CH623529A5 - Method and apparatus for forming a band loop spanning a package - Google Patents

Description

The invention relates to a method for forming a band loop and for arranging it around a pack, a band length being fed in a circular path to form a primary band loop and part of the band length being overlapped by the free band end, the free band end to prevent another Movement of the same is detected, a relative movement between the primary band loop and the band guide is effected in order to form a free space in the vicinity of the primary band loop, the supply of the standing part of the band length to expand the band loop to a certain diameter is continued, a relative movement between the Pack and the expanded tape loop is caused to be placed around the pack and either before or after the relative movement between this pack and the expanded tape loop is performed, the free end of the tape is connected to an adjacent overlapped area of the tape.

Various methods and machines have been developed in the past for forming a band loop spanning a pack, for tensioning the loop, and for connecting the overlapping portions of the tightened loop by friction fusion or otherwise. Typical methods and devices of this type are described in U.S. Patents 3,442,732, 3,442,733.3 442,734.3 442,735, 3,442,203 and 3,586,572.

Some of these lacing machines, such as those described in U.S. Patent 3,442,203, are fully automatic, i.e. in these machines, a thermoplastic packing tape is automatically wrapped around a pack from a tape supply source

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leads, the front end of the band is gripped, the standing length of the band is taken back to tighten the band loop, the overlapping loop parts are friction-fused and the loop is separated from the standing length of the band. However, an automatic tying machine of this type has a relatively large, ring-like, rigid tape feed shaft, into which the package is inserted and which is used for feeding the tape to form a closed loop spanning the package. When using thermoplastic. Tape material has encountered problems in that the tape could buckle or jam around the package in the feed chute. This is due to the relatively low kink resistance of the thermoplastic tape. In addition, a ring-like feed shaft also means that the machine is very bulky, since on the one hand the work or operating space must be large enough to accommodate the feed shaft, and on the other hand it must be sufficiently large so that there is enough space for the insertion and removal of the pack.

The automatic tying machines, in which a ring-like band feed shaft is provided to form the loop encompassing the pack, are sometimes somewhat inefficient when packs of different sizes are to be tied. If, for example, large packs are to be tied up on a tying machine, such as those with a diameter of around 90 cm, the ring-shaped belt feed shaft must also have a diameter of at least 90 cm. If the machine is then used to tie up smaller packs, which may have a diameter of 30 cm, for example, in this case the strap loop around the smaller pack will initially have a diameter of 90 cm, and the machine must tighten one during the tightening process Pull off a considerable amount of loose tape length to reduce the diameter of the loop and tighten it around the pack with a diameter of 30 cm. It is obvious that this is inefficient.

The lacing machines available today, which process thermoplastic strip material, also have certain defects with regard to the formation of the friction fusion weld. In order to form a frictional fusion welding point in the overlap area of the belt loop, an anvil or an attachment part must be inserted between the packing and the belt loop so that a rigid contact surface is available against which the overlapping strip parts can be pressed by a vibration welding element. The anvil part thus prevents the band loop from lying flat against the surface of the pack at this point, so that the loop therefore contains a loose addition length. Thanks to the elasticity of the band, a tight loop can usually be created with large and somewhat springy packs. In the case of very small packs and / or packs with relatively rigid, incompressible surfaces, the slackness caused by the anvil introduced into the band loop can reach significant dimensions, with the result that the band loop sits loosely between the band and the pack after the anvil has been pulled out .

The object of the invention is to provide a method which enables the formation of a belt loop of any size without the aid of a large feed shaft into which the pack has to be inserted.

This object is achieved in that when the strip length is fed in to form a primary strip loop, only one side of the strip is guided in the path of a strip guide.

The invention also relates to a device for carrying out the method according to the invention, which is characterized by a guide device for receiving a free end of the tape length in order to force the tape to form a primary tape loop with an area overlapped by the free tape end, merely by one side of the tape is guided.

Exemplary embodiments of the invention are explained below with reference to the accompanying drawings. In it show:

Fig. A partial perspective view of a preferred embodiment of the device according to the invention;

FIG. 2 is a partial perspective view similar to FIG. 1, the pack being shown on the device and the cap provided for the band being guided into the high position;

3 shows a perspective partial view similar to FIG. 2, the cap provided for the band being guided into the down position and the band loop being expanded to a predetermined larger diameter;

FIG. 4 is a partial perspective view similar to FIG. 3, here showing the widening of the extended band loop around the pack;

FIG. 5 is a partial perspective view similar to FIG. 4, here showing the tightening of the band loop spanning the pack;

FIG. 6 is a partial perspective view of the device shown in FIG. 1, with parts broken away in the drawing;

FIG. 7 is a top view of the device of FIG. 2, held on a larger scale and shown in detail, the cap provided for the band being brought into the high position and the band length being deformed into a loop inside the cap;

Figure 8 is a sectional view in a section generally along plane 8-8 in Figure 7;

FIG. 9 is a top view similar to FIG. 7, which is held on a larger scale and shown in the detail, but the cap provided for the band is here brought into the lower position and the band loop is expanded to a predetermined larger diameter;

Figure 10 is a sectional view in a section generally taken along plane 10-10 in Figure 9;

FIG. 11 is a sectional view similar to FIG. 10, here showing the widening of the extended loop around the pack;

FIG. 12 is a top view of the device shown in FIG. 6, which is held on a larger scale and is shown in detail, in which the details of the band tightening feeler device are shown;

13 shows a schematic illustration of the compressed air control system for the device according to the invention;

14 shows a simplified control block diagram for the device according to the invention;

FIG. 15 shows an upper view similar to FIG. 2 of the band loop formation area in a second embodiment of the device for tying up a package according to the method according to the invention;

FIG. 16 is a view similar to FIG. 15, the method of expanding the band loop to a larger diameter being shown here;

Figure 17 is a cross-sectional view in a section generally along plane 17-17 in Figure 15;

FIG. 18 is a view similar to FIG. 8 to show the band loop formation area in a third embodiment of the device for tying a package according to the method according to the invention;

19 is a cross-sectional view of the band loop formation area in a fourth embodiment of the pre

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device for tying a package according to the method according to the invention;

Fig. 20 is a cross-sectional view, on a smaller scale, in a section taken generally along the plane 20-20 in Fig. 19;

FIG. 21 shows a top view of the band loop formation area in a fifth embodiment of the device for tying a package according to the method according to the invention;

22 shows a schematically simplified top view of the band loop formation area in a sixth embodiment of the device for tying a package according to the method according to the invention;

Fig. 23 is a view similar to Fig. 22 of the sixth embodiment, illustrating the formation of a primary ribbon loop;

Fig. 24 is a view similar to Fig. 23 of the sixth embodiment, illustrating the formation of an expanded ribbon loop;

Fig. 25 is a view similar to Fig. 24, but on a much smaller scale, of the sixth embodiment, showing an expanded band loop wrapped around a package;

FIG. 26 shows a top view of the band loop formation area in a seventh embodiment of the device for tying up a package according to the method according to the invention; FIG.

Fig. 27 is a cross-sectional view in a section generally along plane 27-27 of Fig. 26 showing the lifting of a primary band loop from a guide;

FIG. 28 is a top view similar to FIG. 26 of the seventh embodiment, in which an expanded band loop is shown;

29 is a cross-sectional view of the band loop formation area in an eighth embodiment of the device for tying a package according to the method according to the invention;

Figure 30 is a cross-sectional view in a section generally along plane 30-30 in Figure 29; and

31 shows a simplified, partially schematic representation to illustrate another form of a primary belt loop according to the method according to the invention.

The invention can be embodied in many different ways and only various preferred embodiments of the invention are shown in the drawings, the details of which will be described below. It is therefore to be assumed that this description is intended to illustrate the principles of the invention by way of example and is not to be interpreted in a sense restricting the invention.

For the sake of clarity of presentation, the various embodiments of the device for tying a package according to the method according to the invention are to be described in the normal working position, and terms such as “above”, “below”, “horizontally” etc. are to be referred to this normal working position. However, it should be noted that the device used to carry out the method according to the invention can of course also be manufactured, stored, transported, set down and operated in a different spatial position than the normal working position described.

The device shown, which can be used to carry out the method according to the invention, has certain conventional drive mechanisms and control mechanisms, which, although not shown and described in detail, are familiar to the person skilled in the art, and so far as to understand how these drive devices work Context of proper operation of the device is necessary, this will be explained.

A preferred embodiment of the device according to the invention for forming an extended band loop and for frictional fusion is generally designated by the reference number 20 in the illustration in FIG. 1. The size of the device is preferably such that it can be placed on a work table or desk, and preferably the device is used to tie rectangular-parallelepiped packs with dimensions from 12.5 cm to just over 100 cm used on each side. However, the device also offers space for much larger or smaller packs and for packs of another shape. 15 As can be seen from FIG. 2, the device 20 according to the invention has a pack support surface 22 for supporting a pack 24. The device 20 is also provided with a lower surface or shoulder 26, which forms a gradation below the packing support surface 22. 20 For a better understanding of the structural details of the device 20, the process of forming and securing a band loop spanning a pack will first be briefly explained.

