant along the turret rotation direction R. The circumferential position of the first horizontal section 124b is the same as the circumferential position of the end of the horizontal section 123b that is opposite to the turret rotation direction.

[0123] The lowering section 124c is connected to the end of the first horizontal section 124b in the turret rotation direction R, and extends downward as it moves toward the turret rotation direction R.

[0124] The molding section 124d is connected to the end of the lowering section 124c in the turret rotation direction R and extends in the turret rotation direction R. The vertical position of the molding section 124d is constant along the turret rotation direction R.

[0125] The rising section 124e is connected to the end of the molding section 124d in the turret rotation direction R, and extends upward as it moves toward the turret rotation direction R. The circumferential positions of the lowering section 124c, the molding section 124d, and the raising section 124e are the same as the circumferential positions of the intermediate portion of the horizontal section 123b located between the two ends in the circumferential direction of the turret.

[0126] The second horizontal section 124f connects to the end of the upward section 124e in the turret rotation direction R and extends in the turret rotation direction R. The vertical position of the second horizontal section 124f is constant along the turret rotation direction R. The circumferential position of the second horizontal section 124f is the same as the circumferential position of the horizontal section 123b at the end in the turret rotation direction R.

[0127] The rear lifting section 124g is connected to the end of the second horizontal section 124f in the turret rotation direction R, and extends upward as it moves toward the turret rotation direction R. The position of the rear lifting section 124g in the turret circumferential direction is the same as the position of the head lifting section 123c in the turret circumferential direction.

[0128] The lower cam mechanism 127 is composed of a lower cam 124 and a lower cam follower 91 that engages with the lower cam 124. In other words, the capping device 120 includes the lower cam mechanism 127.

[0129] As the spindle assembly 80 is rotated by the turret 121 in the turret rotation direction R around the turret axis T, the upper cam mechanism 126 moves the lifting shaft 81 and pressure block 2, as well as the spindle 85 and body 1, in the vertical direction. In other words, the upper cam mechanism 126 moves the capping head 10 in the vertical direction. The lower cam mechanism 127 also moves the lifting cylinder 90 and its cone cam 7 in the vertical direction.

[0130] Here, we will explain in detail the process of attaching (capping) the cap 300 to the mouthpiece 200 of the screw-on can B using the capping device 120. First, as shown in Figures 12(a) and (b), the unmolded cap 300 is supplied to the mouth portion 200 of the screw-on can B, which is introduced into the capping device 120, and placed over it.

[0131] The screw-top can B, with its cap 300 placed over the mouthpiece 200, is transported along the outer circumference of the capping device 120 and positioned directly below the capping head 10 of the spindle assembly 80, as shown in Figure 12(c). More specifically, the central axis O of the spindle assembly 80 and the can axis of the screw-top can B are coaxially positioned, and while maintaining this positional relationship, the spindle assembly 80 and the screw-top can B move in the turret rotation direction R from Figure 12(c) to Figure 12(g).

[0132] As shown in Figure 12(d), the upper cam follower 83 of the spindle assembly 80 is guided from the head lowering portion 123a to the horizontal portion 123b of the upper cam 123, causing the lifting shaft 81 and pressure block 2, as well as the spindle 85 and body 1, to move downward (see Figures 10 and 11). Also, the lower cam follower 91 of the spindle assembly 80 is guided from the front lowering portion 124a to the first horizontal portion 124b of the lower cam 124, causing the cone cam 7 of the lifting cylinder 90 to move downward following the body 1. Therefore, from Figure 12(c) to Figure 12(d), the contact between the rolling elements 42 of the cam follower 4 and the large-diameter rolling surface 72 of the cone cam 7 is maintained (see Figure 3).

[0133] In Figure 12(d), the pressure block 2 presses against the top wall of the cap 300 from above, and the thread forming roller 5A and the hem rolling roller 5B face the peripheral wall 301 of the cap 300 from the radially outer side, with a gap between them.

[0134] As shown in Figures 12(e) and (f), the lower cam follower 91 is guided from the lowering portion 124c of the lower cam 124 to the forming portion 124d, causing the cone cam 7 of the lifting cylinder 90 to move downward relative to the body 1. Due to this movement and the biasing force of the biasing member 6, the position in which the rolling elements 42 of the cam follower 4 contact the cone cam 7 changes from the large-diameter rolling surface 72 to the tapered rolling surface 73, and further from the tapered rolling surface 73 to the small-diameter rolling surface 71.

