Cap seaming mechanism

Abstract

To provide a cap seaming mechanism capable of suppressing defective seaming, capping with increased precision, composing the mechanism at a low cost by using a general motor and a cam, and being easily mounted on an existing mechanical capping device.SOLUTION: When a chuck opening / closing mechanism 4 is being driven to seam a gripped cap C on a mouth part of a container B, if a screw thread of the cap C held by a descending capping head 1 descends to a height just before contacting the screw thread of the container B, a chuck 5 is once opened to release the gripped cap C. Then, when the screw thread of the cap C pressed downward by a cap pressing body 16 of the descending capping head 1 exceeds the screw thread of the container B, an opening / closing of the chuck 5 is adjusted again so that the chuck 5 is closed to grip the cap C.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a capping mechanism for winding a cap held by a capping head around the mouth of a container.

Background Art

[0002] Conventionally, in a capping mechanism, a cap is gripped by a capping head provided on a head shaft that always rotates by driving a motor, and the capping head is lowered to wind it around the mouth of a container filled with contents. In the winding in a state where the capping head is rotated and lowered in this way, at the matching point where the starting point of the thread formed on the cap and the starting point of the thread formed on the mouth of the container coincide, poor meshing (commonly known as "battering") between the starting points of the threads easily occurs. As a result, troubles such as the cap being mounted obliquely on the container and normal winding not being obtained easily occurred.

[0003] In particular, in the case of a flexible container such as a mayonnaise bottle, the container itself has no rigidity, or when winding the cap when the contents are at a certain high temperature, the container buckles, and the mouth of the container positioned in the advancing and retreating direction of the head shaft tilts. For these reasons, the above-mentioned meshing failure often occurs. Also, when an aluminum foil seal member is attached as an inner lid to the mouth of the flexible container, a part of the seal member (such as the corner of the rectangular seal member) covers the matching point of the threads, which may cause the above-mentioned meshing failure.

[0004] As a countermeasure, in recent years, a servo motor has been mounted on the head shaft, and reverse rotation is performed until the matching point of the threads is detected by monitoring the torque acting on the capping head. When the threads exceed the matching point, the rotation is switched to forward rotation, and the rotation of the head shaft, that is, the rotation of the cap, is controlled so that the meshing between the starting point of the thread formed on the cap and the starting point of the thread formed on the mouth of the container is performed smoothly (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, since individual devices such as servo motors and torque detection means are required for each head shaft, the mechanisms equipped with these are expensive. Also, space and work for installation are required. In particular, in a rotary winding device equipped with a plurality of head shafts, this has been a reason to hesitate to adopt the technology.

[0007] The present invention has been made in view of such problems, and by reducing expensive servo motors and individual devices that require installation space and work, and adopting a mechanical mechanism, the starting point of the thread formed on the cap and the starting point of the thread formed on the mouth part of the container are smoothly engaged, and an object of the present invention is to provide a cap winding mechanism and a winding method capable of performing trouble - free winding.

Means for Solving the Problems

[0008] In order to achieve the above object, the cap tightening mechanism of the present invention is a cap tightening mechanism for tightening a gripped cap onto the mouth portion of a container. It is disposed within a head case fixed to a rotatable and vertically movable rotating shaft, and includes a chuck that is movable to grip or release a cap by driving a chuck opening / closing mechanism, a lower rotating disk that contacts the upper portion of the gripped cap, and a pair of an upper rotating disk disposed via a bearing with the lower rotating disk, and a cap pressing body connected to the lower end of the rotating shaft extending into the head case and always rotating together by the rotational drive of the rotating shaft. The chuck opening / closing mechanism is configured such that, during driving for tightening the gripped cap onto the mouth portion of the container, when the thread of the cap held by the descending capping head descends to a height immediately before contacting the thread of the container, the chuck is once opened to release the gripped cap, and then, when the thread of the cap pressed downward by the cap pressing body of the descending capping head descends to a height beyond the thread of the container, the chuck is closed again to grip the cap. That is, the opening and closing of the chuck are adjusted.

