JPS6356087B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a band guide arch provided in the main body of a packaging machine.

[Technical background]

An automatic packing machine equipped with a so-called band guide arch feeds packing bands into the band guide arch by a band supply mechanism within the packing machine main body, and arranges the bands in a loop so as to surround the machine to be packed. After the leading end of the band is gripped and fixed by the band tip gripping mechanism in the main body, the band feeding end side is pulled back by the band tightening mechanism in the main body, and the band is released from the flap in the band guide arch, and the band is removed. After tightening the object to be packed, the band supply end side is gripped and fixed by the band supply end side gripping mechanism, and the overlapping parts of the band tip side and the supply end side are welded by the band welding mechanism in the main body, and the band supply end side is The structure is such that packaging is performed by cutting near the welded part.

[Prior art and problems]

In the case of a known general-purpose automatic packaging machine, the band guide arch is provided perpendicularly to the upper surface of the main body in a downward U-shape, and the inside extends to the bandway forming the band passage path and the entire length of the bandway in the longitudinal direction. A plurality of flaps that can be opened and closed cover the upper surface of the main body of the bandway through a gap that allows the band to pass through, and are biased through the material itself or springs so that they are closed in normal times and open when the band is pulled back. and an arch frame that is integrated with the bandway or attaches and fixes the bandway, and these parts are installed inside, and when pulling back the band placed on the bandway from its supply end side, the flap is pushed open and the flap is opened. It consists of an arch cover arranged with an opening that forms a gap in the width direction that allows the band to pass through. Then, when the band is pulled back, the band being pulled back opens a large number of flaps that are normally biased to be closed, the band is pulled out from the flaps, and the band is wound around the item to be packed. In order to increase the efficiency of packing operations, it is necessary to carry out the packing as quickly as possible at high speed;
In addition, since there is a distance between the bandway and the loop-shaped band inserted into the flaps and the circumferential surface of the object to be packed, the band that escapes from the numerous flaps that are opened meander, so to speak, toward the object to be packed. For example, if the band is tightened due to friction with the top corner of an object whose top surface is rectangular, and the object is wrapped diagonally with the band, then the object is wrapped.
Since the packing distance is not the shortest distance from the packaged item, the extra band becomes loose during transportation, and in the worst case, the band comes off from the packaged item, resulting in a fatal defect. Particularly in the case of narrow bands of 5 to 6 mm, which have come into widespread use in recent years for economical reasons, the above-mentioned meandering during escape is large, and styrofoam boxes, which are often used as packaging materials, have large friction. Such packaging defects are likely to occur. Therefore, as a means to solve this drawback, Japanese Patent Publication No. 52-7400 discloses a series of arch guides made of flexible resin and having a U-shaped cross section, as shown in FIGS. 6 and 7. 1 is curvature-deformed into a loop shape so that its both ends are exposed under the band welding mechanism, and the U-shaped opening surface is pressed against the inner wall surface of the arch cover 2 by a plurality of springs 3 to form a band passage path 4. At the same time, the entrance horizontal portion of the arch guide 1 is forcibly expanded when the band is pulled back. However, with this method, the opening surface of the flexible resin arch guide is cut at the edge of the band made of general-purpose polypropylene, polyester, etc. when the band is released, so it is not durable, and the following drawbacks and problems have been found. It was issued. First, according to the above means, as shown in FIG. 8, when the band is pulled back by the arch guide in the straight section, the band is pulled out in the lateral direction with respect to the arch guide 1. The end edge of the band B becomes ridged or wavy inside the arch guide 1, causing a situation where the edge of the band B becomes locked to the inner wall of the arch guide 1 and the band cannot escape from the arch guide 1 and cannot be pulled back. Suppose that the arch guide 1 is tightly stuck to the arch center direction, that is, the inner surface, and the band is locked to the inner surface, and when the band is pulled back, the horizontal part of the arch guide 1 on the band entrance side is forcibly expanded. Also, a situation occurred in which the band could not be pulled out smoothly from the arch guide 1. This kind of situation often occurs especially at corners. Then, the mechanism that tightens the band after it is pulled back has already started operating by a cam, a timer, etc., and as a result, the band is tightened without completely escaping from the arch guide 1, and the welding process that follows A problem has arisen in that the arch guide 1 itself is wrapped in a band. Second, this problem is particularly noticeable in thin, stiff, narrow bands and relatively inexpensive foreign-made bands, but plastic bands for packaging machines, such as polypropylene bands, are manufactured through a manufacturing process that involves stretching or a paper core tube. Because meandering occurs during the winding process (left and right on a plane) (for example, a 6 mm wide band is 150 to 270
mm) The band that runs in the arch guide while being bent in a wave shape (waving) becomes even more severe in the wave or mountain shape shown in FIG. In addition, the band may not run inside the arch guide 1, and the band may become locked to the arch guide 1, preventing the band from escaping and making it impossible to pull it back. In addition, the height of the band passing path of the arch guide is formed as low as possible in order to correct the waveform, that is, the wave-like sag component force in the linear direction. However, in order to avoid the above-mentioned situation, the height of the arch guide 1, that is, the band passage path 4
If the band B is formed high, as shown in Figure 9A and B, the band B will stand up when being supplied or the waveform will become large, and especially weak bands will fold overlappingly, so the band is not running and
At the time of pulling back, the band B is twisted and clogged within the arch guide 1, and in this case as well, the band cannot escape, making it impossible to pull back. Furthermore, if the arch guide is made higher than the band width, the band will stand upright when the band is supplied, and will eventually turn over within the arch guide 1. Third, if the width of the arch guide is widened in an attempt to absorb the meandering of the band, it becomes even more difficult for the band to escape even if the horizontal portion of the arch guide on the entrance side is expanded.

