JPH0152301B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for adjusting the tension of a belt-like member in the process of being transported, and in particular, to maintain an appropriate tension in the belt-like member such as a plastic film during transport in the direction of transport. The present invention relates to a tension adjustment device for a band-shaped member, which is large in size and reduces tension on the side opposite to the transport direction so as not to hinder processing of the band-shaped member.

In recent years, plastic bags have been widely used as packaging materials because they are hygienic and can be mass-produced at low cost. In addition, the strip-shaped member, which is a continuous member of such a plastic bag, can be folded in half and stored in a cardboard box, etc., so that it can be taken out one by one and used as needed, like pop-up tissue paper. (Japanese Unexamined Patent Publication No. 168412, filed as Japanese Patent Application No. 55-168412)
No. 57-96948, Special Publication No. 59-40702). When manufacturing such pop-up plastic bags, the tube-shaped plastic film that is folded flat is supplied from the original film, perforated or heat-sealed at predetermined lengths, and then sequentially folded. However, when folding the belt-shaped member, unnecessary slack tends to occur in the belt-like member, which hinders proper folding work. This is different from when the strip is wound up using a roller-like winder, etc. When the strip is folded, the movement of the strip is complex and the movement involves frequent changes in direction. Therefore, if the belt-shaped member is always supplied to the folding mechanism at a constant speed, the belt-shaped member will not have adequate tension, resulting in oversupply.

Normally, in order to prevent the belt-shaped member from sagging during the transportation process, a so-called tancer mechanism is used, which is configured to wrap the belt-shaped member between a group of fixed pulleys and a group of movable balance pulleys. However, in this dancer mechanism, not only the belt-shaped member on the side of the transfer direction from the dancer mechanism,
Tension is also applied to the strip member on the side opposite to the transport direction. Therefore, when perforating or heat-sealing a plastic film as a band-like member on the side opposite to the transfer direction from the dancer mechanism, tension toward the dancer mechanism acts on the plastic film being processed, and the processing It has not been possible to use a dancer mechanism because it would prevent the seal from being placed in the correct position, or because the melted area would be pulled with such great force that the sealing process would fail.

For this reason, the present applicant has already proposed a device that adjusts the tension of the strip member so as to apply tension only to the strip member on the side of the strip member in the transfer direction. (Utility Model Application No. 57-203044, filed as Utility Model Application No. 56-89192, Utility Model Application No. 62-11881). This previously proposed device includes a reversing roller that rotates in a direction opposite to the direction in which the belt-like member is transported, and a pressing roller that clamps the belt-like member between the reversing roller and the reversing roller while contacting the reversing roller with a predetermined pressing force. However, since the belt-like member is brought into local contact at the location where it is held between the two rollers, there is a risk of damaging the belt-like member. Furthermore, the tension of the belt-like member on the side opposite to the transport direction of the reversing roller is not necessarily stable, and the state of transport tends to become unstable, which sometimes causes meandering of the belt-like member during transport.

An object of the present invention is to maintain a high tension in the belt-like member on the side of the transport direction and a small tension on the belt-like member on the side opposite to the transport direction, without damaging or meandering the belt-like member during transport. It is an object of the present invention to provide a tension adjustment device that can stably adjust the tension of a belt-like member.

The present invention provides a reversing roller around which a belt-shaped member is wound and which rotates in a direction opposite to the direction in which the belt-shaped member is transported, and operates this reversing roller while the belt-shaped member is being transported to apply tension only to the belt-shaped member on the transporting direction side. The above objective is achieved by increasing the directional stability of the belt-shaped member during transport while increasing the number of belt-shaped members and by providing a dancer roller on the side opposite to the transport direction of the reversing roller to prevent the belt-shaped member on the side opposite to the transport direction from loosening. It is something.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment in which the belt-like member tension adjusting device according to the present invention is applied to a belt-like member folding device. After being wound up at a predetermined speed by the winding roller 3, the processing mechanism 5
is supplied to Further, the lifting roller 3A is movable up and down, and is designed to apply a slight tension to the plastic film 1 by its own weight.

After the plastic film 1 is subjected to predetermined perforations and heat sealing in the processing mechanism 5, it is supplied to the belt-like member tension adjustment device 10 according to the present invention.