[0009] According to the cap tightening mechanism of the present invention, in which the opening and closing of the chuck are adjusted by the chuck opening / closing mechanism, when the thread of the cap held by the descending capping head contacts the thread of the container, the chuck is open. Moreover, due to the load (resistance) generated by the contact between the thread of the cap and the thread of the container, and the bearing disposed between the lower rotating disk and the upper rotating disk of the cap pressing body that is in surface contact with the upper surface of the cap, the rotational force of the rotating shaft is not transmitted to the cap. In this state where the cap is non-rotating, the capping head is lowered, the cap is pressed downward by the cap pressing body to cause the thread of the cap to cross over the thread of the container, and then the chuck is closed to grip the cap. Since the rotational force of the rotating shaft is transmitted to the gripped cap via the chuck and the cap pressing body, tightening with a desired torque can be performed.

Advantages of the Invention

[0010] As described above, according to the cap tightening mechanism of the present invention, during the driving of the rotating shaft, the rotation of the cap is temporarily stopped by a mechanical mechanism, and after fitting the starting point of the thread formed on the cap and the starting point of the thread formed on the mouth part of the container in a state where poor meshing is unlikely to occur, the cap is tightened. Therefore, it is possible to suppress the occurrence of tightening failure and perform capping with improved accuracy. In addition, by using a general motor and a cam without using expensive parts such as a servo motor, the mechanism can be configured at low cost, and it is also easy to mount on an existing mechanical capping device.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0012] The cap tightening mechanism of the present embodiment is mounted on each of a plurality of tightening machines disposed in the vicinity of the upper part of the rotating body, so as to simultaneously apply caps to the mouths of a plurality of filled containers B that are gripped and conveyed by grippers (not shown) arranged at equal intervals on the outer peripheral edge of the rotating body (not shown) that constitutes the conveying means of the container B in the capper area of the conveying path of the container B formed in a rotary filling device (not shown).

[0013] As shown in FIGS. 1 to 5, the cap tightening mechanism of the present embodiment has a capping head 1 that grips the cap C. In the present embodiment, the tightening mechanism is supported by the rotary filling device and is vertically provided so as to be rotatable and vertically movable, and includes a rotating shaft 2 that rotates by the driving force of a motor (not shown) as a driving source. The capping head 1 is disposed at the lower end of the rotating shaft 2, and is configured to be vertically movable with respect to the mouth of the container B conveyed to the capper area.

[0014] A head case 3 that constitutes the capping head 1 is fixed near the lower end of the rotating shaft 2. Inside the cylindrical cup-shaped head case 3 with its central top fixed to the rotating shaft 2, a chuck 5 is disposed that can be moved to grip or release the grip of the cap C by driving a chuck opening and closing mechanism 4.

[0015] In the present embodiment, a plurality of chucks 5 formed in an arc shape in plan view are annularly arranged around the axial direction of the rotating shaft 2 inside the cylindrical cup-shaped head case 3, and are always biased by a biasing member 15 so as to be separated radially outward from the rotating shaft 2. The biasing force of this biasing member 15 acts so that the chuck 5 pushes up a piston block 10 described later.

[0016] Each chuck 5 is composed of a sliding block 6 disposed within the head case 3, a claw block 7 positioned below the opening on the lower surface of the head case 3 and contacting the peripheral wall of the cap C to grip the cap C, and a thin plate-shaped connecting portion 8 connecting the sliding block 6 and the claw block 7.

[0017] The sliding block 6 is slidably placed on the horizontal edge portion 3a forming the opening of the head case 3, and the upper corner in the outer peripheral direction is chamfered to form a tapered surface 6a.

[0018] And the chuck opening / closing mechanism 4 is a mechanism for adjusting the opening and closing of the chuck 5 such that, during the drive for winding the gripped cap C around the mouth of the container B, when the thread of the cap C held by the capping head 1 that is descending reaches a height immediately before contacting the thread of the container B, the chuck 5 is once opened to release the gripped cap C, and then, when the thread of the cap C pressed downward by a cap pressing body 16 (described later) of the descending capping head 1 has passed over the thread of the container B, the chuck 5 is closed again to grip the cap C. Specifically, it is a mechanism for raising and lowering a piston block 10 disposed within the head case 3 within the head case 3.