As can be seen from the illustration in FIG. 2, a package 24 is first placed on the package support surface 22 near the shoulder 26. A cylindrical cap 28 is raised from a position below the surface height of the shoulder 26 to a high position above the surface of the shoulder 26. By means, which will be described in more detail below, a length of the band is introduced into the cone to form a primary band loop. The cap 28 is then brought down to a position below the surface of the shoulder 26 while the loop is held in the higher position in which it is expanded to a predetermined larger diameter, so that in this form it is an extended loop 30 forms, as shown in Fig. 3. Next, the operator pushes the package 24 forward until it protrudes over the shoulder 26 and then wraps the extended loop 30 around the package 24 as shown in FIG. 4. The tape is placed under tension to pull the loop that now spans the package taut. At the end of the entire process, the tightened loop is friction-welded to form a connection and then separated from the tape supply.

Next, the special features of the device which is used to carry out the above-described process of tying a package will now be discussed in detail. The essential structural characteristics or Me-50 mechanisms of this device are the following: 1) the mechanism for forming the belt loop; 2) the mechanism for tape feeding and tightening; 3) the mechanism for frictional fusion of the strap loop; 4) the mechanism for cutting the ribbon; 5) the air operated 55 system; and 6) the electrical control system.

The mechanism for forming the tape loop is to be described first, more precisely the mechanism which serves to form a primary tape loop, which can then be expanded to a larger diameter, which is to be regarded as an inventive feature. The device for forming the primary band loop is most clearly shown in FIGS. 6 to 11.

The tape is fed into a tape guide means by a tape feeder to be described later. A circular strip part or cap 28 represents a circular guiding means for the formation of the primary ribbon loop. The cap 28 is a substantially cylindrical part and can be open or closed at the end.

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In the preferred embodiment shown, the hat 28 has a partially closed base and an open top. Part of the vertical cylinder wall of the hat 28 is recessed, so that a relatively large opening or slot 34 is formed for receiving a band length 36, as shown in FIG. 7. The cap serves to guide the free band end 38 along a closed arc path, whereby the free band end 38 is returned to the band length 36 for the initial formation of the primary band loop, the free band end covering part of the band loop thus formed.

The hat 28 is movable between an upper position or a high position and a low position. The mechanism for raising and lowering the hat 28 can be of any suitable type. As can be seen from the illustration in FIG. 6, the cap 28 is fastened here to a drive part 64 which is connected to an actuating solenoid 66.

The spatial position of the tape length 36 is such that its side surfaces extend perpendicular to the plane of the package support surface 22, and the tape length is guided below the package support surface 22 in a tape transport zone 40 which lies between the package support surface 22 and the plane of the shoulder 26. The height of the belt transport zone 40 corresponds essentially to the width of the belt length 36 and this is essentially a layer in which the belt length 36 is transported, guided, deformed into a primary loop, expanded into a larger loop, tightened, friction-welded and severed becomes. In the high position (as shown in FIG. 2) the cap 28 lies in the belt transport zone 40. In the lower position (shown in FIGS. 1 and 6) the hat 28 lies below the belt transport zone 40. The belt length 36 becomes within the belt transport zone 40 guided through corresponding guideways 42, as shown in Fig. 6. The tape is fed in the guideways 42 in the tape transport zone 40 by suitable traction drive means in the forward direction and tensioned in the reverse direction, which will be discussed later.

During loop formation, the free band end 38 is (1) inserted into the slot 34 of the hat, (2) held within the hat 28 by an upper and lower guide, and (3) when the hat 28 is lowered and the loop is subsequently widened above the cone 28 held. These guides and belt holding means will be explained with reference to FIG. 7. In addition to the slot 34, an anvil 44 is provided, which is carried by a sliding carriage 46. On a part of the anvil 44 located near the band length 36, a cushion 48 made of polyurethane with a smooth surface is fastened, which serves to guide the band length 36 and bears against it, as will be explained in more detail below. In contrast to the cushion 48, a welding head 52 designed as a cylindrical part is provided, which serves two functions in a special way: (1) for gripping the free band end 38 and (2) for welding the free band end to the overlapping part of the loop. The function of welding will be discussed later. For the time being, only the mode of operation of capturing or holding the strip by the welding head should be considered. The welding head 52 is supported by a shaft 53 and is designed as an essentially cylindrical part with a rough engagement surface 54 on the circumference, which can rest against the one side surface of the free band end 38. The welding head 52 as well as the anvil 44 are located in the belt transport zone 40, as can be seen in FIG. 8. The anvil 44 can be displaced within the band transport zone 40 by a compressed air actuating cylinder, which will be described in the following, in a horizontal plane in proximity to the welding head 52 and away from it. When the cap 28 is in the high position, as shown in FIGS. 7 and 8, the anvil 44 can be brought up to the welding head 52 into a position in which it still remains at a distance from the contact surface 54 of the welding head , because part of the anvil 44 touches the cap 28 on a contact surface 56 and remains loaded against it. In this position, there is sufficient space between the contact surface 54 of the welding head and the cushion 48 made of polyurethane, so that the band length 36 and the overlapping free band end 38 can extend between them. If the cap 28 is then brought down to below the surface of the shoulder 26, the anvil 44 moves closer to the welding head 52 as a result of the load on the welding head 52 and the cushion 48 comes to rest against the intermediate band length 36, as a result of which the overlapping free band end 38 is now held against displacement movements.

As can be seen from FIG. 6, the movement of the carriage 46 intended for the anvil is brought about by a compressed air actuating cylinder 120 which acts via a piston rod 122 connected at one end to the cylinder piston (not shown) and at the other end to the carriage 46.

Reference is now made to FIG. 7 for a more detailed description of the formation of the primary band loop. First, the free end 38 of a length of tape 36 is fed into the tape transport zone 40 in the tape guideways 42 and through the slot 34 of the cap 28 in the forward direction. The free end of the band 38 is guided into the interior of the hat 28 by the cushion 48 made of polyurethane and by a part of the anvil 44. The free band end 38 is then continued to form an initially formed primary loop on the inner surface of the cap 28 along a closed arc path until the free band end 38 overlaps a portion of the loop between the anvil 44 and the welding head 52. The supply of the tape length 36 is terminated by suitable control means to be described when the primary tape loop is formed, as essentially shown in FIG. 7.

At the stage of the formation of the primary loop as well as in the subsequent stages of tightening and welding, it is desirable to keep the overlapped part of the band length 36 and the free band end 38 at the level of the band transport zone 40. A corresponding upper and lower guide is provided for this purpose. A flange 60 is provided at the lower end of the welding head 52 in order to prevent the overlapped part of the band length 36 and the free band end 38 from sliding under the welding head 52. Above the belt transport zone 40, a slide cover 62, which can be moved together with the slide 46, is fastened to the slide 46 and prevents the overlapped part of the belt length 36 and the free belt end 38 from sliding upwards over the welding head 52 and the cushion 48 made of polyurethane.

After the primary belt loop has been formed, the cap 28 must be brought down from the high position in the belt transport zone 40 to a second position below the belt transport zone 40. When the cap is lowered, the primary band loop formed is not carried into the lower position in the cap 28, but instead slides out of the cap and remains in the upper position. This can be attributed in combination to the relatively small diameter of the cap 28, the rigidity of the band, the low coefficient of friction between the band and the cap and the fact that the band length 36

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is supported at the bottom in the guideways 42 of the belt transport zone. When the cap 28 is pulled down, the primary band loop formed therefore remains at the level of the band transport zone 40 above the upper surface of the shoulder 26.

After the cap 28 has moved completely downward from the primary band loop, any inclination of the loop to roll up or unroll cannot take effect. Because of the proximity of the welding head 52 and the cushion 48 on both sides of the overlapping band parts of the loop, the loop cannot open and therefore remains in this form.

According to the invention, a combination of mechanisms is used in order to expand the primary band loop initially formed into a larger loop of a predetermined diameter. If the cap 28 is brought into the low position shown in FIGS. 9 and 10, the slide cover 62, the anvil 44 and the cushion 48 made of polyurethane move closer to the welding head 52 with the slide 46 due to the action of loading means still to be described . The anvil 44 is moved forward and presses the cushion 48 against the band loop in an area in which the free band end 38 reaches over the overlapped part of the loop formed by the band length 36. The cushion 48 then comes into abutment against one side of the band length 36, as a result of which this as well as the overlapping free band end 38 are pressed against the welding head 52. By means, which will be described in the following, the cushion 48, which is made of polyurethane, is held against the loop with relatively little force, so that the free end of the band 38 is carried out by the roughened contact surface 54 on the circumference of the welding head is prevented. However, this force is so low (about 0.9 kg) that, on the other hand, the overlapped band length 36 between the free band end 38 and the smooth polyurethane surface of the cushion 48 can nevertheless move forward when the band length 36 is replenished to expand the loop. When expanding the primary strap loop, the surface of the shoulder 26 can preferably act as a support for the underside of the strap loop.

