U.S. patent application number 11/836176 was filed with the patent office on 2009-02-12 for sealing system for a packaging apparatus.
This patent application is currently assigned to Rennco LLC. Invention is credited to Brian C. Bowerman, Robin G. Thurgood.
Application Number | 20090038273 11/836176 |
Document ID | / |
Family ID | 40345205 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090038273 |
Kind Code |
A1 |
Thurgood; Robin G. ; et
al. |
February 12, 2009 |
Sealing System for a Packaging Apparatus
Abstract
A sealing jaw apparatus for a film wrapping machine utilizes a
continuous web of thermoplastic film. The sealing jaw apparatus
includes a first jaw unit to one side of a film travel path. The
first jaw unit includes spaced-apart clamp arms and a heated
sealing bar located between the spaced-apart clamp arms. The heated
sealing bar includes spaced-apart noses defining a slot
therebetween. A second jaw unit is to an opposite side of the film
travel path. The second jaw unit includes spaced-apart gripping
surfaces that are engaged by the spaced-apart clamp arms for
gripping the thermoplastic film. Spaced-apart sealing surfaces are
engaged by the noses of the heated sealing bar for sealing the
thermoplastic film at spaced-apart locations in a film running
direction. A knife assembly severs the thermoplastic film between
the spaced-apart locations.
Inventors: |
Thurgood; Robin G.;
(Marshall, MI) ; Bowerman; Brian C.; (Quincy,
MI) |
Correspondence
Address: |
THOMPSON HINE L.L.P.;Intellectual Property Group
P.O. BOX 8801
DAYTON
OH
45401-8801
US
|
Assignee: |
Rennco LLC
Homer
MI
|
Family ID: |
40345205 |
Appl. No.: |
11/836176 |
Filed: |
August 9, 2007 |
Current U.S.
Class: |
53/477 ;
53/373.7 |
Current CPC
Class: |
B29C 66/849 20130101;
B29C 65/305 20130101; B29C 65/7451 20130101; B29C 66/81457
20130101; B29C 66/81427 20130101; B29C 66/8322 20130101; B29C
66/81431 20130101; B29K 2101/12 20130101; B29C 65/18 20130101; B29C
66/344 20130101; B29C 66/4312 20130101; B65B 51/303 20130101; B29C
66/1122 20130101; B29C 66/43121 20130101; B29C 65/7841
20130101 |
Class at
Publication: |
53/477 ;
53/373.7 |
International
Class: |
B65B 51/10 20060101
B65B051/10 |
Claims
1. A sealing jaw apparatus for a film wrapping machine utilizing a
continuous web of thermoplastic film, the sealing jaw apparatus
comprising: a first jaw unit to one side of a film travel path, the
first jaw unit comprising spaced-apart clamp arms and a heated
sealing bar located between the spaced-apart clamp arms, the heated
sealing bar including spaced-apart noses defining a slot
therebetween; and a second jaw unit to an opposite side of the film
travel path, the second jaw unit comprising spaced-apart gripping
surfaces that are engaged by the spaced-apart clamp arms for
gripping the thermoplastic film, spaced-apart sealing surfaces that
are engaged by the noses of the heated sealing bar for sealing the
thermoplastic film at spaced-apart locations in a film running
direction, and a knife assembly for severing the thermoplastic film
between the spaced-apart locations.
2. The sealing jaw apparatus of claim 1, wherein the knife assembly
is moveable between a retracted position where a cutting edge of
the knife assembly is recessed from the sealing surfaces within a
slot defined therebetween and an extended position where the
cutting edge is extended beyond the sealing surfaces and into the
slot between the noses.
3. The sealing jaw apparatus of claim 2 further comprising an
actuator carried by the second sealing jaw unit that extends the
knife assembly.
4. The sealing jaw apparatus of claim 1 further comprising metal
support members carried by the second jaw unit that define the
gripping surfaces.
5. The sealing jaw apparatus of claim 4 further comprising sealing
members connected to the metal support members, the sealing members
formed of an elastic material and forming the sealing surfaces.
6. The sealing jaw apparatus of claim 4, wherein the sealing
members are located within respective recesses formed in the metal
support members.
7. The sealing jaw apparatus of claim 1, wherein the clamp arms
each include a gripping member located at an end of the clamping
arm, the gripping member including a contoured end surface that
engages the gripping surface.
