U.S. patent application number 10/366812 was filed with the patent office on 2003-06-26 for film material for air-filled packing cushions.
This patent application is currently assigned to Free-Flow Packaging International, Inc.. Invention is credited to Borchard, Philipp, De Luca, Nicholas P., Perkins, Andrew, Reyes, Oliver M..
Application Number | 20030118778 10/366812 |
Document ID | / |
Family ID | 24561679 |
Filed Date | 2003-06-26 |
United States Patent
Application |
20030118778 |
Kind Code |
A1 |
Perkins, Andrew ; et
al. |
June 26, 2003 |
Film material for air-filled packing cushions
Abstract
A machine which inflates and seals pillows in packaging is
compact in overall size, can be conveniently operated to produce
varied lengths of strips of inflated pillow-type packaging as
needed, can begin production of inflated pillow-type strip
packaging immediately after being held out of a production cycle
for some period of time, and applies a heated sealing element
directly to and in sliding contact with a web of film to securely
seal the inlet port of an inflated pillow while the pillow is under
pressure and as the web of film is continuously and uninterruptedly
advanced through the machine.
Inventors: |
Perkins, Andrew; (Berkeley,
CA) ; Reyes, Oliver M.; (Berkeley, CA) ;
Borchard, Philipp; (San Francisco, CA) ; De Luca,
Nicholas P.; (San Francisco, CA) |
Correspondence
Address: |
Edward S. Wright, Esq.
Suite 3400
Four Embarcadero Center
San Francisco
CA
94111-4187
US
|
Assignee: |
Free-Flow Packaging International,
Inc.
Redwood City
CA
|
Family ID: |
24561679 |
Appl. No.: |
10/366812 |
Filed: |
February 13, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10366812 |
Feb 13, 2003 |
|
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09638843 |
Aug 14, 2000 |
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Current U.S.
Class: |
428/166 ;
428/178 |
Current CPC
Class: |
B29C 66/81465 20130101;
Y10T 428/24744 20150115; Y10T 156/1712 20150115; B29L 2031/7138
20130101; Y10T 428/1345 20150115; B29C 66/00441 20130101; B29L
2031/714 20130101; B32B 3/12 20130101; B29C 66/439 20130101; B29C
66/344 20130101; Y10T 156/1737 20150115; B29C 66/232 20130101; B29C
66/1122 20130101; B29C 66/133 20130101; B65D 81/052 20130101; B29C
66/8122 20130101; Y10T 428/1334 20150115; B29L 2022/02 20130101;
B31D 5/0073 20130101; Y10T 428/24562 20150115; B29C 66/83413
20130101; B29C 66/83411 20130101; B29C 66/8511 20130101; Y10T
428/24612 20150115; Y10T 428/24661 20150115; B29C 65/223 20130101;
B29C 66/8122 20130101; B29K 2827/18 20130101 |
Class at
Publication: |
428/166 ;
428/178 |
International
Class: |
B32B 003/00 |
Claims
1. A machine for inflating and sealing pillow patterns in a web of
film while continuously and uninterruptedly advancing the web of
film through the machine, said machine comprising, a first film
transport station for gripping and advancing a web of film in the
machine, said web of film having uninflated pillow patterns and an
uninflated inflation channel which are preformed in the web of film
before the web of film is gripped at the first film transport
station, said uninflated pillow patterns comprising multiple,
spaced-apart, pillow patterns aligned along one side of the
inflation channel which extends longitudinally and continuously
along the entire length of the web of film, each uninflated pillow
pattern having a narrow width inlet port extending generally
transversely to the longitudinally extending inflation channel and
connecting the uninflated pillow pattern to the uninflated
inflation channel so that when pressurized air is introduced into
the inflation channel the pressurized air can be transmitted
through the inlet port to inflate the pillow pattern, an inflating
station for inflating pillows in the web of film, a sealing station
for sealing inflated pillows by sealing the narrow width inlet
port, a slitting station for slitting the inflation channel to
permit removal of a strip of inflated, sealed pillows from the
machine, and a second film transport station for gripping and
advancing the web of film, said sealing station including a sealing
wheel and a heated sealing element biased toward engagement with a
preselected force, and wherein a longitudinally extending portion
of the web of film which contains the inlet ports is interposed
between and pressed between the heated sealing element and the
sealing wheel with one film surface engaged directly and in sliding
contact with the heated sealing element and the other film surface
wrapped in rolling contact around a part of the peripheral surface
of the sealing roller as the web of film is continuously and
uninterruptedly advanced through the sealing station, and wherein
the seal is formed complete and secure at the time the web of film
moves out of rolling contact with the sealing wheel without the
need for additional pressing together of the web of film after the
sealing station and without the need for additional cooling of the
seal across the inlet port.
2. The machine defined in claim 1 wherein the web of film is
gripped at the first film transport station between a first pair of
nip rollers and wherein the film is gripped at the second film
transport station between a second pair of nip rollers and wherein
the sealing roller is positioned with respect to the first and
second pairs of nip rollers so as to cause the web of film to wrap
around a part of the peripheral surface of the sealing roller both
in a circumferential direction and also in a lateral direction to
create a dead zone in the area where the inlet port is being
sealed.
3. The machine defined in claim 1 including adjustable means for
adjusting the amount of said preselected force.
4. The machine defined in claim 1 wherein the sealing wheel is
mounted for rotation at a fixed location in the machine and the
heated sealing element is movable toward and away from the sealing
wheel.
5. The machine defined in claim 1 wherein the heated sealing
element is mounted at a fixed location in the machine and the
sealing wheel is movable toward and away from the heated sealing
element.
6. The machine defined in claim 2 wherein the axes of rotation of
at least the second pair of nip rollers are canted at a slight
angle with respect to the axis of rotation of the sealing
roller.
7. The machine defined in claim 2 wherein the second pair of nip
rollers are rotated at a speed slightly faster than the speed of
rotation of the first pair of nip rollers so as to maintain tension
in the web of film between the second and first pair of nip
rollers.
8. The machine defined in claim 1 wherein the heated sealing
element has a longitudinal dimension, in the direction of movement
of the web of film, which is about the same as the width of the
inlet port of a pillow pattern.
