U.S. patent application number 10/085447 was filed with the patent office on 2003-08-28 for vacuum packaging apparatus and method.
Invention is credited to Grove, Timothy A., Knowlton, Scott.
Application Number | 20030159405 10/085447 |
Document ID | / |
Family ID | 27753629 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030159405 |
Kind Code |
A1 |
Knowlton, Scott ; et
al. |
August 28, 2003 |
Vacuum packaging apparatus and method
Abstract
A combined cutting blade and heat bar for use with a vacuum
packaging device having a lid for sealing over the cavity of a base
is disclosed. The cutting blade and heat bar are connected to one
another and movable via a single actuating mechanism mounted to the
lid. In use, in one step the combined mechanism is lowered with the
heat bar unheated and the cutting element cuts slits in the bag for
evacuation of the air. After air evacuation, the combined mechanism
is lowered with the heat bar heated, melting the bag closed behind
the slitted area of the bag.
Inventors: |
Knowlton, Scott; (Blue
Springs, MO) ; Grove, Timothy A.; (Independence,
MO) |
Correspondence
Address: |
HOVEY WILLIAMS LLP
2405 GRAND BLVD., SUITE 400
KANSAS CITY
MO
64108
US
|
Family ID: |
27753629 |
Appl. No.: |
10/085447 |
Filed: |
February 28, 2002 |
Current U.S.
Class: |
53/434 ;
53/479 |
Current CPC
Class: |
B29C 66/8221 20130101;
B29C 66/82421 20130101; B29C 66/8324 20130101; B29C 65/226
20130101; B29C 66/1122 20130101; B29C 66/43121 20130101; B29C
66/81457 20130101; B29C 66/872 20130101; B29C 66/8161 20130101;
B29C 65/7451 20130101; B29C 65/743 20130101; B65B 31/024 20130101;
B29C 66/81431 20130101; B29C 66/0044 20130101; B29C 65/228
20130101; B29C 66/8227 20130101; B29C 65/229 20130101; B29C 66/849
20130101; B29C 65/222 20130101; B29C 66/00145 20130101; B29C
65/7437 20130101 |
Class at
Publication: |
53/434 ;
53/479 |
International
Class: |
B65B 031/00 |
Claims
What is claimed is:
1. A method of vacuum packaging a product comprising the steps of:
extending a cutting blade and a connected heat bar as one element
against a bag having an open end and a closed distal end; cutting a
portion of said bag with said cutting blade; retracting the cutting
blade and the connected heat bar as one element; evacuating air
from inside said bag through the cut portion; heating the connected
heat bar; and extending the cutting blade and the connected heat
bar as one element with the connected heat bar contacting a part of
said bag spaced from the portion of said bag cut with said cutting
blade toward the distal closed end.
2. The method of claim 1, wherein said extending steps further
comprise the step of inflating an air bladder connected to said
connected cutting blade and heat bar.
3. The method of claim 1, wherein said cutting blade and heat bar
are actuatingly connected and are connected to a lid of a vacuum
packaging apparatus and said extending steps comprise the step of
lowering said cutting blade and heat bar downwardly from said
lid.
4. The method of claim 1, further including the step of melting
said bag when said heat bar extends against said bag.
5. The method of claim 1, wherein said cutting step comprises the
formation of a multiplicity of intermittent slits in said bag.
6. The method of claim 1, further including the step of locating an
open end of said bag outside of a sealed base and lid of a vacuum
packaging device.
7. The method of claim 6, further including the step of evacuating
a portion of the air in said vacuum packaging device before said
cutting step.
8. The method of claim 1, wherein the extending steps comprise
connecting said cutting blade and said heat bar to a first end of
each arm of a pair of arms, and rotatably connecting said arms at
their second ends to a lid of a vacuum packaging device.
9. The method of claim 1, wherein the cutting blade and the heat
bar are connected and the extending and retracting steps comprise
simultaneously extending and actuating the cutting blade and heat
bar.