8. The sealing jaw apparatus of claim 3, wherein at least one of
the first and second jaw units is moveable toward and away from the
other of the first and second jaw units.
9. The sealing jaw apparatus of claim 8, wherein the apparatus
operates such that the knife assembly is maintained in the
retracted position until the noses engage the spaced-apart sealing
surfaces.
10. A method of sealing layers of plastic film from a continuous
film web, the method comprising: engaging the layers between a
first jaw unit and a second jaw unit, the first jaw unit comprising
spaced-apart clamp arms that engage spaced-apart gripping surfaces
of the second jaw unit; sealing the layers at two seal locations
that are spaced-apart in a web running direction using a heated
sealing bar carried by the first jaw unit and located between the
spaced-apart clamp arms, the sealing bar including spaced-apart
noses defining a slot therebetween, the spaced-apart noses engaging
spaced-apart sealing surfaces carried by the second jaw unit; and
severing the layers between the first and second seal locations
using a knife assembly carried by the second jaw unit.
11. The method of claim 10, wherein the step of severing the layers
includes extending the knife assembly from a retracted position
where a cutting edge of the knife assembly is recessed from the
sealing surfaces within a slot defined therebetween, beyond the
sealing surfaces and into the slot between the noses.
12. The method of claim 11, wherein the step of severing the layers
occurs after the step of sealing the layers.
13. The method of claim 11, wherein the knife assembly is extended
using an actuator carried by the second jaw unit.
14. The method of claim 10, wherein the step of sealing the layers
at two seal locations further includes, after the spaced-apart
clamp arms engage the spaced-apart gripping surfaces of the second
jaw unit, extending the heated sealing bar relative to the clamp
arms until the spaced-apart noses engage spaced-apart sealing
surfaces carried by the second jaw unit.
15. The method of claim 14, wherein the step of extending the
heated sealing bar includes extending the heated sealing bar
relative to the knife assembly.
16. A sealing jaw apparatus for a film wrapping machine utilizing a
continuous web of thermoplastic film, the sealing jaw apparatus
comprising: a first jaw unit to one side of a film travel path, the
first jaw unit comprising spaced-apart clamp arms and a heated
sealing bar located between the spaced-apart clamp arms, the heated
sealing bar including spaced-apart noses defining a slot
therebetween; and a second jaw unit to an opposite side of the film
travel path, the second jaw unit comprising spaced-apart gripping
surfaces that are engaged by the spaced-apart clamp arms for
gripping the thermoplastic film and spaced-apart sealing surfaces
that are engaged by the noses of the heated sealing bar for sealing
the thermoplastic film at spaced-apart locations in a film running
direction; and a knife assembly for severing the thermoplastic film
between the spaced-apart locations; wherein the heated sealing bar
moves relative to the knife assembly to bring the noses into
contact with the spaced-apart sealing surfaces.
17. The sealing jaw apparatus of claim 16, wherein the knife
assembly is carried by the second jaw and is moveable between a
retracted position where a cutting edge of the knife assembly is
recessed from the sealing surfaces within a slot defined
therebetween and an extended position where the cutting edge is
extended beyond the sealing surfaces and into the slot between the
noses.
18. The sealing jaw apparatus of claim 17 further comprising an
actuator carried by the second sealing jaw unit that extends the
knife assembly.
19. The sealing jaw apparatus of claim 16, wherein the clamp arms
each include a gripping member located at an end of the clamping
arm, the gripping member including a contoured end surface that
engages the gripping surface.
20. The sealing jaw apparatus of claim 16 further comprising metal
support members carried by the second jaw unit that define the
gripping surfaces.
Description
TECHNICAL FIELD
[0001] The present application relates to packaging apparatus and
more particularly to a sealing system for a packaging
apparatus.
BACKGROUND
[0002] Packaging apparatus have been provided that are used to seal
product within wrapped film. Typically, a film sheet is formed into
a tube or folded and product is placed in the tube or folded film.
A sealing system is used to seal and sever the tube or folded film
to form a bag with product located therein that is separated from
the film sheet.
[0003] U.S. Pat. No. 5,131,213 provides a sealing jaw apparatus for
a plastic film wrapping machine. The sealing jaw apparatus provides
a heated sealing jaw with a reciprocal knife. The jaw operates
against a heated elastomeric bed that has a slot to receive the
knife during a cutting operation.