9. The machine defined in claim 1 wherein the inflating station
includes an inflation tube which is inserted within the inflation
channel of the web of film so that air under pressure can be
introduced into the inflation channel and wherein the inflation
tube includes a generally ball-shaped outlet end having a diameter
which is substantially the same diameter as the inside diameter of
the inflation channel in the web of film and wherein the spherical
shaped end of the inflation tube has an outer coating of Teflon for
facilitating sliding movement of the inflation tube within the
inflation channel of the web of film.
10. The machine defined in claim 1 wherein the heated sealing
element comprises a fabric covered Nichrome wire with a Teflon
coating on the side of the fabric which is engaged in sliding
contact with the web of film.
11. The machine defined in claim 1 wherein the sealing station
includes a ceramic part which mounts the Nichrome wire within the
ceramic material so that the ceramic part provides insulation
against the spread of heat into the mounting structure for the
Nichrome wire.
12. The machine defined in claim 1 wherein the preformed pattern in
the web of film includes a series of longitudinally spaced outlet
ports on the side of the inflation channel opposite the side having
the inlet ports for maintaining calibration of the pressure within
the inflation channel and for preventing excessive pressure buildup
in the inflation channel and in the inflated pillows.
13. The machine defined in claim 12 including a sensor positioned
to monitor flow of pressurized air out of the outlet ports and
wherein the monitored flow can be used for counting the number of
inflated pillows produced in a production run and can be used also
for maintaining accurate positioning of the web of film within the
machine.
14. The machine defined in claim 2 wherein the preformed pattern in
the web of film includes a series of longitudinally spaced outlet
parts on the side of the inflation channel opposite the side having
the inlet ports and wherein the outlet ports provide an outlet for
pressure in the inflation channel during the time when the film
adjacent the inlet port being sealed is being pulled closed in the
dead zone of the film engaged with the periphery of the sealing
wheel.
15. The machine defined in claim 5 including a cartridge unit which
contains the heated sealing element and which is constructed so as
to be removed and replaced as a unit without the need to replace
any individual components of the cartridge unit, said cartridge
unit comprising a sub-frame, a guide block having an opening in one
end for the heated sealing element, at least one Nichrome wire
mounted within the opening in the guide block, a storage reel and a
take-up reel, a strip of fabric for covering the Nichrome wire and
wound on the storage reel and the take-up reel, and a drive for
rotating the take-up reel, said strip of fabric having a Teflon
coating on a side engageable in sliding contact with a surface of
the film at the sealing station and wherein the strip of fabric
extends across said opening in the guide block so as to cover the
Nichrome wire when the sealing wheel is moved to a position in
which the sealing wheel pushes the film against the fabric and the
underlying Nichrome wire during continuous movement of the film
through the machine.
16. A machine for inflating and sealing pillow patterns in a web of
film while continuously and uninterruptedly advancing the web of
film through the machine, said machine comprising, a first film
transport station for gripping and advancing a web of film in the
machine, said web of film having uninflated pillow patterns and an
uninflated inflation channel which are preformed in the web of film
before the web of film is gripped at the first film transport
station, said uninflated pillow patterns comprising multiple,
spaced-apart, pillow patterns aligned along one side of the
inflation channel which extends longitudinally and continuously
along the entire length of the web of film, each uninflated pillow
pattern having a narrow width inlet port extending generally
transversely to the longitudinally extending inflation channel and
connecting the uninflated pillow pattern to the uninflated
inflation channel so that when pressurized air is introduced into
the inflation channel the pressurized air can be transmitted
through the inlet port to inflate the pillow pattern, an inflating
station for inflating pillows in the web of film, a sealing station
for sealing inflated pillows by sealing the narrow width inlet
port, a slitting station for slitting the inflation channel to
permit removal of a strip of inflated, sealed pillows from the
machine, and a second film transport station for gripping and
advancing the web of film, said sealing station including a sealing
wheel and a heated sealing element biased toward engagement with a
preselected force, the heated sealing element being mounted at a
fixed location in the machine and the sealing wheel being movable
toward and away from the heated sealing element, and wherein a
longitudinally extending portion of the web of film which contains
the inlet ports is interposed between and pressed between the
heated sealing element and the sealing wheel with one film surface
engaged directly and in sliding contact with the heated sealing
element and the other film surface wrapped in rolling contact
around a part of the peripheral surface of the sealing roller as
the web of film is continuously and uninterruptedly advanced
through the sealing station, a cartridge unit which contains the
heated sealing element and which is constructed so as to be removed
and replaced as a unit without the need to replace any individual
components of the cartridge unit, said cartridge unit comprising a
sub-frame, a guide block having an opening in one end for the
heated sealing element, at least one Nichrome wire mounted within
the opening in the guide block, a storage reel and a take-up reel
mounted for rotation on the sub-frame, a strip of fabric for
covering the Nichrome wire and wound on the storage reel and the
take-up reel, and a drive for rotating the take-up reel, said strip
of fabric having a Teflon coating on a side engageable in sliding
contact with a surface of the film at the sealing station, and
wherein the strip of fabric extends across said opening in the
guide block so as to cover the Nichrome wire when the sealing wheel
is moved to a position in which the sealing wheel pushes the film
against the fabric and the underlying Nichrome wire during
continuous movement of the film through the machine. and wherein
the seal is formed complete and secure at the time the web of film
moves out of rolling contact with the sealing wheel without the
need for additional pressing together of the web of film after the
sealing station and without the need for additional cooling of the
seal across the inlet port.
