JP4739964B2 - Web point seal device - Google Patents

Description

  The present invention relates to a web point seal device that periodically forms a point seal on the overlapping portion of the web during the web conveyance process, and more particularly to a web used for packaging food such as nigiri or rolled sushi. The present invention relates to a point seal device suitable for the above.

  In recent years, foods such as nigiri and sushi rolls have been sold in a packaged state, but this type of packaged food has a double-layered outer film and medium film to separate the laver from the cooked rice. In order to realize the structure, point sealing is performed on the heat-sealable web for forming the outer film and the middle film. Yes.

Such a point seal is implemented by a point seal device disposed in the web conveyance path. The point seal device includes a rotatable heating roller as a heat sealer and a rubber receiving roller disposed rotatably. These rollers are arranged with the conveyance path interposed therebetween.
More specifically, the heating roller has a built-in temperature sensor such as an electric heater or a thermocouple, and has a protrusion for point sealing on its outer peripheral surface (see paragraphs 0040 and 0041 of FIG. 1). 7).

When the web passes between the rotating heating roller and the receiving roller, the overlapping portion of the web to form the point seal is periodically sandwiched between the protrusion of the heating roller and the receiving roller. A point seal is formed at the overlapping portion. Therefore, the point seal formation interval is determined by the period in which the protrusion of the heating roller contacts the receiving roller via the web.
Japanese Patent Laid-Open No. 11-208709

  In the case of the point seal device described above, since the heating roller incorporating the heater and temperature sensor is rotated, a slip ring or the like that electrically connects the heater or temperature sensor to the outside of the heating roller while allowing the heating roller to rotate. The presence of such a slip ring complicates the mechanical and electrical structure of the point seal device.

  The present invention has been made based on the above-mentioned circumstances, and the object thereof is not only easy mechanical and electrical connection to a heater or the like of a heat sealer but also a point seal can be formed reliably and stably. It is to provide a point seal device for a web.

In order to achieve the above object, a web point seal device according to the present invention is a rotatable receiving roller that is disposed on one surface side of a web on a conveyance path and guides the conveyance of the web, and conveys the web. A receiving roller having an eccentric outer circumferential surface that is periodically reciprocally displaced in a direction intersecting the path, and a heat sealer disposed on the other surface side of the web on the transport path when the heat sealer is in a sealing position A heat sealer having a sealer projection capable of periodically sandwiching a web overlap portion with the outer peripheral surface of the receiving roller as the receiving roller rotates, and a separation position away from the sealing position downstream in the conveying direction. and at between the seal position, it is reciprocally supported along the same moving path connecting the disengagement position the sealer projection heat sealer and sealing position support And the step, is forcibly moved toward the disengaged position from the sealing position the sealer projections heat sealer just after pinched site-overlay webs between the receiving and the sealer projection roller, thereafter, the seal from the detached position And a detaching means for returning to the position .

According to the point seal device described above, during the rotation of the receiving roller, the eccentric outer peripheral surface periodically sandwiches the overlapped portion of the web with the sealer protrusion of the heat sealer, and at this time, the overlapped portion of the web A point seal is formed.
Further, immediately after the point seal is formed, the heat sealer is forcibly moved from the seal position to the release position by the support means and the release means, so that the sealer protrusion of the heat sealer is downstream of the receiving roller in the web conveyance direction. By moving away from the receiving roller , the point seal is quickly released from the sealer protrusion and the receiving roller.

Specifically, the sealer protrusion has an arc surface convex toward the outer peripheral surface of the receiving roller in order to sandwich the overlapped portion of the web with the receiving roller, and the receiving roller is made of an elastic material. (Claim 2). The arcuate surface of the sealer protrusion makes point contact with the receiving roller across the overlapped portion of the web, ensuring a point seal with a small seal area.
Furthermore, the above-mentioned supporting means includes a rotatable rotation shaft to which the heat sealer is attached, a biasing spring that biases the heat sealer toward the seal position, and a heat sealer that receives the biasing force of the biasing spring. And a detaching means attached to the roller shaft of the receiving roller near the driven lever and the driven lever attached to the rotating shaft. A release lever that rotates integrally with the roller, and a contact member that is provided on the release lever and periodically contacts the driven lever as the release lever rotates and rotates the rotating shaft via the driven lever. (Claim 4).

  According to the supporting means of claim 3, when an excessive seal pressure (clamping pressure) is applied to the overlapping portion of the web when the point seal is formed, the heat sealer resists the urging force of the urging spring, and its sealing position Escape to the leaving position. According to the detaching means of the fourth aspect, since the detaching lever rotates integrally with the receiving roller, the heat sealer moves from the sealing position toward the detaching position at an accurate timing.

