U.S. patent application number 13/661610 was filed with the patent office on 2014-05-01 for fill system and method including visual indicator device for empty condition.
This patent application is currently assigned to NORDSON CORPORATION. The applicant listed for this patent is NORDSON CORPORATION. Invention is credited to Justin A. Clark, Peter W. Estelle.
Application Number | 20140116569 13/661610 |
Document ID | / |
Family ID | 50545863 |
Filed Date | 2014-05-01 |
United States Patent
Application |
20140116569 |
Kind Code |
A1 |
Clark; Justin A. ; et
al. |
May 1, 2014 |
FILL SYSTEM AND METHOD INCLUDING VISUAL INDICATOR DEVICE FOR EMPTY
CONDITION
Abstract
A fill system is configured to supply particulate adhesive such
as pellets to an adhesive dispensing system and is configured to
provide a visual indication when a supply container approaches an
empty condition. The fill system includes the supply container,
which has an interior space for holding pellets, and an indicator
device that emits a visual indication by actuating a light source
communicating with the interior space. As a result, when the level
of pellets within the interior space drops to a threshold
approaching the empty condition, the light energy emitted by the
indicator device is visible outside the supply container. The fill
system may then be refilled before the completely empty condition
is reached.
Inventors: |
Clark; Justin A.; (Sugar
Hill, GA) ; Estelle; Peter W.; (Norcross,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NORDSON CORPORATION |
Westlake |
OH |
US |
|
|
Assignee: |
NORDSON CORPORATION
Westlake
OH
|
Family ID: |
50545863 |
Appl. No.: |
13/661610 |
Filed: |
October 26, 2012 |
Current U.S.
Class: |
141/1 ;
141/95 |
Current CPC
Class: |
B05C 11/1042 20130101;
B05C 11/101 20130101 |
Class at
Publication: |
141/1 ;
141/95 |
International
Class: |
B65B 1/48 20060101
B65B001/48 |
Claims
1. A fill system configured to supply particulate adhesive to an
adhesive dispensing system, comprising: a supply container
including an interior space for receiving the particulate adhesive
and defined by at least one sidewall and a bottom, the at least one
sidewall including at least a portion defined by translucent or
transparent material; and an indicator device for emitting a visual
indication when the supply container is approaching an empty
condition, the indicator device including at least one light source
communicating with the interior space such that light energy is
emitted in the interior space so as to be visible through the
translucent or transparent material to an operator when the supply
container is approaching the empty condition.
2. The fill system of claim 1, wherein the supply container further
includes a window defined by the translucent or transparent
material at the sidewall, and the light energy emitted by the light
source is visible through the window when the supply container is
approaching the empty condition.
3. The fill system of claim 1, wherein the light source emits light
energy throughout the interior space such that a majority of the
supply container is internally illuminated when the supply
container is approaching the empty condition.
4. The fill system of claim 1, wherein the light source is mounted
at least partially in additional structures located within the
interior space such that the light source provides minimized
resistance to gravity-driven flow of particulate adhesive towards
the bottom of the interior space.
5. The fill system of claim 4, further comprising: a pump including
a venturi pump housing and configured to selectively remove
particulate adhesive from the interior space, the light source
being mounted at least partially within the venturi pump
housing.
6. The fill system of claim 1, wherein the indicator device
includes a plurality of light sources that are positioned to emit
light energy in different directions within the interior space.
7. The fill system of claim 1, wherein the light source is a rugged
light emitting diode resistant to high temperatures.
8. The fill system of claim 1, wherein the supply container further
includes a ramp configured to direct gravity-driven flow of
particulate adhesive within the interior space towards the bottom,
and the light source is mounted on or adjacent to the ramp such
that the light source communicates with the interior space
proximate the bottom, the light source being uncovered when the
supply container approaches the empty condition.
9. The fill system of claim 8, wherein the ramp is painted with a
color contrasting to the particulate adhesive or to the light
energy emitted by the light source, thereby further increasing
visibility of the visual indication.
10. The fill system of claim 8, wherein the light source is coupled
to the ramp so as to be located within the interior space of the
supply container.
11. The fill system of claim 8, wherein the ramp includes at least
one ramp aperture and the light source is positioned behind the
ramp and adjacent to the ramp aperture such that light energy is
emitted through the ramp aperture into the interior space.
12. The fill system of claim 8, wherein the indicator device
includes a plurality of light sources positioned in a series along
an elongate length of the ramp such that the series of light
sources is sequentially uncovered as the supply container
approaches the empty condition.
13. The fill system of claim 8, wherein the indicator device
includes at least a first portion of light sources and a second
portion of light sources that emits light energy at a different
intensity or color than the first portion, and the second portion
of light sources is positioned so that the second portion of light
sources is uncovered after the first portion of light sources is
uncovered to thereby change the visual indication when the supply
container approaches the empty condition.
14. The fill system of claim 8, wherein the light source emits
light energy in a flashing pattern so that the light energy emitted
in the interior space may be initially detected as a pulsing of
light energy through the particulate adhesive when the light source
is nearly uncovered, and then detected as a flashing light energy
when the light source is uncovered.
15. The fill system of claim 1, wherein the light source is
positioned within the supply container such that the light source
is uncovered when the particulate adhesive in the interior space
has emptied to a selected fill percentage within the range of about
2% filled to about 25% filled.