17. A method of inflating and sealing pillow patterns in a web of
film while continuously and uninterruptedly advancing the web of
film through a machine, said method comprising, gripping a web of
film at a first film transport station to draw a web of film from a
store, said web of film having an uninflated pillow pattern and an
uninflated inflation channel which are preformed in the web of film
before the web of film is gripped at the first film transport
station, said uninflated pillow patterns comprising multiple,
spaced-apart, pillow patterns aligned along one side of the
inflation channel which extends longitudinally and continuously
along the entire length of the web of film, each uninflated pillow
pattern having a narrow width inlet port extending generally
transversely to the longitudinally extending inflation channel and
connecting the uninflated pillow pattern to the uninflated
inflation channel so that when pressurized air is introduced into
the inflation channel the pressurized air can be transmitted
through the inlet port to inflate the pillow pattern, introducing
pressurized air into the inflation channel in the web of film at an
inflating station and inflating at least one of pillow patterns
prior to the time the web of film is transported through a sealing
station, gripping the web of film at a second film transport
station to continuously advance the web of film from the first
transport station to and through the sealing station and then to
and through the second film transport station, maintaining pressure
in the inflated pillow pattern during the time that the web of film
is being transported through the sealing station, sealing the inlet
port at the sealing station by applying a heated sealing element
directly to and in sliding contact with the web of film and across
the inlet port while the air in the inflated pillow is under
pressure and as the web of film is continuously advanced through
the sealing station, said sealing station including a sealing
roller disposed opposite the heated sealing element, said sealing
roller having part of its periphery engaged in rolling contact with
the film at the sealing station on the side of the film opposite
that engaged in sliding contact with the heated sealing element,
positioning the sealing roller to create a dead zone in the area of
the film engaged in rolling contact with the periphery of the
sealing roller, and forming the seal complete and secure by the
time the web of film moves out of contact with the sealing wheel
without the need for additional pressing together of the film after
the sealing station and without the need for additional cooling of
the seal across the sealed inlet port.
18. The method defined in claim 17 wherein the pre-formed pattern
in the web of film includes a series of longitudinally spaced
outlet ports on the side of the inflation channel opposite the side
having the inlet ports and wherein the outlet ports provide an
outlet for pressure in the inflation channel during the time when
the film adjacent the inlet port is being pulled closed in the dead
zone of the film engaged with the periphery of the sealing
wheel.
19. The method defined in claim 17 wherein the pattern on the web
of film includes longitudinally spaced outlet ports connected to
the side of the inflation channel opposite the side of the
inflation channel having the inlet ports and wherein the outlet
ports maintain calibration of the pressure within the inflation
channel and prevent excessive pressure buildup in the inflation
channel and in the inflated pillows.
20. The method defined in claim 19 including sensing the flow of
pressurized air out of the outlet ports and monitoring the flow to
count the number of pillows inflated in a production run of the
film through the machine.
21. A web of film formed with a pattern of pillows to be inflated
and sealed and then used in packaging, said web of film and pattern
comprising, two sheets of plastic film overlaid one on the other to
form a web of film, said web of film being sealed together in a
pattern, said pattern comprising, an inflation channel which
extends longitudinally and continuously along the entire length of
the web of film, multiple, spaced-apart, pillow patterns aligned
along one side of the inflation channel, each pillow pattern having
a narrow width inlet port extending generally transversely to the
longitudinally extending inflation channel and connecting the
pillow pattern to the inflation channel so that when pressurized
air is introduced into the inflation channel, the pressurized air
can be transmitted through the inlet port to inflate the pillow
pattern, a plurality of longitudinally spaced-apart outlet ports on
the side of the inflation channel opposite the side having the
inlet ports, and wherein the outlet ports are constructed to permit
exhausting the overflow of pressure in the inflation channel while
the pillow patterns are being inflated and being sealed under
pressure.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to methods and apparatus for
inflating and sealing pillows in packaging.
[0002] This invention relates particularly to the construction and
operation of a machine which is small enough to be installed for
operation on site where articles packaged for transport are placed
in shipping containers with protective inflated pillow-type strip
packaging.
[0003] This invention relates particularly to a machine which is
compact in overall size, which can be conveniently operated to
produce varied lengths of strips of inflated pillow-type packaging
as needed, which can begin production of inflated pillow-type strip
packaging immediately after being held out of a production cycle
for some period of time and which applies a heated sealing element
directly to and in sliding contact with a web of film to securely
seal the inlet port of an inflated pillow while the pillow is under
pressure and as the web of film is continuously and uninterruptedly
advanced through the machine.
[0004] This invention relates particularly to a machine which forms
the seal complete and secure during a short path of travel and
during a short interval of time. The seal is made without the need
for additional pressing together of the film after the sealing and
without the need for additional cooling of the seal after the
sealed inlet port moves out of contact with the sealing
structure.
[0005] Webs of plastic film which are constructed to permit the
production of strips of air filled envelopes, cushions and pillows
have (in the past ten years or so) been used extensively for
cushioning objects to be transported in containers.
[0006] The thin webs of plastic film are inexpensive, tough,
resilient and recyclable. Strips of inflated pillow packaging which
are created from these webs of plastic film are used for void-fill
packaging to replace products such as crumpled paper or polystyrene
peanuts and for protective packaging to replace molded or extruded
foams.
[0007] U.S. Pat. No. 5,454,642; U.S. Pat. No. 5,651,237; U.S. Pat.
No. 5,755,328; U.S. Pat. No. 4,017,351; and U.S. Pat. No. 5,824,392
disclose methods, apparatus, and webs of plastic film used for
making strips of inflated pillow packaging of this general kind.
Each of these U.S. patents is incorporated by reference in this
application.
[0008] Co-pending application Ser. No. 09/207,129 filed Dec. 8,
1998 and entitled "Method and Apparatus for Manufacturing
Air-Filled Sheet Plastic Shipping Cushions and the Like", Nicholas
P. De Luca and Andrew Perkins, inventors and co-pending application
Ser. No. 09/439,552 filed Nov. 12, 1999 and entitled "Machine and
Method for Manufacturing a Continuous Production of Pneumatically
Filled Inflatable Packaging Pillows", Andrew Perkins, Philipp
Borchard, and Nicholas P. De Luca, inventors also disclose methods,
apparatus and webs of plastic film of this general kind. Each of
these two co-pending applications is assigned to the same assignee
as the assignee of this application. Each of these two co-pending
applications is incorporated in this application by reference.
[0009] Sealing an inflated pillow made a web of plastic film while
the air inflates the pillow under pressure and while the web of
plastic film is being transported through the machine presents
problems.
[0010] The seal must be secure and must not leak in order for the
inflated pillow packaging to be used effectively for cushioning
objects transported within a container.
[0011] The seal needs to be formed efficiently, quickly and without
extensive, related pressing and/or cooling structure in order to
make the machine as compact as possible in size and as efficient as
possible in production rate.
[0012] To simplify machine construction and to provide a high
efficiency of production, it is desirable to be able to make the
seal as the web of plastic film is moved continuously and without
any interruption and/or intermittent stopping of the film transport
during the sealing operation.