  Since the web point seal device according to the first aspect does not use the rotation of the heat sealer for forming the point seal, a slip ring or the like is not required for electrical connection to the heater or the temperature sensor built in the heat sealer. Therefore, not only the mechanical and electrical connection to the heat sealer is facilitated, but also the point seal device can be provided at low cost.

Also, immediately after the point seal is formed, the sealer protrusion of the heat sealer escapes from the receiving roller, so that the pinching between the sealer protrusion and the receiving roller is eliminated in a short time, and a point seal with a small seal area is reliably formed. be able to. As a result, wear of the sealer protrusion and the receiving roller is reduced, and the durability of the point seal device is greatly improved.
In the point seal device according to claim 2, since the sealer projection has an arc surface, the seal area of the point seal can be further reduced, and the receiving roller made of an elastic material can overlap the web when the point seal is formed. The mechanical load applied to the mating portion can be reduced.

In the point seal device according to the third aspect, the heat sealer resists the biasing force of the biasing spring and can escape from the seal position toward the disengagement position. It is possible to reliably prevent the sealing pressure from being applied.
In the point seal device according to the fourth aspect, since the release lever of the release means rotates integrally with the receiving roller, the release timing of the heat sealer becomes accurate, and no separate drive source for the release lever is required.

FIG. 1 shows a sheet forming system for forming a double wrapping sheet for a hand grip.
This system includes a roll R _0, and an outer web W ₀ that can be heat-sealed from the roll R ₀ is fed out along a predetermined upper conveyance path. The outer web W ₀ forms an outer film of a double packaging sheet.
The upper feeding path is arranged the cutting device 2 in the middle thereof, the cutting device 2 when the outer web W ₀ through to divide the both side edge portions in the width direction central portion of the outer web W ₀ at a predetermined width . That is, the outer web W ₀ is divided into three web portions by two parallel slits.

On the other hand, a pair of rolls _RT are disposed in the vicinity of the upper transport path, and the adhesive tape T is disposed at a predetermined position on the upper transport path, specifically, a downstream position of the cutting device 2 from these rolls _RT. Each sticking roller 4 is fed out.
When the outer web W ₀ and the pair of adhesive tapes T pass through the application roller 4, the pair of adhesive tapes T are attached to the outer web W ₀ in a divided state so as to cover the corresponding slits. adjacent web portion of the outer web W ₀ is another coupled by the adhesive tape T, the outer web W ₀ is integrated again.

Further, sticking on the downstream side of the roller 4 the roller-type cut forming device 6 is located, the cut forming device 6 to the outer web W _0, an interval corresponding to the length of the double package sheet in the conveying direction To form a cut. This cuts an arc shape, positioned in the center of the outer web W _0.
The flow of processing for the outer web W ₀ described above will be more apparent with reference to FIG. 2, and (b) and (c) in FIG. 2 indicate the division position of the outer web W ₀ and the application position of the adhesive tape T, respectively. .

A pair of pinch rollers 8 is disposed at the end of the upper conveyance path of the outer web W ₀ , and a sheet-like conveyance surface for laver N is disposed on the left side of the pinch roller 8 as viewed in FIG. A pusher type conveyor 10 is disposed immediately below the conveying surface, and this conveyor 10 supplies laver N toward the pair of pinch rollers 8.
Further, a lower conveyance path for the intermediate web extends from the pair of pinch rollers 8, and the lower conveyance path is branched into two from the middle and connected to rolls R ₁ and R ₂ , respectively. From these rolls R ₁ , R ₂ , heat-sealable intermediate webs W ₁ , W ₂ are respectively fed toward a pair of pinch rollers 8, and the intermediate webs W ₁ , W ₂ are the middle films of the double packaging sheet described above. Form.

Downstream of the roll R _1, which is the point seal device 14 is sequentially arranged in the folded device 12 and the present invention, when the folding apparatus 12 to pass through the middle web W _1, the transport direction of the one side edge of the middle web W ₁ folded along, to form a folded portion in the middle web W ₁ (superposed section). Thereafter, when the folded portion of the medium web W ₁ passes through the point seal device 14, the point seal device 14 with respect to the folded portion, that a predetermined interval in the conveying direction periodically to form a point seal. Details of the point seal device 14 will be described later.

