EP0043171A1

EP0043171A1 - Apparatus for packing articles fed in a continuous flow

Info

Publication number: EP0043171A1
Application number: EP81200728A
Authority: EP
Inventors: Johannes Dominicus Van Maanen
Original assignee: Tevopharm Schiedam BV
Current assignee: Tevopharm Schiedam BV
Priority date: 1980-07-01
Filing date: 1981-06-26
Publication date: 1982-01-06
Also published as: NL8003809A; EP0043171B1; DE3166313D1

Abstract

An apparatus for packing articles or bundles of articles, comprising means for continuously feeding the articles to be packed in spaced apart relation, means for the continuous supply of a continuous web of packing material, means for wrapping said material around the articles, means for advancing the wrap, means for adhering the longitudinal sealing seam portions to each other, and means for forming the transverse sealing seams and severing these seams, while with respect to the direction of movement of the web of packing material before said means for forming a wrap, a perforating device is provided consisting of two rollers (6,7) driven in synchronism, of which the one roller is provided with at least one perforating knife (8) and of which the other roller is provided with at least an anvil (9) for cooperating with the perforating knife, and means for guiding the web of packing material between said rollers.

Preferably the rollers (6,7) are in driving connection with each other, whereas one of said rollers is in driving connection with a crank mechanism (26) the connecting rod (27) of which is coupled at its other end to a second crank mechanism (28) which is in driving connection with a driving shaft of the packing apparatus, one of the crank mechanisms mounted for displacement so that the axis of the pivot shafts of the two crank mechanisms may be displaced in parallel relations in a direction with respect to each other.

Description

The invention relates to a method for packing articles or bundles of articles,comprising means for continuously feeding the articles to be packed in spaced apart relation, means for the continuous supply of a continuous web of packing material, means: for wrapping said material around the articles, means for advancing the wrap, means for adhering the longitudinal sealing seam portions to each other, and means for forming the transverse sealing seams and severing these seams. Such an apparatus is generally known and is called a flow pack apparatus.,
In such an apparatus excellent packed articles or products are obtained in an extremely rapid way, however, the obtained packages are difficult to be opened especially when a strong and tenacious packing material is used. the
It is the object of the invention to provide an apparatus of/ above-mentioned type in which packages for articles to be opened easily are obtained.
This object is achieved, in that in the apparatus according o the invention, with respect to the direction of movement of the web of packing material before said means for forming a wrap, a perforating device is provided consisting of two rollers driven in synchronism, of which the one roller is provided with at least one perforating knife and of which the other roller is provided with at least an anvil for cooperating with the perforating knife, and means for guiding the'web of packing material between said rollers.
In this way a packed article is obtained of which the package has a cap-shaped portion which may be readily torn off along the perforated line, whereas when the ends of the perforated line are spaced apart from the adjacent edges of the web of packing material, which spacings are at least equal to the width of the longitudinal sealing seam, said cap-shaped portion of the package has a'pivot line so that said cap-shaped portion may be folded back around the article again.
In order to prevent that by the perforated line the package becomes less air-tight, at least at the location of the perforated line the packing material is coated by a fusible sealing agent which agent is subsequently heated for sealing by fusion the perforations.
As it is often desired that in one and the same apparatus articles of different lengths may be packed, for which the velocity at which the web of packing material is supplied, should be variable, also the rotational velocity of the two rollers driven in synchronism should be adaptable to the varying velocities of the web of packing material at the moment at which the perforating knife cooperates with the anvil, since the perforating knife together with the anvil should have nearly the same velocity as the web of packing material during their cooperation, as otherwise the web of material would tear.
In order to provide for this the rollers are in driving connection with each other, whereas one of said rollers is in driving connection with a crank mechanism the connecting rod of which is coupled at its other end to a second crank mechanism which is in driving connection with a driving shaft of the packing apparatus, one of the crank mechanisms being mounted for displacement so that the axis of the pivot shafts of the two crank mechanisms may be displaced in parallel relation in a direction with respect to each other.
In this way, by displacing the one crank mechanism the rotational velocity of both rollers at the moment of cooperation between the knife and the anvil may be changed, whereas the rollers always make one complete revolution during a predetermined invariable unit of time, the overall speed of revolution being determined by the rotational velocity of the driving shaft.
Preferably the driving shaft is coupled to the second crank means mechanism by means of a chain, being provided for adjusting the position of the second crank mechanism with respect to the driving shaft. In this way the location at which the perforation line is formed on the packing material may be adjusted.
The invention will be explained in more detail while refe- ring to the embodiments shown in the drawing.

