Note: Descriptions are shown in the official language in which they were submitted.
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HAND HELD DISPENSER FOR FOAMABLE COMPOSITIONS
AND DISPENSING SYSTEM
Field of the Invention
~ This invention relates to cushioned packaging
apparatus and techniques and, in particular, relates to
a device for forming foam cushioning of the type in
which a foamable composition is dispensed into a
container that carries an object to be cushioned. The
foamable composition generates gases while hardening so
that the result is a container filled with hardened
foam that surrounds the packaged object in customized
l0 fashion.
~ackaround of the Invention
The present invention relates to the use of
foamable compositions for packaging purposes. In a
number of packaging applications, fragile articles or
those otherwise needing protection from undesired
movement or breakage, particularly items with irregular
shapes and sizes, have been packed in loose, friable or
dunnage-type materials or in protective foamed polymer
packaging materials, such as injection molded
Styrofoam, Styrofoam chips, or other similar materials.
The present invention relates to
foam-in-place packaging. Foam-in-place packaging is a
useful alternative for packaging fragile or other
items.
One technique for packaging articles in foam
comprises generating the foam in place while the
articles are being packaged. For example, when certain
chemicals are mixed, they form polymeric products while
at the same time generating gases, such as carbon
dioxide and water vapor. If such chemicals are
selected as being those that harden relatively quickly,
they can be used to form hardened polymer foams in
which the foam is produced by the gaseous carbon
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dioxide and water vapor leaving the mixture as it
hardens. Typical foamable compositions include
urethane precursors which, when mixed, generate
polyurethane, carbon dioxide, and water vapor. As the
urethane forms and hardens, these gases are
concurrently generated so that by the time the urethane
sets (generally a relatively short period of a few
minutes or less) it takes the form of a polymer foam
that has expanded to fill the void spaces in the
container and to thereby cushion the item being
packaged.
One technique for foam-in-place packaging is
to place the object to be packaged in a container,
cover it with a polymer film or other material which
will protect it from liquids, inject a certain amount
of foamable composition into the remainder of the
container, and then close the container. As the
composition foams, it fills the remainder of the
container, forming a custom-shaped foam cushion
surrounding the article.
For larger volume packaging operations, i.e.,
those requiring a number of foam protective packages to
be made in relatively rapid succession, a number of
automated devices have been developed and are assigned
to the assignee of the present invention. Exemplary
devices are described and claimed in U.S. Patents Nos.
4,674,268; 4,800,708; and 4,854,109.
In other circumstances, however, the need for
foam-in-place packaging still exists, but the use of
automated machinery is unnecessary or undesired from a
cost, efficiency, or other standpoint. In such
circumstances, foam-in-place packaging can be ,
accomplished with a supply of foamable chemicals,
usually two, and an injection dispenser connected to
the supplies of the respective chemicals. The
chemicals are mixed within the gun. to form the foamable
composition. Examples of earlier versions of such guns
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include those described in U.S. Patent Nos_ 3,687,370;
3,945,569; 4,023,733; 4,159,079; and 4,426,023.
One of the more recently successful versions
of such a hand-held packaging system is the INSTAPAK~
808/870 foam packaging systems from Sealed Air
Corporation's Instapak Division in Danbury,
Connecticut. The "808" system represented a
significant improvement in hand-held devices, primarily
because of its use of an electric motor, rather than
a
pneumatic pumping system, and its incorporation of a
number of significant features that are the subjects
of
other commonly-assigned patents.
In an effort to enhance the 808 systems,
however, various features were identified that could
be
subject to such improvement_ For example, the hand-
held dispenser or "gun" portion of the 808 system is
formed of metal. The metal adds significant weight to
the hand-held portion, a factor which can increase
operator fatigue and tend to lower efficiency. Metal
can also be more expensive than alternative materials,
and requires particular tooling and fabricating
equipment.
Additionally, the electric motor driving the
808 dispenser is located above the injection cartridge.
As a result, in close circumstances, it can block the
operator's view of the opening of the injection
cartridge from which the foamable compositions exit.
Accordingly, in an effort to offer further
improvements to this device, and to foam dispensers in
general, there exists the need for a more ergonomically
satisfactory dispenser, and one of reduced weight, and
7 which maintains the significant advantages of the 808
system, but which offers significant improvements as
well.
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Summary of the Invention
The present invention provides a series of
improvements in foam dispensing systems of this type.
