[0001] This invention relates to packaging machines and in particular to packaging machines
for packaging articles in flexible sheet material.
[0002] Hitherto packaging machines for packaging articles in flexible sheet material have
taken many forms and in some cases the resulting package has been sealed so that the
article does not make contact with atmosphere until opened. In its simplest form the
article may be placed in an open-ended bag, the open end being sealed after insertion.
However with this and other arrangements the article is freely movable within the
sealed package and, in cases in which the article is bulky, the resultant package
occupies considerable volume and contains a large volume of air.
[0003] In some packaging machines there have been attempts to ensure that the packaging
material closely conforms to the shape of the article, for example in U.S. Patent
No. 4,244,158 in which pockets are formed in cooperating rollers to receive the articles,
and sheets of packaging material are sealed around each article during passage between
the rollers. British Patent No. 1,481,240 discloses a packaging machine in which articles
are located in pockets, the shape of the article, during packaging in sheet material.
[0004] Such machines are unable to accept articles other than those which fit into the pockets
and during packaging there is no requirement to reduce the bulk of the packaged articles.
[0005] An object of the invention is to provide an improved packaging machine capable of
enveloping articles in flexible sheet material closely conforming to the article and
with the possibility of reducing the bulk of the article.
[0006] According to the invention a packing machine comprises support means for articles
to be packaged, a rotatable member located above the support means, drive means for
causing relative movement between the support means and the rotatable member, and
sealing means, whereby the article, enveloped in packaging material, is moved between
the support means and the rotatable member, the rotatable member having yielding means
about its periphery and the yielding means and the support means being so positioned
relative to one another that the yielding means yields under engagement by the article
during said movement and the sealing means sealing the packaging material around the
article.
[0007] Preferably the support means comprises conveyor means for conveying the article relative
to the rotatable member but the rotatable member may be moved relative to the support
means.
[0008] Conveniently the packaged article passes over downwardly-directed support means after
said movement between the support means and the rotatable means. In this way after
the article has been enveloped and sealed in the packaging material the package moves
downwardly about a transversely-extending line adjacent the rotatable means and this
places the packaging material in tension. In one arrangement the downwardly-directed
means is a support surface inclined downwardly from the rotatable member.
[0009] Preferably the rotatable member is in the form of a roller around which is located
said yielding means, the periphery of the yielding means being in close proximity
to the support means. Alternatively the rotatable means may be in the form of endless
belt or web about which the yielding means is located. In either case the yielding
means may be in the form of a web of resilient yieldable material, the thickness of
the web being selected according to the nature of the article to be packaged.
[0010] The sealing means may include at least one sealing element reciprocatable transverse
to the direction of said movement to seal together packaging material located above
and below the article immediately after the passage of the article between the rotatable
member and the support member. The sealing means may also include sealing elements
for sealing together the longitudinal edges of the packaging material during a packaging
operation.
[0011] Preferably the sealing means includes ultrasonic sealing means for sealing the packaging
material together and the sealing means may be in the form of a wheel and cooperating
support between which the packaging material passes to seal the upper'and lower sheet
material together at one end or both ends of the package and at the sides of the package.
[0012] The machine may include packaging material feed means for feeding sheet packaging
material above and below the article prior to the passage of the article between the
support means and the rotatable member.
[0013] Further features of the invention appear from the following description of an embodiment
of the invention given by way of example only and with reference to the drawing which
is a perspective view of a packaging machine.
[0014] Referring to the drawing a packaging machine is shown which is suitable for packaging
articles in flexible sheet material to form packages which are sealed from atmosphere
and which have minimum air content within the package. The machine is intended to
have particular application to the packaging of soft articles whose bulk can be reduced
during the packaging operation but it may also find application in the packaging of
other articles.
[0015] The machine includes a feed conveyor 10 in the form of an endless belt 11 driven
by drive means (not shown) to convey articles 12 towards and through a packaging station.
The conveyor 10 provides a support for the article 12 during a packaging operation
and for this purpose the belt 12 is either rigidly constructed in its transverse direction
or a support for the upper side of the belt is provided to resis downward deflection
of the belt.
[0016] A compression conveyor 13 is located above the conveyor 10 and i.s inclined downwardly
in the directi of travel of the article 12 to approach the conveyor 10 at one end.
The conveyor 13 is in the form of an endless belt 14 passing over rollers 15 and driven
by drive means (not shown).