[0013] It is a primary object of the present invention to construct
and to operate a machine which is compact in size, which is
efficient in production, which is continuous and uninterrupted in
operation and which produces seals which are secure and which do
not leak.
SUMMARY OF THE PRESENT INVENTION
[0014] In a specific embodiment of the present invention, a machine
inflates and seals pillows in packaging while continuously and
uninterruptedly advancing a web of film through an inflating
station and a sealing station. The inflating station sequentially
inflates pillows at preformed patterns in the web of film by
introducing pressurized air through a narrow width inlet port of a
preformed pattern. The sealing station seals each inlet port by
applying a heated sealing element directly to and in sliding
contact with the web of film while the air in an inflated pillow is
under pressure as the inlet port moves across the heated sealing
element.
[0015] The web of film has an uninflated pillow pattern and an
uninflated inflation channel preformed in the film. The uninflated
pillow patterns comprise multiple, spaced apart, pillow patterns
aligned along one side of an inflation channel. The inflation
channel extends longitudinally and continuously along the entire
length of the film. Each uninflated pillow pattern has a narrow
width inlet port extending generally transversely to the
longitudinally extending inflation channel and connecting the
uninflated pillow pattern to the uninflated inflation channel so
that, when pressurized air is introduced into the inflation
channel, the pressurized air can be transmitted through the inlet
port to inflate the pillow pattern. In some cases the preformed
pattern is also formed with outlet ports connected to the inflation
channel in such a way that air entering the inflation channel can
move into a pillow through an inlet port and can also exit out of
the inflation channel through the outlet port. The outlet port is
generally shaped smaller than the inlet port.
[0016] By allowing the air above a desired pressure to escape
through an outlet port or ports, the pressure in the inflation
channel is maintained at a desired level for inflating the pillows
without creating over-pressurization.
[0017] The air escaping through the outlet port is also sensed to
detect where the pillows are in the machine. These detected outlet
port positions are then used as signals for an associated
electronic unit to count the number of pillows inflated in a
particular run through the machine. This also facilitates being
able to stop the movement of the film through the machine after one
production run of a selected number of inflated pillows at a
position which is the right position to start a subsequent
production run of a selected number of inflated pillows.
[0018] In a specific embodiment of the present invention, the web
of film with the preformed patterns is stored on a storage roller
of the machine and is advanced through the machine by a first set
of nip rollers and a second set of nip rollers at a respective
first film transport station and a second film transport
station.
[0019] Pressurized air is introduced into the inflation channel of
the web of film at an inflating station as the web of film is
transported through the first film transport station. The
pressurized air inflates at least one of the pillow patterns prior
to the time the web of film is continuously transported through a
sealing station.
[0020] Pressure is maintained in the inflated pillow pattern within
a calibrated pressure range during the time that the web of film is
continuously transported through the sealing station.
[0021] At the sealing station the inlet port of an inflated pillow
is sealed by applying a heated sealing element directly to and in
sliding contact with the web of film. The heated sealing element
slides across the inlet port while the air in the inflated pillow
is under pressure and as the web of film is continuously and
uninterruptedly advanced throughout all components of the
machine.
[0022] The heated sealing element has a relatively small
longitudinal dimension in the direction of movement of the web of
film. In a specific embodiment the length of the heated sealing
element is about the same as the width of the inlet port of a
pillow pattern. This small size of the heated sealing element helps
minimize the amount of sealing heat applied to the web of film.
[0023] The sealing station includes a sealing roller disposed
alongside the heated sealing element so as to permit the web of
film to be advanced between the sealing roller and the heated
sealing element. Adjustable biasing means provide for adjustment of
the force with which the heated sealing element and the sealing
roller are pressed toward engagement with one another.
[0024] The sealing roller is positioned with respect to the first
and second pairs of nip rollers so as to cause the web of film to
wrap around a part of the peripheral surface of the sealing roller
both in a circumferential direction and also in a lateral
direction. This helps create a dead and flat zone right at and
adjacent to the line of sealing across the inlet port. This in turn
facilitates making a secure seal without leaking while the pillow
is inflated under pressure.
[0025] The axes of rotation of at least the second pair of nip
rollers are preferably canted at a slight angle with respect to the
axis of rotation of the sealing roller.
[0026] The second pair of nip rollers are preferably rotated at a
speed slightly faster than the speed of rotation of the first pair
of nip rollers so as to maintain tension in the web of film between
the second and first pair of nip rollers.
[0027] In one specific embodiment of the present invention the
heated sealing element is a fabric covered Nichrome wire disposed
at the end of a bar element which is biased toward engagement with
a sealing roller. The fabric covering of the Nichrome wire has a
Teflon coating on its outer surface for facilitating sliding of the
heated sealing element on the engaged surface of the film as the
web of film is advanced through the machine.
[0028] The bar on which the heated sealing element is mounted is a
composite bar. The very tip of the bar is a ceramic having good
insulating qualities, and the remainder of the bar is a different
material selected to provide enhanced mechanical durability.
[0029] The seal is formed complete and secure during a short path
of travel through the sealing station.
[0030] The seal is complete and secure at the time the web of film
moves out of contact with the wheel at the sealing station and
without the need for additional pressing together of the film after
the sealing station and without the need for additional cooling of
the film across the sealed inlet port after the sealed inlet port
moves out of contact with the sealing station.
[0031] In a second specific embodiment of the present invention the
sealing wheel is pressure biased toward engagement with the heated
sealing element.
[0032] In both the first and second specific embodiments the heated
sealing element and the sealing wheel are spaced apart from one
another when the machine is not transporting the web of film
through the machine in a production run. This enables the heated
sealing element to be maintained at a desired temperature level
while preventing contact with and possible burning of the unmoving
film at the sealing station.
[0033] In one specific embodiment of the invention the fabric
covering for the Nichrome wire is held in a fixed position at the
end of the bar element and is replaced as needed.