The invention provides a system for dispensing
foamable compositions that includes a hand-held
dispenser for dispensing foamable compositions, and
that is particularly useful for foam-in-place packaging
systems. The dispensing system comprises a pump for
pumping foamable compositions from a supply to a
dispenser; a hose connected to the pump for carrying
foamable compositions from the pump; and a hand-held
dispenser connected to the hose. The hand-held
dispenser in turn comprises a housing, a motor in the
housing, a transmission in the housing driven by the
motor, and a valuing cartridge in the housing driven by
the transmission for dispensing foamable compositions
upon demand. In particular, the motor is positioned
below the valuing cartridge and provides an
ergonomically superior clear line of sight along the
top of the housing.
The foregoing and other advantages of the
invention, and the manner in which the same are
accomplished, will be more readily understood when
taken in conjunction with the accompanying detailed
description and drawings in which:
Description of the Drawings
Figure 1 is a perspective view of a dispenser
system according to the present invention in typical
use;
Figure 2 is a perspective view of the
dispenser according to the present invention;
Figure 3 is a partially isolated perspective
view of certain working portions of the dispenser
according to the present invention; and
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Figure 4 is an exploded perspective view of
the motor and the transmission portions according to
the present invention.
petailed Description
The present invention is a system for
dispensing foamable compositions that includes a hand-
held,dispenser for dispensing the foamable compositions
and that is particularly useful for foam-in-place
packaging systems.
Figure 1 gives a good overall perspective
view of a typical installation and use of such a
system. Figure 1 shows two pumps 20 and 21 that pump
foamable composition from the respective supply drums
22 and 23. As known by those familiar with foaming
systems, a typical polyurethane foam is formed from
precursors of an isocyanate and a polyol, and thus a
system according to the present invention will commonly
include two pumps, one for each of the precursor
chemicals. A pair of hoses which are generally
strapped together and are designated herein by the
single reference 24 extend from the supply pumps 20 and
21 to a hand-held dispenser broadly designated at 25.
As illustrated in Figure 1, the hoses 24 are preferably
maintained above the floor for ease of movement and
overall safety, and are held in place by a hose hanger
28 which is shown supported from the bracket 26.
The dispensing system further comprises an
electronic controller broadly designated at 27 which
is
remote from both the pump and the dispenser and will
be
described in more detail further herein.
,. As Figure 1 illustrates, a typical use of the
system by an operator comprises selecting a portion of
plastic sheet material from the roll 30 and using it
to
line a container, such as the cardboard box 31. A
fragile object can be placed in the box and either
wrapped or draped with some of the film from the roll
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30, after which a certain portion of foam is dispensed
into the container. When the container is then closed
and sealed, the foamabie composition generates the
cured, hardened foam which, because it was originally
dispensed as a liquid, expands, occupies and takes the
shape of the empty portion of the container to thus
form a custom foam cushion around the fragile object.
Figure 2 is a perspective view of the
dispenser 25 according to the present invention. The
dispenser comprises a housing broadly designated at 32,
a motor 33 in the housing, a transmission 34 in the
housing and driven by the motor, and a valuing
cartridge 35 in the housing 32 and driven by the
transmission 34 for dispensing foamable compositions
upon demand. The motor 33 is positioned below the
valuing cartridge 35 for providing a clear line of
sight along the top of the housing. As can be
understood with respect to Figure 1, such a clear line
of sight is of significant advantage to an operator of
the dispenser and the overall dispensing system.
The valuing cartridge 35 is readily and
easily detachable from the valuing clamp assembly 36.
The design and operation of detachment are described in
commonly-assigned U.S. Patent No. 4,469,251 to Sperry
et al. The design and operation of the valuing
cartridge 35 are described in detail in commonly-
assigned U.S. Patent No. 4,568,003 to Sperry et al.
Figures 2 and 3 illustrate that the dispenser
25 further comprises means shown as the valuing clamp
assembly 36 for delivering foam precursors to the
valuing cartridge 35. The design and operation of the
valuing clamp assembly 36 are described in great detail
in commonly-assigned U.S. Patent No. 5,215,226 to
Bertram et al. As shown therein, the cartridge 35 is
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typically designed to be removable from the valuing
clamp assembly 36. In order to prevent the foam from
being dispensed when the cartridge 35 is not properly
in place, the design of the clamp 36 requires that the
handles 37 (and thus the flow of precursors) be turned
off before the cartridge 35 can be removed.
Alternatively, before fluids can flow back into the
cartridge 35, the clamp handles 37 must be rotated back
into their clamping position.
Figure 1 illustrates the hoses 24 connected
to the dispenser 25. The hoses are not shown in
Figures 2 and 3 for the sake of clarity, but they
connect to the rear portions of the valuing clamp
assembly 36. Accordingly, the valuing cartridge 35
further comprises a mixing chamber along with means for
separately delivering two foam precursors to the mixing
chamber. The mixing chamber and the entry ports to it
are likewise discussed in significant detail in
commonly-assigned U.S. Patent No. 5,186,905 to Bertram
et al.