10. The method of claim 1, wherein the air is evacuated after the
cutting blade is retracted.
11. A mechanism for use with a vacuum packaging device which vacuum
seals a bag, the mechanism having a base with a cavity therein and
a lid, and said mechanism comprising: a cutting blade; a heat bar
connected to the cutting blade; actuating means for simultaneously
actuating said cutting blade and connected heat bar, said actuating
means mounted to the lid of said vacuum packaging device, said
actuating means for extending the cutting blade and the connected
heat bar as one element with the connected heat bar contacting a
part of said bag spaced from a portion of said bag cut with said
cutting blade toward a distal closed end of the bag.
12. The mechanism of claim 11, wherein said means for actuating
comprises an air bladder.
13. The mechanism of claim 11, wherein said cutting blade has a
first side and a second side and cutting teeth formed in only one
of said sides.
14. The mechanism of claim 11, wherein said cutting blade has at
least one set of cutting teeth separated from another set of
cutting teeth.
15. The mechanism of claim 14, wherein said cutting teeth extend
along an edge of said blade, said sets of cutting teeth separated
by at least one slot extending into said blade along said edge.
16. The mechanism of claim 11, wherein said heat bar comprises a
heatable wire mounted in a base and covered by a covering.
17. The mechanism of claim 11, further including an air bladder
connecting plate, said cutting blade and heat bar connected to said
plate.
18. The mechanism of claim 11, further including an anvil mounted
to said base of said vacuum packaging device.
19. The mechanism of claim 18, wherein said anvil comprises a
neoprene material.
20. The mechanism of claim 11, wherein the cutting blade and heat
bar are actuatingly coupled.
Description
BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] The present invention relates to a mechanism for use with a
vacuum packaging apparatus. More particularly, the invention is a
combined cutting blade and heating bar for use in cutting and
sealing vacuum packing bags, and in particular, oversized
compressible content in vacuum packing bags.
[0003] B. Description of the Related Art
[0004] Manufacturers often desire to package their products in
air-tight or shrinked wrapped bags. For example, a manufacturer may
wish to seal a food product in an air-tight package to ensure its
freshness or may wish to vacuum pack a compressible product in
order to reduce the size of the packaging. Also, it is sometimes
either expensive to package a product in a box or desirable to
visibly display the product. In these cases, the manufacturer may
shrink-wrap the product in a clear plastic bag. This type of
packaging allows the consumer to see the product, protects the
product during shipping and, in certain instances, when the content
can be compressed through the vacuum packaging process, reduces the
size of the package.
[0005] Currently, machinery is available for packaging products in
air-tight bags. This machinery typically comprises a base member
having an upstanding wall defining an internal cavity in which a
bagged product may be placed. A lid is movable over the base, the
lid having a perimeter sealing element for forming a seal against
the top of the wall of the base.
[0006] A movable heated element is connected to the lid. The heated
element can be extended downwardly against a portion of the base.
Means are provided for evacuating the air from the cavity.
[0007] The prior teaches several ways in which to pull vacuum
through the bag and seal the container. One such approach is to
place the bag in the cavity of the base, such that the open end of
the bag is oriented so that it extends across a portion of the
base, with the free end also located in a slot within the cavity.
Thus the entire bag is placed within the cavity.
[0008] Once the bag is placed in the cavity, the lid is lowered and
sealed against the base. The cavity and thus the bag therein, is
evacuated of air. The air leaving the bag through its open end
located within the cavity. Evacuation of the air in the bag draws
the bag tightly around the product and itself. The heated element
is then heated and lowered against the bag. The heat element melts
the bag distal of its open end, sealing it shut. Air is returned to
the cavity, the lid opened, and the product is removed.
[0009] This packaging arrangement suffers the drawback that the
entire bag must be located in the cavity in order to evacuate the
air therein. When there is excess bag to wrap the product, the bag
material is bunched around and often extends from the product. This
bag material increases the total size of the package, and is
visually unappealing. Furthermore, this type of machine is not well
suited to package large items by reducing the size of the items by
pulling a vacuum through the package. This system would tear the
pouch completely loose during the initial vacuum draw down and
disrupt the packaging cycle.