[0034] In another specific embodiment of the invention the heating
station includes a cartridge unit which can be quickly and easily
interchanged with another cartridge unit. The cartridge unit
includes an elongated strip of the fabric covering. The strip is
mounted on two rotatable reels. The fabric always covers the
Nichrome wire, as in the first specific embodiment, and the fabric
has a Teflon coating on the side which engages the film in sliding
contact, as in the first specific embodiment. The elongated strip
of fabric covering is wound between the two reels so as to be moved
across the length of the Nichrome wire at a speed which is much
slower than the speed of movement of the film through the machine
but which is fast enough to ensure that the covering strip of
fabric is always effective to function properly without any burn
through of the fabric or damage to the film from the heated
Nichrome wire. The cartridge unit permits the Nichrome wire of the
heated sealing element to be easily disconnected from its power
supply. The cartridge units are constructed to be readily
interchanged as units, rather than having to replace individual
components of the cartridge unit.
[0035] Methods and apparatus which incorporate the features noted
above and which are effective to function as described above
comprise further, specific objects of this invention.
[0036] Other and further objects of the present invention will be
apparent from the following description and claims and are
illustrated in the accompanying drawings, which by way of
illustration, show preferred embodiments of the present invention
and the principles thereof and what are now considered to be the
best modes contemplated for applying these principles. Other
embodiments of the invention embodying the same or equivalent
principles may be used and structural changes may be made as
desired by those skilled in the art without departing from the
present invention and the purview of the appended claims.
BRIEF DESCRIPTION OF THE DRAWING VIEWS
[0037] FIG. 1 is an isometric view of a machine, constructed in
accordance with one embodiment of the present invention, for
inflating and sealing pillows in packaging. FIG. 1 is a general
view which illustrates how a web of film is transported through the
machine. FIG. 1 shows how the web of film has a preformed pattern
of spaced-apart, inflatable pillows aligned along one side of a
longitudinally extending inflation channel. FIG. 1 illustrates how
rollers (at a first transport station, at a sealing station, and at
a second transport station) are positioned to engage the underside
(as viewed in FIG. 1) of the web of film.
[0038] FIG. 2 is another isometric view of the machine shown in
FIG. 1, but in FIG. 2 the lower part of the figure has been revised
to (in effect) see through the web of film in order to show details
of certain structure of the machine. FIG. 2 shows the inflation
tube of the inflating station, the nip rollers of the first
transport station, the heated sealing element and the associated
sealing roller at the sealing station, and the nip rollers at the
second transport station.
[0039] FIG. 3 is an isometric view of the machine of FIGS. 1 and 2,
but without the web of film material. FIG. 3 shows the main
structural and operative features of the machine itself.
[0040] FIG. 4 is an isometric, enlarged view showing details of the
features of the first film transport station, the inflation station
structure, the sealing station structure, the slitting station
structure, and the second film transport station structure.
[0041] FIG. 5 is an isometric, enlarged view like FIG. 4 but shows
details of just the mechanism for driving the various rollers of
the machine. FIG. 5 does not show the inflation station structure,
the heated sealing element at the sealing station, or the slitter
structure for opening up the inflation tube of the web of film
after the sealing station.
[0042] FIG. 6 is an isometric view showing details of the structure
of the sealing station. FIG. 6 shows the heated sealing element
pressed toward engagement with the sealing wheel in the positions
occupied by those two components during a production run of the
inflated pillow packaging through the machine.
[0043] FIG. 7 is a top plan view, taken along the line and in the
direction indicated by the arrows 7-7 in FIG. 6, but showing the
heated sealing element retracted away from the sealing wheel in the
positions occupied by those two components when no film is being
transported through the machine.
[0044] FIG. 8 is a top plan view of a specific embodiment of a web
of film constructed in accordance with the present invention and
having a specific pattern of inflatable pillows, inlet ports for
permitting inflation of the pillows, and escape ports for
preventing over pressurization of the pillows and for also
permitting more accurate position sensing of the pillows as the web
of film moves through the machine.
[0045] FIGS. 9A-9G are a series of the isometric views showing
details of the structure, components and sequence of assembly of
certain components of the heated sealing element at the sealing
station.
[0046] FIG. 10 is an isometric view of a machine constructed in
accordance with a second embodiment of the present invention. The
embodiment of the machine shown in FIG. 10 includes a cartridge
unit which is mounted on a separate sub-plate or sub-frame and
which permits all of the components of the cartridge unit to be
quickly and easily removed and replaced by another, replacement
cartridge unit. The cartridge unit provides the heated sealing
element components for the sealing station. FIG. 10 shows the
sealing wheel of the sealing station positioned to engage the web
of film in sliding contact with the heated sealing element during a
production run of packaging.
[0047] FIG. 11 is an isometric view like FIG. 10 but showing the
sealing wheel moved to a retracted position which permits the web
of film to move out of contact with the heated sealing element when
the machine is stopped between production runs and the film is not
being transported through the machine.
[0048] FIG. 12 is an enlarged, isometric view of the replaceable
cartridge unit itself. FIG. 12 shows the strip of covering fabric
in stored positions on the reels of the cartridge unit prior to
installation of the cartridge unit in the machine. When installed
in the machine, a portion of the strip of covering fabric is
positioned over the wire of the heating element (as illustrated in
FIGS. 10 and 11).
[0049] FIG. 13 is an enlarged, isometric view of the sealing wheel
and the related actuator mechanism for positioning the sealing
wheel at the sealing station.
[0050] FIG. 14 is an enlarged, side elevation view of the sealing
station structure with the structure in the operative position
shown in FIG. 10; and,
[0051] FIG. 15 is an enlarged, side elevation view of the sealing
station structure with the structure in the non-operating position
shown in FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] FIGS. 1, 2 and 3 are isometric view of a machine,
constructed in accordance with one embodiment of the present
invention, for inflating and sealing pillows in packaging.
[0053] The machine is indicated by the general reference numeral 11
in each of FIGS. 1, 2 and 3.
[0054] The machine 11, as most easily viewed in FIG. 3, comprises a
main plate 13 on which various structural and operational features
are mounted.
[0055] A support tube 15 is mounted at the upper (as viewed in
FIGS. 1-3) of the main plate 13 for supporting a roll 17 of a web
of film 19 (see FIGS. 1 and 2).
[0056] Guide tubes 21 and 23 are mounted on the plate 13 below the
tube 15. The tubes 21 and 23 serve to guide the web of film 19 from
the roll 17 to the operating mechanism 25 of the machine 11. The
operating mechanism 25 is described in more detail below.
[0057] The mechanism 25 is illustrated in detail in FIG. 4 and
comprises a first film transport station 27, a second film
transport station 29, an inflating station 31, a sealing station
33, and a slitting station 35.