16. The fill system of claim 1, wherein the fill system is
configured to perform a method of supplying particulate adhesive to
an adhesive dispensing system, the method comprising: receiving
particulate adhesive within an interior space of the supply
container; removing particulate adhesive from the interior space of
the supply container to supply the particulate adhesive to the
adhesive dispensing system; and illuminating the light source such
that light energy is emitted by the light source in the interior
space so as to be visible through the translucent or transparent
material to an operator when the supply container is approaching
the empty condition.
17. A method of supplying particulate adhesive to an adhesive
dispensing system using a fill system including a supply container
having at least one sidewall with at least a portion defined by
translucent or transparent material and including an indicator
device having a light source, the method comprising: receiving
particulate adhesive within an interior space of the supply
container; removing particulate adhesive from the interior space of
the supply container to supply the particulate adhesive to the
adhesive dispensing system; and illuminating the light source such
that light energy is emitted by the light source in the interior
space so as to be visible through the translucent or transparent
material to an operator when the supply container is approaching
the empty condition.
18. The method of claim 17, wherein the supply container includes a
window defined by the translucent or transparent material, and the
method further comprises: emitting the light energy from the light
source through the window when the supply container is approaching
the empty condition, thereby providing a visual indication
detectable outside the supply container.
19. The method of claim 17, wherein illuminating the light source
further comprises: flashing the light source intermittently such
that the light energy emitted in the interior space may be
initially detected as a pulsing of light energy through the
particulate adhesive when the light source is nearly uncovered, and
then detected as a flashing light energy when the light source is
uncovered.
20. The method of claim 17, wherein the indicator device includes a
plurality of light sources positioned in a series, and the method
further comprises: uncovering the series of light sources in a
sequential manner as the particulate adhesive is removed and as the
supply container approaches the empty condition.
21. The method of claim 17, wherein the indicator device includes
at least a first portion of light sources and a second portion of
light sources that emits light energy at a different intensity or
color than the first portion, and the method further comprises:
uncovering the first portion of light sources to emit a first light
energy in the interior space; and uncovering the second portion of
light sources to emit a second light energy having a different
intensity or color that the first light energy in the interior
space.
22. The method of claim 17, wherein the indicator device includes a
plurality of light sources positioned in different orientations,
and the method further comprises: illuminating the plurality of
light sources such that light energy is emitted in different
directions throughout the interior space, thereby illuminating a
majority of the supply container when the supply container is
approaching the empty condition.
23. The method of claim 17, further comprising: utilizing the fill
system of claim 1 to receive particulate adhesive, remove
particulate adhesive to supply the adhesive dispensing system, and
illuminate the light source when the supply container is
approaching an empty condition.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to particulate
material filling systems and more particularly, to an adhesive
pellet filling system and method used with adhesive dispensing
systems.
BACKGROUND
[0002] A conventional dispensing system for supplying heated
adhesive (i.e., a hot-melt adhesive dispensing system) generally
includes a melter having an inlet for receiving adhesive materials
in solid or liquid form, a heater grid or cartridge for heating the
adhesive materials, an outlet for receiving the heated adhesive,
and a pump in communication with the outlet for driving and
controlling the dispensation of the heated adhesive through the
outlet. One or more hoses may also be connected to the outlet to
direct the dispensation of heated adhesive to adhesive dispensing
guns or modules located downstream from the melter. Furthermore,
conventional dispensing systems generally include a controller
(e.g., a processor and a memory) and input controls electrically
connected to the controller to provide a user interface with the
dispensing system. The controller is in communication with the
pump, heater grid or cartridge, and/or other components of the
system, such that the controller controls the heating/melting and
dispensation of the heated adhesive.
[0003] In dispensing systems including a melter supplied with solid
material, the solid particulate adhesive material may be provided
on demand to the melter in the form of adhesive pellets. These
adhesive pellets may be supplied into the melter using various
techniques, including hand-filling or automated filling, depending
on the specific design of the melter. Some melters are designed in
such a manner that hand filling is not possible. In some of these
systems, the adhesive pellets are designed to be transferred by
pressurized air from a fill system into the melter, when the melter
requires additional material to heat and dispense. In this regard,
the controller operatively connected to the melter can receive
signals indicating the amount of adhesive material in the melter
and then actuate delivery of more pellets from the fill system when
the amount of adhesive material in the melter is low. The fill
system therefore ensures that the amount of adhesive material
within the melter remains at sufficient levels during operation of
the dispensing system.
[0004] One particular type of fill system is a tote-based pneumatic
fill system used to provide adhesive pellets to a melter. The
tote-based pneumatic fill system includes a supply container (which
may also be referred to as a tote) with an interior space having a
size sufficient to hold enough adhesive material for multiple hours
of operation of the dispensing system. As a result, the fill system
typically only has to be refilled with adhesive pellets once a day
or once per operational shift, in some circumstances. The lengthy
time periods between refilling operations of the supply container
can sometimes lead to operators forgetting to check whether the
fill system is getting close to empty. In addition, the level of
pellets within the supply container drops at a slow pace during
normal operation, so it can be difficult to gauge how much material
is left in the supply container, and when the supply container will
need to be refilled. These problems of detecting the level of
pellets within the supply container are particularly exacerbated
when the pellet level is only checked by an operator opening a lid
at the top of the supply container and looking down into the supply
container. If the supply container of the fill system runs out of
adhesive material, operation of the dispensing system must be shut
down until the supply container can be refilled. This refilling
process and the resulting restart process for the dispensing system
can cause significant downtime if the empty condition of the supply
container is not anticipated and addressed in advance of the supply
container reaching the empty condition.