[0135] As a result, each cam follower 4 moves radially inward, and each molding roller 5 connected to each cam follower 4 via each support member 3 is also moved radially inward. Furthermore, with the fixed gear 122 and the spindle gear 86 meshed, the spindle assembly 80 is moved in the turret rotation direction R, causing the spindle 85 and body 1 to rotate around the central axis O.

[0136] Therefore, each roller 5 of the screw-forming roller 5A and the hem-wrapping roller 5B contacts the peripheral wall 301 of the cap 300 and rolls on the peripheral wall 301 around the central axis O (can axis). As a result, the screw-forming roller 5A forms a screw portion (female screw portion) on the peripheral wall 301 of the cap 300 that screws into the male screw portion of the mouthpiece portion 200. The hem-wrapping roller 5B forms a hem around the lower end of the peripheral wall 301 of the cap 300, below the bulge portion 201 of the mouthpiece portion 200.

[0137] Next, the lower cam follower 91 is guided from the molded portion 124d of the lower cam 124 to the rising portion 124e, causing the cone cam 7 of the lifting cylinder 90 to move upward relative to the body 1. Due to this movement and the biasing force of the biasing member 6, the position where the rolling elements 42 of the cam follower 4 contact the cone cam 7 changes from the small-diameter rolling surface 71 to the tapered rolling surface 73, and then from the tapered rolling surface 73 to the large-diameter rolling surface 72.

[0138] As a result, each cam follower 4 moves radially outward, and each forming roller 5 connected to each cam follower 4 via each support member 3 is also moved radially outward. Therefore, each roller 5 of the screw forming roller 5A and the hem rolling roller 5B moves radially outward from the peripheral wall 301 of the cap 300.

[0139] As shown in Figure 12(g), the upper cam follower 83 is guided from the horizontal section 123b of the upper cam 123 to the head rising section 123c, causing the lifting shaft 81 and pressure block 2, as well as the spindle 85 and body 1, to move upward (see Figures 10 and 11). This causes the pressure block 2 to move upward away from the top wall of the cap 300. Additionally, the lower cam follower 91 is guided from the second horizontal section 124f of the lower cam 124 to the rear rising section 124g, causing the cone cam 7 of the lifting cylinder 90 to move upward following the body 1.

[0140] In this way, the cap 300 is capped onto the mouth portion 200 of the screw-on can B, and the screw-on can B is sealed. In this embodiment, the series of actions in which each roller 5 of the screw-forming roller 5A and the hem-rolling roller 5B contacts the peripheral wall 301 of the cap 300, rolls on the peripheral wall 301, and then separates from the peripheral wall 301 is considered as one operation. In other words, the capping device 120 performs capping by a single action.

[0141] In this embodiment, during a series of actions (single action) in which each roller 5 contacts the peripheral wall 301 of the cap 300, rolls on the peripheral wall 301, and then separates from the peripheral wall 301, each roller 5 (screw forming roller 5A and hem rolling roller 5B) makes two rotations on the cap peripheral wall 301 around the cap's central axis (can axis).

[0142] As described above, the capping head 10 comprises a pressure block 2, a thread forming roller 5A, and a hem roller 5B, and the spindle assembly 80 includes this capping head 10. Therefore, in this embodiment, it can be said that the spindle assembly 80 comprises a pressure block 2, a thread forming roller 5A, and a hem roller 5B.

[0143] More specifically, the spindle assembly 80 includes a pressure block 2 positioned on the capping head 10 that presses against the top wall of the cap 300 as the upper cam follower 83 moves downward; a plurality of thread forming rollers 5A provided on the capping head 10 that contact the peripheral wall 301 of the cap 300 as the lower cam follower 91 moves downward and form a threaded portion on the peripheral wall 301 that screws into the mouth portion 200; and at least three hem-rolling rollers 5B provided on the capping head 10 that contact the peripheral wall 301 of the cap 300 as the lower cam follower 91 moves downward and form a hem around the lower end of the peripheral wall 301 onto the mouth portion 200.

[0144] Next, the capping system 100 of this embodiment will be described. As shown in Figure 13, the capping system 100 includes a filler (filling machine) 110 that fills screw-top cans B with contents such as beverages, and a capping device 120 to which the screw-top cans B discharged from the filler 110 are supplied.

