[0001] Flexible bands with transversely applied suction tubes (hereinafter called "suction
tube bands") are used in the packaging industry to make possible the mechanical and
automatic application of suction tubes to packing containers. The suction tube band
comprises suction tubes which are wrapped in individual protective envelopes adapted
to the shape of the suction tube. The protective envelopes in turn are joined to one
another so that a band of coherent, wrapped, suction tubes is formed. The wrapped
suction tubes are arranged transversely in relation to the band are event ly spaced.
The protective envelopes may be in the form of separate sleeves, which are joined
to one another by means of narrow bands or strips of paper or plastics, but they may
also constitute integrated parts of the flexible band. A suction tube band thus may
comprise two webs of plastic material between which the suction tubes are placed.
The webs are joined to one another at least in the zones surrounding the suction tubes
are held enclosed in individual, closed protective envelopes.
[0002] Suction tube bands of the type described above are used to make possible the mechanical
and automatic application of individual suction tubes wrapped in the protective envelopes
to packing containers e.g. for juice or other beverages which are intended to be drunk
directly from the packing container with the help of suction tubes. To facilitate
the automatic handling of the wrapped suction tubes, the suction tubes are fed to
the machine in the form of the said suction tube band, whereupon the machine separates
one wrapped suction tube at a time from the band and transfers and applies it to a
packing container passing through the machine. A machine of this type is described
e.g. in Swedish patent application no. 780 10 67-5.
[0003] As the suction tube band is in the form of two plastic webs sealed to one another,
between which are enclosed the suction tubes, certain difficulties arise sometimes
for the application machine or the applicator in separat ting the individual, wrapped
suction tubes from the suction tube band. These difficulties are associated with the
fact that the demand for accurate and exact cutting off of the individual protective
sleeves is difficult to combine with the high operating speed of the applicator. Moreover,
the plastic material of which the suction tube band is made is comparatively tough
and difficult to break up, causing the material to stretch, so that the severing is
rendered more difficult and the cut will be incomplete or end up in an incorrect position,
which involves the risk of the protective envelope being broken, so that it can no
longer fulfil its object of protecting the wrapped suction tube from contaminations.
[0004] It is an object of the present invention to provide a flexible suction tube band
which overcomes the aforementioned disadvantages and which is particularly suitable
for use in suction tube applicators which operate at high speed.
[0005] It is a further object of the present invention to provide a flexible suction tube
band wherein the individual suction tubes, wrapped in protective envelopes, are securely
joined to one another, but still allow separation from each other in connection with
the application to the individual packing containers.
[0006] It is a further object of the present invention to provide a suction tube band which
at the lowest possible cost is optimally adapted to co-operate with the suction tube
applicator described in Swedish patent application no. 780 10 67-5.
[0007] These and other objects have been achieved in accordance with the invention, in that
a flexible band with transversely applied suction tubes has been given the characteristic
that the band is provided between two suction tubes with a transverse cutting line
which at some distance inside the longitudinal edges of the band meets cuts which,
seen in longitudinal direction of the band, take up a many times greater extent than
the said transverse cutting line. By providing the webs forming the band already during
the manufacture of the flexible suction tube band with suitably located cuts between
the suction tubes, the separation of the individual protective envelopes from each
other in the applicator is facilitated. A special design of the said separating lines
makes it possible, moreover, to ensure, in spite of the flexible character of the
material, a complete separation of the individual suction tube envelopes from one
another even when the applicator operates at high speed.
[0008] Further embodiments of the flexible suction tube band in accordance with the invention
have been given the charactert istics which are evident from one or more of the enclosed
subsidiary claims.
[0009] A flexible suction tube band in accordance with the invention will now be described
in greater detail with special reference to the enclosed schematic drawing which only
shwos the details necessary for an understanding of the invention.
Figure 1 shows part of a suction tube band in accordance with a first embodiment of
the invention.
Figures 2, 3 4 and 5 show further embodiments of the suction tube band in accordance
with the invention.
[0010] The suction tube band in accordance with the invention comprises a band 1 which consists
of two webs of thermoplastic material of equal width placed against each other. The
suction tube band comprises moreover suction tubes 2 which are placed between the
said thermoplastic material webs and are wholly enclosed by the same. The suction
tubes 2 are placed transversely in relation to the band 1, that is to say substantially
at right angles to the longitudinal edges 3 and 4 of the band. The two webs forming
the band 1 are of a width which somewhat exceeds the length of the suction tubes 2,
thus making it possible to seal the two webs to one another in a zone (which is indicated
as a hatched area in figure 1, corresponding zones existing also in the other embodiments
shown, but having been left out in figures 2 - 5, so as not to impair the clarity
of the figures) which wholly encloses each individual suction tube 2, so that each
suction tube is enclosed in an airtight suction tube envelope 5.