[0005] For reasons such as these, an improved fill system would be
desirable for use with dispensing systems.
SUMMARY OF THE INVENTION
[0006] According to one embodiment of the invention, a fill system
configured to supply particulate adhesive to an adhesive dispensing
system includes a supply container having an interior space for
receiving the particulate adhesive and defined by at least one
sidewall and a bottom. The at least one sidewall includes at least
a portion defined by translucent or transparent material. The fill
system also includes an indicator device for emitting a visual
indication when the supply container is approaching an empty
condition. The indicator device has at least one light source
communicating with the interior space such that light energy is
emitted in the interior space so as to be visible through the
translucent or transparent material to an operator when the supply
container is approaching the empty condition.
[0007] In one aspect, the supply container also includes a window
defined by the translucent or transparent material at the sidewall.
As a result, the light energy emitted by the indicator device is
visible through the window at the exterior of the supply container
when the supply container is approaching the empty condition. This
visual indication is therefore provided without requiring an
operator to open the lid of the supply container. The light source
may emit light energy throughout the interior space such that a
majority of the supply container lights up with internal
illumination when the supply container approaches the empty
condition.
[0008] In another aspect, the light source is mounted at least
partially in additional structures located within the interior
space. To this end, the additional structures are already present
in the interior space and so the addition of the light source
provides minimized additional resistance to the flow of particulate
adhesive towards the bottom of the interior space. One type of
structure already located within the interior space is a venturi
pump housing of a pump configured to selectively remove particulate
adhesive from the interior space. In these embodiments, the light
source is mounted at least partially within the venturi pump
housing. It is also possible for the drivers or other electronics
associated with the light source to be housed within the pump
housing, thereby minimizing more space required by the indicator
device.
[0009] The light source may be mounted in various locations within
or adjacent to the interior space of the supply container. For
example, the light source may be mounted on or adjacent to a ramp
located at the interior space and configured to direct
gravity-driven flow of particulate adhesive towards the bottom of
the interior space. The ramp may be painted with a color
contrasting to the particulate adhesive or to the light energy
emitted by the light source to thereby increase the visibility of
the visual indication. Thus, the light source may be coupled to the
ramp so as to be located within the interior space, or the light
source may be positioned behind a ramp aperture in the ramp so that
the light source is not within the interior space yet still emits
light energy into the interior space via the ramp aperture. This
positioning behind the ramp and outside the interior space may be
preferred if it is desired to minimize the impedance to the flow of
particulate adhesive within the interior space.
[0010] In yet another aspect, the indicator device includes a
plurality of light sources that are positioned to emit light energy
in different directions within the interior space. Such mounting of
a plurality of light sources will ensure that some light energy is
transmitted throughout the interior space regardless of whether the
piling of particulate adhesive within the supply container takes a
different formation during different operational cycles. The
plurality of light sources may alternatively be positioned in a
series located along an elongate length of the ramp. In these
embodiments, the series of light sources will be sequentially
uncovered as the supply container approaches the empty condition,
thereby increasing the intensity of light energy within the
interior space as the supply container approaches the empty
condition. The indicator device may include first and second
portions of light sources, with the first portion configured to
emit a different color or intensity of light energy compared to the
second portion. In these embodiments, the first portion of light
sources is positioned to be uncovered before the second portion of
light sources such that the difference in color or intensity can be
used to indicate how close the supply container is to the empty
condition.
[0011] In still another aspect, the light source emits light energy
in a flashing pattern. This flashing pattern causes the light
energy to be initially detected as a pulsing light energy through
the particulate adhesive when the light source is nearly uncovered,
and then later detected as a flashing light energy when the light
source is uncovered. The light source may be a rugged light
emitting diode that is resistant to high temperatures and other
environmental conditions typical at the supply container. The light
source may be positioned within the supply container such that the
light source is uncovered when the particulate adhesive in the
interior space has emptied to a selected fill percentage within the
range of about 2% filled to about 25% filled. Even more preferably,
the light source may be positioned to be uncovered when the
particulate adhesive in the interior space has emptied to a
selected fill percentage within the range of about 2% filled to
about 10% filled. This amount of fill percentage generally provides
adequate time for an operator to notice the visual indication and
then refill the supply container before the supply container runs
out of particulate adhesive.
[0012] In another embodiment according to the invention, a method
of supplying particulate adhesive to an adhesive dispensing system
includes receiving particulate adhesive within an interior space of
a supply container. The method also includes removing particulate
adhesive from the interior space of the supply container to supply
the particulate adhesive to the adhesive dispensing system. A light
source is illuminated such that light energy is emitted by the
light source in the interior space when the supply container is
approaching an empty condition. The supply container includes a
sidewall with at least a portion defined by translucent or
transparent material, and the emission of light energy in the
interior space is visible through the translucent or transparent
material to provide a visual indication detectable by an operator
outside the supply container. Therefore, the supply container can
be refilled before reaching the empty condition.