【the purpose】

The present invention has been developed to correct the above-mentioned drawbacks of the prior art, and makes it possible to make the band passageway of the arch guide as low and wide as possible, thereby facilitating smooth band supply. In addition to having the
When pulling back the band, the band can be pulled out sequentially from the arch guide reliably and smoothly, and even if the band stands in a chevron shape inside the arch guide when the band is pulled out, the rotatable piece that makes up the arch guide can be used to move the band inside the arch guide. To provide a band guide arch that can effectively prevent a band from being locked in the arch guide and allow the band to travel reliably within the arch guide and smoothly and continuously escape. .

【composition】

The structure of the present invention for achieving the above object will be explained based on FIGS. 1 to 4 corresponding to the embodiment. In the band guide arch 10 in a packing machine having a cross-section, the U-shaped cross section of the arch guide 20 has an opening 2
One piece 22 in the direction of the arch center, whose three sides are narrower than a certain band width, and another piece 21 in the opposite direction to the arch center are formed to face each other in parallel, and the one piece 21 in the direction opposite to the arch center is , is provided so as to be rotatable relative to the piece 22 in the direction of the center of the arch, and is biased to maintain the surface of the opening 23 constant. Therefore, the band B fed into the arch guide 20 is pushed into one piece 2 of the arch guide 20 in the direction opposite to the arch center direction by the force with which the band is fed.
1, and when the band is being supplied, even if the band tends to form a waveform within the arch guide, the waveform is lowered to smoothly supply the band, and by pulling back, the first corner portion of the arch guide 20 It moves in the direction of the opening 23 along one piece 22 in the arch center direction of W, and sequentially pushes out the arch guide 20 from the second to fourth corner portions X→Y→Z and escapes.
Even if the band B to escape is meandering, the piece 21 of the arch guide 20 forming the U-shaped cross section in the direction opposite to the arch center rotates in the direction of widening the opening 23 of the arch guide 20. The band B is not locked within the arch guide 20 and can escape from the arch guide 20 extremely smoothly.