The contact surface 54 of the welding head 52 is preferably roughened (especially for better grip in the subsequent friction fusion process described below), but this is not absolutely necessary. As far as the operation of the welding head 52 in the process of expanding the loop is concerned, the welding head 52 only needs to have a relatively higher coefficient of sliding friction than the cushion 48. There is also the alternative possibility of providing a mechanism with cylindrical rollers instead of the cushion 48, which an axis can be rotated parallel to the shaft 53 of the welding head so as to enable the tape to be fed and tightened. The roll could be locked against rotation if necessary in the subsequent friction fusion process (described below).

After the loop has been expanded to the predetermined larger diameter and has been wrapped around the pack 24 in the manner shown in FIGS. 4 and 11, the expanded loop is placed under tension and tightened around the pack 24. The details of the device for applying tension to the belt will be discussed below. First of all, the mode of action of the cushion 48 made of polyurethane and the welding head 52 during the tightening process must be explained. At the beginning of the tightening phase, the extended loop 30 is wrapped around the pack 24 in the manner shown in FIG. 11. To this

At this point in time, the cap 28 is in the down position below the surface of the shoulder 26. The extended loop 30 is placed under tension to form a tight-fitting loop, as shown in FIG. 5, and is tightened on the pack 24. During the tensioning, a tensile force is transmitted over the band length 36, which is considerably stronger than the low compressive force exerted on the band feed for forming the extended loop in the band part between the band feed device and the cushion 48 made of polyurethane. The stronger force that occurs in the band during tightening therefore seeks to release the free band end 38 from the holding engagement on the welding head 52. This possibility is prevented by the fact that the cushion 48, which is made of polyurethane, is pressed with a stronger pressure against the band and against the welding head 52 during the band tightening 15, so that the free band end 38 remains held on the welding head 52. In the preferred embodiment of the invention, it was found that

that a compressive force of approximately 13.6 to 18.1 kg is sufficient to hold 20 the free band end 38 when the overlapped band length 36 is tensioned between the cushion 48 and the welding head 52. Typically, the strap loop is tightened with a tensile force of approximately 4.5 to 6.8 kg.

As can be seen from the illustration in FIG. 11, the upper band edge in the region of the band overlap between the cushion 48 made of polyurethane and the welding head 52 is closer to the lower surface of the pack 24 than the lower edge of the band. The extended loop 30 is preferably held in the arrangement shown in FIG. 11, rotated by 90 °, so that the upper and lower edge of the band are in the area between the cushion 48 and the welding head 52 when the loop is tightened around the pack 24 are in the plane of the loop. 11, the slidable surface 35 of the cushion 48 made of polyurethane and the face 54 of the welding head 52 facing it extend perpendicular to the slide cover 62 and to the underside of the pack 24, but this spatial position is not absolutely necessary. The surfaces on the cushion 48 and on the welding head 52 could thus also be angled against the plane of the extended loop 30 spanning the pack 24.

During the tightening process, the sled cover 62 is between the lower surface of the pack 24 and the extended loop 30. In flexible packs 45 of some type and at certain high levels of tension, the sled cover 62 serves to pull the loop 30 out of engagement therebetween Prevent existing polyurethane cushion 48 and the welding head 52. If the carriage cover 62 is guided out of the position between the pack 24 and the loop 30 in the manner to be described after the band has been tightened in this way, the tightened loop therefore still contains to a certain extent a loose band length or a surcharge. Thanks to the elasticity of the plastic band and thanks to the compressibility of the pack 24, a tight loop is nevertheless achieved when the slide cover 62 is returned. In addition, the carriage cover 62 (in the vertical direction of FIG. 11) may be relatively thin and may be relatively narrow in relation to the package width (i.e. 60 in the horizontal direction in FIG. 2) so as to prevent the occurrence of a loose length of counteract as far as possible beforehand. Furthermore, the carriage cover 62 can be dispensed with in the case of packs of a certain type (for example those with rather rigid and incompressible surfaces) and with low values of the loop tension. The reason for this is that when the loop tension is weak, the strap loop is less likely to result from the engagement between the one made of polyurethane

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Solve cushion 48 and the welding head 52. The relative incompressibility of the pack 24 would also prevent the band loop from cutting into the pack and pulling out the loop between the cushion 48 and the welding head 52.

In the illustration in FIG. 11, the tightening process takes place when the overlapped portions of the band loop are aligned in a plane parallel to the plane of the band loop spanning the pack, but the extended loop 30 could also be tightened in a different spatial position. In the case of very large packs and with a very small welding head diameter, it would be possible to insert the pack into the extended loop if it is in the horizontal position shown in FIG. 3. The loop could then also be tightened in this horizontal arrangement. Although the diameter of the welding head 52 would have the effect that a certain loose band length would still be present in the tightened loop, this slackness would nevertheless be negligible in the case of large, compressible packs, and the integrity of the tightened loop would not be impaired thereby If the band loop is to be tightened in a horizontal direction around the pack, the upper surface of the shoulder 26 with respect to the welding head 52 and the band transport zone 40 would advantageously be provided at a lower point than is the case in the illustration in FIG. 6 The greater depth would leave space for the placement of large packs and for their introduction into the horizontally aligned loop. If the loop is to be tightened in the horizontal direction, appropriate precautions could of course also be taken to automatically move the welding head 52 from its position between the volume and d of the pack after the firming process is finished.

The mechanism for tape feeding and tensioning will now be discussed in more detail. A pulling wheel arrangement serves for feeding as well as for tightening the band. A pulling wheel 68 and an adjacent idling wheel 70 are arranged to carry out horizontal rotary movements in the belt transport zone 40, as shown in FIG. 6. The idle wheel 70 is preferably spring-loaded against the pull wheel 68. The band length 36 is inserted into the guideways 42 and between the pull wheel 68 and the idle wheel 70. The pulling wheel 68 is carried by a shaft 72 and can be driven by an electric motor 76, which is connected to the shaft by a conventional drive belt 78, for rotary movements in both directions. The electric motor can first drive the pulling wheel 68 for tape feed in the sense of loop formation (in the viewing direction of FIG. 6) clockwise and then for tightening the loop (also in the viewing direction of FIG. 6) counterclockwise.

A bulk supply of the tape is preferably wound onto a conventional type self-supporting spool (not shown) which may be provided near the device 20 and which rotates in response to the pulling force applied by the pull wheel to the tape for feeding the tape.

At the end of the shaft 72 opposite the pulling wheel, a control unit 74 for rotary steps is provided, which triggers the lowering of the cap 28 by the actuating solenoid 66 after the primary band loop has been formed. The control unit 74 is of a conventional type and has an electrically operated clutch. When the clutch is actuated, a cam part rotates for one revolution with the shaft 72, whereupon the clutch disengages the cam part from the shaft 72 and locks it against further rotation. The actuating solenoid 66 is de-energized to lower the cap 28 by a limit switch provided in the control unit 74, which is actuated by the rotating control cam part after one revolution. So that a single turn of the pulling wheel 68 is sufficient to form 5 the primary band loop within the cone 28 when part of the loop overlaps with the free band end, it is provided that the traction wheel 68 has a larger diameter than the cone 28.

After the formation of the primary band loop in the cap io 28, the latter is moved downward from the loop so that the loop can be expanded to a predetermined size by the pull wheel 68. Since the cap 28 is very quickly guided downward by the actuation solenoid 66, it is in fact not necessary at all to interrupt the process of feeding the tape during the lowering of the cap 28. The tape is thus fed in without interruption until the desired diameter of the extended loop is reached.

The tightening process is ended as soon as the desired degree of tension in the loop is determined. A sensor arrangement for determining the tension is provided in the belt transport zone 40, which is shown in FIGS. 7, 9 and 12. A traction wheel 83 is rotatably mounted on a shaft 84 provided on an arm 86. A spring 92 is attached at one end to the arm 86 and at the other end to an armature 94 which is arranged on the housing. The spring 92 seeks to pivot the arm 86 counterclockwise about a shaft 88, so that the traction wheel 83 is loaded against a side wall region 95 in the guide track 42 of the belt transport zone. The tension of the spring 92 is adjustable and can be dimensioned such that a given value of the spring elongation is achieved at a certain degree of band tensioning. If the band is hardly or not at all under tension, the band length 36 is pressed 35 by the pull wheel against the side wall region 95 in the guideway 42, as shown in FIGS. 7 and 9. If the tension increases, the band length 36 pushes the traction wheel 83 away from the side wall region 95, since the tightened band length 36 is stretched to a straight line between the 40 position 96 and the position 97 in the guideway 42. The existing spring tension is dimensioned such that the belt length 36 between the positions 96 and 97 can only be stretched to a straight line when the tension of the belt reaches the predetermined value. 45 Once this predetermined value has been reached, the pull-button wheel 83 is guided from the straight part of the band length 36 into the position shown in FIG. 12, in which the arm 86 presses against a contact arm 98 of a limit switch 100. By actuating the limit switch 50 100 in this way, the circuit of the electric motor 76 is interrupted, so that the tightening process is ended.