[0013] These and other objects and advantages of the invention will
become more readily apparent during the following detailed
description taken in conjunction with the drawings herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and, together with a general description of the
invention given above, and the detailed description of the
embodiments given below, serve to explain the principles of the
invention.
[0015] FIG. 1 is a schematic view of an adhesive dispensing system,
including a fill system having a supply container according to one
embodiment of the current invention.
[0016] FIG. 2 is a perspective view of the fill system of FIG. 1,
with a portion of the supply container cut away to show a pump and
an indicator device located along a ramp.
[0017] FIG. 3 is a front perspective view of the ramp of FIG. 2,
specifically showing the portions of the pump and the indicator
device located within the supply container.
[0018] FIG. 4 is a cross-sectional side view of the fill system of
FIG. 2, specifically illustrating components located behind the
ramp.
[0019] FIG. 5 is a perspective view of a lower portion of the pump
of FIG. 3.
[0020] FIG. 6 is a cross-sectional view through the pump of FIG. 5
along line 6-6, to illustrate the mounting of one or more LEDs
within the pump housing.
[0021] FIG. 7 is a perspective view of another embodiment of the
lower portion of the pump of FIG. 3, including a series of LEDs
positioned along the length of the pump housing.
[0022] FIG. 8 is a cross-sectional side view of another embodiment
of the fill system with different mounting arrangements for LEDs
within the supply container.
[0023] FIG. 9 is a schematic cross-sectional side view of the fill
system according to the invention including a supply container
filled with a high amount of pellets, thereby blocking light energy
from being emitted through the pellets as shown.
[0024] FIG. 10 is a schematic cross-sectional side view of the fill
system of FIG. 9, with the pellet level within the supply container
lowered such that a minimum amount of light energy is emitted
through the pellets.
[0025] FIG. 11 is a schematic cross-sectional side view of the fill
system of FIG. 10, with the pellet level within the supply
container lowered below the LED such that the light emitted inside
the supply container is at a higher intensity than in FIG. 10.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
[0026] Referring to FIG. 1, an adhesive dispensing system 10 in
accordance with one embodiment of the invention includes a fill
system 12 that is configured to provide a visual indication when
the particulate adhesive within a supply container 14 is
approaching an empty condition. More specifically, the fill system
12 is used to provide adhesive pellets to a melter 16 of the
adhesive dispensing system 10, and the melter 16 feeds liquefied
molten adhesive to an applicator module or nozzle 18 using a liquid
pump 20. In this regard, the fill system 12 is operated to
continually replenish the supply of adhesive within the melter 16
as the pump 18 removes molten adhesive for dispensing at the
applicator module or nozzle 18. The adhesive material may define
any form or shape that is convenient for delivering by the fill
system 12 and for melting by the adhesive melter 16; however,
"pellets" have been chosen for illustrative purposes in the
illustrated embodiment. It will be understood that the material
moved by the fill system 12 may define other solid or semi-solid
particulate forms and may consist of non-adhesive materials in
other embodiments consistent with the invention. The supply
container 14 of the fill system 12 can hold a significant amount of
pellets of adhesive such that the fill system 12 only needs to be
refilled or serviced by an operator every few hours, or on another
relatively infrequent basis. However, the provision of an indicator
device in the form of one or more light emitting diodes (LEDs) 22
causes the emission of light energy in the supply container 14,
which can be detected when the supply container 14 approaches an
empty condition. The supply container 14 may then be refilled
before being completely empty, which enables continuous operation
of the adhesive dispensing system 10 without significant downtime,
when continuous operation is desirable. Furthermore, this indicator
device may also avoid the use of active level sensors that would
add more expense to the fill system 12 while also requiring
additional maintenance.
[0027] With continued reference to FIG. 1, the adhesive dispensing
system 10 may also include a controller 24 that is operatively
connected to the melter 16 and to the fill system 12. The
controller 24 receives signals from a level sensor or some other
monitoring device within the melter 16 that correspond to the
amount of adhesive within the melter 16. When the amount of
adhesive within the melter 16 drops below a certain threshold, the
controller 24 sends another signal to the fill system 12 to actuate
delivery of an amount of pellets into the melter 16 to refill the
melter 16. For example, the fill system 12 may include an outlet
port 26 connected to a hose 28 extending between the supply
container 14 and the melter 16. The delivery of the pellets through
the outlet port 26 and the hose 28 may be produced with pressurized
air, as well understood in the filling and dispensing field.
However, it will be understood that the pellets in the supply
container 14 may be removed in other embodiments using other known
methods including mechanical agitators and simple gravity flow. The
control process for periodically refilling the melter 16 continues
as long as the melter 16 is operating so that the melter 16 (and
subsequently, the applicator module or nozzle 18) never runs out of
adhesive material. It will be understood that the controller 24 may
be incorporated into one or more control systems (not shown) that
also actuate the liquid pump 20 and the applicator module or nozzle
18 in accordance with external or pre-programmed control signals,
without departing from the embodiments of the invention.
[0028] The fill system 12 may be used with various types of
adhesive dispensing systems 10. In one example, the melter 16,
liquid pump 20, and applicator module or nozzle 18 may include a
wall-mounted melt assembly as described in U.S. Patent Application
No. 61/703,454 to Clark et al. (entitled "Adhesive Dispensing
Device Having Melt Subassembly with Optimized Reservoir and
Capacitive Level Sensor"), which is co-owned by the assignee of the
current application and the disclosure of which is hereby
incorporated by reference herein in its entirety. However, it will
be understood that the fill system 12 is designed for use with any
type of adhesive dispensing system requiring periodic refilling of
material without departing from the scope of the invention.