[0017] Sheet plastics film 17 and 18 is fed to the conveyors 10 and 13 to lie above and
below the articles 12 and to be drawn with the article towards the packaging station.
The lower sheet 18 is fed off a film carrier 19 over the feed end of the conveyor
belt 11 to be on tho upper surface of the belt 11 and below the articles 12. The upper
sheet 17 is fed off a further film carrier (not shown) around the upper end of the
conveyor 13 and along the lower surface of the belt 14 to lie on top of the article
12.
[0018] The plastics film 17 and 18 is flexible and is of the kind capable of being welded
together by the application of heat either by ultrasonic welding means (as described)
or alternatively by electrically heated welding elements or bars.
[0019] It will be seen that when the articles to be packaged are relatively bulky, as for
example with pillows, blankets, clothing and the like, the conveyor 13 engages the
upper sides of the articles and as the article moves along the conveyor 10 compression
of the article takes place progressively over the length of the conveyor 13.
[0020] As the articles pass from under the leading end of the conveyor 13 the longitudinal
edges of the film 17 and 18 are welded together by welding means 21 at opposite sides
of the conveyor 10. As shown the welding means 21 (of which only one is seen) are
in the form of ultrasonic welding wheels 22, above the film, which rotate about a
horizontal axis and cooperate with a fixed anvil 23 located below the film. The application
of the wheels 22 to the film generates heat in the film and this causes the two sets
of longitudinal edges to be welded together to form longitudinal seals between the
film sheets 17 and 18.
[0021] After passing under the leading end of the conveyor 13 the article passes between
a gap defined by the conveyor 10 and a roller 25. The roller 25 is driven to rotate
about its axis by drive means (not shown) and the periphery of the roller is formed
by a layer 26 of yielding material which yields in the radially inwards direction
of the roller. The outer surface of the roller 25 is normally in engagement with or
in close proximity to the upper surface of the conveyor 1.0, but when an article passes
between the roller and the conveyor 10 the yielding material deforms to create a gap
through which the article passes, at the same time applying a downward pressure on
the article to compress the article, if it is compressible, to force out air between
the sheets 17 and 18, and to cause the sheets 17 and 18 at the front and rear and
sides of the article to come together.
[0022] The yielding material of the roller is generally resilient and may take several forms.
It may be flexible foamed or cellular plastics or rubber material, it may be an inflatable
annular bag, or a plurality of axially extending inflatable bags around the roller.
The roller may alternatively carry a plurality of radially-extending filaments or
brushes. The yielding material may be fixed to an inner cylindrical member or the
material may be in the form of an annular sleeve replaceable to enable sleeves of
different thicknesses to be employed for different- sized articles.
[0023] The axis of the roller 25 may be vertically adjustable to accommodate differently-sized
sleeves and/or differently-sized articles.
[0024] Transverse seals between successive articles are formed in the packaging material
17 and 18 after the material has emerged from under the roller 25. Sealing means 27
is provided for this purpose and in the illustrated arrangement the sealing means
27 is an ultrasonic sealing wheel 28 rotatable about a horizontal axis and reciprocable
at right angles to the direction of movement of the articles 12. The sealing means
27 is mounted on rails 29 carried on supports 32 and is driven along the rails 29
by a drive arrangement including a rotatable rod 30 extending through a carrier 31
and including an archmedian screw drive (not shown) between the rod 30 and the carrier
31. The rod 30 is rotated by drive means (not shown) to move the carrier and the wheel
in a film sealing operation along the rails 29. The material 17 and 18 is welded together
by a transverse strip of the material being located between the wheel 28 and an anvil
33 under the material, and is heated and sealed by the generation of heat in the material
by the ultrasonic wheel 28.
[0025] In one arrangement the welded strip produced is wide enough for a transverse cutting
operation to be effected along the centre of the weld to separate the resulting packages
from one another. Alternatively two wheels 28 may be provided which are arranged to
make spaced transverse welds and the material may be cut between the welds to separate
the articles from one another.
[0026] In either case the wheel 18 or wheels may effect a weld during each transverse movement
or a welding movement may alternate with a return, non-operative movement.
[0027] A welding movement of the wheel 28 is initiated when sensing means (not shown) senses
that the articles 12 emerging from the roller 25 have moved past the wheel 28 and
material 17 and 18 between successive articles lips between the wheel 28 and the anvil
33. Operation of the conveyors 10 and 13 and the roller 25 is temporarily interrupted
to arrest the articles 12 during a transverse, welding operation.