In the case of this embodiment, the middle web W ₁ is folded back to the heat seal layer is formed only on the back surface, if the heat seal layer is formed on both sides thereof, the above-described wrapping unnecessary is there.
A merging roller 16 is disposed downstream of the point seal device 14, and the intermediate webs W ₁ and W ₂ merge at the merging roller 16. At this point, the web W _1, W ₂ among these and one edge of the folded portion and the middle web W ₂ of the middle web W ₁ are superposed each other, their backside each other are bonded.

Thereafter, the intermediate webs W ₁ and W ₂ sequentially pass through the temporary sealing device 18, the main sealing device 20, and the punching device 22. Tack sealing device 18, tack and at a predetermined interval and one side edge of the folded portion and the middle web W ₂ of the web W ₁ in the conveying direction in superimposed each other and, the external sealing device 20 is continuously attached in the conveying direction to the folded portion and one side edge.

Here, temporary attachment and permanent attachment are performed by heat sealing, but the sealing strength of these heat seals is so weak that the intermediate webs W ₁ and W ₂ can be easily separated. It medium web W ₁ is when passing through a tack seal device 18, since the folded portion to a point seal of the middle web W ₁ has already been formed, the temporary attachment and the attachment described above are performed correctly become.
The flow of processing for the above-described middle webs W ₁ and W ₂ will become more apparent with reference to FIG. 3, where FIG. 3 (a) shows the folding of the middle web W ₁ , and FIG. FIG. 3C shows the overlapping of the intermediate webs W ₁ and W ₂ , and FIG. 3D shows the tacking and the main seal.

The punching device 22 forms a cut-out opening in the combined web W ₃ in which the middle webs W ₁ and W ₂ are integrated. The cutout opening is positioned in the center in the width direction of the combined web W _3, it is disposed at a predetermined interval in the conveying direction, in which corresponding with break of the outer web W ₀ as described above.
Thereafter, combined web W ₃ being fed to the pair of pinch rollers 8 described above, combined with the outer web W ₀ and Nori N at the pinch roller 8, to form a set web with these outer webs W ₀ and Nori N . This state is shown in FIG. 4, seaweed N As apparent from FIG. 4 is sandwiched between the outer web W ₀ and coalescence web.

From the pinch roller 8, a conveyance path 24 for the collective web extends in the opposite direction to the pusher type conveyor 10 described above, and this conveyance path 24 is connected to a discharge conveyor 26. In the conveyance path 24, a horizontal sealing device 28, a vertical sealing device 30, a pair of feeding rollers 32 that convey the collective web, and a cutting device 34 are sequentially arranged from the pinch roller 8 side. When the collective web passes the horizontal seal device 28 and the vertical seal device 30, the horizontal seal device 28 periodically forms a horizontal seal before and after the laver N in the conveying direction with respect to the collective web, and the vertical seal The apparatus 30 forms a pair of vertical seals on both sides of the laver N in the conveying direction with respect to the collective web. Therefore, the outer web W ₀ and the combined web W ₃ are bonded to each other by the horizontal seal and the vertical seal in a state where the seaweed N is surrounded by the horizontal seal and the vertical seal.

  Thereafter, when the collective web passes through the cutting device 34, the cutting device 34 cuts the collective web at a predetermined interval as seen in the conveying direction, whereby the double packaging sheet for gripping shown in FIG. This double packaging sheet contains laver N inside. In FIG. 5, reference signs A to E denote the point seal, the tack, the main seal, the horizontal seal, and the vertical seal, respectively.

Next, referring to FIG. 6, the point seal device 14 described above is shown more specifically, and the point seal device 14 will be described in detail below.
The point seal device 14 includes a drive shaft 36, and both ends of the drive shaft 36 are rotatably supported by left and right side frames 40 as viewed in FIG. 1 via bearings 38. One end of the drive shaft 36 protrudes from the corresponding side frame 40, and a drive sprocket 42 is attached to the protruding end. The drive sprocket 42 is connected to a drive source via a power transmission path (not shown), and is rotated in one direction in response to power from the drive source.

Receiving roller 44 to the drive shaft 36 is provided, the receiving rollers 44 form part of the transport path of the web W ₁ in the above-described, to guide the conveyance of the middle web W _1. The receiving roller 44 is made of an elastic material such as rubber and rotates integrally with the drive shaft 36. Further, the receiving roller 44 is mounted in an eccentric state with respect to the drive shaft 36. Therefore, the top of the outer peripheral surface of the receiving roller 44 is periodically displaced up and down as the receiving roller 44 rotates.