[0145] The reference numeral 130 in Figure 13 represents the layout of a conventional capping device 130. Conventionally, the transport direction E of the screw-top cans B discharged from the filler 110 and heading toward the capping device 130 is curved when viewed from above. In contrast, in this embodiment, the transport direction D of the screw-top can B discharged from the filler 110 and heading toward the capping device 120 extends along the tangent to the outer circumference of the turret 121 when viewed from the turret axis direction (i.e., from above).

[0146] According to the capping device 120 of this embodiment described above, at least three hem-rolling rollers 5B are provided on the capping head 10 of the spindle assembly 80. In other words, because a large number of hem-rolling rollers 5B are provided, even if the operation of each hem-rolling roller 5B in forming the hem of the cap 300 is limited to one time (single action), the accuracy of the hem-rolling can be maintained well.

[0147] Therefore, it is possible to keep the circumference (total length) of the lower cam 124 extending around the turret axis T short, and to keep the diameter of the turret 121 (turret diameter) small, thereby making the device more compact. Alternatively, compared to conventional double-action type capping devices, the single-action type capping device 120 of this embodiment can significantly increase the rotational speed of the turret 121 around the turret axis T, provided that the turret diameter is the same.

[0148] Based on the above, this embodiment makes it possible to maintain good accuracy in the hem-rolling molding of the cap 300 while making the device more compact and improving production efficiency by increasing the capping processing speed.

[0149] In this embodiment, the lower cam 124 is provided with only one set of the lowering portion 124c, the molding portion 124d, and the raising portion 124e. In this case, the lower cam follower 91 is guided downward by the lowering portion 124c of the lower cam 124, and as a result, the thread forming roller 5A and the hem rolling roller 5B come into contact with the peripheral wall 301 of the cap 300. Also, while the lower cam follower 91 is guided by the forming portion 124d of the lower cam 124, the thread forming roller 5A forms the threads on the peripheral wall 301 of the cap 300, and the hem rolling roller 5B forms the hem on the lower end of the peripheral wall 301 of the cap 300. Furthermore, the lower cam follower 91 is guided upward by the rising portion 124e of the lower cam 124, and as a result, the thread forming roller 5A and the hem rolling roller 5B move away from the peripheral wall 301 of the cap 300. Through the action of each roller 5, the peripheral wall 301 of the cap 300 is well formed.

[0150] In this embodiment, at least three screw forming rollers 5A are provided on the capping head 10. In this case, since a large number of screw forming rollers 5A are available, even if the operation of each screw forming roller 5A forming the screw portion on the cap 300 is limited to one time (single action), good accuracy in screw forming can be maintained.

[0151] In this embodiment, the capping head 10 is provided with three screw forming rollers 5A and three hem-rolling rollers 5B. As shown in the above configuration, by providing three screw forming rollers 5A and three hem-wrapping rollers 5B, the molding accuracy of the cap can be stably improved even if the operation of each roller 5 forming the cap peripheral wall 301 is limited to one time. Furthermore, while ensuring molding accuracy, the number of rollers can not be increased excessively, allowing the device to be made more compact and lighter.

[0152] Furthermore, in the capping head 10 of this embodiment, the rolling elements 42 of the cam follower 4 are rotatably supported at the lower end of the shaft portion 41. Therefore, compared to conventional capping heads, the rolling elements 42 can be positioned closer to the upper surface 1a of the body 1. If this configuration were applied to a conventional capping head, there would be a risk of the lower end of the cone cam coming into contact with the upper surface of the body. However, in this embodiment, the body 1 is provided with a cone cam housing recess 13. That is, at least the lower end of the cone cam 7 can be accommodated in the cone cam housing recess 13, so that the cone cam 7 and the body 1 can be positioned closer together in the vertical direction, while preventing contact (interference) between these components.

[0153] Therefore, the pressure block 2 and molding roller 5 that form the cap 300 and the cone cam 7 can be positioned closer together in the vertical direction, thereby reducing the vertical dimensions of the body 1. Therefore, according to the capping head 10, spindle assembly 80, and capping device 120 of this embodiment, the external dimensions of the capping head 10 can be made compact and lightweight, increasing the capping processing speed and improving production efficiency.