[0011] To facilitate the separation of the individual suction tube envelopes 5 from the
coherent suction tube band 1 on applit cation of a suction tube wrapped in an envelope
to a packing container with the help e.g. of the suction tube applicator, which is
shown in Swedish patent application no. 780 10 67-5, the suction tube band in accordance
with the invention has been provided between each individual suction tube with a transverse
cutting line 6, which linearly cuts through the two webs forming the band 1 in the
sealed region between the individual, airtight suction tube envelopes 5. The cutting
line 6 extends transversely over the suction tube band 1 but terminates at some distance
inside the two longitudinal edges 3, 4 of the band 1, so that two strips or bridges
7 are formed in the band material which strips or bridges hold together the individual
suction tube envelopes to a coherent band. The two strips 7 extend at a distance frome
one another parallel along the longitudinal edges 3, 4 of the suction tube band, thus
ensuring that the individual suction tube envelopes 5 maintain their correct position
in the suction tube band so that the latter obtains a rope-ladderlike form.
[0012] The provision of cutting lines 6, which are produced with the help of heated knives
in connection with the heat- sealing of the two webs to one another, facilitates appreciably
the subsequent separation of the individual suction tube envelopes 5 from the suction
tube band in the applicator. In the said separation now only a cutting through or
punching through of the relatively narrow strips or bridges 7 is required which remain
between end points of the cutting line 6 and the two longitudinal edges 3, 4 of the
suction tube band. This cutting through can be carried out relatively simply compared
with the cutting over the whole width of the band necessary previously. However, during
continuous operation at high speed certain difficulties arise when the two necessary
cuts have to be placed through the strips 7 in the extension of the cutting line 6
made previously, so that a complete separation is achieved. This is connected with
the capacity : of the suction tube band to stretch and, altogether, its ._ flexible
construction which renders difficult a cutting through with the high precision which
is desirable if the cuts are to coincide. To overcome this difficulty, the suction
tube band in accordance with the invention has also been provided with further cuts
which, like the cutting lines 6, are brought about with the help of heated cutting
elements in connection with the manufacture of the suction tube band, and are placed
at the positions at some distance inside the two longitudinal edges 3, 4 of the suction
tube band where the end points of the cutting lines are situated. Each cutting line
6 thus meets at some distance inside the longitudinal edges of the band at both its
ends cuts 8 which seen in longitudinal direction of the band 1 take up a many times
greater extent than the said transverse cutting line 6, whose main direction is in
fact transversely in relation to the band 1. The width of the cutting lines 6 is negligible
and merely corresponds to the necessary thickness of the heated knife by means of
which they are produced. The cuts 8 are linear and extend substantially at right angles
to the cutting line 6, that is to say, the cuts 8 extend in the longitudinal direction
of the suction tube band 1. By the provision of the cuts, the punching through of
the strips 7 in the applicator is facilitated appreciably, since the punching no longer
needs to be done with the same precision. To ensure a complete separation of a suction
tube envelope 5 from the remaining suction tube band 1 it is now only necessary for
the cut, which severs the strips 7, to meet or cross at some place the respective
cut 8 and the placing of the cut will no longer be critical. The length of the cuts
8 determines the tolerance which can be allowed in the placing of the separating cut
through the strips 7, and the cuts 8 are made therefore as long as is possible without
any risk of their reaching or negatively influencing the unsealed region of the suction
tube band 1 which forms the airtight suction tube envelope 5.
[0013] The cuts 8 located at the end of each cutting line 6 do not have to be rectilinear
and parallel with the two edges 3, 4 of the suction tube band 1. The cuts can also
be endless and enclose portions of the suction tube band which have been removed by
punching-out etc. during the manufacture of the band. As shown schematically in figure
2, each cut thus may be in the form of a circular hole 9 at the end of the cutting
line 6. The hole 9 also serves as a "hollow recess", which prevents that on stressing
of the suction tube band the cutting line 6 is unintentionally widened or extended
to the edge of the suction tube band. The hole 9 is obtained in the same manner as
the linear cuts 8 described earlier, at the same time as when the cutting line 6 is
produced with the help of a heated knife or punching element, during the manufacture
of the suction tube band. In connection therewith, however, waste material is produced
which must be taken care of so as not to affect the manufacturing process by acting
as an obstacle and diminishing the rate of production.