The method and the device for connecting the free band end 38 to the overlapped section of the band length 36, ie the mechanism for frictionally fusing the band loop, will now be described. If a plastic band or a plastic-coated metal band is used, a welded or friction-melt connection can be produced by heating the overlap area of the loop.

60 In the preferred embodiment, the heat of fusion is generated by vigorously moving the free strip end 38 back and forth to generate frictional heat and to melt the boundary surface on both sides of the overlapped section of the strip length 36. More specifically, 65 oscillatory movements of the welding head 52 are triggered for this purpose with a relatively small angle of rotation and a sufficiently high frequency. The welding head 52 carries out oscillating rotary movements around the shaft 53, so

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that the free band end 38 is moved back and forth with respect to the resting overlapped section of the band length 36 by the circumferential engagement surface 54 which engages on one side of the free band end 38. Typically, the oscillation frequency is approximately 50 to 100 Hz, the total amplitude of the circumferential rotation of the attack surface 54 is approximately 4 mm and the oscillation period is 0.75 to 1.0 seconds. To ensure proper welding, the cushion 48, which is made of polyurethane, is pressed against the overlapped section of the band length 36 with a greater pressure load than during the tightening process. Normally, a pressure of approximately 45 kg is applied to the belt during the process of friction fusion.

For the vibration operation of the welding head 52, an electric motor 80 is provided which is connected to an oscillation drive 82. The electric motor 80, the vibration drive 82 and a control means (not shown) are known as such and are commercially available for strapping machines based on the principle of frictional fusion. Such devices are described in U.S. Patent 3,586,572 issued to Ericsson.

An anvil device of a different type than that shown here can also be used to bring about the friction-melt connection. For example, instead of the cushion 48, a cylindrical roller can be provided, which is mounted parallel to the shaft 53 of the welding head to perform rotary movements about an axis and has a roughened contact surface. The belt feed and tensioning can be effected by the roller revolutions. After the loop has been tightened, the roll can be driven by a suitable mechanism to vibrate vertically (along its axis) to rub the length of tape 36 against the free end 38 of the tape to form a fused connection.

After the frictional melt connection has been made, the cap 28 is still held in the down position below the surface of the shoulder 26, while the welding head 52 and the polyurethane pad 48 remain in pressure engagement with the strap loop to keep the strap loop from a standing part of the strap length 36 can be separated, as will be described in detail next.

When using metal tape, other types of connections can be made by using additional conventional mechanisms (not shown in the drawings) for connection formation. These other connections can be, for example, specially provided cuff-like connections or connections with slot engagement. A description of such connections and connection mechanisms can be found in the patents to U.S. Patent 2,710,435, issued to Crosby, to Crosby et al. U.S. Patent 2,801,558 and Beach U.S. Patent 3,303,541.

The mechanism for cutting the tape will now be discussed in more detail. After the loop connection has been made by friction welding, the standing length of the band is separated from the loop by a cutting jaw 102, as can best be seen in FIGS. 6 and 9.

The cutting jaw 102 is held in a sliding block 104, which is slidably mounted for moving towards and away from the band length 36, as can be seen in FIG. 9. A cutting block 106 is provided for guiding the band length 36 in such a way that the band is prevented from bending when it moves away from the cutting jaw 102 when it is extended in order to cut the band.

The cutting jaw 102 is moved by a compressed air actuating cylinder 109 over a linkage. As can be seen from the illustration in FIG. 6, an articulated member 108 is pivotally mounted on a shaft 110 and is pivotally connected at one end 5 to an arm 111 and at the other end to the slide block 104. The arm 111 is connected to the compressed air actuating cylinder 109 of the cutting device by a conventional piston rod (not shown). When the compressed air actuating cylinder 109 is pressurized, the piston rod and the arm 111 are displaced in the direction thereof, so that the articulated member 108 (in the viewing direction of FIG. 6) pivots counterclockwise around the shaft 110 and thereby the cutting jaw 102 for severing the Tape is extended. i5 The compressed air actuation cylinder is provided with an inner spring, through which the piston rod is returned to the extended position (and the cutting jaw 102 to the retracted position) when the pressure is released.

After the band has been cut, the carriage 46 intended for the Am-20 boss is moved away from the welding head 52 in order to return the anvil 44 and the carriage cover 62. When the anvil 44 is moved away, the fused section of the band loop near the welding head 52 is released from its 90 ° rotation with respect to the remaining 25 loop and now lies flat against the lower surface of the pack. Since the carriage cover 62 is also retracted, the taut band loop contracts even further thanks to its elasticity and now lies tightly against the part of the pack surface previously touched by the carriage cover 62. The tied package can then be removed from the device.

The compressed air actuation system will now be discussed. As already mentioned, the movements of the cutting jaw 102 and the slide 46 35 provided for the anvil are caused by compressed air actuating cylinders 109 and 120, respectively. The compressed air actuation actuators are controlled by the compressed air actuation system shown schematically in FIG. 13.

The system includes a feed manifold 124 for supplying 40 air pressure from three pressure regulator valves 126, 128 and 130 with a pressure of 6.3 kg / cm 2, followed by three solenoid valves 132, 134 and 136, which are electrically operated three-way valves . A distribution line 137 for supplying compressed air to the compressed air actuating cylinders 109 and 120 is fed from the solenoid valves. A check valve 138 prevents the pressurized ventilation of the compressed air actuating cylinder 109 for the cutting jaw via the solenoid valves 132 and 134. The compressed air actuating cylinder 109 can therefore only be pressurized by the solenoid valve 136 via a flow control valve 139.

The pressure regulating valves 126, 128 and 130 are set to a «low», a «medium» or a «high» pressure value for pressure control, although the purpose of this precaution will be explained later. Solenoid 55 valves 132, 134, and 136 each have three ports (designated A, B, and C in FIG. 13). In the solenoid valves 134 and 136, the passage opening C is plugged, whereas in the solenoid valve 132 it is not plugged for blowing off to the outside air. In the de-energized state, the solenoid valves are positioned to allow air to pass through ports B and C (though port C is blocked in solenoid valves 134 and 136) while being energized to allow air to pass through ports A and B. -65 are tigbar.

Let us now consider the actuation of the compressed air actuation cylinder 120 for the anvil. If the primary band loop is first formed in the cap 28, then

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the anvil 44 is guided up to the abutment against the abutment surface 56, as shown in FIG. 7. A look at FIG. 13 illustrates that the movement of the anvil 44 into this position is triggered by actuation of the solenoid valve 132 to open the openings A and B, so that 5 a regulated low air pressure from the pressure regulator valve 126 acts on the piston in the compressed air actuating cylinder 120 can, whereby the anvil 44 is loaded with a compressive force of about 0.9 kg against the abutment surface 56 of the cap. The pressure load of 0.9 kg is a nominal value, which guarantees that the anvil 44 lies against the cap 28 in such a way that the free end of the band 38 is correctly aligned and guided during its advancing movement into the slot 34 and when it passes through between the cushion made of polyurethane is 48 and the welding head 52 is guaranteed.

After the formation of the primary band loop in the cap 28, this is brought down to below the surface of the shoulder 26. When the cap 28 is pushed down, the contact surface 56 of the cap on the front of the boss 20 slides vertically downward. As soon as the cap 28 has passed the lower edge of the anvil 44, the anvil 44 is pressed forward against the band and 25 against the welding head 52 due to the still existing application of the pressure force of 0.9 kg, which is maintained by the compressed air actuating cylinder 120 . The loop is expanded to a larger diameter, while the anvil 44 still applies the thickness of 0.9 kg to the belt. If the extended loop is then placed around the pack, a higher pressure must be applied to the 30 overlapped sections next,

so that the free band end 38 cannot come loose from the engagement on the welding head 52 during the tightening process. At this time, therefore, the solenoid valve 134 is energized to open the port A, so that the 35th

Compressed air actuating cylinder 120 for the anvil is fed with compressed air of a medium pressure, with the result that

that the anvil 44 now applies a compressive force of approximately 13.6 to 18.1 kg to the band against the welding head 52. When the tightening process has ended, the solenoid valve 134 40 is de-energized to close the passage opening A. However, since the passage opening C is plugged, the compressed air actuating cylinder 120 remains pressurized and the anvil 44 remains pressed against the belt loop.