SUMMARY
[0004] In an aspect, a sealing jaw apparatus for a film wrapping
machine utilizes a continuous web of thermoplastic film. The
sealing jaw apparatus includes a first jaw unit to one side of a
film travel path. The first jaw unit includes spaced-apart clamp
arms and a heated sealing bar located between the spaced-apart
clamp arms. The heated sealing bar includes spaced-apart noses
defining a slot therebetween. A second jaw unit is to an opposite
side of the film travel path. The second jaw unit includes
spaced-apart gripping surfaces that are engaged by the spaced-apart
clamp arms for gripping the thermoplastic film. Spaced-apart
sealing surfaces are engaged by the noses of the heated sealing bar
for sealing the thermoplastic film at spaced-apart locations in a
film running direction. A knife assembly severs the thermoplastic
film between the spaced-apart locations.
[0005] In another aspect, a method of sealing layers of plastic
film from a continuous film web is provided. The method includes
engaging the layers between a first jaw unit and a second jaw unit.
The first jaw unit includes spaced-apart clamp arms that engage
spaced-apart gripping surfaces of the second jaw unit. The layers
are sealed at two seal locations that are spaced-apart in a web
running direction using a heated sealing bar carried by the first
jaw unit and located between the spaced-apart clamp arms. The
sealing bar includes spaced-apart noses defining a slot
therebetween. The spaced-apart noses engage spaced-apart sealing
surfaces carried by the second jaw unit. The layers are severed
between the first and second seal locations using a knife assembly
carried by the second jaw unit.
[0006] In another aspect, a sealing jaw apparatus for a film
wrapping machine utilizes a continuous web of thermoplastic film.
The sealing jaw apparatus includes a first jaw unit to one side of
a film travel path. The first jaw unit includes spaced-apart clamp
arms and a heated sealing bar located between the spaced-apart
clamp arms. The heated sealing bar includes spaced-apart noses
defining a slot therebetween. A second jaw unit is to an opposite
side of the film travel path. The second jaw unit includes
spaced-apart gripping surfaces that are engaged by the spaced-apart
clamp arms for gripping the thermoplastic film and spaced-apart
sealing surfaces that are engaged by the noses of the heated
sealing bar for sealing the thermoplastic film at spaced-apart
locations in a film running direction. A knife assembly is provided
for severing the thermoplastic film between the spaced-apart
locations. The heated sealing bar moves relative to the knife
assembly to bring the noses into contact with the spaced-apart
sealing surfaces.
[0007] The details of one or more embodiments are set forth in the
accompanying drawings and the description below. Other features,
objects, and advantages will be apparent from the description and
drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIGS. 1 and 1a are diagrammatic, side section views of an
embodiment of a sealing system for use in a packaging apparatus;
and
[0009] FIGS. 2-5 illustrate the sealing system of FIG. 1 in
use.
DETAILED DESCRIPTION
[0010] Referring to FIGS. 1 and 1a, a sealing system 10 for use in
a packaging apparatus includes a first sealing jaw 12 and a second,
opposing sealing jaw 14. It should be noted that while the sealing
jaws 12 and 14 are illustrated as being operated horizontally
(i.e., to sever and seal vertically oriented film material), the
sealing jaws may also be operated vertically (i.e., to sever and
seal horizontally oriented film material). In addition, an L-shaped
sealing system is also contemplated for simultaneously sealing film
along two intersecting edges.
[0011] The first sealing jaw 12 includes outer, spaced-apart clamp
arms 16 and 18. The clamp arms 16 and 18 have a respective gripping
member 20 and 22 that is used to grip the film material. The
gripping members 20 and 22 may be formed of a resilient material
such as an elastomer or rubber and may be press fit or otherwise
attached within grooves 24 and 26 in the clamp arms 16 and 18. The
gripping members 20 and 22 may also include contoured gripping
surfaces 28 and 30, for example, having two peaks separated by a
valley as shown in FIG. 1.
[0012] Located between the spaced-apart clamp arms 16 and 18 is a
heated sealing bar 32. The sealing bar 32 is heated by a heating
element 34 located between sealing bar members 36 and 38. Each
sealing arm member 36 and 38 includes a respective nose 40 and 42
separated from each other thereby defining a slot 44 therebetween.