[0010] To overcome the drawback of bunching when excess baggage is
used, other vacuum packaging machines were designed to allow a user
to leave the end of the bag outside of the chamber during air
evacuation. When using this type of device, the user places the
product in the bag and pulls the end of the bag outside of the
base. The user pulls the bag firmly outwardly, pulling the bag
tightly around the product in the chamber, leaving only the amount
of bag necessary to wrap the product around the product.
[0011] The user then lowers the lid, tightly holding the bag in
place, preventing it from slipping back down into the chamber
around the product. The vacuum packaging machine includes a
segmented cutting blade and heating element for use with the vacuum
packaging device, which may be connected to a single actuating
device, or each connected to their own actuating devise. In either
case, when the lid is closed, the segmented cutting blade, which
extends almost entire across the width of the first vacuum package
machine, cuts segmented portions of the bag located inside of the
chamber, as illustrated by FIG. 2 (Prior Art). The cuts are
segmented so that the bag, when cut, does not slip back down into
the chamber around the product, but so that the excess bag can be
easily removed from the bag containing the product after the bag is
sealed.
[0012] Once the bag is cut, the air in the chamber and in the bag
located inside of the chamber is evacuated, the air escaping from
the bag through the cuts. After the vacuum is pulled through the
chamber, the heating element is lowered, melting the bag distal of
the cut made in the bag and sealing it shut, as illustrated by FIG.
2 (Prior Art). The product is then removed from the container and
the excess bag on the free end away from the seal is then
removed.
[0013] Like the vacuum packaging machine having the entire bag
located in the cavity, the machines allowing for the open end of
the bag located outside the chamber, also suffer the difficulty of
packaging large condensable items by pulling a vacuum through the
package and thereby causing the packaging to condense the product
in the package. For example, such items subject to reduction though
vacuum packaging are clothing, outdoor wear, sleeping bags and
other flexible, resilient compressible materials. Under high vacuum
packaging, such fabric derived products will compress in size by up
to 30% of their original volume.
[0014] The prior art vacuum packaging machines are not currently
equipped to accommodate these type of compressible products. The
prior art vacuum packaging machines, as discussed above, pulls a
small vacuum to hold the chamber closed when the lid is initially
shut and to create a seal between the lid and the base. In the case
of packaging large pouches with sleeping bags or other like large
clothing articles, this system would tear the pouch completely
loose during the initial lid vacuum draw down and disrupt the
packaging cycle.
SUMMARY OF THE INVENTION
[0015] The present invention is a vacuum packaging machine that is
designed to handled packages containing product that will compress
in volume during packaging. The vacuum packaging device of the
present invention has a base and lid. A cavity is located in the
base in which a product to be packaged is positioned. The lid has a
perimeter seal for sealing the lid over the cavity in the base. The
device further includes an apparatus for evacuating air from the
sealed cavity and the bag inside.
[0016] The vacuum packaging machine of the present invention has an
elongated segmented cutting blade that is located in the center of
the seal bar and is sized to leave sections of uncut pouch material
on either side of the pouch. Thus, the length of the blade is less
than the length of the bag.
[0017] The vacuum packaging machine also includes a heating
element, which is used to seal the bag after the air is removed
from the bag. In one embodiment of the invention, the cutting blade
and heating element are connected to one another and to a mounting
bar, which is connected to a single actuating device. This entire
mechanism is mounted preferrable to the lid. On the base, opposite
of the mechanism, is an anvil, for engagement by the cutting blade
and heating bar.
[0018] Accordingly, during the packaging process, a user places
product in a bag, extending the open end of the bag across the
anvil and positions the open end of the bag outside of the base,
leaving the remainder of the bag containing product in the cavity
of the base.