The motor 33 is most preferably an electric
motor, and indeed one of the advantages of the system
is its potential for all-electric operation. A trigger
40 initiates the motor to drive the transmission 34 and
the valuing cartridge 35.
As best illustrated in Figure 2, the housing
32 comprises an upper portion that extends generally
longitudinally parallel to the axis of the valuing
cartridge 35 and a lower portion extending generally
perpendicularly downwardly from the upper portion and
forming a handle 41 for the housing 32 of the dispenser
25. The housing 32 is preferably formed of an
appropriate engineering plastic of which there are a
number of appropriate selections. As commonly used in
this art, the term "engineering plastic" refers to
this art, the term "engineering plastic" refers to
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polymers that exhibit ~~hardness, strength,
machinability, dimensional stability, non-flammability _
and resistance to corrosion, most acids, solvents and
heat . ~~ Lewis, Hawley's Condensed Chemical Dictionary,
12th Ed. (1993).
's
In preferred embodiments, the housing 32 is
formed of several pieces so that it can be quickly and
easi~.y replaced for service reasons without
- disassembling the entire dispenser. Taken together,
Figures 2 and 3 illustrate that the rear portion of the
housing 32 carries the motor 33 and the transmission 34
and form the backbone assembly of the dispenser 25.
Thus, the rear portion of the housing 32 conveniently _
- coiztains most of the essential mechanical elements of
the dispenser.
In relating the positions of the motor 33 to
the transmission 34 and the valuing cartridge 35, it
will be noted that the valuing cartridge 35 is a
cylinder with an axial valuing rod 38. Accordingly, in
the preferred embodiment of the invention, the motor 33
is positioned below the longitudinal axis of the
cylindrical valuing cartridge.
Figure 3 shows some additional details of the
dispenser 25 with the housing 32 and some other
features removed. First, Figure 3 illustrates an
electrical power cord 42 and its appropriate connection
to the rear of the dispenser 25. The motor 33 is
illustrated in more detail in Figures 3 and 4 which
show that the functional portions of the transmission -
are rearward of the motor. Figure 3 also more clearly
shows the relationship of the motor as being below the
axis of the valuing cartridge 35. .
Figure 4 shows the motor 33, a drive gear 43,
a driven gear 44 for the transmission 34, which in turn
drives another gear 45 on a composite shaft broadly
designated at 46. The shaft 46 is in turn attached to
the valuing cartridge 35 in a manner typical of these
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devices and which will not otherwise be described in
detail.
The overall dispensing system comprises a
number of additional features. First, as noted earlier
and illustrated in Figure 1, the system comprises the
electronic controller 27 which is remote from the pump
and remote from the dispenser. The controller will
typically comprise a main board and a power management
board. The main board is that portion of the circuitry
which controls the electrical operation of the pumps,
hoses, and dispenser. In turn, the power management
board converts available electric power into the
frequency and voltage required by the main board.
Four power management boards are exemplary of
this objective: single phase, 50 or 60 cycles (Hz),
170 to 265 volts (alternating current, "Vas"), and 30
amps (predominantly North America); three phase "delta"
configuration, 50-60 Hz, 170 Vas phase to phase, 30 amps
each phase (predominantly North America); three phase
"delta" configuration, 50-60 Hz, 170 Va~ phase to phase,
20 amps each phase (some areas in Europe); and three
phase "Y" configuration, 50 or 60 Hz, 170-265 VB~, phase
to neutral, 16 amps each phase (predominantly Europe,
Pacific Rim, and Far East). The power management board
distributes a specific electrical phase configuration
into one standard configuration designed for the
control board.
The board controls portions of the dispenser
and the pump, and also provides electric current to the
hoses 24 for heating the hoses to maintain a foamable
composition at an elevated temperature (and thus more
. fluid) in the hoses.
Accordingly, the pumps .20 and 21 are
typically electrically driven and electrically
controlled, and thus the dispensing system includes the
respective electric cables shown at 47 in Figure 1.
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As a particular advantage of the invention,
however, the pumps 20 and 21 further comprise their own
electronic pump controls. By placing a portion of the
pump controls at the pumps, the extent to which the
pump must be controlled by signals transmitted between
the pumps 20 and 21 and the controller 27 are greatly
reduced which in turn greatly reduces the radio
frequency (RF) interference produced by signal traffic
between the pumps 20 and 21 and the controller 27. As
known to those in various engineering fields, the
reduction of such RF interference is mandatory in many
countries.
In the drawings and specification, there have
been disclosed typical preferred embodiments of the
invention and, although specific terms have been
employed, they have been used in a generic and
descriptive sense only and not for purposes of
limitation, the scope of the invention being set forth
in the following claims.