[0019] The piston block 10 is disposed inside the chuck 5 of the head case 3. The piston block 10 is slidably fitted to the tip of the rotating shaft 2 and is slid and fitted to the inner peripheral surface of the head case 3 with its outer peripheral surface. And an airtight pressure chamber 12 is formed between the ceiling inner surface of the head case 3 by a seal member 11 fitted between the rotating shaft 2 and the head case 3. Pressure air is supplied to this pressure chamber 12 from an air supply source (not shown) through an air supply passage 13 formed inside the shaft of the rotating shaft 2, and the pressure air in the pressure chamber 12 can be released by a valve (not shown) disposed in the air supply passage 13. Thereby, the piston block 10 descends while being guided by a guide pin 14 that restricts the free rotation of the piston block 10 disposed between it and the head case 3 due to the introduction of pressure air into the pressure chamber 12, and rises by releasing the pressure air in the pressure chamber 12.

[0020] In the present embodiment, the valve disposed in the air supply passage 13 employs a mechanical valve using a cam, and the chuck opening / closing mechanism 4 switches the ON / OFF of the mechanical valve in accordance with the descent of the capping head 1 due to the drive of the rotating shaft 2 to supply and release pressure air, raises and lowers the piston block 10 to open and close the chuck 5, and grips and releases the cap C.

[0021] A tapered surface 10a that slidably contacts the tapered surface 6a of the sliding block 6 described above is formed at the lower corner in the inner circumferential direction of the piston block 10. Therefore, as described above, when the piston block 10 descends, the chuck 5 is configured to close while the sliding block 6 that slidably contacts the tapered surfaces 6a and 10a is pushed radially inward, against the biasing force of the biasing member 15 of the claw block 7.

[0022] And in this embodiment, the capping head 1 has a cap pressing body 16 formed by a pair of a lower rotating disk 17 that contacts the upper part of the cap C held by the chuck 5 and an upper rotating disk 19 disposed via the bearing 18 with the lower rotating disk 17. The cap pressing body 16 is connected by a bolt 20 to the lower end of the rotating shaft 2 extending to the center within the head case 3, and both the lower rotating disk 17 and the upper rotating disk 19 are rotatable together with the rotating shaft 2.

[0023] In the winding mechanism of this embodiment, the lower rotating disk 17 of the cap pressing body 16 is adjusted in the arrangement position so that when the chuck 5 holds the cap C, its lower surface becomes the height position in contact with the top of the cap C. Thereby, the cap C held by the chuck 5 in the closed state by the chuck opening and closing mechanism 4 is wound around the mouth part of the container B by the rotational force of the rotating shaft 2 and the rotational force of the rotating shaft 2 transmitted through the head case 3 fixed to the rotating shaft 2 while being pressed by the cap pressing body 16 disposed on the rotatable rotating shaft 2.

[0024] Subsequently, the operation of the winding mechanism of the cap C provided with the capping head 1 configured in this embodiment will be described. In each winding machine disposed in the capper area in the conveyance path of the container B formed in the rotary filling device, winding of the cap C held by the chuck 5 is performed corresponding to each individual container B held by the gripper. Regarding the operation of the winding machine until each chuck 5 receives, holds the cap C from the cap supply means (not shown) and disposes it above the mouth part of each individual container B held by the gripper in the capper area, a series of operations by the conventional capping head 1 will be applied, and the detailed description thereof will be omitted. Needless to say, also at this time, in this embodiment, the cap C can be gripped by opening and closing the chuck 5 using the air pressure introduced into the pressure chamber 12 of the chuck opening and closing mechanism 4.

[0025] And in the cap tightening mechanism of the cap C of the present embodiment, when the capping head 1 that holds the cap C is positioned above the mouth of each container B gripped by the gripper in the capper area, the chuck opening / closing mechanism 4 transmits the driving force of a motor (not shown) to the rotary shaft 2 and lowers the capping head 1 that holds the cap C while rotating it (see Fig. 1).

[0026] And in the present embodiment, immediately before the thread of the cap C held by the descending capping head 1 comes into contact with the thread of the container B, the cam of the mechanical valve is turned off to open the valve and release the pressurized air in the pressure chamber 12, releasing the held cap C and leaving it simply covering the mouth of the container B (see Fig. 2).