[Examples] Hereinafter, details of the present invention will be explained based on drawings showing examples. In FIG. 1, a band guide arch 10 is mounted on the main body of the packing machine, which has a band reel wrapped with a packing band and houses various mechanisms necessary for packing such as a known band supply, tightening mechanism, and welding mechanism S. An arch cover 11 straddling the arch cover 11 is provided. This arch cover 11 is made up of a pair of front and rear L-shaped cross-section frame bodies and a U-shaped frame body, which are butted against each other, and are fixed vertically onto the packaging machine main body. An arch guide 20 is provided within the arch cover 11. The entire arch guide 20 has a substantially downward C-shape with straight lines other than the corner portions W to Z, and as shown in FIGS. 1 and 5, one end of the arch guide 20 is connected to the band welding mechanism S when supplying the band. The other end faces the band tip gripping mechanism G of the band welding mechanism S and forms the outlet side straight part EX of the band. In the illustrated embodiment, the arch guide 20 includes corner portions W to Z.
Each straight part is molded separately and connected in series, and the length of the straight part can be changed to an appropriate length so that an arbitrary arch size can be obtained. As shown in FIGS. 2A and 2B, the first to fourth corner parts W to Z of the arch guide 20 shown in FIG. It is formed by an inner circumferential piece 22 that forms a piece in the direction of the center of the arch, which is made of a straight and smooth surface, and an outer circumferential piece 21 that forms a piece in the direction opposite to the center of the arch, and the cross section of the inner wall has a substantially horizontal L-shape. The inner surface of the outer circumferential piece 21 is approximately perpendicular to the guide plate 16 formed by the inner wall surface of the arch cover 11, and the inner circumferential piece 22 is substantially perpendicular to the opening 23.
The inner surface thereof is inclined toward the center of the arch and forms an acute angle with respect to the guide plate 16. That is, each corner portion W to Z is, for example, as shown in FIG. 2A.
As shown in the figure, the inner circumferential piece 22 of the arch guide, which is formed into a substantially U-shaped cross section with a constant curvature, is bent gradually from both ends in the longitudinal direction to the center so that it is inclined at an angle of about 25 degrees toward the center of the arch, for example. Alternatively, as shown in FIG. 2B, after forming the arch guide into a substantially U-shaped cross section with a constant curvature, the inner surface of the inner peripheral piece 22 is gradually shaped from both longitudinal ends to the center. It may also be cut so as to be inclined in the same direction toward the center of the arch. Regardless of the forming method, the band passage passages 24 formed in each corner W to Z
are formed so that both ends in the longitudinal direction of the corner portions are continuous with band passing paths of the straight portions described later, and the opening 23 faces are continuous. In addition, each straight portion other than the corner portions W to Z is
As shown in FIGS. A to C, an outer circumferential piece 21 and an inner circumferential piece 22 are formed of metal strips having the same width and the same length and face each other in parallel, and a metal rod having a rectangular cross section and a straight line, for example, The arch frame 36 is formed into a U-shaped cross section, and the opening 23 surface thereof is formed to be continuous with the opening 23 surface of each corner portion, as described above. That is, in the illustrated embodiment, the straight portions of the arch guide 20 include, except for the entrance side straight portion EN, the upper straight portion and the left and right straight portions at appropriate intervals at both ends and the center, and the exit side straight portion. A flap portion 3 is provided at one location on the end of the fourth corner Z side of the portion EX, and is rotatable relative to the inner circumferential piece 22 of the outer circumferential piece 21.
0 is set. This flap part 30 is connected to the opposite side of the guide plate 16 of the arch frame 36 by a pin 31 at a hinge part formed at the rear end of a flap piece 32 made of a straight plate piece and a fixed piece 33 made of an L-shaped plate piece. The outer circumferential piece 21 and the flap piece 32 are rotatably connected at the direction side, and the inner surfaces of each end of the flap piece 32 and the fixed piece 33 are connected to the arch guide 20.
It is fixed to the outer surfaces of the outer circumferential piece 21 and the inner circumferential piece 22 constituting, for example, with a spotting solution. Then, the adjusting bolt 34 is loosely inserted into the hole formed in the flap piece 32 of the flap part 30, and the arch frame 36 and the fixing piece 33 are inserted into the hole formed in the flap piece 32 of the flap part 30.
4, screw it onto the nut 37 and fix it. Also,
A spring 35 is interposed between the head of the adjustment bolt 34 and the flap piece 32. Therefore, the inner peripheral piece 22 of the straight portion of the arch guide 20 fixed to the fixed piece 33 of the flap part 30 is fixed to the arch frame 36 by the adjustment bolt 34 and the nut 37, while the inner circumferential piece 22 of the straight part of the arch guide 20 is fixed to the fixed piece 33 of the flap part 30. The outer circumferential piece 21 of the linear part of the arch guide 20 can be rotated in the direction of widening the opening 23 against the bias of the spring 35, and is returned to its original position by the spring 35, and the arch guide The U-shaped opening surface and the parallel spacing between the outer circumferential piece 21 and the inner circumferential piece 22 are
is maintained constant as a stopper. In addition, the flap piece 32 and the fixing piece 33 that constitute the above-mentioned flap part 30 are connected to the outer peripheral piece 21 of the arch guide 20 and the opening 2.
3 may be integrally punched and press-molded so as to protrude at appropriate locations. In addition, the flap part 30 is constructed by, for example, as shown in FIG. 21