[0058] The first film transport station 27 includes a first pair of
nip rollers 37 and 39 for gripping the web of film 19 (see FIG. 1)
and for pulling the web of film 19 from the roll 17 and under and
over the guide tubes 21 and 23 and through the first film transport
station 27 when the nip rollers are rotated by associated drive
gears 41, 43 and a drive belt 45. The nip rollers 37 and 39 are
rotated in the directions indicated by the direction arrows on the
drive gears 41 and 43 shown in FIG. 4.
[0059] The drive belt 45 is driven by a drive gear 47 which is in
turn driven by a motor 49 (see FIG. 5).
[0060] The second film transport station 29 comprises a second pair
of nip rollers 49 and 51 which grip the web of film 19 to
continuously advance the web of film 19 from the first transport
station 27 to and through the inflating station 25 and to and
through the sealing station 33 and then to and through the second
film transport station 29.
[0061] The nip rollers 49 and 51 are driven by drive gears 53 and
55 and in the rotational directions indicated by the directional
arrows on the drive gears 53 and 55 in FIG. 4.
[0062] Drive shafts 40 and 44 transmit the drive from the drive
gears 41 and 43 to the nip rollers 37 and 39.
[0063] Drive shafts 50 and 52 transmit the drive from the drive
gears 53 and 55 to the nip rollers 49 and 51.
[0064] With continued reference to FIG. 4, the drive belt 45 passes
about an idler gear 57. The drive gears 41, 43, 47, 53, 55 and
idler gear 57 are all mounted for rotation on and are supported by
the main plate 13.
[0065] The inflating station 31 includes an inflation tube 59 and a
generally spherically shaped and partially Teflon coated ball 61
located at the upper end (as viewed in FIG. 4) of the tube 59. The
ball 61 has a plurality of openings 63 for injecting pressurized
air into an inflation channel in the web of film 19.
[0066] As illustrated in FIGS. 1, 2 and 8, the web of film 19 as
stored on the roll 17 shown in FIG. 1 has a pattern of pillows 65,
a longitudinally extending inflation channel 67, inlet ports 69,
and outlet ports 71 preformed in the web of film. The pillows 65,
channel 67, ports 69 and ports 71 are uninflated in the web of film
as stored on the roll 17.
[0067] The uninflated pillow patterns 65 are longitudinally spaced
apart from one another and are aligned (in the embodiment of the
web of film 19 illustrated in the drawings) along one side of the
inflation channel 67.
[0068] The inflation channel 67 extends longitudinally and
continuously along the entire length of the web of film 19.
[0069] The inflation channel 67 is dimensioned to provide a close,
sliding fit over the Teflon coated ball 61.
[0070] Each pillow 65 is connected to the inflation channel 67 by
an inlet port 69. The inlet port 69 extends generally transversely
to the longitudinally extending inflation channel 67 and has a
narrow interior width which is positioned at the sealing station 33
(in a manner to be described more fully below) to facilitate quick
and secure sealing of pressurized air within an inflated pillow 65
in a small path of travel and in a short time of continuous,
uninterrupted travel through the sealing station 33.
[0071] The outlet ports 71 are shaped to be somewhat smaller than
the inlet ports 69. These outlet ports 51 are located on the side
of the channel 67 opposite the inlet ports 69 and are generally
aligned with the inlet ports 69.
[0072] As will be described in greater detail below, the outlet
ports 71 allow air to escape in a way to maintain pressure in the
channel 67 and in the inflated pillows at a calibrated, desired
level without creating over-pressurization in the pillows.
[0073] In addition, the air that exits from an outlet port 71 can
be sensed by a pressure transducer 73 (see FIG. 8) to allow for
accurate position sensing of the pillows as the pillows move
through the machine 11.
[0074] The air escaping through the outlet ports is sensed to
detect where the pillows are in the machine. These detected outlet
port positions are then used as signals for an associated
electronic unit to count the number of pillows inflated in a
particular run through the machine. This also facilitates being
able to stop the movement of the film through the machine, after
one production run of a selected number of inflated pillows, at a
position which is the right position to start a subsequent
production run of a selected number of inflated pillows.
[0075] The upper end of the inflation tube 59 is formed with a
small curvature so as to better follow the path of the film 19 as
the film is advanced through the first transport station 27 and the
sealing station 33.
[0076] Details of the construction and mode of operation of the
sealing station 33 are illustrated and will be described with
reference to FIGS. 4, 6 and 7.
[0077] The sealing station 33 comprises a sealing roller 75 mounted
on a shaft 77 which is in turn mounted for rotation in a bearing
assembly attached to the main plate 13.
[0078] The sealing station 33 also comprises a heated sealing
element located at the outer end (the right hand end as viewed in
FIG. 7) of a bar 81. The very tip 80 of the bar 81 is a ceramic of
aluminum silicate to provide an insulation function, and the
remainder of the bar 81 is a different material selected for
mechanical durability.
[0079] The bar 81 is mounted for sliding motion within a support
83.
[0080] A spring 85 and an adjustment screw 87 provide a selectable
bias force for biasing the bar 81 toward the opposed periphery of
the roller 75 so that the film 19 (in the longitudinally extending
strip which crosses the inlet ports 69) is pressed in rolling
contact with the outer periphery roller 75 and in sliding contact
with the end surface of the bar 81 as the first and second film
transport stations continuously advance the web of film 19 through
the sealing station 33.
[0081] An actuator 89 is included in the sealing station 33 for
retracting the bar 81 against the bias of spring 85 and away from
engagement with the roller 75 when the film 19 is not being
advanced through the machine 11. This facilitates keeping the
heating element energized at the proper heating level and out of
contact with the film 19 during time intervals when the machine 11
is not being used to produce inflated pillow packaging.
[0082] Details of the structure, components and sequence of
assembly of components of the heated sealing element are shown in
the exploded views of FIGS. 9A-9F.
[0083] The heating element disposed at the end of the bar 81, in a
specific embodiment of the present invention, comprises at least
one Nichrome wire 70 which runs vertically (as viewed in FIGS.
9A-9G) along the right hand end of the bar 81.