[0019] The user then closes the lid and a slight vacuum is drawn to
seal the lid tightly against the base. With the bar unheated, the
combined cutting mechanism and heating bar is then lowered, via the
actuator, to cut spaced slits across a portion of the bag, leaving
uncut sections of the bag. Leaving sections of uncut bag on either
side of the bag prevents the pouch trim from tearing both during
the vacuum packaging process and thereafter. The cutting and
heating mechanism is then retracted.
[0020] The vacuum device then evacuates the air in the bag,
compressing the contents of the bag when compressible materials are
being packaged. The air in the bag escapes through the slits formed
by the cutting blade in the portion of the bag that is cut. The
cutting and heating mechanism is then lowered, this time with the
heating element heated, thereby sealing the end of the bag after
the air has been fully evacuated from the bag. While the cutting
the bar does not extend the length of the bag, the heating element
does extend across the length of the bag, thereby sealing the bag
across its entire length to prevent the re-entry of air into the
bag.
[0021] Since the cutting element did not cut through the entire
length of the bag, the excess pouch, instead of being removed,
would remain with the bag. The excess bag, having a slit through
only the mid-section, can then serve as a handle to the bag, which
functions as an especially convenient way to carry light or large
items. .
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] A more complete appreciation of the invention and many of
the advantages thereof will be readily obtained as the same becomes
better understood by references to the detailed description when
considered in connection with the accompanying drawings,
wherein:
[0023] FIG. 1 is a front view of the vacuum packaging device in one
embodiment of the invention with the lid of the vacuum packaging
device partially open and having part of the lid partially cut away
to show the combined heating bar and cutting blade and the
positioning of the bag relative thereto;
[0024] FIG. 2 is a top perspective view of a bag sealed using a
prior art vacuum packaging machine.
[0025] FIG. 3 is a top perspective view of a bag sealed using a
vacuum packaging machine of the present invention.
[0026] FIG. 4 is an end view of the combined cutting blade and heat
bar apparatus of the present invention mounted in a vacuum
packaging device (shown in cross-section) and shown with a lid of
the device open;
[0027] FIG. 5 is a view of the apparatus of FIG. 4, with the lid of
the vacuum packaging device closed and the combined cutting blade
and heat bar shown in a retracted position;
[0028] FIG. 6 is a view of the apparatus of FIG. 5 with the
combined cutting blade and heat bar shown in an extended
position;
[0029] FIG. 7 is a cross-sectional side view of the apparatus of
FIG. 6 taken along line 7-7 thereof;
[0030] FIG. 8 is an enlarged, partial cut-away side view of the
combined cutting blade and heat bar of FIG. 4;
[0031] FIG. 9 is an enlarged end view of the apparatus illustrated
in the position of FIG. 8 through line 9-9 thereof; and
[0032] FIG. 10 is an enlarged cross-sectional end view of the
apparatus in the position of FIG. 8 through line 10-10 thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] As illustrated by FIG. 1, the present invention is a vacuum
packaging machine 18 that is designed to vacuum pack products that
are not subject to reduction, such as food products, as well as
items that are subject to reduction through vacuum packaging, such
as clothing, outdoor wear, sleeping bags, other fabric derived
products and other flexible, resilient compressible materials.
[0034] As illustrated by FIGS. 1 and 4-10, the vacuum packaging
machine 18 of the present invention generally comprises a base 20,
having a cavity 24 located therein, and a lid 22 that seals over
the cavity 24 of the base 20. The cavity 24 is formed within an
upstanding wall 26 of the base, the cavity having an open top end
28. The wall 26 has a flat top surface 30. At least a portion of
the wall 26 includes a slot 32 in which a portion of a packaging
bag 21 may be positioned.
[0035] The lid 22 has a mating surface for engagement with the top
surface 30 of the wall 26 of the base 20, the lid 22 designed for
use in enclosing the cavity 24 in the base. A seal 34 is positioned
in the lid 22 for engagement with the top surface 30 of the wall 26
for sealing the lid to the base. The machine 18 includes means (not
shown) for evacuating the air from the enclosed cavity 24, as is
well known in the art.