The opening surface of the arch guide 20 may be maintained in a U-shape at normal times by biasing the arch guide 20 in the direction of the inner peripheral piece 22 (in the direction of the center of the arch). In this case, the flap part 3
0 need not be formed into a hinge shape, and the aforementioned adjustment bolt 34 is also not necessary. In addition, as shown in FIG. 4B, a hinge-shaped flap portion 3 formed of steel material
The fixing piece 33 of 0 is screwed to the arch frame 36, and a magnet 39 is embedded in the surface of the arch frame 36 facing the flap piece 32, and the magnetic force of the magnet 39 moves the flap piece 32 toward the center of the arch. It may be energized. Further, as shown in FIG. 4C, the rear ends of the flap piece 32 and the fixed piece 33 are connected by a spring 48, and the spring 48 urges the flap piece 32 toward the center of the arch, thereby forming a U-shaped opening. The surface may be maintained. In this case as well, the above-mentioned adjustment bolt 34 is not necessary, and there is no need to form the flap portion into a hinge shape. The height of the arch frame 36 is made higher than the height of the arch guide 20 (distance between the outer circumferential piece and the inner circumferential piece) to make it easier to form the hinge part and to increase the overall strength of the arch guide 20. The purpose is to increase In this way, the arch guide 20, which consists of each corner part W to Z and each straight part, has a usable band width (for example, 4.5
For example, for a used band width of 5 to 6 mm, the band passing path 24 is formed to be about 1.5 to 6 times wider than the band width, for example, about 25 mm, and the height is lower than the band width, for example, about 3 mm. In addition, when using the present invention with a fixed arch size, it is not necessary to separately mold and connect the corner parts and the straight parts of the arch guide 20 as described above. The inner peripheral piece 22 of the section may be molded in a series, and the outer peripheral piece 23 may be molded separately for each corner part and each straight part and connected in a series. In FIG. 1, an arch guide 20 is suspended within an arch cover 11 by a pair of rods 12, 12, and a guide plate in which a series of openings 23 are formed on the inner wall surface of the arch cover 11 by its own weight during normal times. He is facing 16. That is, the bent portions at the lower ends of both rods 12, 12 are connected to the arch guide 2.
It is rotatably fitted into the holes of brackets 14, 14 fixed to the arch frame 36 in the left and right straight sections of 0, and the bent portion of the other end is connected to the arch cover 11 above the upper corner portions X, Y of the arch guide 20. The brackets 15 and 15 are rotatably fitted into holes protruding from the inner wall of the bracket. Both rods 12, 12
The mounting point to the arch guide 20 is bracket 1.
The arch guide 20 is further away from the guide plate 16 formed on the inner wall surface of the arch cover 11 than the attachment points to the arch guides 5 and 15, and therefore the arch guide 20 is always urged toward the guide plate 16 by its own weight, and the outer peripheral piece 21 and the edge of the inner peripheral piece 22 is the guide plate 1
It is in contact with 6. Incidentally, one end of each of the rods 12, 12 may be attached to both corners of the upper side of the arch guide 20, instead of being attached to the left and right substantially vertical straight parts of the arch guide 20 as described above. It is sufficient that the guide plate 16 receives an appropriate force from its own weight in the direction of the guide plate 16. Further, if necessary, the arch guide 20 may be configured to be constantly urged by a spring or the like in the direction of the guide plate 16 with a constant force that is released when the band is pulled back. In the above-mentioned embodiment, each of the corner portions W to Z has a rectangular cross section, and the other straight portions have a U-shape. However, as shown in FIG. 2C, the straight portion on the band entrance side Each of the above-mentioned corner portions W to Z including EN may also have a U-shaped cross section like the other straight portions, and may be provided with an opening/closing mechanism for the outer circumferential piece 21 consisting of a flap portion as shown in FIGS. 3 and 4. In this case, as a means for forcibly expanding the first corner portion W, a sliding member 47 is provided within the packaging machine main body, as shown in FIG. This sliding member 47 has a lower end supported by a shaft, and an upper end connected to the entrance side straight part EN near the band welding mechanism S in the vicinity of the first corner part W of the arch guide 20 via the bracket 43, and also connects the cam follower 42. In preparation, this cam follower 42,
It is configured to rotate in sliding contact with a cam 41 provided at the shaft end of a camshaft 40 that operates a welding mechanism S including a band tip gripping mechanism G. In addition to the structure in which the sliding member 47 is slid by the cam 41 provided on the camshaft 40 as described above, the sliding member 47 may be structured to be slid by using, for example, a solenoid. Further, another sliding member may be provided in the exit-side linear portion EX on the fourth corner Z side so as to be interlocked with the sliding member 47, so that this portion is also forcibly opened. In addition, when each corner part W-Z is formed in the cross-sectional shape of a rectangle, it is sufficient to replace with the said sliding member 47, and to simply support the arch guide 20 of that part so that it can move horizontally. In FIG. 1, there are two stoppers 1 on the inner wall of the arch cover 11, that is, the guide plate 16.
7 and 17 are attached via brackets.