Moreover, the fill system 12 may be modified by including the
indicator device with other types of supply containers in other
embodiments of the invention.
[0029] FIGS. 2 through 6 illustrate one embodiment of the fill
system 12 in accordance with the invention. The fill system 12
includes the aforementioned supply container 14, which defines a
tote having the appearance similar to that of a wheeled waste
container. More specifically, the supply container 14 includes a
main container body 32 defined by a plurality of sidewalls 34 and a
bottom wall 36. In the illustrated embodiment, the plurality of
sidewalls 34 includes four sidewalls 34 that define a
rectangular-shaped main container body 32. The main container body
32 is closed at a top end 38 by a removable lid 40 that may be
pivotally coupled to one of the sidewalls 34 as shown in FIG. 2. An
interior space 42 for holding pellets of adhesive is defined by the
sidewalls 34, the bottom wall 36, and the lid 40 of the supply
container 14. In order to refill this interior space 42, the lid 40
may be pivoted open so that a new supply of pellets can be
delivered manually or automatically through the top end 38. The
supply container 14 of this embodiment also includes wheels 44
coupled to the main container body 32 adjacent the bottom wall 36
so that the supply container 14 can be repositioned easily during
operation and for refilling. Although it will be appreciated that
the specific structure defining the shape of the supply container
14 and the interior space 42 may be varied in other embodiments
consistent with the invention, the interior space 42 is always
sized to contain a significant amount of adhesive material so that
the fill system 12 requires refilling on an infrequent basis.
[0030] The supply container 14 shown in FIG. 2 also includes
windows 46 located in three of the sidewalls 34. The windows 46 are
formed from a transparent or translucent material that enables
light energy to be transmitted from the interior space 42 by the
indicator device, as described in further detail below.
Alternatively, the sidewalls 34 may include at least a portion
defined by a transparent or translucent material without the
provision of windows in other embodiments. An operator may view a
fill level of pellets (not shown in FIG. 2) through the windows 46
during emptying of the supply container 14; however, this process
of monitoring the fill level of pellets is similar to opening the
lid 40 and looking down into the interior space 42, both of which
are relatively inaccurate ways to determine the amount of pellets
remaining in the supply container 14. Therefore, as described in
further detail below, the LED 22 mounted at the supply container 14
is positioned to emit light energy in the interior space 42 and
through the translucent or transparent material of the windows 46
when the supply container 14 approaches an empty condition, thereby
drawing attention to the need to refill the supply container 14. It
will be appreciated that a different number of windows 46,
including no windows 46 at all, may be provided in the sidewalls 34
in other embodiments of the invention.
[0031] The supply container 14 also includes a ramp 48 positioned
along one of the sidewalls 34. The ramp 48 is configured to support
a pump 50 configured to remove pellets from the interior space 42
when pellets need to be delivered to the melter 16. In the
embodiment shown in FIGS. 2 and 3, the ramp 48 is inserted into the
interior space 42 through a cutout portion of a rear sidewall 34
adjacent the wheels 44 or through the top end 38 and then
positioned along the rear sidewall 34 so that the interior space 42
tapers downwardly towards the bottom wall 36. The ramp 48 thereby
directs gravity flow of pellets to a relatively small area at the
bottom wall 36. The pump 50 includes a pump conduit 52 mounted
along the ramp 48 and having an inlet 54 located to adjacent this
relatively small area at the bottom wall 36. The pump conduit 52
extends to the outlet port 26, which is located along the rear
sidewall 34. Accordingly, the pump 50 draws gravity-fed pellets of
adhesive into the inlet 54 from the bottom of the interior space 42
so that the supply container 14 continues to operate until the
interior space 42 is substantially emptied of pellets. As will be
readily understood, the pump 50 may be replaced with alternative
structure for removing adhesive pellets from the interior space 42
in other embodiments, including but not limited to mechanical
agitators.
[0032] With particular reference to FIGS. 3 and 4, further details
of the ramp 48 and pump 50 are shown. To this end, the ramp 48
includes an elongate lower ramp portion 60 and an upper ramp
portion 62 extending from a top side of the lower ramp portion 60.
The lower ramp portion 60 is angled from the sidewall 34 so as to
define the tapering of the interior space 42 towards the bottom
wall 36. The upper ramp portion 62 is configured to overlie a
portion of the rear sidewall 34 and be connected therewith (such as
by a fastener 64 or some other similar connecting device) to retain
the ramp 48 in position within the supply container 14. The outlet
port 26 extends through the upper ramp portion 62 and is configured
to extend through the rear sidewall 34 as well so that the hose 28
can be connected into communication with the pump conduit 52.