[0036] In accordance with one embodiment of the invention, the
combined cutting blade 10 and heat bar 12 are mounted to the lid 22
of the vacuum packaging apparatus 18. The cutting blade 10 and heat
bar 12 are connected to the actuating means 14, namely an
expandable air bladder 36, for movement with respect to the
lid.
[0037] In one embodiment of the invention, as illustrated by FIG.
7, the heating bar extends across the entire length of the lid,
whereas the cutting blade is positioned in the center of the lid
and is of a length that will not cut across the entire packaging
bag, but rather cuts only across the middle portion of the bag, as
shown by FIG. 3, leaving uncut portions at the ends of the bag.
[0038] As best illustrated in FIGS. 4-7, the cutting blade 10
comprises an elongate, thin metal member having a first side 38,
second side 40 and cutting edge 42. While the cutting blade may be
a straight edge, typically, the cutting blade used has a number of
cutting teeth 44 are disposed along the cutting edge 42 of the
blade 10, so that the cutting blade does not cut a packaging bag 21
completely through, but instead cut the bag so that several
portions of the bag remain unsevered.
[0039] As such, the cutting teeth 44 are arranged so that the blade
10 acts to cut the bag in certain areas but not others (as shown in
FIG. 3). Preferably, the sets 46 of the cutting teeth 44 are
separated by non-cutting slot 48 areas extending upwardly into the
blade from the cutting edge. Again, it is not necessary to use a
blade with non-cutting slots 48 since the blade does not extend
across the entire length of the bag.
[0040] The cutting teeth 44 are preferably only disposed on the
first side 38 of the cutting blade 10, the second side 40 of the
blade being flat. The cutting teeth 44 preferably have a cutting
edge slope of about 60 degrees (sloping inwardly from the first
side to the second side of the blade from the top of the tooth
downwardly towards the cutting edge).
[0041] In one embodiment, each cutting tooth 44 is approximately
0.2 inches wide. The tooth 44 has a minimum tooth height of about
0.04-0.06 inches, and most preferably about 0.05 inches, and a
maximum tooth height of about 0.145-0.165 inches, and most
preferably about 0.155 inches.
[0042] The blade 10 may be constructed of any number of durable
materials, but is preferably constructed from stainless steel. The
blade 10 in the present example is about 7 inches long. The length
of the blade 10 may vary, however, dependent on the application for
which it is used and the size of the packaging bag being used in
the machine. .
[0043] A number of apertures extend through the blade 10. Screws 50
or similar mounting elements pass through the apertures for
engagement with a base 54 of the heat bar 12, for mounting the
blade to the actuating mechanism 14 (indirectly) as described in
more detail below. The depth of the blade 10 and its point of
attachment are chosen so that the ends of the teeth 44 extend below
the bottom of the heat bar 12 by approximately 0.05-0.15 inches,
and more preferably, about 0.1 inches, when the teeth have the
configuration described above.
[0044] The heat bar 12 comprises a heat wire 52 mounted in the base
54. A cover 56 extends over the heat wire 52, preventing direct
contact of the heat wire 52 with the bag 21.
[0045] The base 54 comprises an elongate mounting member having a
first end 58 and second end 60. Preferably, the base 54 is
constructed of a lightweight resin material. In order to stiffen
the base 54, an insert 55 (as best seen in FIG. 7), such as a metal
bar, fits within a slot in the base 54.
[0046] The base 54 is preferably slightly longer than the heating
wire, at about 27.25 inches. As best illustrated in FIGS. 5 and 7,
a first slot 62 extends through the base 54 from end to end 58, 60.
The first slot 62 is preferably located adjacent a bottom edge 64
of the base 54 and receives the heat wire.
[0047] A second slot 66 extends into each end 58, 60 of the base 54
above the first slot 62. An aperture 68 extends through the base 54
from side to side at the location of the second slot 66.