On the other hand, a rotating shaft 46 is disposed above the receiving roller 44, the rotating shaft 46 extends in parallel with the drive shaft 36, and both ends of the rotating shaft 46 are also rotatable to the left and right side frames 40 via bearings 48. It is supported. A heat sealer 50 is provided on the rotation shaft 46, and the heat sealer 50 is disposed above the receiving roller 44.
As apparent from FIG. 7A, the heat sealer 50 has a pair of holder rings 52 fixed to the rotating shaft 46, and these holder rings 52 have a predetermined interval in the axial direction of the rotating shaft 46. It is separated. An arm 54 extends downward from the pair of holder rings 52, and a heater block 56 is attached to the lower end of the arm 54. The heater block 56 includes an electric heater 58 and a thermocouple 60 as a temperature sensor, and a power supply line 58a and a signal line 60a for the heater 58 and the thermocouple 60 are led out from the heater block 56 ( (See FIG. 6).

The heater block 56 has a sealer protrusion 62 integrally on its lower surface. The sealer protrusion 62 protrudes toward the outer peripheral surface of the receiving roller 44, and when the top of the outer peripheral surface of the receiving roller 44 is displaced up and down as described above, the middle web W ₁ being conveyed with respect to the top of the outer peripheral surface. , i.e., periodically contact with the folded portion, sandwiched between the outer peripheral surface of the receiving the folded portion of the middle web W ₁ roller 44, thereby forming a point seal described above in the folded portion.

Further, as shown in FIG. 7B, the lower surface of the sealer protrusion 62, that is, the seal surface 64 has a convex arc shape toward the receiving roller 44 that is in rolling contact with the outer peripheral surface of the receiving roller 44. No, this makes it possible to reduce the seal region of the point seal formed folded portion of the middle web W _1. The sealing surface 64 may be hemispherical.
On the other hand, brackets 66 are respectively attached to both ends of the rotating shaft 46, and these brackets 66 project in the radial direction of the rotating shaft 46. Between each bracket 66 and the side frame 40 on the corresponding side, that is, the rod member 68 protruding from the side freight is connected by a tension coil spring 70 as an urging spring. The rotation shaft 46 is urged to rotate. Specifically, the rotation shaft 46 is urged to rotate counterclockwise as viewed in FIG. 7A, and each bracket 66 is in contact with the stopper 72. These stoppers 72 protrude from the corresponding side frame 40.

When the bracket 66 is in contact with the stopper 72, the heat sealer 50, that is, the sealer protrusion 62 of the heater block 56, with respect to the receiving roller 44, the point seal execution position shown in FIG. Held in position.
Further, as shown in FIG. 6, a driven lever 74 is attached to the rotation shaft 46, and the driven lever 74 extends toward the drive shaft 36. On the other hand, a release lever 76 is attached to the drive shaft 36, and the release lever 76 rotates integrally with the drive shaft 36. The release lever 76 extends in the radial direction of the drive shaft 36 and is disposed adjacent to the driven lever 74 when viewed in the axial direction of the drive shaft 36. Therefore, the release lever 76 can rotate without interfering with the driven lever 74.

However, a roller 78 as an abutment is rotatably attached to the tip of the release lever 76, and this roller 78 is a driven lever as shown by the phantom line in FIG. 74 abuts. Therefore, the driven lever 74, that is, the heat sealer 50 is rotated around the rotation shaft 46 against the urging force of the tension coil spring 70 in the clockwise direction as viewed in FIG. Sheila projection 62 of 56 is moved from the sealing position, the withdrawal position apart downstream of the receiving roller 44 as viewed in the transport direction of the middle web W _1.

The removal movement of the sealer protrusion 62 described above is performed immediately after the point seal is executed by the sealer protrusion 62, and the rotational angle position of the release lever 76 with respect to the receiving roller 44 is set to achieve this.
When the rotation of the release lever 76 advances and the engagement between the roller 78 and the driven lever 74 is released, the driven lever 74 is moved back by the urging force of the tension coil spring 70, and the sealer projection 62 of the heater block 56 is moved. Return from the disengaged position to the sealed position.

  As is apparent from the above description, the heat sealer 50 is merely rotated around the rotation shaft 46 when the sealer protrusion 62 reciprocates between the sealing position and the separation position. It is not intended to rotate more than one turn. Therefore, it is not necessary to use a slip ring or the like for electrical connection with the heater 58 and the thermocouple 60 built in the heater block 56.