[0033] The lower ramp portion 60 extends across substantially an
entire width of the interior space 42 and thereby divides the
interior space 42 from an equipment receptacle 66 located behind
the ramp 48. The equipment receptacle 66 is a recessed space
located within the footprint of the supply container 14 and
provides a convenient space outside the interior space 42 for
mounting pump equipment 68 used to generate flow of pellets 70
(shown in phantom in FIG. 4) from the inlet 54 and through the pump
conduit 52. The pump equipment 68 may include one or more solenoids
72 for controlling flow of pressurized air into the pump conduit 52
at a venturi pump housing 74 disposed adjacent to the inlet 54 and
within the interior space 42. The pump equipment 68 may also
include control electronics and other known components typically
used with pneumatic fill pumps, and this equipment may be modified
in other embodiments without departing from the scope of the
current invention.
[0034] With reference to FIGS. 5 and 6, the venturi pump housing 74
of the pump 50 is shown in further detail. The venturi pump housing
74 includes a portion of the pump conduit 52 running along an
elongate direction of the venturi pump housing 74, the elongate
direction being defined from a first end 80 of the housing 74
adjacent to the inlet 54 and a second end 82 of the housing 74
opposite the first end 80. As well understood in venturi-type
pumps, additional flow passages (not shown in FIGS. 5 and 6)
deliver pressurized air from the solenoids 72 into the pump conduit
52 so as to cause a pressure gradient in the pump conduit 52, the
pressure gradient tending to draw pellets 70 into the pump conduit
52 for driving with the pressurized air. In the exemplary
embodiment shown, the venturi pump housing 74 also includes a front
surface 84 facing away from the ramp 48 when installed, a rear
surface 86 abutting the ramp 48 when installed, and a pair of light
apertures 88 extending through the housing 74 from the rear surface
86 to the front surface 84. The light apertures 88 are separate and
independent from the pump conduit 52 and additional flow passages
carrying air through the pump 50. The light apertures 88 are
configured to receive the indicator device, which includes LEDs 22
as described briefly above.
[0035] As most clearly shown in FIG. 6, the LEDs 22 of the
indicator device are mounted at least partially within the light
apertures 88 so that the LEDs 22 are substantially flush with or
slightly projecting beyond the front surface 84 of the venturi pump
housing 74. As a result, the LEDs 22 are mounted or incorporated in
structure already present within the interior space 42 of the
supply container 14. In addition, the LEDs 22 advantageously do not
significantly increase the resistance to flow of pellets 70 towards
the bottom wall 36, as caused by gravity. Therefore, the indicator
device does not adversely affect the flow of pellets 70 within the
interior space 42. In the mounting position shown in FIG. 6, the
wiring (not shown) for powering and controlling the LEDs 22 may
extend through the remainder of the light aperture 88 and into the
equipment receptacle 66 for connection to such a power supply. The
LEDs 22 and light apertures 88 are shown to be positioned about
halfway between the first and second ends 80, 82, but this
positioning may be modified to be closer to one or the other end
80, 82 in other embodiments. It will also be understood that the
LEDs 22 may be mounted in other positions in or out of the venturi
pump housing 74, including but not limited to being recessed within
the light apertures 88, in other embodiments consistent with the
invention. Several of these alternatives are described with
reference to FIGS. 7 and 8 below.
[0036] In the illustrated embodiment, the LEDs 22 are rugged LEDs
that are resistant to high temperatures and other environmental
conditions normally present within the supply container 14. These
rugged LEDs may be similar to those used in taillights or light
bars of modern emergency vehicles. Although LEDs 22 are shown in
the exemplary embodiment, the indicator device could include other
types of light sources, such as incandescent light sources mounted
within the light apertures 88, in other embodiments. Furthermore,
the light sources could be positioned away from the venturi pump
housing 74 and connected to the light apertures 88 via optical
cables that transmit emitted light energy into the light apertures
88 from the light sources. Regardless of the type of light chosen
for use as the indicator device, additional hardware associated
with the light sources may also be positioned at or inside the
venturi pump housing 74. For example, in some embodiments the
controller 24 and/or any associated hardware operating as a driver
for the light sources may also be positioned adjacent to or at
least partially within the housing 74. Consequently, the LEDs 22 or
other light sources define a minimized profile that does not
significantly affect or interfere with the placement and operation
of other components of the fill system 12, whether these components
are located behind the ramp 48 in the equipment receptacle 66 or
within the interior space 42.
[0037] In operation, the LEDs 22 of the indicator device emit light
energy into the interior space 42 of the supply container 14. This
light energy is blocked from transmission into the interior space
42 when the level of pellets 70 in the supply container 14 is high
enough to cover the LEDs 22. When the level of pellets 70 drops
during use, the LEDs 22 become partially uncovered and then
completely uncovered as the level of pellets 70 approaches an empty
condition. This uncovering of the LEDs 22 causes the light energy
emitted from the LEDs 22 to be emitted throughout the entire
interior space 42 to internally illuminate a majority of the supply
container 14. In this regard, the light energy becomes a visual
indication corresponding to the supply container 14 approaching the
empty condition. In other embodiments, the LEDs 22 may be actuated
to illuminate only when the level of pellets 70 reaches a threshold
that approaches the empty condition. The LEDs 22 in such an
arrangement could be located in other positions in the supply
container 14, including but not limited to at the lid 40 where dust
and adhesive pellets 70 cannot affect the transmission of light
energy into the interior space 42. Additionally, the light energy
emitted by the LEDs 22 may be routed directly to the window 46
rather than being emitted throughout the entire interior space 42
in some embodiments.