In the now following step of establishing a connection, the band must be pressed against the welding head 52 with an even greater pressure force, while the latter is driven to oscillate with a high number of oscillations in order to form the friction-melt connection. For this purpose, the solenoid valve 136 is energized to open the 60 passage opening A in order to pressurize the compressed air actuating cylinder 120 for the anvil with compressed air so that the anvil 44 is now pressed against the band and the welding head 52 with a compressive force of approximately 45 kg becomes. 55

The compressed air actuating cylinder 109 for the cutting jaw is now fed with high pressure air from the pressure regulator valve 130 via the solenoid valve 136, since the blocking valve 138 prevents compressed air actuation of the compressed air actuating cylinder 109 with compressed air of low and medium pressure via the 60 pressure regulator valves 126 and 128. It should be noted

that the compressed air actuating cylinder 120 for the anvil and the compressed air actuating cylinder 109 for the cutting jaw are simultaneously supplied with compressed air via the solenoid valve 136. However, the actuation of the compressed air actuating cylinder 109 65 for the cutting jaw is delayed by about half a second, while the compressed air actuating cylinder 120 for the anvil is pressurized with high-pressure air to hold the band in place until the friction welding has ended. When the welding process has ended, the compressed air actuating cylinder 109 can extend the cutting jaw to cut the strip. This is achieved by the flow control valve 139 in the compressed air feed line leading to the compressed air actuating cylinder 109. The flow control valve 139 guarantees a regulated, low speed of the pressurization and, through the interposition of the compressed air actuating cylinder 109 for the cutting jaw, mediates an extension of the cutting jaw 102 in such a way that it reaches the strip length 36 (FIG. 12) just when the welding sequence is finished. After the cutting jaw 102 cuts the tape and has traveled its entire stroke, the solenoid valve 136 is de-energized to close the passage opening B and the solenoid valve 132 is de-energized to close the passage opening A and to open the passage opening C, so that the compressed air from the compressed air actuating cylinder 109 for the cutting jaw and is blown off from the pneumatic actuator 120 for the anvil. The inner return spring devices in the two compressed air actuating cylinders cause the anvil 44 and the cutting jaw 102 to be fully returned to the retracted positions.

The electrical control system is now to be discussed. For proper formation, extension, tightening, frictional fusion and severing the strap loop, it is necessary to control the operating processes accordingly. The actuation processes of the device 20 according to the invention can be triggered automatically and quickly with the aid of a suitable electrical control system. A suitable control system is shown in the simplified control block diagram of FIG. 14. The necessary interlocked interlocking relays and switches are omitted from the block diagram. It is assumed that the device is in the state at which the power is switched on and is ready for operation at the beginning of a snapping cycle, the tape being inserted into the guideways 42 up to the cutting block 106. The cap 28 is guided into the high position by the excited actuation solenoid 66. The solenoid valve 132 is energized to pressurize the air actuating cylinder 120 for the anvil in the sense of bringing the anvil 44 to the cap 28 (as shown in FIG. 7) with a compressive force of approximately 0.9 kg. The field coils of the electric motor 76 for the pull wheel are excited in the sense of motor operation in the direction of the tape feed to the cap 28.

A tape feed switch 143 is provided, which is preferably a foot-operated momentary contact switch. When the tape feed switch 143 is depressed, the electric motor 76 for the pulling wheel is put into operation in the sense of the tape feed. The tape feed switch 143 also serves to actuate the control unit 74 connected to the shaft 72 of the pulling wheel for step-by-step operation in order to lower the cap 28 after the primary tape loop has been formed. When the cap 28 is pulled down, the electric motor still rotates so that the tape feed continues. When the cap reaches the lower position below the surface of the shoulder 26, the anvil 44 is pressed against the band via the solenoid valve 132 due to the supply of compressed air of low pressure to the compressed air actuating cylinder provided for the anvil and in turn presses the band against the welding head 52. As the loop continues to widen, the anvil 44 applies a compressive force of approximately 0.9 kg to the band and to the welding head 52. When the tape feed switch 143 is released, the electric motor 76 comes to a standstill and the tape feed is ended. If you press the

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The tape feed switch 143 continues the tape feeding and the widening of the loop.

If the loop is of sufficient size, the operator releases the tape feed switch 143. If packs with the same dimensions are to be tied up in the course of production on a production line, there is also the alternative option of having the tape feed and the extension of the loop controlled by a timer. In any event, the operator will next raise the strap loop and wrap it around the package as shown in FIG. 4.

A band tensioning switch 148 is provided to reverse the electric motor 76 to tighten the loop around the pack. The band tightening switch 148 is preferably also a foot-operated momentary contact switch. The band tightening switch 148 serves to actuate the solenoid valve 134 in the sense of the pressure actuation cylinder 120 for the anvil being subjected to medium-pressure compressed air, so that the anvil 44 is pressed against the band loop and against the welding head 52 with a compressive force of approximately 18.1 kg. As a result, the free band end 38 is held in contact against the welding head 52, while the overlapping part of the band loop can perform a sliding movement on the anvil 44 when the loop is tightened.

Once the predetermined degree of tension has been reached in the belt loop (in the case of small packs about 4.5 to 6.8 kg), the limit switch 100 used to sense the tension becomes used to switch off the electric motor 76 and to reverse the polarity of the motor field coils for the next operation actuated in the feed direction. The limit switch 100 also de-energizes the solenoid valve 134 for the medium pressure and the solenoid valve 136 for the high pressure supply of the compressed air actuating cylinder 120 for the anvil and the compressed air actuating cylinder 109 for the cutting jaw. This causes (1) compressed air actuating cylinder 120 to apply the high clamping pressure (approximately 45 kg) required to hold the overlapped band portion of the loop when making the frictional melt connection, and (2) cutting jaw 102 is extended by the compressed air actuating cylinder 109 to cut the strip after the weld connection has been made. The limit switch for palpating the tension also actuates the electric motor 80 for the welding process and a timer 152 which deactivates this electric motor when the welding process has ended (after approximately% to 1 second). The timer 152 also de-energizes the solenoid valve 136, thereby stopping the supply of high pressure air, and de-energizes the solenoid valve 132 to blow off to the outside air, so that the air actuating cylinder 109 for the cutting jaw as well as the air actuating cylinder 120 for the anvil come back in by their internal spring devices be brought into the operating state in which the cutting jaw 102 and the anvil 44 are guided completely into the retracted position.

To set the device for the next duty cycle, timer 152 also energizes two more timers 154 and 156. Timer 154 energizes actuation solenoid 66 to raise cone 28 while timer 156 expires solenoid valve 132 to extend anvil 44 excited to plant against the hat 28. The timer 154 is set in such a way that a certain period of time remains for the removal of the tied package before the hat 28 is brought upwards. The timer 156 is set to a longer period of time than the timer 154 to ensure that the cap 28 is in the high position when the anvil 44 is extended.

Further embodiments of the device for carrying out the method according to the invention will now be described. In the case of the device described in FIGS. 1 to 14 described above, a movable circular guide (the cap 28) is used to form the band loop. The formation of the band loop can, however, also take place in another way within the scope of the method according to the invention.

It can be assumed that in each of these embodiments certain mechanisms are present which are not always shown in the drawing, but whose mode of operation is analogous to that described above in connection with the embodiment shown in FIGS. 1 to 14. Examples of such mechanisms or devices i5 are the guideways 42 of the belt transport zone, the pulling wheel 68, the idle wheel 70 and the cutting jaw 102 as well as the necessary drive means, controls and supporting structures. In all these further embodiments, an anvil and an associated slide are provided (schematically shown and shown in FIGS. 15 to 17; 18; 19 and 20; 21; 22 to 25; and 26 to 28 with the reference numbers 144 and, respectively, 146, 244 or 246,344 or 346, 444 or 446, 544 or 546 and 644 or 646). In all of these embodiments, the anvil and the carriage have the same function as the anvil 44 and the carriage 46 in the embodiment shown in FIGS. 1 to 14 and described above.

15 to 17 schematically show another possibility for carrying out the step of forming a primary band loop and expanding the band loop to a larger diameter with the aid of a second embodiment of the mechanism used to form the band loop. The device shown here is intended for use in the context of a tying device such as device 20 shown in FIGS. 1 to 14 and would then have its place in the area of the device used for forming the belt loops (for device 20 in FIGS. 8 and 9 shown). In particular, instead of the welding head 52, a wheel 112 is used to form the loop, which functions as an inner guide for the band 40 length 36 in the tangential feeding of the free band end 38 on the wheel circumference.