As a result, not only enable easy electrical connection to the heat sealer 50, the mechanical support structure of the heat sealer 50 is also simplified, the point seal device can be provided inexpensively.
Further, Sheila projection 62 immediately after the implementation of point seals, escapes from the sealing position to the disengaged position, never sealing region of point seals increases undesirably, even for a narrow folded portion of the medium web W ₁ accurate And a point seal | sticker can be formed reliably.

Furthermore, since the heat sealer 50 is elastically supported by the coil spring 70 tension, when point seal, when an excessive seal pressure is applied to the folded portion of the sealer projections 62 and medium web W _1, sealer projections 62 tension coil spring able to escape toward the disengaged position against the biasing force of 70, it is not applied to the folded portion of the excessive seal pressure medium web W _1.
Furthermore, since the seal surface 64 of the sealer protrusion 62 has an arc shape, not only can the seal area of the point seal be further reduced, but also the wear of the seal surface 64 and the outer peripheral surface of the receiving roller 44 can be further reduced, resulting in durability. It is possible to provide a point seal device excellent in performance.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, if the folding of the middle web W ₁ as described above is not necessary, the medium web W _1, W ₂ is one side edge with each other simply superimposed, point seal device 14 a point sealed to the overlapping portion Will be formed.
The detaching means for the heater block 56 can include a cam instead of the above-described detaching lever 76. In this case, the driven lever 74 is provided with a cam follower that cooperates with the cam.

Further, the heat sealer 50 is not limited to being rotated about the pivot shaft 46, it reciprocates possible well along the transport path of the medium web W _1, also leaving means heat sealer 50 has its own drive The heat sealer 50 may be reciprocated with a source.
Furthermore, the point seal device of the present invention is not limited to a web for double packaging sheets for gripping, but can be applied to point seals for various heat-sealable webs.

It is the schematic which showed the sheet forming system of the double packaging sheet for a handshake. It is a figure which shows the processing process of the outer web for a double packaging sheet in order of (a)-(c). It is a figure which shows the formation process of the united web for a double packaging sheet in order of (a)-(d). It is sectional drawing which showed the assembly web for a double packaging sheet. It is the figure which showed the double packaging sheet. It is the figure which showed the point seal device. It is sectional drawing which follows the VII-VII line in FIG. It is sectional drawing which follows the VIII-VIII line in FIG.

Explanation of symbols

36 Drive shaft 44 Receiving roller 46 Rotating shaft (support means)
50 Heat sealer 56 Heater block 62 Sealer projection 70 Tension coil spring (support means)
72 Stopper 74 Follower lever 76 Release lever 78 Roller (contact)

Claims (4)

A web point seal device that transports a heat-sealable web along a transport path and periodically forms point seals in the transport direction for overlapping portions extending in the transport direction of the web in the transport process. In
A rotating receiving roller that is arranged on one surface side of the web on the transport path and guides the transport of the web, and eccentrically displaces the web periodically in a direction crossing the transport path. A receiving roller having an outer peripheral surface,
A heat sealer disposed on the other surface side of the web on the transport path, and when the heat sealer is in a sealing position, the web is in contact with the outer peripheral surface of the receiving roller as the receiving roller rotates. A heat sealer having a sealer protrusion capable of periodically sandwiching the overlapping portion of
The sealer projection of the heat sealer can reciprocate along the same movement path connecting the seal position and the release position between the release position and the seal position that are separated from the seal position downstream in the transport direction. Supporting means for supporting
The sealer protrusion of the heat sealer is forcibly moved toward the disengaged position from the sealing position immediately after the superimposed portion of the web is pinched between the receiving roller and the sealer projection, thereafter, A web point seal device, comprising: release means for returning from the release position to the seal position . The sealer projection has a convex arc surface toward the outer peripheral surface of the receiving roller in order to sandwich the overlapping portion of the web with the receiving roller,
2. The web point seal device according to claim 1, wherein the receiving roller is made of an elastic material. The support means is
A rotatable rotation shaft to which the heat sealer is attached;
A biasing spring that biases the heat sealer toward the sealing position;
3. The point seal device for a web according to claim 2, further comprising a stopper for positioning the heat sealer that receives the biasing force of the biasing spring at the seal position. The detaching means is
A driven lever attached to the pivot shaft;
A release lever attached to a roller shaft of the receiving roller in the vicinity of the driven lever and rotating integrally with the receiving roller;
A contactor provided on the release lever, periodically contacting the driven lever as the release lever rotates, and rotating the rotation shaft via the driven lever; The point seal device for a web according to claim 3.

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