[0027] At the same time, the released cap C is pressed downward by the lower rotating disk 17 of the cap pressing body 16 disposed in the head case 3 that abuts on the upper surface thereof. At this time, in the present embodiment, the chuck 5 is open, and moreover, due to the load (resistance) generated by the contact between the thread of the cap C and the thread of the container B and the bearing 18 disposed between the lower rotating disk 17 and the upper rotating disk 19 of the cap pressing body 16 that is in surface contact with the upper surface of the cap C, the lower rotating disk 17 does not rotate even though it is in contact with the cap C, so the rotational force of the rotary shaft 2 is not transmitted to the cap C. With the cap C in a non-rotating state, the rotary shaft 2 is rotated, the capping head 1 is lowered, and the cap C is pressed downward by the cap pressing body 16 to cause the thread of the cap C to pass beyond the matching point with the thread of the container B (see Fig. 3). At this time, since the lower rotating disk 17 that abuts on the cap C does not rotate, it is possible to prevent the cap C from being damaged by friction and also to prevent it from being scratched.

[0028] Subsequently, again, turn on the cam of the mechanical valve to close the valve, supply pressurized air to the pressure chamber 12, push down the piston block 10, move the chuck 5 radially inward, close the claw block 7, and grip the cap C (see Fig. 4). Then, transmit the rotational force of the rotary shaft 2 to the gripped cap C via the chuck 5 and the cap pressing body 16, and perform winding with a desired torque (see Fig. 5). At the time of this re-winding, since the starting point of the thread formed on the cap C and the starting point of the thread formed on the mouth part of the container B are already fitted, the state is such that poor meshing is less likely to occur.

[0029] After that, by turning off the cam of the mechanical valve to open the valve and releasing the pressurized air in the pressure chamber 12, the biasing member 15 pushes up the piston block 10 toward the pressure chamber 12, and releases the gripping of the cap C by the chuck 5. Then, raise the capping head 1 to prepare for capping the next container B.

[0030] Thus, according to the winding mechanism of the cap C of the present embodiment, during the driving of the rotary shaft 2, the rotation of the cap C is temporarily stopped by a mechanical mechanism, and after fitting the starting point of the thread formed on the cap C and the starting point of the thread formed on the mouth part of the container B in a state where poor meshing is less likely to occur, the cap C is wound. Therefore, even for a soft container B such as a mayonnaise bottle, even when an aluminum foil seal member is attached as an inner lid to the mouth part thereof, poor meshing can be suppressed and accurate capping can be performed. Also, even if battering occurs, an excessive load is not applied, and it can be dealt with in a shorter time than the case of reversing the cap C to eliminate poor meshing as described above. And, it can be configured at low cost by using an inexpensive motor and cam without using an expensive component such as a servo motor. Also, the cap C is not damaged by friction with the cap pressing body 16, and it is easy to mount on an existing mechanical capping device.

[0031] Note that the winding mechanism of the cap C of the present invention is not limited to the above-described embodiments, and various modifications can be made without impairing the features of the present invention. For example, the ON / OFF of the air valve of the chuck opening / closing mechanism 4 of the present embodiment does not necessarily have to be mechanically performed by a cam mechanism.

Explanation of Reference Numerals

[0032] 1 Capping head 2 Rotating shaft 3 Head case 3a Horizontal edge 4 Chuck opening / closing mechanism 5 Chuck 6 Sliding block 6a Tapered surface 7 Claw lock 8 Connecting part 10 Piston block 10a Tapered surface 11 Sealing member 12 Pressure chamber 13 Air supply passage 14 Guide pin 15 Biasing member 16 Cap pressing body 17 Lower rotating disk 18 Bearing 19 Upper rotating disk 20 Bolt C Cap B Container

Claims

Claim 1 A cap tightening mechanism for winding a gripped cap around the mouth of a container, comprising: a chuck disposed within a head case fixed to a rotatable and vertically movable rotating shaft, the chuck being movable to grip or release a cap by driving a chuck opening and closing mechanism; a pair of a lower rotating disk that contacts the upper portion of the gripped cap and an upper rotating disk disposed via a bearing, the pair being connected to the lower end of a rotating shaft extending into the head case and always rotating together by rotational driving of the rotating shaft, the pair serving as a cap pressing body; a capping head having the above; The chuck opening and closing mechanism is configured such that during driving for winding a gripped cap around the mouth of a container, when the capping head descends to a height immediately before the thread of the cap held by the descending capping head comes into contact with the thread of the container, the chuck is once opened to release the gripped cap, and then, when the capping head descends to a height at which the thread of the cap pressed downward by the cap pressing body of the descending capping head has passed over the thread of the container, the chuck is closed again to grip the cap, and the opening and closing of the chuck is adjusted. A cap tightening mechanism characterized by this.

Images