[0084] The Nichrome wire 70 at this location has a length about the
same as the throat width of an outlet port 69 in the film 19, and
the Nichrome wire 70 is covered by a fabric 72 having a Teflon
coating on the surface which contacts the film 19. The fabric
covering 72 helps to form the wire 70 to a preferred shape for
engagement with the film 19, and the Teflon coating facilitates
sliding movement of the film 19 with respect to the heated sealing
element.
[0085] The heated sealing element comprises at least one Nichrome
wire 70, but (as illustrated in FIGS. 9A-9F) the present invention
also encompasses using a plurality of parallel extending and
laterally spaced apart Nichrome wires 70 for providing multiple
seal lines across inlet ports 69 of the pillows 65.
[0086] As best illustrated in FIGS. 6 and 7, wires 91 and 93
conduct electricity to the Nichrome wire for heating the Nichrome
wire.
[0087] The slitting station 35 (see FIG. 4) includes a blade 95
attached to the inflation tube 59 and positioned to slit the
inflation channel 67 in the film 19 after the outlet port 69 of a
pillow 65 has been sealed at the sealing station 33. This enables
strips of inflated packaging to be removed from the machine 11.
[0088] It is an important feature and benefit of the present
invention that the components of the mechanism 25 and the coaction
between those components enable a seal to be formed complete and
secure in a short path of travel of the film through the sealing
station 33 and in a short period of time and without the need for
additional pressing together of the web of film after the sealing
station and without the need for additional cooling of the seal
across the inlet port after the sealed inlet port moves out of
contact with the sealing station. The sealing of the inlet port at
the sealing station is performed by applying the heated sealing
element directly to and in sliding contact with the web of film and
across the inlet port while the air and the inflated pillow is
under pressure and as the web of film is continuously and
uninterruptedly advanced through the mechanism 25 shown in FIG.
4.
[0089] A number of features of the present invention contribute to
obtaining this efficient and beneficial sealing result.
[0090] As described above, the outermost tip of the bar 81 is a
ceramic material which functions as an insulator to help confine
the heat of the heating element to substantially just the linear
area of contact of the fabric covered Nichrome wire with the film
19.
[0091] The roller 75 is laterally offset outwardly (as viewed in
FIGS. 1-5) and is positioned with respect to the pairs of nip
rollers 37-39 and 49-51 so as to cause a bump in the film 19 at the
sealing station 33. This helps to create a dead zone adjacent the
inlet port 69 to be sealed by causing the web of film 19 to wrap
around a part of the peripheral surface of the sealing roller 75
both in a circumferential direction and also in a lateral
direction.
[0092] Driving the second pair of nip rollers 49-51 at a slightly
higher speed than the first pair of nip rollers 37-39 helps to
insure that the film 19 is maintained flat and in substantially
pressure sealing engagement with the periphery of the sealing
roller 75.
[0093] As best shown in FIG. 5, the axes of rotation of at least
the second set of nip rollers 49-51 are preferably canted at a
slight upward (as viewed in FIG. 5) angle with respect to the axes
of rotation of the main drive gear 47 and the sealing roller
75.
[0094] In a specific embodiment of the present invention the axes
of rotation of the first set of nip rollers 37-39 are also canted
at this same slightly upwardly inclined angle.
[0095] The inclusion and positioning of the outlet ports 71 (see
FIG. 8) and the smaller size of these outlet ports contribute to
allowing air to escape through the outlet ports in an amount to
maintain sufficient pressure in the channel 67 without permitting
over-pressurization in that channel 67 or in the pillows 65.
[0096] The present invention permits sealing the inlet port at a
sealing station by applying a heated sealing element directly to
and in sliding contact with the web of film and across the inlet
port while the air and the inflated pillow is under pressure and as
the web of film is continuously and uninterruptedly advanced
through each of the first transport station, inflating station,
sealing station, second transport station and slitting station.
[0097] In FIGS. 1, 2 and 8 of the drawings the pillows 65 are shown
in a generally rectangular-shaped pattern. It should be noted,
however, that the pillows 65 can be any preformed pattern
configuration. The patterns of the pillows 65 can, for example,
include preformed seal line elements within the interior of the
pillows which permit the pillows to be folded along one or more of
the preformed interior seal lines. This in turn permits one pillow
to cushion an object in more than one direction when placed within
a shipping container.
[0098] Score lines (not illustrated in the drawings, but similar to
score lines shown in webs of plastic film described in numerous
ones of the prior U.S. patents incorporated by reference in this
application) permit ready detachment of single ones or groups of
inflated pillows from the film 19 after the pillows are inflated
and sealed.
[0099] A number of different film compositions (also as noted in
U.S. patents incorporated by reference in this application) can be
used as the composition material for the web of film 19.
[0100] The machines that are used to preform the patterns on the
web of film 19 include conventional presses which impress multiple
pillow patterns (and the related ports and inflation channel) on a
strip of film 19 on each pressing operation. The pattern is formed
while there is no inflation pressure anywhere in the web 19.
[0101] The preformed pattern can also be formed by a roller
arrangement in which at least one roller is heated and configured
to form the desired patterns.
[0102] Pattern forming machines of these kinds are also disclosed
in several of the U.S. patents incorporated by reference in this
application.
[0103] Such machines for forming preformed patterns in the film 19
can be associated with the machine 11 shown in FIG. 1 to replace
the storage roll 17 so that the preformed patterns can be preformed
continuously at the site where the machine 11 is installed.
However, in most cases it is more practical to use a storage roll
17 with preformed patterns than it is to preform the patterns at
the job site where the machine 11 is to be used.
[0104] A second embodiment of a machine constructed in accordance
with the present invention is illustrated in FIGS. 10-15 of the
drawings. This second embodiment is indicated by the general
reference numeral 101.
[0105] The components and parts of the machine 101 which correspond
to the machine 11 shown in FIGS. 1-9 are indicated by corresponding
reference numerals.
[0106] The machine 101 includes a cartridge unit 103 (see FIG. 12)
which is mounted on a separate sub-plate or sub-frame 105. The
sub-frame 105 is mounted on the main plate or main frame 13. This
cartridge unit technique permits the components of the entire
cartridge unit to be quickly and easily interchanged (as a unit)
with another replacement cartridge unit. Individual components of
the cartridge unit do not have to be removed and replaced.