The stoppers 17, 17 are located between the flap parts 30, 30, 30 of the upper straight part of the arch guide 20, and are located on the opposite side of the surface facing the guide plate 16 of the arch frame 36 forming the upper straight part of the arch guide 20. When the upper straight part of the arch guide 20 moves horizontally when the band is released, the arch frame 36 in that part comes into contact with the stoppers 17, 17. In contact, the width of movement of the arch guide 20 is limited to a distance slightly smaller than the band width. Further, in the figure, reference numerals 45 and 46 are feed rollers that feed the band to the arch guide 20 and pull it back from the arch guide 20 to make it escape. Next, the operation of the above embodiment will be described. Now, the band B is moved between the arch guide 20 and the arch cover 1 by normal rotation of the feed rollers 45 and 46.
The band is fed into a band passing path 24 that is a space between the guide plate 16 and the inner wall surface of the band. The band runs in a wavy manner in each straight section of the arch guide 20, and in the corner section, the outer circumferential piece 21 runs in the opposite direction to the arch center.
It travels along the inner surface of the band, passes through the straight section EN on the U-shaped band entrance side near the first corner W, and reaches the first corner W, where the inner wall cross section is L-shaped. After passing through the second, third, and fourth corner portions X to Z of the shape and the straight portion with a U-shaped cross section between the corner portions,
It goes around the arch guide 20 through the U-shaped straight part EX on the band exit side near the fourth corner Z and reaches the lower surface of the slide table 31, and when the start button is turned on, a camshaft (not shown) rotates. The tip of the band B is gripped and fixed by a gripping mechanism G.
In addition, if the width of the arch guide EX in the straight part near the fourth corner Z near the band welding mechanism S is formed to be slightly narrower than other parts according to the band width,
(For example, the inner width of the arch guide may be made narrower by providing a guide body (not shown) within the arch guide.) The bands on the supply end side and the tip side overlap accurately within this straight portion EX. Simultaneously with gripping the tip of the band B, the feed rollers 45 and 46 are reversed, and the band B is pulled back. As a result, the band B in the band passage path 24 formed by the arch guide 20 and the guide plate 16 is first
It moves in the direction of the opening 23 along the inner surface of the inner circumferential piece 22 at the corner part W, and sequentially pushes out the arch guide 20, which is biased in the direction of the guide plate 16 by its own weight (and spring), and the first corner part W The opening edge of the inner peripheral piece 22 and the guide in the order of the upper straight part, the second corner part X, the upper straight part, the third corner part Y, the straight part below the third corner part Y, and the fourth corner part Z. It escapes from the arch guide 20 while being restricted by the surface of the plate 16. At this time, the band B trying to escape from the arch guide 20 may move toward the opening 23 in a somewhat twisted state. Since the band B is inclined toward the center of the arch toward the opening 23, the band B moves extremely smoothly into the arch guide 2.
0 (Fig. 2), and in each straight section of the arch guide 20, the outer circumferential piece 21 pressed from inside the arch guide by the edge of the band B that rises like a mountain flaps. The opening 23 is inserted through the flap piece 32 of the portion 30 against the spring 35.
The arch guide 20 rotates in the direction of expanding the
The band B will not be locked inside and become unable to escape (Fig. 3 A, B). In addition, since the inner circumferential piece 22 of the arch guide 20 is fixed, the escape position of the band B is restricted in such a way that both ends of the band B in the width direction are held between the tip edge of the inner circumferential piece 22 and the guide plate 16. Therefore, the band B becomes mountain-shaped inside the arch guide 20, and the edge of the band stands between the inner circumferential piece 22 and the outer circumferential piece 21, and even if the outer circumferential piece 21 opens when the arch guide 20 is locked, the band B becomes discontinuous. The situation where the band B escapes from the arch guide 20 and wraps around the packaged item in a meandering manner is reliably prevented, and the band B escapes from the first corner W to the fourth corner Z of the arch guide 20 in sequence. . Further, the horizontal movement distance of the arch guide 20 is regulated to be slightly smaller than the band width by the aforementioned stoppers 17, 17, and the rods 12, 12 bias the arch guide 20 toward the guide plate 16 by their own weight, so that the band The escape posture of the vehicle can be more reliably regulated. In addition, if the entire arch guide 20 is formed in a U-shape and the outer circumferential piece 21 is configured to be open, and a forced expansion mechanism is provided in the band entrance side linear portion EN of the arch guide 20, the band When the sliding member 47 (and other sliding members interlocking with this) slides via the cam follower 42 by the cam 41 provided on the rotating camshaft 40 at the same time as the tip is gripped, the straight line on the entrance side of the arch guide 20 Part EN
(and the straight section EX on the exit side) moves toward the front of the paper in FIG. 1, and at the same time, the feed rollers 45 and 46 reverse, and the band is pulled back. Then, in the area where Band B's escape has ended,
The arch guide 20 sequentially returns under its own weight (and spring) in the direction in which the edges of the outer circumferential piece 21 and the inner circumferential piece 22 abut against the guide plate 16. The pulling back of band B is completed by reversing the feed rollers 45 and 46 (the rotation time is usually adjusted by a timer according to the arch size).
Subsequently, the band wound around the object to be packed is tightened by the rotation of the camshaft 40 or feed rollers 45 and 46 that tighten the band, and at the same time, the sliding member 47 tightens the straight portion of the arch guide 20 on the entrance side.
Return EN (and exit side straight section EX) to the old position. Next, through a series of processes of gripping the band supply end, cutting, and welding, the band is fed into the arch guide 20 for next packing, and one packing process is completed.