[0154] In this embodiment, the vertical positions of the multiple screw forming rollers 5A (and their roller bodies 52) are offset from one another. In this case, the molding locations of the multiple screw forming rollers 5A on the peripheral wall 301 of the cap 300 are offset in the vertical direction, thereby suppressing defects such as excessive screw forming at the same location on the cap peripheral wall 301 (especially near the upper groove, which is the starting position of the screw). This suppresses variations in the amount of screw forming at each position in the vertical direction, and equalizes the amount of screw forming in the vertical direction.

[0155] In this embodiment, the spindle mounting portion 15 of the body 1 overlaps with the cone cam housing recess 13 when viewed from the radial direction. As shown in the above configuration, the spindle mounting portion 15 and the cone cam housing recess 13 are arranged to overlap when viewed from the radial direction, which makes it possible to further reduce the vertical dimension of the body 1.

[0156] In this embodiment, the body 1 has a biasing member housing hole 23 that extends in the vertical direction, and the biasing member 6 is placed in the biasing member housing hole 23. In this case, the biasing member 6 is housed in a biasing member housing hole 23, which is provided by hollowing out the body 1 in the vertical direction. This allows the biasing member 6 to be covered from its periphery while maintaining high rigidity of the body 1. Furthermore, compared to the case where a pocket 11e and a separate cover 8 covering the pocket 11e are provided in the body 1, as in the modified example of this embodiment described later, the machining process for cutting the biasing member housing hole 23 into the body 1 is not complex, thus simplifying the manufacturing of the body 1. Moreover, with an integrated body body 11 as in this embodiment, it is easy to further reduce the weight of the body body 11 by removing material while maintaining the rigidity of the body body 11.

[0157] Furthermore, in this embodiment, the skirt portion 11h prevents the multiple support projections 17, multiple roller shaft housing pockets 19, housing cylinder 16, and part of the pressure block 2 from being exposed to the outside of the device. This enhances the aesthetic appearance of the device.

[0158] Furthermore, the skirt portion 11h and the multiple support projections 17 are connected to each other. This increases the rigidity of each support projection 17, and each support shaft 31, which is supported by each support projection 17 via a bearing member, rotates accurately around the shaft central axis A. As a result, the cap peripheral wall 301 can be formed with higher precision by each forming roller 5 connected to each support shaft 31.

[0159] Furthermore, the body 1 of this embodiment is made of a lightweight aluminum alloy. This allows for weight reduction while ensuring the overall rigidity of the device.

[0160] Specifically, in this embodiment, it was found that the following processing performance could be obtained as a result of making the capping head 10 more compact and lighter. Although not specifically illustrated, for example, in a spindle assembly equipped with a conventional 4-roll type (4 forming rollers) capping head, a capping device equipped with 10 such spindle assemblies, and a capping system equipped with such a capping device, the maximum capping speed for screw-top cans was 300 cpm. "cpm" is a unit representing the number of cans processed (capped cans) per minute. In contrast, in the spindle assembly 80 equipped with a 6-roll type (6 molding rollers 5) capping head 10 of this embodiment, a capping device 120 equipped with 10 of the spindle assemblies 80, and a capping system 100 equipped with the capping device 120, the capping processing speed of screw-on cans B was increased to a maximum of 600 cpm.

[0161] In this embodiment, a portion of the pressure block 2 is housed in a housing cylinder 16 that protrudes downward from the lower surface 1b of the body 1. In this case, by housing a portion of the pressure block 2 in the housing cylinder 16, it becomes unnecessary to provide a housing space (insertion space) for the pressure block 2 inside the body 1, and the vertical dimension between the lower surface 1b of the body 1 and the cone cam housing recess 13 can be further reduced. As a result, the body 1 can be made even more compact and lighter.

[0162] In this embodiment, the body 1 has weight-reducing sections between the support projection 17 and the housing cylinder 16, and between adjacent support projections 17 in the circumferential direction. Therefore, further weight reduction of body 1 can be achieved.

[0163] In this embodiment, a deformation assist groove 36 is provided in at least one of the upper clamp portion 32a and the lower clamp portion 33a of the support member 3. In this case, a deformation assist groove 36 extending in the vertical direction is provided on the circumferential surface (circumferential surface of the clamp) of the upper clamp portion 32a or the lower clamp portion 33a (hereinafter sometimes simply referred to as the clamp portion), making it easier for the clamp portion to deform in a direction that presses against the outer circumferential surface of the support shaft 31 (inward in the shaft diameter direction). This makes it possible to keep the outer diameter dimension (diameter dimension) of the support shaft 31 small (i.e., make the support shaft 31 thinner), and accordingly, the outer diameter dimension of the capping head 10 as a whole can also be kept small, making further weight reduction possible.