This belt-shaped member tension adjustment device 10, which is also shown enlarged in FIG. A roller 12 is provided. This reversing roller 12 is driven by a drive motor (not shown) and is constantly rotated in a direction opposite to the direction in which the plastic film 1 is transported, and the surface of this reversing roller 11 is formed of an extremely smooth metal surface. This prevents the surface of the wrapped plastic film 1 from being damaged. Further, a free roller 13 is rotatably provided at a predetermined interval near the lower side of the reversing roller 12 between the brackets 11, and the plastic film 1 wound around the reversing roller 12 is also wound around this free roller 13. By being wrapped, the film 1 is brought into surface contact with the reversing roller 12 over a relatively wide range, and the amount of wrapping on the reversing roller 12 is kept approximately constant.

A pillow 14 is provided at a predetermined position on one side edge of each of the two brackets 11, and a swing arm 15 made of a metal rod or the like is swingably supported by the pillows 14. A dancer roller 16 having a flange 16A is rotatably provided between one end of the swing arm 15 attached to each bracket 11, and a balance weight 17 is attached to the other end of the swing arm 15. It is attached via a screw 17A so that the attachment position can be adjusted. Further, this dancer roller 16 is slightly lighter than the elevating roller 3A.

A swing range regulating device 21 is provided on the side edge of one of the two brackets 11 opposite to the side edge where the pillow 14 is provided, that is, the side edge where the dancer roller 16 is placed. It is provided. This swing range restrictor 21 includes a threaded rod 22 of a predetermined length provided along the side edge, and an upper stopper 23 that is screwed into the threaded rod 22 and can come into contact with the swing arm 15. and a lower stopper 24, the stopper 2
The upper and lower limits of the swinging of the swinging arm 15 are regulated by adjusting the screwing positions of the swinging arms 3 and 24 with respect to the threaded rods 22.

A folding device 30 is provided below the tension adjusting device 10 for continuously folding the plastic film 1 to a predetermined folding width. This folding device 30
a clamping roller 31 consisting of two free rollers clamping the plastic film 1 supplied from the tension adjustment device 10 and reciprocating between the folded ends;
Opening/closing wings 32 are disposed at both folding end positions and are opened and closed as appropriate to sequentially fold the plastic film 1 supplied from the holding roller 31, and the plastic film 1 that is being folded sequentially is stacked. It has a pedestal 33 that gradually descends as the amount of folding increases.

Next, the operation of this embodiment will be explained.

One end of the plastic film 1 is pulled out from the original film 2 and wound around a take-up roller 3, an elevating roller 3A, and a guide roll 4. After passing through the processing mechanism 5, it is transferred to a dancer roller 16, a reversing roller 12, and a reversing roller 12 of a tension adjustment mechanism 10.
The paper is sequentially wound around the free roller 13 and then passed between the clamping rollers 31 of the folding device 30.

A processing mechanism 5 is located at the center of the plastic film 1 being folded onto the pedestal 33.
In order for all the perforations made in The plastic film 1 is rocked so that the length of the plastic film 1 from the perforation at the top position of the plastic film 1 back to the processing mechanism 5 is an integral multiple of the predetermined interval between the perforations of the plastic film 1. The position of the upper stopper 23 of the movement range restrictor 21 is adjusted and the processing mechanism 5 is activated. For example, when perforating the plastic film 1 every 340 mm, when the clamping roller 31 is at one dead center position, the plastic film 1 at the uppermost position folded on the pedestal 33 is cut. When the length from the perforation to the processing mechanism 5 is an integral multiple of 340 mm, for example 1020 mm, which is equivalent to 3 times, the processing mechanism 5
The swing range regulating device 21 is adjusted and the timing of operation of the processing mechanism 5 is adjusted so that perforations are formed in the plastic film 1 by the operation.

When the folding operation is started while feeding the plastic film 1 from the original film 2, the clamping rollers 31 begin to fluctuate from one dead center to the other dead center, and the plastic film 1 enters a state where it is most likely to loosen. However, plastic film 1
Since the middle part of the roller is wound around the reversing roller 12, there is no slack between the free roller 13 and the clamping roller 31.