【effect】

As described above, the present invention provides a band guide arch for a packaging machine that has a U-shaped cross section in which both ends of the arch guide face the band welding mechanism, and the U-shaped cross section of the arch guide has its opening. It is formed by parallelly facing one piece in the direction of the arch center, which forms a surface narrower than a certain band width, and the other piece in the opposite direction to the arch center direction, and the one piece in the direction opposite to the arch center direction is in the direction of the arch center direction. Since it is rotatable in one piece and is biased to maintain the opening surface constant, the band passing path of the arch guide can be formed low and wide, so even a weak band can fit inside the arch guide. In addition, even if the band that tries to escape from the arch guide stands in a mountain shape within the arch guide when pulling back, one piece in the direction opposite to the arch center direction widens the opening surface. Since the arch guide is opened by rotating the arch guide, it is possible to effectively prevent the band from being locked in the arch guide and to pull out the band reliably and smoothly. Also, as mentioned above,
Even if the piece in the direction opposite to the arch center opens the arch guide, the fixed piece in the direction of the center of the arch reliably restricts the band from escaping from the arch guide, allowing the band to smoothly move from the arch guide. It can be made to escape continuously and wrap around the packaged item without causing any damage.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention, in which FIG. 1 is an overall schematic diagram, and FIGS. 2 A to C are enlarged views showing connecting parts of corner parts and straight parts, respectively.
3A and 3B are cross-sectional views taken along the line A-A in FIG. 1 showing the released state of the band, FIG. FIG. 5 is a sectional view showing another embodiment of the present invention, and FIG. 5 is a side view showing an example of a forced opening means for the arch guide. In addition, FIGS. 6 to 9 show the prior art, where FIG. 6 is a perspective view, FIG. 7 is a cross-sectional view, and FIGS. 8 and 9 A and B are schematic portions showing problems in the conventional technology. FIG. 10...Band guide arch, 20...Arch guide, 21...Outer circumference piece, 22...Inner circumference piece, 23...
...Opening, 30...Flap part, 32...Flap piece.

Claims (1)

[Scope of Claims] 1. In a band guide arch for a packaging machine having a U-shaped cross section with both ends of the arch guide facing the band welding mechanism, the U-shaped cross section of the arch guide has its opening surface facing the band welding mechanism. One piece in the direction of the arch center that is narrower than a certain band width and another piece in the opposite direction to the arch center are opposed in parallel, and the one piece in the direction opposite to the arch center is one piece in the direction of the arch center. 1. A band guide arch for a packaging machine, characterized in that the band guide arch is rotatable relative to the band guide arch and is biased to maintain the opening surface constant.