A plurality of pivotable guide plates 114 are provided at a distance around the wheel 112, which are spring-loaded in the vertical position and represent a band guide on the outside of the loop of the band length 36. In Fig. 17 one of the pivotable guide plates 114 is shown, which is loaded into the vertical position by a suitable spring device 116, and it is also a part of the band length 36 on one side of the guide plate 114 Darge-50, the band on this is led. The size and number of guide plates can vary from case to case. In the embodiment shown, four guide plates are provided which give a roughly polygonal shape, or more precisely, four sixths of a hexagon. 55 The fifth side of the hexagon is formed by a fixed guide plate 115 and the sixth side of the hexagon by a cushion or anvil 144 with a smooth surface, which can be guided to and removed from the wheel 112 by a carriage 146. 60 In the introductory stage of the loop formation, the free band end 38 is transported into the area between the wheel 112 and the anvil 144 used for loop formation and is guided on the wheel 112 and on the guide plates 114 and 115 for loop formation. After the band has been transported in a circle over a distance corresponding to a little more than the full circumference (arch dimension 2ir) so as to form the loop by overlapping a section by the free band end 38, the anvil 144 becomes

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to apply a predetermined pressure to the overlapped parts of the belt loop between the anvil and the wheel closer to the wheel 112 so that the overlapped parts are held together with light pressure. The wheel 112 preferably has a rough peripheral surface for contact with one side of the free band end 38. The belt is transported further against the guide plates 114 and the free belt end 38 is held on the wheel 112 so that it cannot move. With a corresponding choice of the spring force of the spring device 116 which serves to load the guide plates 114 into the vertical position, the guide plates 114 are pivoted outwards and downwards by the pressure applied by the widening band loop and now assume the position indicated by broken lines in FIG. 17 a. This enables the band loop to be expanded to a larger diameter, so that the extended loop 30 ″ shown in FIG. 16 is obtained.

If the loop is expanded to the corresponding predetermined size, the tape feeding process is ended. Next, a pack can now be passed over part of the loop and the loop can be rotated by 90 ° (i.e. from the plane of FIGS. 15 and 16) in order to put it around the pack for subsequent tightening, as is the case for the first Embodiment has been described in connection with FIG. 4. The wheel 112 can be relatively small and may have a diameter of 25 to 50 mm, for example, but can also be much larger. Regardless of whether a plastic band or a plastic-coated metal band is being processed, the wheel 112 can be driven with a sufficiently high number of oscillations to make reciprocating movements over a small angle of rotation in order to produce a frictional fusion connection in a manner similar to that for the preferred embodiment of the Welding head 52 was described above in connection with FIGS. 1 to 14.

The tape loop can be separated from the rear tape length using a suitable tape cutting device (not shown), for example by means of the cutting jaw 102 described above for the preferred embodiment and shown in FIG. 7.

A third embodiment of the mechanism used for forming the loop in a device for tying a package according to the method according to the invention is shown in FIG. 18 and is similar to the mechanism used for forming the loop in the first embodiment shown in FIGS. 1 to 14. A cap 228 is provided to accommodate the band length 36 and to guide the free band end 38 on the inner circumference when a primary band loop is formed. Arranged inside the hat 228 is a welding head 252, which has a lower guide flange 260, so that the level of the band length 36 in the hat 228 can be kept at the appropriate height. An anvil 244 and a slide 246 are shown schematically and their mode of operation is analogous to that of. Anvil 44 and carriage 46 in the first embodiment shown in Figs. 1-14. In the embodiment shown in FIG. 18, the hat 228 is, however, articulated or pivotably mounted with a pin 262, so that after the primary band loop has been formed, it can be brought into an inclined position (indicated by broken lines in FIG. 18). As a result, a free space is available in the vicinity of the primary belt loop in which the subsequent expansion of the belt loop can take place. The hat 228 is guided into the inclined position by suitable drive or actuating means (not shown). If the band has the appropriate strength, width and flexibility in combination, moving or tilting the cap is not even absolutely necessary. If the cap has a correspondingly shaped wall, it could also remain in the rest position after the primary ribbon loop has been formed. The further feeding of the ribbon into the cap then causes the ribbon to jump out of the cap, so that the loop can expand without hindrance.

19 and 20 show a fourth embodiment of the mechanism used for forming the loop loops in a device for tying a pack according to the method according to the invention. In this embodiment, the band loop is formed in a plane perpendicular to a package support surface 322 on a device for tying ge-15. First, the package 324 is placed on the package support surface 322 near the loop formation area. A band length 36 is then transported between two adjacent guide rings 326 and 328, in which it is guided. The guide rings 326 and 20 328 are pivotally mounted on pins 330 and 332, which in turn are arranged in recessed channels 334 and 336, respectively. The guide rings 326 and 328 can therefore be pivoted 90 degrees into a position below the packing support surface 322 and parallel to it. For this purpose, cutouts 338 and 340 are provided for the guide rings 326 and 328, respectively, in which these can be received. The tape length 36 can be inserted into a slot (not shown) between the guide rings 326 and 328 using a suitable pull wheel device. 30 In a manner analogous to that in the embodiment shown in FIGS. 1 to 14, a plastic band or a plastic-coated metal band can be deformed into a primary band loop and then used to carry out the subsequent process steps of loop extension, loop tensioning and frictional fusion between a welding head 352 and one Anvil 344 can be clamped. The schematic representation of FIG. 19 shows that the anvil 344 can be guided and moved away from the strip length 36 and the welding head 352 by a carriage 346, while the welding head 352 is mounted on a shaft 353 and by a suitable drive means or an electric motor 355 is driven.

The band length 36 is introduced with the aid of suitable control means between the guide rings 326 and 328 until a primary band loop is formed in which the free band end 38 overlaps a portion of the loop. At this time, the anvil 344 is pressed against the overlapping band parts and the guide rings are guided into the horizontal position below the package contact surface 322 by suitable means in order to make a free space available in the vicinity of the loop. The loop is then extended by continuously feeding the length of the tape until the desired large diameter is achieved. The package is then pushed into the loop 55 and the loop is then pulled together, tightened and severed in a similar manner, as was described in connection with the embodiment shown in FIGS. 1 to 14. 19 and 6o 20, however, the loop does not need to be rotated by 90 degrees around the package, since the loop is already formed in a plane perpendicular to the package support surface 322 and consequently the package 324 consequently can be inserted into the loop without having to twist it in any way.

When the loop around the pack 324 is tightened, the small welding head 352 is of course inevitably between the pack and the band loop, as a result

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has that the loop is slightly larger than the scope of the pack. After tightening, frictional fusion (or some other suitable connection of the overlapping ends) and separation from the rear band length to which the loop is subjected, the welding head 352 must be brought out of its position between the pack and the band loop. This can be accomplished by moving the combined arrangement consisting of the welding head 352, the shaft 353 and the electric motor 355 away from the package using suitable devices (not shown) (to the right in the viewing direction of FIG. 19). With very large packs and with a very small welding head diameter, it is negligible that the loop that spans the pack has a slightly larger diameter, due to the position of the welding head between the loop and the packing. In addition, if a large package is somewhat elastic, the package stretches a little until it has a larger diameter (and the band itself contracts to a slightly smaller diameter), so that a tight loop is obtained around the package.

21 shows a fifth possibility for carrying out the step of forming a primary band loop and expanding this band loop to a larger diameter. The mechanism shown in FIG. 21 is intended for a lacing device such as the device 20 for lacing packs shown in FIGS. 1 to 14 and is provided in the area serving for forming the loop (the area of forming the loop in the device 20 is shown in FIGS. 8 to 10) ). Specifically, instead of the cap 28 used for guiding and the welding head 52 of the device 20, a flexible guide band 428 and a stop block 452 for the free band end 38 are provided. In contrast to the stop block 452, an anvil 444 is arranged, which can be brought to the stop block 452 by a slide 446 and moved away from it. The band length 36 is guided to the inner periphery of the flexible guide band 428 between the anvil 444 and the stop block 452. The free band end 38 is then guided in a circular line along the inner circumference of the flexible guide band 428 and after it has measured a little more than the full circumference (radian measure 2-rr), it comes to bear against the stop block 452, so that a primary band loop is formed is at which the free band end 38 overlaps a portion of the loop.

The flexible guide band 428 can be made of any suitable flexible material, such as polyethylene or rubber, or even thin metal. In the loop formation position, the guide band 428 extends from an anchoring point 454 along a circular local line, the free end 455 of the guide band abutting against the anvil 444. A pin or guide pin 457 is provided on the free end 455 of the flexible guide band, which protrudes into a guide track or an arcuate slot 458 in the surface of the shoulder 26 of the device. 21, the shape of the arcuate slot 458 of an involute corresponds to the circular line which the flexible guide band 428 occupies when it is in the position shown in FIG. 21 to form the primary band loop. After the primary band loop has been formed, the free end 455 of the guide band 428 is moved along the location line of the arcuate slot 458. For this purpose, the guide pin 457 at the free end 455 of the guide band 428 is guided to the point B by suitable drive means (not shown) in the arcuate slot 458, so that the flexible guide band 428 is essentially stretched to a straight line, as shown by broken lines is indicated, the guide band being designated by the reference number 428 'after being pulled out. In the rectilinear alignment, the flexible guide band 428 'has thus moved away from the primary band loop 5 formed and a free space is now available in the vicinity of the loop. Next, the anvil 444 is brought closer to the loop to apply a relatively small compressive force to the overlapped portions of the band loop so that the free band end 38 cannot detach from the stop block 452. The length of the band 36 can then be replenished by suitable feeding means until the loop is widened to the desired larger diameter. A pack can then be slid over part of the loop and the loop can be wrapped around the pack i5. The loop can then be tightened and tightened to the package in a manner similar to that described above for the embodiment shown in Figs. 1-14. The overlapping parts of the band loop can be connected to one another by suitable means, for example by frictional fusion, fitting a separate sleeve or by forming a blocking slot connection. The formation of a frictional fusion would require that the stop block 452 be driven to vibrate or vibrate enough to generate the necessary frictional heat and interfere with the interface. The devices for applying a separate sleeve or for forming a blocking slot connection would be of a conventional type and would then be connected to the anvil 444 and the stop block 452, as may be necessary or desired.