As will be described below, the sealing bar 32 is extendable and
retractable relative to the spaced-apart clamp arms 16 and 18. The
sealing bar 32 may be moveable using a linear actuator, such as a
pneumatic cylinder. In some embodiments, the sealing bar 32 is
biased (e.g., using a spring) toward the retracted position shown
in FIG. 1.
[0013] The second sealing jaw 14 opposes the first sealing jaw 12.
The second sealing jaw 14 includes support members 46 and 48 (e.g.,
formed of metal, such as aluminum or steel) that are arranged to
engage with the gripping surfaces 28, 30 of the spaced-apart clamp
arms 16 and 18. The support members 46 and 48 also provide support
for sealing members 50 and 52, which are located within recesses 58
and 60 formed in the support members. The sealing members 50, 52
provide sealing surfaces 54 and 56 that engage the noses 40 and 42
of the heated sealing bar 32. In some embodiments, the sealing
members 46 and 48 are formed of a resilient material, such as
rubber.
[0014] A knife assembly 62 is carried by the second sealing jaw 14.
The knife assembly 62 includes a blade 64 and a blade clamp 66. As
shown in FIG. 1, the knife assembly 62 is in its retracted position
with a cutting edge 68 of the blade 64 being recessed with respect
to the sealing surfaces 54 and 56 within a slot 70 formed between
the sealing surfaces of the sealing members 50 and 52. As will be
described in greater detail below, the knife assembly 62 can be
extended relative to the sealing members 50, 52 to position the
cutting edge 68 beyond the sealing surfaces 54, 56 and into the
slot 44 between the noses 40, 42 of the sealing bar 32. In some
embodiments, the knife assembly 62 is extended and retracted using
a pneumatic cylinder 71 capable of delivering pressurized air into
a rear chamber 72 behind the knife assembly. Other configurations
are contemplated for extending and retracting the knife assembly,
such as a hydraulic cylinder. In some embodiments, the knife
assembly may be connected to an output shaft of the cylinder.
[0015] Referring now to FIG. 2, a film sheet 74 including layers
75, 77 is located along a film path between the first sealing jaw
12 and the second sealing jaw 14. A product 76 may be located
between sides 78 and 80 of the folded film sheet 74, below the
sealing jaws 12 and 14.
[0016] Referring to FIG. 3, the first and second gripping jaws 12
and 14 come into contact and the spaced-apart clamp arms 16 and 18
with gripping members 20 and 22 engage the support members 46 and
48 thereby gripping the film layers therebetween at locations on
opposite sides of the knife assembly 62, holding the folded film
taught for sealing and cutting operations. In this regard, one or
both of the jaws 12 and 14 may be moveable toward and away from the
other jaw for this purpose.
[0017] Referring to FIG. 4, the sealing bar 32 is brought into
engagement with the sealing members 50 and 52 with the noses 40 and
42 applying pressure against the film layers on either side of the
knife assembly 62. In some embodiments, the noses 40 and 42 engage
the sealing members within a central portion of the sealing members
spaced from the side corners of the sealing members. The sealing
bar 32 is heated and heat seals the film layers along two
transversely extending lines that are spaced-apart from each other
in the web running direction. The lower seal line is a top seal for
portion 82 of the film 74 and the upper seal line is a bottom seal
for the upper portion 83 of the film. As can be seen, the knife
assembly 62 is in its retracted position with the cutting edge 68
recessed behind the sealing surfaces 54 and 56.
[0018] Referring to FIG. 5, the knife assembly 62 is actuated to
extend the knife blade 64 into the slot 44 formed between the noses
40 and 42 of the sealing bar 32. This actuation severs the film
layers between the upper and lower seal lines. Once the film 74 is
severed, the sealing assembly 10 returns to its original position
as shown by FIG. 2.
[0019] The above-described sealing system 10 can provide a low
energy system operating at temperatures between about 180.degree.
F. and about 220.degree. F. Advantageously, the knife assembly is
located on the jaw opposite the heated sealing bar.
[0020] It is to be clearly understood that the above description is
intended by way of illustration and example only and is not
intended to be taken by way of limitation, and that changes and
modifications are possible. Accordingly, other embodiments are
within the scope of the following claims.
* * * * *