[0164] In this embodiment, a stepped portion 37 is formed on the radially inward-facing surface of the lower arm 33. In this case, by using the assembly jig 60 to move the cam follower 4 and the forming roller 5 radially outward against the biasing force of the biasing member 6 (open state), the locking arm 61 can be locked to the stepped portion 37 of the lower arm 33, thereby stably maintaining the open state. The cone cam 7 can be stably inserted radially inward of the multiple cam followers 4 arranged in the circumferential direction, making the assembly work of the capping head 10 and the cone cam 7 easier.

[0165] Furthermore, in this embodiment, the capping system 100 has a transport direction D for the screw-top can B discharged from the filler 110 and heading toward the capping device 120 that extends along the tangent to the outer circumference of the turret 121 when viewed from the direction of the turret axis T. According to the capping system 100 of this embodiment, the screw-top cans B discharged from the filler 110 are smoothly supplied to the capping device 120 without their direction of transport being abruptly changed, that is, they are less affected by centrifugal force. As a result, the capping processing speed can be stably increased, and production efficiency can be further improved.

[0166] The present invention is not limited to the embodiments described above, and modifications to the configuration, etc., are possible without departing from the spirit of the invention, as described below. In the illustrations of modified examples, the same reference numerals are used for the same components as in the embodiments described above, and the main differences will be described below.

[0167] Figures 14 and 15 show modified versions of the capping head 10 described in the above-described embodiment. As shown in Figures 14 and 15, in this modified version, the capping head 10 is equipped with a cylindrical cover 8. The body 1 also has a pocket 11e, a pin insertion hole 11f, and a locking pin 11g. In this modified version, the body 1 does not have a skirt portion 11h.

[0168] As shown in Figure 15, the pocket 11e is concave, recessed radially inward from the outer circumferential surface 1c of the body 1, and extending vertically. The pocket 11e has a portion recessed radially inward from the outer circumferential surface of the peripheral wall portion 11c, and a portion that is connected to the lower side of this portion and recessed radially inward from the upper portion of the outer circumferential surface of the support projection 17. Multiple pockets 11e are provided arranged in the circumferential direction, although not specifically shown. The number of pockets 11e is the same as the number of support members 3 and the same as the number of biasing members 6.

[0169] The intermediate portion of the support shaft 31, located between the body flange 12 and the lower part of the support projection 17 in the vertical direction, is placed in the pocket 11e. Each biasing member 6 is housed in each pocket 11e.

[0170] The pin insertion hole 11f opens onto the outer circumferential surface of the lower portion of the support projection 17 and extends radially. The pin insertion hole 11f is, for example, circular in shape. Multiple pin insertion holes 11f are provided, spaced apart from each other in the circumferential direction.

[0171] The locking pin 11g is inserted into the pin insertion hole 11f. The locking pin 11g is columnar or cylindrical in shape and extends radially; in this embodiment, for example, it is cylindrical. The locking pin 11g may be fixed in the pin insertion hole 11f by fitting, by screwing, or by adhesive. The locking pin 11g has a portion that protrudes radially outward from the pin insertion hole 11f. That is, the locking pin 11g has a portion that protrudes radially outward from the outer circumferential surface of the support projection 17. Multiple locking pins 11g are provided at intervals from each other in the circumferential direction. For example, three or more locking pins 11g are provided at equal pitches in the circumferential direction.

[0172] The cover 8 is cylindrical with a central axis O and extends in the vertical direction. As shown in Figures 14 and 15, the cover 8 surrounds the body 1 from the radial outside to the entire circumference. Specifically, the cover 8 surrounds the body body 11 and the body flange 12 from the radial outside to the entire circumference. The cover 8 also surrounds the peripheral wall portion 11c, the bottom wall portion 11d, the multiple pockets 11e, the multiple biasing members 6, the multiple support projections 17, the multiple roller shaft housing pockets 19, the housing cylinder 16, and a part of the pressure block 2 from the radial outside. The cover 8 also covers the portion of each support member 3 that is placed in the pocket 11e (the intermediate portion of the support shaft 31) from the radial outside.