[0048] The wire 52 has a first end and a second end, corresponding
to the ends 58, 60 of the base 54. The wire 52 is preferably
constructed of metal, and has a rectangular cross-section. At its
ends the wire 52 first bends upwardly for extension along the ends
58, 60 of the base 54, and then bends inwardly.
[0049] To support the ends of the wire 52 and retain the wire in
place, the wire extends over a lock bar 80 at each end. Preferably,
the supporting/attaching structure is the same at both ends of the
wire 52 and bar, and thus only one end will be described. As
illustrated in FIG. 5, the lock bar 80, which is generally
`L`-shaped, extends from a slot in a pin 76 passing through the
aperture 68. A set screw 79 extends inwardly from one side of the
pin 76, engaging the lock bar 80 and retaining it in place. From
the pin, the lock bar 80 extends outwardly towards the first end 58
of the base 54, and then downwardly towards the bottom edge 64.
[0050] The heat wire 52 extends upwardly over the lock bar 80
within the slot 66. The first end of the wire 52 is retained
against the lock bar 80 and in the pin 76 via a set screw 78 which
passes downwardly from the top edge of the base 54.
[0051] As illustrated in FIG. 5, a spring 74 extends between the
end of a countersunk bore in the base 54 near the second slot 66
and the lock bar 80, pressing the lock bar 80 outwardly against the
heat wire 52.
[0052] A cover 56 extends over the bottom edge 64 of the base 54
from the first to the second ends 58, 60. The cover 56 is
preferably a Teflon(.TM.) tape formed into a `U`-shape. The tape is
connected to each side of the base 54 and extends across the bottom
edge 64 of the base 54.
[0053] As illustrated, the front side of the base 54 has an inset
area for acceptance of the cutting blade 10. A first number of
apertures 82 pass through the base 54 of the heat bar 12 at the
inset area. The first set of apertures are designed for acceptance
of the screws 50 (or other mounting members) which connect the
cutting blade 10 to the base 54.
[0054] A second number of apertures 84 pass through the base 54 of
the heat bar 12 slightly above the first set. The second set of
apertures 84 are designed for mounting the heat bar 12 (with blade
connected thereto) to the actuating mechanism 14, as described
below.
[0055] As best illustrated in FIGS. 2, 4 and 6, the actuating
mechanism 14 comprises a means for moving/actuating the combined
cutting blade 10 and heat bar 12 between a first (retracted) and a
second (extended) position. Preferably, the actuating mechanism 14
comprises an air bladder 36. The air bladder 36 includes an
inflatable element 86, such as a section of firehose or similar
durable expandable material. The inflatable element 86 is mounted
on a plate 88 having a flat surface and upstanding inside
protective edge.
[0056] An air line 90 extends through the lid 22, an aperture in
the plate 88, and into the inflatable element 86 of the air bladder
36. The air line 90 is connected to a source of high and low
pressure air (not shown) for inflating and deflating the air
bladder 36.
[0057] The air bladder 36 is connected to the cutting blade 10 and
heat bar 12 via a mounting bar 92, as illustrated in FIGS. 4 and 7.
The mounting bar 92 is approximately as long as base 54 of the heat
bar 12 and thus slightly longer than the cutting bar 10. The
mounting bar 92 has a first end 94 and second end 95 which are
tapered to facilitate retraction of the mechanism along the sloping
ends of the lid 22 of the vacuum packaging device 18, as best
illustrated in FIG. 4.
[0058] Preferably, four large washers 96 are connected to each side
of the mounting bar 92 with screws or the like. The base 54 of the
heat bar 12 (to which the cutting blade 10 is connected by screws
50) is connected to the washers 96 with screws passing into the
apertures 84 described above.
[0059] The mounting bar 92 is in turn connected to the flat portion
of the plate 88 of the air bladder 36. Screws or similar attachment
means pass through the plate 88 along its length and into mating
apertures in the top edge of the mounting bar.
[0060] As connected, the mounting bar 92, the heat bar 12 and the
cutting blade 10 move as one element as actuated by the air bladder
36, as described in more detail below. Thus, the cutting blade and
heat bar are actuatingly coupled.