[0028] After articles 12 have passed from under the roller 25 they move onto a discharge
chute 35 which is inclined at an acute angle to the horizontal, downwardly away from
the roller. While on the chute 35 the articles tend to slide down the chute 35 and
put the sheet material connecting the article on the chute with the next succeeding
article under tension about the line of the anvil 33 or the upper edge of the chute.
The tension thus generated tends to even out any unevenness in the material and ensures
an even finish to the packages thus formed.
[0029] By the machine described it will be seen that a continuous succession of packaged
articles is produced in which the articles may be compressed and retained in their
compressed condition in the package until the package needs to be opened. Moreover
the package can be sealed against atmosphere and the package can be arranged to contain
a minimal amount of air. Thus the packaging machine can be of particular application
to the packaging of textile articles which, if well dried before packaging, will quickly
recover their original shape, if compressed, packed and maintained in their dry state,
when removed from the packaging material.
[0030] The machine may also find application with incompressible articles to be sealed between
the sheets of packaging material.
[0031] Instead of using individual lengths of sheet material, as described, the articles
may be packaged in plastics bags, open at one end to admit the articles, and placed
on the conveyor 10 so that the open end is directed upstream during movement along
the conveyor 10 and under the roller 25. In this case the article may be compressed
as before and much of the air removed from the bag before the bag emerges from under
the roller. The open end is sealed by transversely moving sealing means a described,
the longitudinal sealing means being omitted.
[0032] As an alternative to the use of a cylindrical roller 25 and upper conveyor 13 a combined
arrangement including an endless rotatable web around which is located a yielding
material may be provided. Over its operative part the web may extend obliquely downwardly
towards the conveyor 10 and then around a cylindrical roller corresponding to the
roller 25.
[0033] Instead of the transverse welding arrangement described the roller 25 may incorporate
an axially-extending heated welding bar or bars cooperating with a fixed anvil to
effect a transverse weld or welds during rotation of the roller without interrupting
movement of the articles along the conveyor 10.
[0034] The conveyor 10 may be replaced by a reciprocable table on which the articles are
successively placed, the table moving under the roller to effect a packaging operation
and then returning for a further article to be placed thereon.
[0035] The ultrasonic welding wheels described may be replaced by an ultrasonic welding
horn of known form.
1. A packing machine comprises support means (10) for articles (12) to be packaged,
a rotatable member (25) located above the support means, drive means for causing relative
movement between the support means and the rotatable member, and sealing means (22,
28), whereby the article (12), enveloped in packaging material (17, 18), is moved
between the support means and the rotatable member, characterised in that the rotatable
member (25) has yielding means (26) about its periphery and the yielding means and
the support means (10) being so positioned relative to one another that the yielding
means yields under engagement by the article (12) during said movement, and the sealing
means (22, 28) sealing the packaging material (17, 18) around the article.
2. A machine according to claim 1 wherein the support means comprises conveyor means
(10) for conveying the article (12) relative to the rotatable member (25).
3. A machine according to claim 1 or 2 wherein the packaged article (12) passes over
downwardly-directed support means (35) after said movement between the support means
(10) and the rotatable means (25).
4. A machine according to claim 3 wherein the downwardly-directed means (35) is a
support surface inclined downwardly from the rotatable member (25).
5. A machine according to any one of the previous claims wherein the rotatable member
(25) is in the form of a roller around which is located said yielding means (26),
the periphery of the yielding means being in close proximity to the support means
(10).
6. A machine according to any one of the preceding claims wherein the yielding means
(26) is in the form of a web of resilient yieldable material, the thickness of the
web being selected according to the nature of the articles (12) to be packaged.
70 A machine according to any one of the preceding claims wherein the rotatable member
(25) is a cylindrical roller and the yielding means (26) is a sleeve of yielding material
located about the roller.
8. A machine according to any one of the preceding claims wherein the sealing means
includes at least one sealing element (28) reciprocable transverse to the direction
of said movement to seal together packaging material (17, 18) located above and below
the article (12) immediately after the passage of the article between the rotatable
member (25) and the support member (10).
9. A machine according to claim 8 wherein the sealing means (22, 28) includes ultrasonic
sealing means for sealingthe packaging material (17, 18) together.
10. A machine according to any one of the preceding claims comprising packaging material
feed means (19) for feeding sheet packaging material (17, 18) above and below the
article (12) prior to the passage of the article between the support means (10) and
the rotatable member (25).