[0173] The cover 8 has a locking recess 8a. The locking recess 8a penetrates the peripheral wall of the cover 8 radially and extends vertically. The locking recess 8a is a notched or slit-shaped recess. The locking recess 8a opens onto the outer peripheral surface, inner peripheral surface, and lower end surface of the cover 8. Multiple locking recesses 8a are provided at intervals from each other in the circumferential direction. For example, three or more locking recesses 8a are provided at equal pitches in the circumferential direction. The number of locking recesses 8a is the same as the number of locking pins 11g.

[0174] The portion of the locking pin 11g that protrudes from the pin insertion hole 11f is inserted into the locking recess 8a. Specifically, the locking pin 11g faces a pair of inner surfaces of the locking recess 8a that face in the circumferential direction, from the circumferential direction. The locking pin 11g also contacts the inner surface of the locking recess 8a that is located at the upper end and faces downward, from below.

[0175] The cover 8 is fitted onto the body 11 and body flange 12, and the locking pin 11g is locked into the locking recess 8a, thereby fixing the cover 8 to the body 1. The cover 8 can also be removed from the body 1 by moving it upward relative to the body 1. In other words, the cover 8 is detachably attached to the body 1.

[0176] The body 1 and cover 8 are made of metal, for example, an aluminum alloy. Specifically, the body 1 and cover 8 are made of duralumin, for example.

[0177] According to this modification, the cover 8 prevents the peripheral wall portion 11c, the bottom wall portion 11d, the multiple pockets 11e, the multiple biasing members 6, the intermediate portions of the multiple support shafts 31, the multiple support projections 17, the multiple roller shaft housing pockets 19, the housing cylinder 16, and part of the pressure block 2 (hereinafter sometimes abbreviated as biasing members 6, etc.) from being exposed to the outside of the device. This improves the aesthetic appearance of the device. In addition, the cover 8 prevents contents of beverages, etc. (especially sugars that tend to solidify), oils, and other liquids that splash from outside the capping head 10 toward the body 1 from entering the body 1. This improves maintainability and ensures that the performance (function) of each component, such as the biasing members 6, provided on the body 1 is well maintained.

[0178] Furthermore, in this modified version, the body 1 and cover 8 are made of lightweight aluminum alloy. This allows for weight reduction while maintaining the overall rigidity of the device.

[0179] Furthermore, although the above-described embodiment showed an example where the capping head 10 has six molding rollers 5, it is not limited to this. The number of molding rollers 5 in the capping head 10 may be eight, for example, or more than six.

[0180] The present invention may be combined in any way that does not depart from the spirit of the invention, as described in the above embodiments and modifications, and the configurations may be added, omitted, substituted, or otherwise modified. Furthermore, the present invention is not limited by the above embodiments, but is limited only by the claims. [Examples]

[0181] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples.

[0182] <Capping confirmation test> As a comparative example 1, a capping device was used that employed a capping head equipped with a total of four forming rollers: two screw forming rollers and two hem-rolling rollers. The series of actions in which each of the screw forming rollers and hem-rolling rollers contacts the peripheral wall 301 of the cap 300, rolls along the peripheral wall 301, and then separates from the peripheral wall 301 was set to occur twice (double action). This capping device was then used to cap a number of screw-on cans B of any desired size with caps 300. Note that, unlike the present invention, the capping head in comparative example 1 is a conventional capping head whose body does not have a cone cam housing recess or the like.

[0183] In Comparative Example 1, the set diameter of the screw forming roller was φ43.5 mm, and the set diameter of the hem-wrapping roller was φ45.3 mm. The "set diameter" corresponds to the inner diameter dimension (the diameter of the rotational trajectory at the inner end of the roller) of the rotational trajectory obtained by rotating the forming roller around the central axis of the capping head. Depending on the set diameter, the roller tip load at which the forming roller presses the cap circumferential wall radially inward, and the contact length per contact (circumferential length around the cap) of the forming roller against the cap circumferential wall are adjusted.

[0184] Furthermore, as Comparative Example 2, a capping device was used in which each roller of the screw forming roller and the hem rolling roller was set to make contact with the peripheral wall 301 of the cap 300, roll on the peripheral wall 301, and then move away from the peripheral wall 301, in a single action. Capping was performed using this capping device under the same conditions as Comparative Example 1.