22 to 25 show a further possibility for carrying out the step of forming a primary band loop 35 and expanding the band loop to a larger diameter with the aid of a sixth embodiment of the mechanism for forming the band loop. The mechanism shown is intended for use in a strapping device such as the device 20 for strapping the straps shown in FIGS. 1 to 14 and described further above. The mechanism for band loop formation would have to be arranged in the region of this device used for band loop formation (the region of band loop formation in the device 20 is shown in FIGS. 8 to 10).

In this sixth embodiment, a tape guide is not required. Instead, a wheel 552 is provided (instead of the welding head 52 of the first embodiment, shown in FIGS. 8 to 10), this wheel having a slot 554 50 for receiving the free band end 38 of a band length 36. When the tape is fed by means of suitable feed means (not shown) with a pull wheel, the free end 38 of the tape enters slot 554, abuts against the end of the slot in wheel 552, and the wheel is rotated (namely, in 22 to 24 counterclockwise). The band length 36 is replenished until the wheel 552 has rotated over a distance corresponding to somewhat more than the full circumference (radian measure 2-rr), so that a primary band loop is formed, in which 60 the free band end 38 overlaps part of the loop . After the primary belt loop has been formed, the wheel can be locked against further rotational movement while the belt length 36 is being replenished. An anvil 544 is provided near the wheel 552 and can be guided to and removed from the wheel by a carriage 65 546 (shown schematically in FIGS. 22 to 25). The anvil 544 is brought into contact with the outside of the band length 36 in the area of the overlapped section of the loop,

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to hold the tape in place at this point against moving off the wheel 552. When the wheel 552 is no longer able to rotate, the primary belt loop widens starting from the circumference of the wheel 552 to form an enlarged loop 30, which can be of any desired larger diameter, as shown in FIG.

If the wheel 552 is relatively small and the pack 24 is relatively large, the pack 24 can be inserted into the enlarged loop in the manner shown in FIG. 25. With the aid of the means already described in connection with the other embodiments, the loop can then be tightened around the pack. The mode of operation of the wheel 552 can then also be analogous to that of the welding head 52, as was described for the embodiment shown in FIGS. 1 to 14, in that a friction-melt connection is now produced. After the friction melt connection has been formed, the wheel 552 is brought out of the position between the pack and the loop.

Instead of inserting the pack 24 into the extended loop as shown in FIG. 25, it can also be provided, if desired, to first twist the extended loop through 90 degrees (i.e. out of the plane of FIG. 25). to then insert the package into the loop above the wheel 552 and anvil 544. Such a twist of the loop by 90 degrees is similar to the twist alignment in the course of the corresponding method step, as is carried out in the preferred embodiment described above and as illustrated in FIG. 11.

When using metal tape, the overlapping parts of the tape loop can also be joined together by conventional separate cuffs or by blocking slot connections. The mechanisms for making such conventional connections are not shown in Figure 25, but could be provided near the wheel 552 and anvil 544 in an arrangement encompassing the overlapped portion of the belt loop.

A seventh embodiment of the belt looping mechanism is shown in Figs. 26-28. The device shown here is intended for a lacing device such as the device 20 for lacing packs shown in FIGS. 1 to 14 and should be provided there in the area of the band loop formation (the area of band loop formation in the device 20 is shown in FIGS. 8 to 10).

A substantially circular guide 628 for receiving the band length 36 is provided on the surface of the device. Instead of a welding head (such as the welding head 52 shown in FIGS. 6 to 10), a stop block 652 is provided near the circumference of the circular guide 628. In contrast to the stop block 652, an anvil 644 is arranged, which can be brought to the stop block and moved away from it by a carriage 646, which is shown schematically in FIGS. 26 and 27.

If the band length 36 is initially introduced into the guide 628, the free band end 38 slides between the stop block 652 and the anvil 644, which has been moved away from the stop block 652 to enable the band to pass through. The free band end 38 is then guided around the circumference of the guide 628 until it has made a circular movement over a distance corresponding to slightly more than the full circumference (radian measure 2it), so that a band loop is formed, part of the loop being formed by the free one Tape end 38 is overlapped, and until the free tape end 38 has hit the stop block 652.

Next, the anvil 644 is pressed against the overlapped portion of the loop with a relatively weak force, and the primary band loop formed is partially lifted out of the guide 628 so that the

Loop can be expanded. For this purpose, a lifting arm 650 is provided below the primary band loop formed and the underside of the guide 628. The lifting arm 650 is pivotably mounted below the guide 628 on a pin 651 and articulated at one end to a rod 657 which is fixedly connected to an actuating means 659. The actuating means 659 can move the rod 657 back and forth vertically in the viewing direction of FIG. 27, as a result of which the lifting arm 650 is raised and lowered.

If the lifting arm 650 is guided upwards into the position shown in FIG. 27, the band length 36 can be replenished further, so that a loop 30 enlarged to a desired larger diameter is obtained, as shown in FIG. 28. A package to be tied is then placed over the stop block 652 and anvil 644 and the extended loop is similarly turned up and wrapped around the package, as shown for the preferred embodiment in FIG. 11. The loop can then be tightened by using a suitable mechanism with a pulling wheel, as described for the preferred embodiment of the device shown in FIGS. 1 to 14.

After the band tensioning, a conventional separate cuff can be applied to the overlapped section of the band loop by means of a device (not shown) or a slot connection can be produced. There is also the alternative possibility of driving the stop block 652 to rapid oscillatory or vibratory movements in order to produce a friction-melt connection on a plastic band or a plastic-coated metal band. Instead of the stop block 652, a welding head similar to the welding head 52 shown in FIGS. 6 to 10 could also be provided. It is also not absolutely necessary for the free band end 38 to come into contact with a stop block or a similar part in order to complete the formation of the primary band loop. The tape feed can namely also be regulated by a suitable automatic rotary indexing control, so that the feed of the tape length 36 is automatically ended with the desired degree of overlap after the primary tape loop has been formed.

An eighth embodiment of the belt looping mechanism is shown in FIGS. 29 and 30. The mechanism shown here is intended for a lacing device such as the device 20 for lacing packs shown in FIGS. 1 to 14 and would be provided in the area of this device used for forming the loop loops (the area of the device 20 used for forming the loop loops is shown in FIGS ). This eighth embodiment is somewhat reminiscent of the fourth embodiment shown in FIGS. 19 and 20 and described above. In the eighth embodiment, guide rings 726 and 728 for the band for pivoting movements are pivotably mounted in a recess 738 provided below the packing support surface 722. Meanwhile, the guide rings 726 and 728 are pivotable about axes 727 and 729, respectively, which extend perpendicular to the plane of the formation of the primary loop, whereas the guide rings 326 and 328 provided in the fourth embodiment are pivotable about axes which are parallel to the plane of formation of the primary band loop extend. The two guide rings 726 and 728 have the same cross section and are essentially H-shaped. From the illustration of the guide ring 728 in FIG. 30, it can be seen that the H-shaped cross section forms an inner channel with side walls 731 and 733 and an arcuate guide wall 735 perpendicular thereto, these walls all opening up

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Take and guide the tape in the formation of the primary loop serve.

In contrast to the fourth embodiment, the eighth embodiment also does not have a welding head arranged in the central region of the guide rings. An anvil 744, on the other hand, is mounted for executing pivoting movements around a shaft 745 and has (1) an upper surface which is flush with the packing support surface 722 and (2) a belt contact surface which is in contrast to one in combination with the belt feed, belt tensioning and as a welding head serving wheel 752 is provided and facing this. After the tying process has been completed, the anvil 744 can be swiveled out of its position between the pack and the strap loop by means of a suitable actuating means and linkage 747.

The band length 36 is inserted between the anvil 744 and the wheel 752, which serves for band feeding, band tightening and as a welding head, and is passed on by the rotation of the wheel 752 in the viewing direction of FIG. 29 counterclockwise on the inner circumference of the vertically arranged guide rings 726 and 728, until the free band end 38 overlaps a portion of the loop. In order that the loop can be expanded, the guide rings 726 and 728 have to be pivoted about the axes 727 and 729 into the lower position indicated by broken lines in FIG. 29. As a result, of course, an area for unimpeded expansion becomes available in the vicinity of the primary loop, so that the loop can now be expanded to a predetermined larger diameter. The pivotal movement of the guide rings 726 and 728 is effected by a suitable actuating means 765 such as a solenoid or an air operated actuating cylinder in conjunction with link members 766, 677 and 769.