[0014] In figure 3 is shown a further embodiment of the flexible suction tube band in accordance
with the invention, wherein the cut has been given the form of a substantially triangular
hole 10. The triangular hole 10 has the advantage over the circular hole described
earlier that it has a distinctly limited area which makes it possible to produce the
hole by melting off the thermoplastic material in connection with the production of
the cutting line 6. Consequently the handling and taking care of.waste material during
the manufacture of the suction tube band can be avoided.
[0015] Naturally the portions removed, or the holes, may also have other shapes. The important
thing is, that the extension of the hole, seen in longitudinal direction of the band,
is greater than the corresponding width of the cutting line 6, so that the placing
of the supplementary cuts, in connection with the separation of the individual suction
tube envelopes from the band, is facilitated, and that the shape of the hole is such
that the hole serves as a recess at the end of the cutting line. A hole of approx.
5mm diameter has been found to be satisfactory and appreciably increases the area
within which the supplementary cuts can be placed, since normally the width of the
main cut will be less than 1 mm. The distance between two suction tubes located next
to each other is typically l5mm.
[0016] In figures 4 and 5 further ambodiments of the suction tube band in accordance with
the invention are shown, which embodiments differ from the embodiments shown earlier
in that the strips or bridges 7, which hold together the individual, airtight suction
tube envelopes 5 to a coherent suction tube band, are situated a small distance inside
the two edges 3 and 4 of the suction tube band. The reason for this is that the feed
and the guiding of the suction tube band through the applicator should be possible,
through the collaboration between the feed and guiding elements of the applicator
and edge area of the suction tube band, without the severing of the strips 7 being
affected by or hindering the feed. This has been achieved in accordance with the invention
in that further cutting lines 6' extend from the edges 3, 4 of the web inwards between
two suction tubes 2, which cutting lines 6' are terminated by cuts 8' which in longitudinal
direction of the suction tube band 1 take up a many times greater extent than the
said cutting line 6'. The two cuts 8 and 8' together demarcate the strips or bridges
7 holding together the suction tube envelopes, and in the subsequent separation of
the individual suction tube envelopes from the suction tube band in the applicator,
the severing may be carried out anywhere along the whole length of the strips 7, thus
reducing the need for precision and ensuring good and faultless functioning of the
applicator.
[0017] As indicated in figure 5, the cuts 8' may also enclose removed portions of the band,
so that the cuts substantially obtain the form of circular holes 9'.
[0018] By the invention a suction tube band is provided which, in spite of being easy to
handle and extremely simple, can be broken up into individual suction tube envelopes
with the help of a suction tube applicator of known type. Owing to the design of the
suction tube band, the division into individual suction tube envelopes may be done
at great speed without safety being endangered, and, owing to the special design of
the suction tube band, moreover, optimum operational safety is achieved, even if the
position of the band, owing to its flexibility, varies within wide limits at the instant
of severance.
1. Flexible band with transversely applied suction tubes, characterized in that the
band (1) is provided between two suction tubes (2) with a transverse cutting line
(6) which at some distance inside the longitudinal edges (3, 4) of the band meets
cuts (8) which, seen in longitudinal direction of the band (1) take up a many times
greater extent than the said transverse cuting line (6).
2. Flexible band in accordance with claim 1, characterized in that the cuts (8) are
linear and extend substantially at right angles to the cutting line (6).
3. Flexible band in accordance with claim 1 characterized in that the cuts (8) enclose
portions of the band (1) which have been removed.
4. Flexible band in accordance with claim 3, characterized in that the cuts are constituted
by circles (9).
5. Flexible band in accordance with claim 3, characterized in that the cuts are constituted
by triangular holes (10).
6. Flexible band in accordance with anyone of the preceding claims, characterized
in that the cuts terminate the cutting line (6).
7. Flexible band in accordance with anyone of the preceding claims, characterized
in that further cutting lines (6') extend from the edges (3, 4) of the web (1) and
in between two suction tubes (2) which cutting lines (6') are terminated by cuts (8')
which, seen in longitudinal direction of the band (1) take up a many times greater
extent than the said cutting lines (6').