[0185] Furthermore, as Embodiment 1 of the present invention, caps 300 were capped onto any number of screw-on cans B using the capping head 10 and capping device 120 described in the above embodiment. Specifically, capping was performed using a capping head 10 equipped with a total of six forming rollers 5, consisting of three screw forming rollers 5A and three hem-rolling rollers 5B, and a capping device 120 in which each roller 5 of the screw forming rollers 5A and hem-rolling rollers 5B contacts the peripheral wall 301 of the cap 300, rolls on the peripheral wall 301, and then separates from the peripheral wall 301, all in a single action. In Example 1, the set diameter of the screw forming roller 5A was set to φ43.0 mm, and the set diameter of the hem rolling roller 5B was set to φ43.0 mm.

[0186] For each of Comparative Examples 1 and 2 and Example 1, a predetermined number of screw-on cans B were arbitrarily selected from a large number of screw-on cans B capped with caps 300. For each screw-on can B, the following items were measured: "thread depth," "opening angle," "bottom roll," and "thread length." The mean (Ave), maximum (Max), minimum (Min), and standard deviation (σ) were then calculated.

[0187] For more details, the "screw depth" (mm) was measured as follows: Figure 16 is a schematic diagram of a screw illustrating the method for measuring screw depth, showing the number of turns of the screw unfolded on a plane. As shown in Figure 16, the starting point of the screw thread formed on the cap peripheral wall 301 is designated as No. 1, and the threads are numbered No. 1, 2, 3, etc., at 60° intervals around the cap's central axis (can axis) from the start to the end of the thread. The screw depth was then measured at seven points from No. 5 to No. 11, and the maximum value among them was defined as the "screw depth" mentioned above.

[0188] Furthermore, the "opening angle" (°) is the angle of rotation from the start of the operation to rotate the cap 300 attached to the nozzle portion 200 in the opening direction around the can axis until all of the multiple bridges in the cap peripheral wall 301 are broken.

[0189] Furthermore, "hem curling" was measured by sensory evaluation by inspectors (numerical range 1.0 to 5.0). Figures 17(a) to (d) are cross-sectional (longitudinal) images showing the vicinity of the lower end of the peripheral wall 301 of the cap 300 after capping, and are diagrams illustrating the evaluation of hem curling.

[0190] For details, Figure 17(c) shows the state after hem rolling when the hem rolling roller 5B contacts the lower end of the peripheral wall 301 of the cap 300 at the correct position (height) in the vertical direction. In Figure 17(c), there is no gap around the entire circumference between the lower end of the peripheral wall 301 and the lower part of the bulge 201. This state in Figure 17(c) is called "correct (3.0)".

[0191] Furthermore, Figure 17(a) shows the state after hem rolling when the hem rolling roller 5B contacts the lower end of the peripheral wall 301 of the cap 300 at a position higher than the appropriate position described above. In Figure 17(a), a gap is created between the lower end of the peripheral wall 301 and the lower part of the bulge 201, extending from halfway around the cap's central axis to its entire circumference. This state shown in Figure 17(a) is called "hakama (1.0)".

[0192] Furthermore, Figure 17(b) shows the state after hem rolling when the hem rolling roller 5B contacts the lower end of the peripheral wall 301 of the cap 300 at a position between "appropriate" and "skirt" in the vertical direction. In Figure 17(b), there is no gap between the lower end of the peripheral wall 301 and the lower part of the bulge 201, but the tongue piece 301a protrudes downward from the lower end of the peripheral wall 301 in an area of ​​less than 1 / 4 of the circumference around the cap's central axis. This state in Figure 17(b) is called "tongue protrusion (2.5)".

[0193] Furthermore, Figure 17(d) shows the state after hem rolling when the hem rolling roller 5B contacts the lower end of the peripheral wall 301 of the cap 300 at a lower position than the appropriate position described above. In Figure 17(d), a gap is created between the lower end of the peripheral wall 301 and the lower part of the bulge 201, extending from halfway around the cap's central axis to its entire circumference. This state shown in Figure 17(d) is called "loose (5.0)". In the hem roll evaluation, a value between 2.5 and 3.5 within the numerical range of 1.0 to 5.0 is judged as good hem roll, while values ​​below 2.5 and above 3.5 are judged as poor hem roll.

[0194] Furthermore, the "thread length" (mm) was determined by setting the average thread length of the two-turn threaded portion formed on the cap periphery wall 301 of Comparative Example 1 as the reference value (zero), and measuring the length of the threaded portion relative to the reference value using a measuring tape. The results of this capping confirmation test are shown in Table 1.