[0061] A wire 99 from an electrical power source (not shown)
extends to electrical contact elements 98 connected to the mounting
bar 92. Each contact element 98 has a first flat section which is
attached, via a screw or the like to the mounting bar 92. Each
element further includes a `U`-shaped, spring section. As
illustrated, the spring section of the elements 98 contact the pin
76 to which the heat wire 52 is connected. The wire 99 is connected
to the elements 98 for heating the heat wire 52. The elements 98
are mounted beyond the ends of the cutting blade 10, so as to not
contact the cutting blade.
[0062] The entire mechanism is preferably hingedly connected to the
lid 22 of the vacuum packaging device 18, as best illustrated in
FIGS. 1-3. Two mounting blocks 100 (only one of which is
illustrated) are connected to the inside of the lid 22 of the
vacuum packaging device 18. An arm 102 extends from each mounting
block 100 to a connection with the mounting bar 92 and plate
88.
[0063] Each arm 102 has a generally `L`-shaped cross-section, and
is generally about 15-16 inches, and most preferably about 15.75
inches long. The length of the arm 102 depends primarily on the
size of the lid in which the mechanism is mounted. Preferably, the
arm 102 is connected at one end to the mounting block 100 near the
center of the lid. The arm 102 is long enough that the combined
cutting blade 10 and heat bar 12 are positioned adjacent the outer
edge of the lid 22, as illustrated in FIG. 1. The arm 102 is
hingedly connected to the mounting block 100 at a first end via a
pin 104.
[0064] The second end of each arm 102 is connected to the ends,
respectively, of the flat portion of the plate 88 (see FIG. 5). The
arms 102 are connected to the plate 88 with screws or similar
attachment means.
[0065] The second end of each arm 102 includes a slot 106 (FIG. 6)
for mating engagement with a corresponding slot 108 (FIG. 7) in the
top edge of the mounting bar 92. Preferably, the slot 106 in the
arm 102 is longer than the mounting bar 92 is wide, and the slot
108 in the mounting bar 92 is deeper than the depth of the
downwardly extending portion of the arm 102, to facilitate relative
movement of the two elements. Further, in order to accommodate
mounting of the arm 102 under the plate 88 and between the plate
and mounting bar 92, the mounting bar includes a recessed top edge
section 110 at each end.
[0066] Springs 112 bias the mechanism upwardly into a recessed
position within the lid 22 when the air bladder 36 is deflated, as
illustrated in FIGS. 1 and 3. Preferably, two pins 114 (see FIG. 4)
extend downwardly from the plate 88 and engage a flange 116
extending inwardly from the inside surface of the lid 22. The
springs 112 are mounted on the pins 114 between the flange 116 and
plate 88.
[0067] An anvil 118 is positioned in the wall 26 of the base 20 of
the vacuum packaging apparatus 18 directly below the cutting blade
10, as illustrated in FIGS. 1 and 2. Preferably, the anvil 118
comprises an elongate segment of neoprene extending within a slot
in the wall 26 along that portion of the wall 26 beneath the
mechanism of the present invention.
[0068] While one embodiment to the present invention uses a
combination heating bar and cutting blade, actuated by a single
actuator, such as a air bladder, or other similarly functioning
devise, the present invention may also utilize a heating bar that
is separately actuated from the cutting blade. Furthermore, one
skilled in the art can modify the arrangement of the cutting blade
and the heating bar to be utilized in a chamberless vacuum
packaging machine or in other types of vacuum packing machines.
[0069] In operation, a user will first select the appropriate
length of the blade to be used in the vacuum packaging process.
This is determined by the size the of vacuum packaging bad and
article to be packaged therein. The length of the blade should be
selected so that the blade leaves enough pouch trim on each side of
the cut to prevent the bag from pulling away from the cutting edge
of the machine during operation. Larger products and products that
reduce to a large percentage of their original size tend to pull
away from the edge when the air is being evacuated. Thus, the user
must select a cutting blade length that leaves enough trim on each
side of the cut to prevent the bag from pulling away during
evacuation.