[0038] The positioning of the LEDs 22 within the interior space 42
is tailored to provide the initial visual indication at a time when
the supply container 14 requires refill, but with sufficient time
for an operator to see the visual indication and cause the refill
to happen in advance of reaching the completely empty condition.
For example, the LEDs 22 may be positioned within the supply
container 14 such that the LEDs 22 are uncovered by the pellets 70
when the pellets 70 have emptied to a selected fill percentage
within the range of about 2% filled to about 25% filled. More
preferably, the pellets 70 will uncover the LEDs 22 at a selected
fill percentage within the range of about 2% filled to about 10%
filled. This selected fill percentage for uncovering the LEDs 22
should provide the visual indication for a sufficient period of
time to cause a refill of the supply container 14 before the supply
container 14 becomes completely empty. In addition, an operator can
determine immediately from the outside environment whether a supply
container 14 requires refill by looking through the windows 46 to
see if light energy is being emitted in the interior space 42. As a
result, periodic checks on the fill level by opening the lid 40 of
the supply container 14 are no longer necessary, and the operator
of the adhesive dispensing system 10 can be reasonably assured of
preventing the supply container 14 from running out of pellets 70.
The melter 16 and other downstream components of the adhesive
dispensing system 10 can therefore be operated substantially
continuously without lengthy delays caused by refilling the supply
container 14.
[0039] The visual indication provided by the indicator device can
be enhanced or modified in a number of ways. In one example, the
LEDs 22 are operated to provide light energy in an intermittent
flashing pattern rather than a solid pattern. The flashing light
energy will be initially detectable within the interior space 42 as
a pulsing light emerging through the pellets 70 when the LEDs 22
are nearly uncovered. This pulsing light will later be detected as
a flashing light energy when the LEDs 22 are completely uncovered.
In this way, the indicator device can draw more attention to the
supply container 14 approaching the empty condition so that the
empty condition can be avoided. In another example, the ramp 48 is
painted so as to be a color contrasting to one or both of the
pellets 70 or the light energy emitted by the LEDs 22. This
contrasting color is chosen to be more readily visible through the
windows 46. Thus, regardless of whether the light energy is emitted
as solid light or as flashing light, the high contrast provided by
the color of the ramp 48 will enhance the likelihood that the
visual indication will be seen by an operator of the adhesive
dispensing system 10. More particularly, the visibility of the
visual indication is increased by one or more of these
modifications.
[0040] With reference to FIG. 7, another alternative for enhancing
the visual indication provided by the indicator device is shown. In
this embodiment, the venturi pump housing 100 has been modified to
include a series of light apertures 102a, 102b, 102c, 102d, 102e
located along the elongate length of the housing 100 between the
first and second ends 80, 82. In all other respects, the venturi
pump housing 100 of this embodiment is identical to the venturi
pump housing 74 of the first described embodiment, and the same
reference numbers have been used on identical components and
surfaces where appropriate without further explanation. By
providing LEDs 22 in each of the series of light apertures 102a-e,
the intensity of light energy emitted throughout the interior space
42 may be increased multiple times as the supply container 14
approaches the empty condition. The intensity increases as the
level of pellets 70 is lowered because the pellets 70 sequentially
uncover new pairs of LEDs 22 when approaching the empty condition.
To this end, when the level of pellets 70 is approaching the first
end 80 of the housing 100 near the inlet 54, the intensity of light
energy emitted in the interior space 42 and through the windows 46
is significantly increased compared to when the level of pellets 70
is at the second end 82 of the housing 100. Accordingly, a more
critical need for an immediate refill of the supply container 14
draws more attention with a more intense visual indication.
[0041] The LEDs 22 shown in FIG. 7 or other embodiments may also be
oriented in different directions such that light energy emitted by
the LEDs 22 is more likely to spread quickly throughout the entire
interior space 42 when the supply container 14 approaches the empty
condition. This varied positioning of the LEDs 22 also helps ensure
that an uneven pile of pellets 70 within the interior space 42 does
not adversely affect the amount of time provided by the visual
indication to refill the supply container 14. The LEDs 22 shown in
FIG. 7 may also be divided into multiple portions of LEDs 22
defining different intensities or colors of light emitted by the
LEDs 22. For example, a first portion of the LEDs 22 in the light
apertures 102a, 102b may emit light energy at a first color or
intensity, and a second portion of the LEDs 22 in the light
apertures 102c, 102d, 102e may emit light energy at a second color
or intensity. The second portion of the LEDs 22 is uncovered after
the first portion, and the modified color or intensity of light
energy emitted by the second portion of the LEDs 22 causes a change
in the visual indication provided within the interior space 42 and
through the windows 46. To this end, an operator may be able to
determine different levels of reaction based on the type of visual
indication provided. When only the first color or intensity of
light is emitted, the operator will understand that refill is
necessary but the empty condition is not imminent. When the second
color or intensity of light is emitted, the operator will
understand that refill needs to happen promptly because the empty
condition is imminent. It will be appreciated that the number of
LEDs 22 in each portion may be modified without departing from the
scope of the invention.