[0107] In the machine 101 shown in FIGS. 10-15, the construction
and mounting of the cartridge unit 103 permits the entire cartridge
unit to be pulled out of a box and plugged in as a unit at the
production site. This cartridge unit permits all of the components
of the cartridge unit to be replaced as a unit. It is never
necessary, for example, to replace the Nichrome wires as individual
elements in the field. Instead, the entire cartridge unit is just
pulled out and replaced as a unit with a replacement cartridge
unit.
[0108] The structure, components and mode of operation of the first
film transport station 27, the second film transport station 29,
the inflation station 31, and the slitting station 35 are the same
as the corresponding mechanism, components and mode of operation
described above with reference to the machine 11, and will not be
reviewed in more specific detail at this point.
[0109] The specific structure of the sealing station 33 of the
machine 101 is different from the machine 11 and will be described
in more detail below. However, the method of making seals across
the inlet ports 69 in the machine 101 is the same as the method of
machine 11, as will be understood from the description to
follow.
[0110] One difference between the sealing station structure of the
machine 11 and the sealing station structure of the machine 101 is
in the way that the heated sealing element and the sealing wheel
are moved apart from one another during those times when the
machine is stopped between production runs of inflated pillows.
[0111] In the machine 11 (and as illustrated in FIG. 7) the heated
sealing element which is mounted on the end of the bar 81 is
retracted away from the sealing wheel 75. In the machine 11 the
shaft 75 of the heated sealing wheel 75 is held in a fixed position
with respect to the frame 13 in all modes of operation of the
machine 11.
[0112] In the machine 101 the heated sealing element is held in a
fixed position with respect to the frame 13. The rotational shaft
77 of the sealing wheel 75 is mounted for rotation in a movable
support bracket 75 so that the sealing wheel 75 is movable toward
and away from the heated sealing element.
[0113] As best illustrated in FIG. 13, the support bracket 75 is
mounted on a rod 82 of an actuator 84. The actuator 84 is mounted
on a support plate 86, and the support plate 86 is mounted on the
main plate 13 of the machine 101.
[0114] The actuator 84 extends and retracts the rod 82 to move the
sealing wheel 75 between the retracted position of the rod 82 shown
in FIGS. 11 and 15 and the extended position shown in FIGS. 10 and
14.
[0115] In the retracted position illustrated in FIGS. 11 and 15 the
sealing wheel 75 is positioned to let the film 19 remain out of
contact with the heated sealing element when the machine 101 is not
operated in a production run.
[0116] In the extended position shown in FIGS. 10 and 14 the
sealing wheel 75 is positioned to engage the film 19 and to press
that film 19 in sliding contact with the heated sealing element as
the film 19 is continuously and uninterruptedly advanced through
the machine during a production run of inflated pillows.
[0117] The force with which the film 19 is engaged in sliding
contact with the heated sealing element is determined by selecting
the pressure level within the actuator 84.
[0118] As best illustrated in FIGS. 12, 10, and 14, the cartridge
unit 103 comprises a guide block 107 mounted in a fixed position on
the sub-plate 105, two reels 109 and 111, each mounted for rotation
on the sub-plate 105, and a guide post 113 mounted on the sub-plate
105.
[0119] The reels 109 and 111 are storage and take-up reels for a
strip of covering fabric 72. The fabric 72 has a Teflon coating on
the side engaged in sliding contact with the film 19.
[0120] The strip of covering fabric 72 is trained around a guide
post 113 and into the guide slots 115 and 117 which are recessed
within the outer and forward surfaces of the flanges 119 and 121 of
the guide block 107.
[0121] The way that the strip of covering fabric 72 is conveyed
from the storage roller 109, around the guide post 113, through the
guide slot 115, over the Nichrome wires 70, through the guide slot
117 and onto the reel 111 is best illustrated in FIGS. 10, 11, 14
and 15.
[0122] In a specific embodiment of the machine 101 the lower reel
111 is driven, through reduction gearing, and by an electric motor
(not shown), to pull the strip of covering fabric 72 across the
Nichrome wires 70 at a relatively slow speed (a speed considerably
slower than a speed at which the web of film 19 is transported
through the machine 101 during a production run), but at a speed
fast enough to insure that no part of the covering fabric 72 is
ever in contact with the Nichrome wires 70 long enough to permit
any burn through of the fabric by the Nichrome wires 70. The reel
storage of the covering fabric 72 and the slow movement of the
fabric with respect to the Nichrome wires 70 during operation of
the machine 101 thus insure that the area of the fabric engageable
with the Nichrome wires is, in effect, renewed soon enough to
prevent any burn through.
[0123] As best illustrated in FIGS. 12 and 15, the outer tips of
the flanges 119 and 120 extend slightly beyond the outer surfaces
of the Nichrome wires 70. This insures that the covering fabric 72
is engaged with the Nichrome wires 70 only when the sealing wheel
75 is moved to the position shown in FIGS. 10 and 14 during a
production run of the machine 101.
[0124] The strip of covering fabric 72 is held out of contact with
the Nichrome wires 70 when the machine 101 is not being operated in
a production run of packaging.
[0125] While not illustrated in FIGS. 10-15, the Nichrome wires 70
are energized by detachable leads 91 and 93 (as illustrated for the
machine 11 in FIGS. 9A-9G).
[0126] The sealing roller 75 of the machine 101 is laterally offset
outwardly in the same way as the sealing roller 75 of the machine
11 so as to cause a bump in the film 19 at the sealing station 33.
This helps to create a dead zone adjacent the inlet port 69 to be
sealed by causing the web of film 19 to wrap around a part of the
peripheral surface of the sealing roller 75 both in a
circumferential direction and also in a lateral direction (as
described above with reference to the machine 11).
[0127] The machine 101 permits sealing the inlet port at a sealing
station by applying a heated sealing element directly to and in
sliding contact with the web of film and across the inlet port
while the air in an inflated pillow is under pressure and as the
web of film is continuously and uninterruptedly advanced through
each of the first transport station, inflating station, sealing
station, second transport station and slitting station.
[0128] While we have illustrated and described the preferred
embodiments of our invention, it is to be understood that these are
capable of variation and modification, and we therefore do not wish
to be limited to the precise details set forth, but desire to avail
ourselves of such changes and alterations as fall within the
purview of the following claims.
* * * * *