[0195] [Table 1]

[0196] As shown in Table 1, Comparative Example 1, in which each roller performed molding twice (double action), received a favorable evaluation. In the remarks column of the table, "low screw resistance" indicates that some caps had low torque (reseal torque) when reattaching the cap 300 to the mouthpiece 200 after opening.

[0197] Furthermore, in Comparative Example 2, where each roller performed only one molding cycle (single action), the evaluation was unsatisfactory. Specifically, the thread depth was too shallow, the opening angle was excessive, resulting in a judgment of poor hem wrapping, and the thread length was shorter compared to Comparative Example 1. In the table, "Hinging" in the remarks column indicates that there were instances where a bridge that did not break during opening acted like a hinge, resulting in the cap 300 being connected to the mouthpiece 200 (hinging phenomenon).

[0198] On the other hand, in Example 1, a good evaluation was obtained despite the molding being performed only once by each roller 5 (single action). Specifically, in Example 1, despite being a single-action capping, the evaluation of the "hem wrapping" was better than in Comparative Example 1, which was a double-action (all scores were "appropriate (3.0)"), and sufficient thread depth was also ensured. [Industrial applicability]

[0199] The capping apparatus and capping system of the present invention make it possible to maintain good accuracy in the hem-rolling of caps while making the apparatus more compact and increasing the capping processing speed to improve production efficiency. Therefore, it has industrial applicability. [Explanation of Symbols]

[0200] 2...Pressure block, 4...Cam follower, 5...Forming roller (roller), 5A...Thread forming roller, 5B...Bottom rolling roller, 10...Capping head, 80...Spindle assembly, 83...Upper cam follower, 85...Spindle, 91...Lower cam follower, 100...Capping system, 110...Filler, 120...Capping device, 121...Turret, 123...Upper cam, 124...Lower cam, 124c...Lowering section, 124d...Forming section, 124e...Rising section, 200...Mouthpiece section, 300...Cap, 301...Peripheral wall, B...Threaded can, D...Conveying direction, R...Turret rotation direction, T...Turret axis

Claims

1. A capping device for attaching a top-shaped cylindrical cap to the mouthpiece of a bottom-shaped cylindrical screw-top can, A turret that rotates around a turret axis that extends vertically, A spindle assembly is positioned on the outer circumference of the turret, extending vertically, with a capping head positioned at its lower end, An upper cam extending around the turret shaft and engaging with the upper cam follower of the spindle assembly, A lower cam extending around the turret shaft and engaging with the lower cam follower of the spindle assembly, It comprises a fixed gear that extends around the turret shaft and meshes with the spindle gear of the spindle assembly, The spindle assembly is A pressure block positioned in the capping head, which presses against the top wall of the cap as the upper cam follower moves downward, Multiple thread forming rollers are provided on the capping head and, as the lower cam follower moves downward, contact the peripheral wall of the cap and form a threaded portion on the peripheral wall that screws into the mouth portion, The capping head is provided with at least three hem rollers that contact the peripheral wall of the cap as the lower cam follower moves downward and hem the lower end of the peripheral wall onto the mouthpiece, The series of movements in which each roller of the screw forming roller and the hem rolling roller contacts the peripheral wall of the cap, rolls on the peripheral wall, and then separates from the peripheral wall is considered one cycle. Capping device.

2. The aforementioned lower cam is, A downward portion that extends downward as it moves in the direction of rotation of the turret around the turret axis, A molding section is connected to the end of the lowering section in the direction of the turret rotation and extends in the direction of the turret rotation, It has an upward portion connected to the end of the molding portion in the direction of the turret rotation, and extending upward as it moves toward the direction of the turret rotation, The lower cam is provided with only one set of the lowering portion, the molding portion, and the raising portion. The capping device according to claim 1.

3. The screw forming rollers are provided in at least three locations on the capping head. The capping device according to claim 1 or 2.

4. Three screw forming rollers are provided. Three of the aforementioned hem-rolling rollers are provided. A capping device according to any one of claims 1 to 3.

5. A filler for filling a screw-top can with its contents, The capping device according to any one of claims 1 to 4, wherein the screw-top can discharged from the filler is supplied, The transport direction of the screw-on cans discharged from the filler and heading toward the capping device extends along the tangent to the outer circumference of the turret when viewed from the turret axis direction. Capping system.

Images