[0042] With reference to FIG. 8, another alternative arrangement
for the indicator device is shown. More specifically, FIG. 8
illustrates a similar side view, as shown in FIG. 4 of the first
embodiment described above. Alternatively or in addition to
providing a LED 22 within a light aperture 88 in the venturi pump
housing 74, the indicator device of this embodiment may include a
LED 22a coupled to the lower ramp portion 60 of the ramp 48 and/or
a LED 22b positioned immediately behind a ramp aperture 110 located
in the lower ramp portion 60 of the ramp 48. As with the previous
embodiments, the LEDs 22a, 22b are rugged LEDs that are resistant
to high temperatures and other environmental conditions normally
present within the supply container 14. The LED 22a coupled to the
ramp 48 is located within the interior space 42 and within the flow
path of the pellets 70 of adhesive, so the LED 22a is designed with
a minimized profile to limit the additional resistance to the flow
of pellets 70 towards the bottom wall 36 and the inlet 54. The LED
22b positioned behind a ramp aperture 110 in the ramp 48 is located
within the equipment receptacle 66 and so is out of the flow path
of the pellets 70 in the interior space 42. However, the light
energy emitted by the LED 22b is directed through the ramp aperture
110 and into the interior space 42 for use in the same manner as
the other LEDs 22, 22a described above. The ramp aperture 110 may
include a transparent window blocking communication between the
interior space 42 and the equipment receptacle 66, or the ramp
aperture 110 may be open in some embodiments. It will be
appreciated that one or more of the LEDs 22, 22a, 22b and mounting
arrangements described in the various embodiments may be provided
individually or in any combination according to the preferences of
the end user.
[0043] With reference to FIGS. 9 through 11, the generalized method
of operation for the fill system 12 is shown. In these Figures, the
LED 22 is shown mounted on the ramp 48 which guides the pellets 70
towards the bottom wall 36. No other structure in the interior
space 42 or in the equipment receptacle 66 is shown in detail. As
shown in FIG. 9, the supply container 14 is filled with a high
amount of pellets 70 such that the supply container 14 is not
approaching the empty condition. In this state, the level of
pellets 70 in the interior space 42 covers up the LED 22 to such an
extent that effectively none of the light energy (shown
schematically by wave lines 120) escapes through the pellets 70 and
into the portion of the interior space 42 where that light energy
could be detected through the windows 46. Therefore, no visual
indication is provided to refill the supply container 14 in this
operational state of the fill system 12.
[0044] When the level of pellet fill within the supply container 14
is reduced to an intermediate level as shown in FIG. 10, the
pellets 70 may still substantially cover the LED 22. However, the
amount of pellets 70 located on top of the LED 22 is reduced to the
extent that a small amount of the light energy 120 emitted by the
LED 22 escapes through the pellets 70 into the remainder of the
interior space 42. For example, in the embodiments where a flashing
light energy is emitted by the LED 22, this small amount of light
energy 120 may be detected through the windows 46 as a soft pulsing
light signal. As will be readily understood, as the level of
pellets 70 drops lower, the amount of light energy 120 escaping
through the pellets 70 will increase, thereby increasing the
intensity of the visual indication corresponding to the supply
container 14 approaching the empty condition.
[0045] Finally, the level of pellet fill within the supply
container 14 will eventually be reduced to the low level shown in
FIG. 11. In this operational state, the pellets 70 no longer cover
the LED 22. As a result, the light energy 120 is largely
transmitted throughout the interior space 42 and through the
windows 46 for detection by an operator of the fill system 12.
Consequently, the visual indication is provided at a maximum
intensity when the level of pellets 70 within the interior space 42
falls below the threshold set by the location of the LED 22. When
this visual indication is detected, a refill of the supply
container 14 may be performed, which will return the supply
container 14 back to the state of FIG. 9, in which no visual
indication is visible in the interior space 42 or through the
windows 46. As noted above, the threshold at which the visual
indication is provided may be modified to fit the needs of the end
user (e.g., a more frequently monitored fill system 12 can provide
the visual indication at a lower level of fill because the refill
will be actuated promptly upon emission of the visual
indication).
[0046] Consequently, the LEDs 22, 22a, 22b of the indicator devices
that are provided in the supply containers 14 according to the
invention operate to emit a visual indication when the supply
container 14 approaches an empty condition. In this regard,
operators of a fill system 12 including the supply container 14 may
be notified of an imminent empty condition well enough in advance
to allow for refilling of the supply container 14 prior to the
interior space 42 becoming completely empty. Thus, system downtime
for refilling the supply of material is minimized for a melter 16
and other components of an adhesive dispensing system 10 using the
fill system 12. Furthermore, the indicator device is a passive
device that operates effectively to provide the visual indication
without the need for complex or expensive level sensors in some
embodiments. Therefore, the fill system 12 of the current invention
includes a reliable mechanism for indicating an imminent empty
condition without adding significant complexity or expense to the
manufacture and maintenance of the fill system 12. The reduced
downtime enabled by use of this fill system 12 makes the fill
system 12 beneficial for applications in all filling technologies,
whether related to adhesive dispensing or otherwise.
[0047] While the present invention has been illustrated by a
description of several embodiments, and while such embodiments have
been described in considerable detail, there is no intention to
restrict, or in any way limit, the scope of the appended claims to
such detail. Additional advantages and modifications will readily
appear to those skilled in the art. Therefore, the invention in its
broadest aspects is not limited to the specific details shown and
described. The various features disclosed herein may be used in any
combination necessary or desired for a particular application.
Consequently, departures may be made from the details described
herein without departing from the spirit and scope of the claims
which follow. What is claimed is:
* * * * *