Furthermore, at the moment when the perforation is formed on the plastic film 1 by the processing mechanism 5, the clamping roller 31 is located at one dead center of its reciprocating motion, so the processed portion of the plastic film 1 is stopped. Moreover, since the reversing roller 12 does not act to pull the workpiece in the transport direction during processing, no extra force is applied to the film 1 during perforation or heat sealing, and the dancer roller 16 and A slight tension is applied to the film 1 located between the lifting roller 3A, which is slightly heavier than the dancer roller 16, and the processing in the processing mechanism 5 is carried out very appropriately.

When the plastic film 1 between the reversing roller 12 and the clamping roller 31 is in a state where it is easy to loosen, that is, while the clamping roller 31 is moving from one dead center to the other dead center, the processing mechanism 5 and the reversing roller 12.
However, since the dancer roller 16 provided between the processing mechanism 5 and the reversing roller 12 is lowered, the film 1 is effectively prevented from loosening during this time. In addition, dancer roller 1
6, the plastic film 1 is always wound around the circumferential surface of the reversing roller 12 over a predetermined range in a surface-contact state.

Further, the directional stability of the plastic film 1 between the processing mechanism 5 and the reversing roller 12 is enhanced by the dancer roller 16, and in particular, since the dancer roller 16 is provided with the flange 16A, the directional stability of the film 1 is further enhanced. This prevents the film 1 from meandering or the like.

This embodiment has the following effects.

Appropriate tension is always applied to the plastic film 1 on the folding device 30 side from the tension adjustment device 10, and a weak tension is applied to the plastic film 1 on the processing mechanism 5 side from the tension adjustment device 10 to ensure proper processing. Since no extra tension is applied other than the tension, there is an effect that both the folding operation in the folding device 30 and the processing operation in the processing mechanism 5 are performed properly. That is, the film 1 being processed in the processing mechanism 5 will not be pulled and the processing will not fail, and the folding device 30 will not cause wrinkles in the film 1.

In addition, the dancer roller 16 causes the reverse rotation roller 12 to
Since the film 1 is always wrapped in surface contact over a predetermined range or more, the reversing roller 12 and the film 1 are never brought into local contact.
Therefore, there is an effect that the film 1 is less likely to be scratched. Furthermore, since the directional stability of the film 1 is significantly improved by the dancer roller 16 and meandering phenomenon does not occur during transport, the effect is that not only the processing mechanism 5 but also the folding device 30 can be properly configured. There is.

Moreover, the structure as a whole is simple and compact, and it can be easily installed and utilized.

Note that the reversing roller 12 is not limited to being made of metal with a smooth surface, and may be coated with heat-shrinkable resin, for example. Alternatively, in the case where the tension of the belt-like member on the transport direction side is increased, a material with a large frictional force such as a rubber roller may be used, or a plurality of reversing rollers may be provided.

Further, although it is assumed that the dancer roller 16 is provided with the flange 16A, the flange 16A is not necessarily necessary, but the meandering of the film 1 can be more effectively prevented if the flange 16A is provided. There is an effect.

As described above, according to the present invention, the tension is large for the strip member on the side of the transport direction, while the tension is high for the strip member on the opposite side of the transport direction, without damaging or meandering the strip member being transferred. This has the effect that the tension of the band member can be stably adjusted so that the tension becomes small.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the overall configuration when an embodiment of the belt-shaped member tension adjustment device according to the present invention is applied to a belt-shaped member folding device, and FIG. 2 is an enlarged view showing the main parts of the embodiment. It is a front view. 1...Plastic film as a strip member,
5... Processing mechanism, 10... Tension adjustment device, 12... Reverse roller, 16... Dancer roller, 30... Folding device for band-shaped member, 31... Holding roller.

Claims (1)

[Claims] 1. A belt-like member tension adjustment device disposed between a belt-like member processing mechanism and a folding device that folds a belt-like member subjected to a predetermined processing by the processing mechanism, the belt-like member being wound around; A reversing roller that rotates in the opposite direction to the direction in which the belt-shaped member is transported is arranged closer to the processing mechanism than the reversing roller, and the belt-shaped member is wound around it, and the belt-shaped member is rotated by its own weight, which is acted on by the weight of the balance weight. 1. A tension adjustment device for a band-shaped member, comprising a dancer roller that is vertically movable to prevent loosening.