[0070] Once the blade length is selected, the user fits the vacuum
packaging machine with the blade. The user then opens the lid 22 of
the vacuum packaging device 18 fitted with the mechanism of the
present invention, illustrated in FIG. 4. The user positions an
item to be sealed with a bag 21 and places the bag 21 in the cavity
24 within the base 20 of the device 18, extending the open end 23
of the bag outside of the device.
[0071] The user then closes the lid 22, as illustrated in FIG. 4.
The seal 34 on the lid 22 seals the lid against the base 20. A
slight vacuum is then drawn, evacuating some of the air from within
the cavity 24. This partial vacuum is drawn in order to better seal
the lid 22 to the base 20, and to prevent the lid 22 from raising
when the cutting blade 10 is lowered and cuts the bag 21. Care is
taken, however, not to draw an excessive vacuum, as such could have
the effect of rupturing the bag 21, as the air within the bag at
that time has no path of escape.
[0072] The combined cutting bar 10 and heat bar 12 is then lowered
into the position as illustrated in FIG. 5. In particular, air is
forced through the air line 90 into the inflatable element 86 of
the air bladder 36. Inflation of the air bladder 36 presses the
combined cutting blade 10 and heat bar 12 downward until it engages
the anvil 118, as illustrated in FIGS. 3, 6 and 7.
[0073] Most importantly, at this time the heat bar 12 is unheated.
When in the extended position, the cutting bar 12 cuts the bag 21,
across only the center portion of the bag, forming spaced slits
therein and leaving uncut pouch trim on either side of the bag 21.
Air is then removed from the air bladder 36 through the air line
90, the air bladder collapsing and the spring force generated by
the springs 112 pressing the mechanism upwardly into the lid 22 as
illustrated in FIG. 2. At the same time, full vacuum is drawn
within the device 18, drawing the remaining air from the cavity 24
and the bag 21. The air in the bag 21 escapes through the slits cut
in it by the cutting blade 10.
[0074] The heat wire 52 of the heat bar 12 is then heated, and the
mechanism lowered to the positioned illustrated in FIG. 3 again. At
this time, the heat bar 12 melts the bag 21 closed inward of the
slits. The mechanism is again raised, air returned to the cavity
24, such as by venting to the outside atmosphere, and the user
opens the lid. The user then removes the sealed bag 21. If desired,
the user may then open the slit area by breaking the portions of
the perforated slit which are still attached to one another. With
the slit open, the remaining pouch with the center slit can serve
as a handle for the convenient carrying of the packaged
articles.
[0075] Notably, the cutting blade 10 extends below the heat bar 12
a sufficient distance to cut through the bag 21 when the mechanism
is lowered against the anvil 118. This extension distance is
chosen, however, so that the heat bar 12 still contacts the bag 21
as necessary to melt the bag closed. At the same time, the teeth 44
of the blade 10 do not penetrate so far into the anvil 118 so as to
become lodged or stuck, which would hinder operation of the
machine.
[0076] The sequence of (1) pulling initial vacuum; (2) lowering
mechanism to cut the bag; (3) raising the mechanism and pulling
fill vacuum; (4) heating heat bar and lowering mechanism to seal
bag; and (5) raising mechanism is preferably accomplished with
relays or the like so as to be automatic.
[0077] While an air bladder 36 has been described as the preferred
actuating device, many other similar mechanisms could be employed.
For example, hydraulic or air cylinders could be used to move the
combined cutting blade and heat bar up and down.
[0078] Further, the specific configuration of the heat bar or
connecting apparatus could be change substantially without falling
from the scope of the invention. A wide variety of heating elements
are well known in the art, and may be employed instead of the one
described herein.
[0079] It will be understood that the above described arrangements
of apparatus and the method therefrom are merely illustrative of
applications of the principles of this invention and many other
embodiments and modifications may be made without departing from
the spirit and scope of the invention as defined in the claims.
* * * * *