Fig. 1 shows in three dimensional views a packed article produced by the method according to the invention, and figure 2 the same article, in which a cap-shaped portion of the package is torn open.
Fig. 3 shows in side-elevation the device according to the invention .for forming a perforated line in the web of packing material.
Fig. 4 shows on an enlarged scale said perforating device in front-view.
Fig. 5 is a cross-section along the line V-V in figure 4.
Fig. "6 shows schematically the operation of the crank mechanism of the perforating device.
Fig. 7 shows in side-elevation the driving mechanism of the perforating device.

As shown in fig. 1 and 2 the package comprises a sheet of packing material enclosing the article, said material being closed by means of a longitudinal sealing seam 1 and two transverse sealing seams 2 and 2'. With reference number 3 a perforated line is indicated formed in the packing material and extending around the article except for the upperside along which the longitudinal sealing seam extends. As shown in fig. 2 in which the package is illustrated reversely with respect to fig. 1, a cap-shaped portion 4 may be torn off along the perforated line 3 and may be folded downwards along a pivot line extending in the plane where the perforated line does not extend, so that the article 5 may be removed from the package, while the exposed portion of the article if eatable may be bitten off, whereafter the cap-shaped portion 4 may be folded back again.
As shown in the figures 3, 4 and 5 the device for producing a perforated line in the web of packing material comprises two rollers 6 and 7 of which the roller 6 is provided with a perforating knife 8 capable of cooperating with an anvil 9 in the roller 7. The perforating knife 8 is supported within the roller 6 through taps 10 by springs not shown. The rollers 6 and 7 are journaled in the arm 11 fixed to the upright 12 of the packing apparatus. On said upright 12 a further arm 13 is fixed in which a roll of packing material 14 is supported. From said roll 14 the web packing material 15 is guided through guiding means 16, 17 and 18 between the rollers 6 and 7 and thereafter over the guiding means 19 and 20 to the proper packing portion of the packing machine.
The rollers 6 and 7 are connected with the shafts 21 and 22 respectively on which intermeshing gears 23 and 23 are provided. The ends of the shafts 21 and 22 are supported in the arm 25, through which the shaft 21 continues and is coupled with a first crank 26. Said first crank 26 is driven by the connecting rod 27, the other end of which is connected with a second crank 28 being driven-'through the chain sprocket 29 and the chain 30 by the driving shaft 31 (see fig. 7). The second crank 28 is provided with a stub axle 32 received for displacement in the plate 33, in which said stub axle 32 is fixed by the nut 34 so that after releasing said nut 34 said stub axle can be shifted up and down by means of the screw 35 with the actuating wheel 36, by which the axis of the pivot shaft of the second crank 28 can be displaced in parallel relation with the pivot shaft of the crank 26.
The operation of the cranks 26 and 28 is illustrated schematically in fig. 6, in which the first crank is indicated by the line 26', the second crank by the line 28' and the connecting rod by the line 29'. The axis of rotation of the second crank is M and that of the first crank N. By rotating the second crank 28' its end a moves along the circular path 37, in which the movement of the crank is_uniform as indicated by the.points b,c........ w,x, which points are equally spaced apart, while for covering the distance between each two points the same time is necessary. The end a' of the crank 26' will move along the circular path 38 and will be positioned at the moments determined by the points a,b ...... _w,x at the points a',b'...... w',x', so that the overall movement of the second crank is not uniform. In passing the points n',o',p', q' the movement of the crank 26' is approximately uniform, the speed along said stretch being equal to the speed of the web of packing material 15, so that along said stretch the perforating knife 8 cooperates with the anvil 9.
When by means of the actuating wheel 36 the distance between the axis of rotation M and the axis of rotation N is changed, as indicated by the position N', the points a" ,b" ... w" ,x" are passed, the points n" ,o" ,p" , q" indicating clearly that the rotational speed of the rollers 6 and 7 is faster during the cooperation of the perforating knife 8 with the anvil 9.
It is also possible that the rollers 6 and 7 are not driven directly through the crank mechanism 26,27 and 28 but through a deceleration mechanism, for example consisting of intermeshing gears, which deceleration mechanism is arranged between the crank mechanism 26,27 and 28 and the driven shaft 21 so that along two or more parts of complete revolution the rollers 6 and 7 obtain the velocity distribution produced by the crank mechanism 26, 27 and 28 as shown in.fig. 6, so that two or more perforating knifes and cooperating anvils can be mounted in the rollers 6 and 7 respectively.
As shown in fig. 7 the chain sprocket 29 is driven through a chain 30 by the driving shaft 31, said driving shaft making a complete revolution for each product passed through the packing apparatus. The chain 30 is guided through two fixed guiding wheels 37 and 38 along two displacable guiding wheels 39 and 40 to the chain sprocket 29. The guiding wheel 39 is journaled in a pivotable arm 41, which arm can be moved up and down by means of the threaded rod 42 and the actuating wheel 43. The guiding wheel 40 is supported in a pivotable arm 44 to which a spring 45 is fixed, by which the guiding wheel 40 is always maintained in engagement with the . chain 30. By rotating the actuating wheel 43 the position of the guiding wheel 39 is varied, by which also the guiding wheel 40 is displaced and the chain sprocket 29 is rotated with respect to the driving shaft 31, by which the locations where the perforated lines are formed onto the packing material can be adjusted.