30, the wheel 752 is mounted on the shaft 753 of an electric motor 755. The electric motor 755 is in turn mounted on a carriage 757, by means of which the electric motor, the shaft and the wheel can be moved in the vertical direction with the aid of suitable drive means (not shown). The wheel 752, which acts as a welding head, has a generally cylindrical shape and has an area of attack for the band on the circumference. During the formation of the primary loop and during the subsequent operations, the wheel 752 is aligned against the band length 36 in the manner shown in FIG. 30.

After the primary loop is formed, the wheel 752 serving as a welding head can be pressed against the band length 36 by a corresponding movement of the carriage 757, so that the free band end 38 is held in frictional contact with the anvil 744. The guide rings 726 and 728 are then pivoted to the lower position shown in phantom lines in FIG. 29 and the band length 36 is then advanced further to form the extended band loop, sliding along the claimed free band end 38.

After expanding the loop, the direction of rotation of the wheel 752 is reversed to tighten the loop by a pack inserted therein. If necessary, an increased compressive force can be applied to the band length 36 overlapping the free band end 38 during the tightening process by appropriately raising the carriage 757 via the wheel 752 in order to hold the free band end 38 in position.

After the tightening is complete, a connection can be made between the free band end 38 and the overlapped band length 36, for example by frictional fusion, whereby the wheel 752 is driven to produce violent oscillations or vibrations to produce a frictional fusion connection on a plastic band or a plastic-coated metal band. As an alternative, a friction-melt connection can also be established by rapid vibration movements of the anvil 744. In any case, the parameters of the number of oscillations and the amplitude which are considered for the establishment of such a connection are the same, as was mentioned above in connection with the explanations about the mechanism for frictional fusion of the belt loop 10.

A loop can also be formed, in which an overlap joint area is provided which is constructed differently from those previously discussed. A primary band loop thus formed is shown schematically in FIG. 31. A band length 36 is fed to form a primary band loop along a closed path, a portion of the band loop being overlapped by the free band end 38. It should be noted here that with this loop 20 the band surface located on the “inside” of the loop remains in such an orientation that the “inside” surfaces of the band in the overlap area 812 face each other. The loop can be formed in this form by hand or mechanically (e.g. 2S by feeding the tape length 36 along a closed path to form a loop of this type). Following the formation of the primary band loop, the free band end 38 is fixed against movement, while the standing band length is replenished in order to expand the loop to a predetermined size. A pack can then be inserted into the expanded loop, whereupon the loop around the pack is tightened. The free band end 38 is then joined by suitable means to the overlapped section of the band length 36, so that a connection is made and the loop is secured in the arrangement spanning the pack.

When the loop is widened, the free end of the band against movement can be fixed in that it is pressed by a first part 814 in the overlap area 812 onto the over-lapped section of the band length 36. A second part, which is provided in comparison to the first part and which opposes the band movement with a relatively lower frictional resistance, namely part 816, is pressed against the band length 36. Specifically, the two parts 814 and 816 could, for example, be a welding head or an anvil similar to the welding head 52 and the anvil 44, which in connection with the preferred embodiment described above and shown in FIGS. 1 to 14 were discussed. It should be noted that after a loop such as the one shown in Fig. 31 has been expanded, the overlapping parts can be connected to one another by any suitable means, e.g. by frictional fusion, the formation of blocking slots or by applying a separate cuff. Of great importance, however, is the fact that the connection can be made, for example, by parts 814 and 816 (or also by other parts arranged nearby) without it being necessary to even partially insert one of these organs 60 into the loop and bring it into a position between the belt and the package. This gives the advantage that the residual tension in the loop can be increased, since the loop is tightened around the pack during tightening. It should also be noted that the strap loop does not necessarily have to be "twisted" to put it around the 65 pack. The loop can be formed and expanded in one plane and the pack can then be inserted into the loop perpendicular to this plane.

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The method according to the invention can advantageously be used for compressible objects, bundles or bales. In the one case, preformed metal or plastic tape sections (e.g. bale tapes) could be stacked or filled in the magazine of a suitable device for feeding one after the other in order to (1) initially form a primary tape loop and (2) subsequently the Extend loop. This could be accomplished in part using a device similar to that described for the various illustrated embodiments. After the loop has been expanded to a predetermined larger diameter, the overlapping loop ends could be connected to one another by suitable means. Next, a compressed bale could then be inserted into the band loop, which then expands against the band, so that a tied bale is obtained in this way. There is also the alternative possibility of removing the formed and assembled band loop from the device for band loop formation and placing it around a compressed bale, which can then stretch, whereby a tied bundle is formed.

Instead of using separate preformed band sections, a compressed one can be provided

To tie bales with a loop, which is formed from a continuous length of tape. A device similar to that shown in Figs. 1 through 14 could serve to form an extended loop. However, instead of tightening the loop around the bale, only the connection needed to be made in the loop. The compressed bale could then be inserted into the loop and then left to expand to form the tied bale. If desired, the loop formed and assembled could be removed from the device and then placed around the bale.

With regard to the setting of a compressed bale described above, it is important to determine

that it is not absolutely necessary to apply tension to the extended belt loop. In the case of bales of a certain type, it may be sufficient to allow the compressed bale to self-expand until it binds to the formed and joined band loop.

From the foregoing, it is apparent that numerous changes and modifications are possible that fall within the scope of the invention. The illustrated and described embodiments are therefore not to be understood in a sense restricting the invention.

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Claims (10)

623 529 2nd PATENT CLAIMS 1. A method of forming a band loop and arranging it around a package, wherein a band length is fed in a circular path to form a primary band loop and a part of the band length is overlapped by the free band end, the free band end to prevent further movement thereof is detected, a relative movement between the primary band loop and the band guide is effected in order to form a free space in the periphery of the primary band loop, the supply of the standing part of the band length to expand the band loop to a certain diameter is continued, a relative movement between the pack and the extended band loop is caused to be placed around the pack and either before or after the relative movement between this pack and the extended band loop is performed, the free end of the band is connected to an adjacent overlapped area of the band, characterized in that at m feeding the tape length (36) to form a primary tape loop only one side of the tape is guided in the path of a tape guide. 2. The method according to claim 1, characterized in that before the free end of the band is connected to an adjacent overlapped area of the band, the band loop is tightened around the package. 3. The method according to claim 1, characterized in that the step of effecting a relative movement includes disengaging the tape guide with the primary tape loop. 4. The method according to claim 1, characterized in that the method step of bringing about a real movement between the pack and the extended loop, the steps of holding a region of the extended loop and then rotating the remaining band loop around this fixed region in order to fold the band loop around around the pack. 5. The method according to claim 4, characterized in that the step of holding the band loop the compression of the free end of the band and an overlapped part of the band loop between a rough part lying against one side of the free end of the band in the form of a welding head and against one side of the overlapped part of the band loop engaging the flat surface in the form of an anvil. 6. The apparatus for carrying out the method according to claim 1, comprising a frame which has a device for supporting a length of tape on an edge of the tape, a device for feeding a length of tape to form a primary tape loop, a device for holding the free end of the tape against one Movement, means for continuing to supply the length of the tape to expand the tape loop to a predetermined size, means for tensioning the tape to tension the tape loop around the object, and means for connecting the free end of the tape to an adjacent overlapping area of the Band, characterized by a guide device for receiving a free end (38) of the band length in order to force the band into a web to form a primary band loop with an area overlapped by the free band end (38), by guiding only one side of the band . 7. The device according to claim 6, characterized in that the guide device is a hollow, substantially cylindrical part which has a slot (34) for passing the band length (36) from the outside of the cylindrical part (28) into the Has interior of the cylindrical part. 8. The device according to claim 7, characterized in that the slot (34) to one end of the cylindrical part (28) is open and that a drive device is provided to move the cylindrical part (28) between a first position in which the primary Band loop is formed, and to move a second position away from the first position so that the primary band loop can be expanded to the specified size without contact with the cylindrical part (28). 9. The device according to claim 6, characterized in that the band consists of a non-metallic material or of a metallic material provided with a non-metallic coating, that the device for supplying, holding, tightening and connecting the band is a rotatably mounted rough surface attack part in the housing (52), that the device for holding the free band end (38) has an anvil (44), that a device for causing a relative movement between the anvil (44) and the engaging part (52) is provided around the free band end and compressing an adjacent overlapping portion of the strap loop (30) therebetween and to frictionally contact the free end of the strap (38) and the adjacent overlapping portion of the strap loop (30) and that drive means is provided for swinging the engaging member (52) in order to cause a sliding friction movement of the free band end (30) and cause the interfaces to melt, thereby welding the free tape end to the adjacent overlapping area of the tape loop. 10. The device according to claim 6, characterized in that the means for holding the free band end (38) has a rough surface part (52) and an opposing smooth surface part (44) for compressing the free band end (38) and an adjacent overlapping region of the Has band loop (30).