Claims

1. An apparatus for packing articles or bundles of articles, comprising means for continuously feeding the articles to be packed in spaced apart relation, means for the continuous supply of a continuous web of packing material, means for wrapping said material around the articles, means for advancing the wrap, means for adhering the longitudinal sealing seam portions to each other, and means for forming the transverse sealing seams and severing these seams, said apparatus being characterized in that with respect to the direction of movement of the web of packing material before said means for forming a wrap, a perforating device is provided consisting of two rollers driven in synchronism, of which the one roller is provided with at least one perforating knife and of which the other roller is provided with at least an anvil for cooperating with the perforating knife, and means for guiding the web of packing material between said rollers.

2. Apparatus according to claim 1, characterized in that the rollers are in driving connection with each other, whereas one of said rollers is in driving connection with a crank mechanism the connecting rod of which is coupled at its other end to a second crank mechanism which is in driving connection with a driving shaft of the packing apparatus, one of the crank mechanisms being mounted for displacement so that the axis of the pivot shafts of the two crank mechanisms may be displaced in parallel relations in a direction with respect to each other..

3. Apparatus according to claim 2, characterized in that a driving shaft is coupled with a second crank mechanism by means of a chain, whilst means are provided for adjusting the position of the crank mechanism with respect to the driving shaft.

4. Apparatus according to claims 1-3, charactenzed in that said perforating knife has a length such that the ends of the formed perforated line are spaced apart from the adjacent edges of the web of packing material, said spacings being at least equal to the width of the longitudinal sealing seam.

5. Apparatus according to claims 1-4, characterized in that means are provided for coating the packing material, at least at the location of the perforated line, by a fusable agent and heating said agent, for closing the perforation openings.